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In [[combinatorics]], an '''expander graph''' is a [[sparse graph]] that has strong [[connectivity (graph theory)|connectivity]] properties, quantified using [[vertex (graph theory)|vertex]], [[edge (graph theory)|edge]] or spectral expansion as described below. Expander constructions have spawned research in pure and applied mathematics, with several applications to [[Computational complexity theory|complexity theory]], design of robust [[computer network]]s, and the theory of [[error-correcting code]]s.<ref>{{harvtxt|Hoory|Linial|Widgerson|2006}}</ref> | |||
==Definitions== | |||
Intuitively, an expander is a finite, undirected [[multigraph]] in which every subset of the vertices "that is not too large" has a "large" boundary. Different formalisations of these notions give rise to different notions of expanders: ''edge expanders'', ''vertex expanders'', and ''spectral expanders'', as defined below. | |||
A disconnected graph is not an expander, since the boundary of a connected component is empty. Every connected graph is an expander; however, different connected graphs have different expansion parameters. The [[complete graph]] has the best expansion property, but it has largest possible degree. Informally, a graph is a good expander if it has low degree and high expansion parameters. | |||
===Edge expansion=== | |||
The ''edge expansion'' (also ''isoperimetric number'' or [[Cheeger constant (graph theory)|Cheeger constant]]) ''h''(''G'') of a graph ''G'' on ''n'' vertices is defined as | |||
: <math>h(G) = \min_{0 < |S| \le \frac{n}{2} } \frac{|\partial(S)|}{|S|},</math> | |||
where the minimum is over all nonempty sets ''S'' of at most ''n''/2 vertices and ∂(''S'') is the ''edge boundary'' of ''S'', i.e., the set of edges with exactly one endpoint in ''S''.<ref>Definition 2.1 in {{harvtxt|Hoory|Linial|Widgerson|2006}}</ref> | |||
===Vertex expansion=== | |||
The ''vertex isoperimetric number'' <math>h_{\text{out}}(G)</math> (also ''vertex expansion'' or ''magnification'') of a graph ''G'' is defined as | |||
: <math>h_{\text{out}}(G) = \min_{0 < |S|\le \frac{n}{2}} \frac{|\partial_{\text{out}}(S)|}{|S|},</math> | |||
where <math>\partial_{\text{out}}(S)</math> is the ''outer boundary'' of ''S'', i.e., the set of vertices in <math>V(G)\setminus S</math> with at least one neighbor in ''S''.<ref name="BobkovHoudre">{{harvtxt|Bobkov|Houdré|Tetali|2000}}</ref> In a variant of this definition (called ''unique neighbor expansion'') <math>\partial_{\text{out}}(S)</math> is replaced by the set of vertices in ''V'' with ''exactly'' one neighbor in ''S''.<ref name="AlonCapalbo">{{harvtxt|Alon|Capalbo|2002}}</ref> | |||
The ''vertex isoperimetric number'' <math>h_{\text{in}}(G)</math> of a graph ''G'' is defined as | |||
: <math>h_{\text{in}}(G) = \min_{0 < |S|\le \frac{n}{2}} \frac{|\partial_{\text{in}}(S)|}{|S|},</math> | |||
where <math>\partial_{\text{in}}(S)</math> is the ''inner boundary'' of ''S'', i.e., the set of vertices in ''S'' with at least one neighbor in <math>V(G)\setminus S</math>.<ref name="BobkovHoudre" /> | |||
===Spectral expansion=== | |||
When ''G'' is [[regular graph|''d''-regular]], a [[linear algebra]]ic definition of expansion is possible based on the [[Eigenvalue#Eigenvalues of matrices|eigenvalues]] of the [[adjacency matrix]] ''A'' = ''A''(''G'') of ''G'', where <math>A_{ij}</math> is the number of edges between vertices ''i'' and ''j''.<ref>cf. Section 2.3 in {{harvtxt|Hoory|Linial|Widgerson|2006}}</ref> Because ''A'' is [[symmetric matrix|symmetric]], the [[spectral theorem]] implies that ''A'' has ''n'' real-valued eigenvalues <math>\lambda_1 \ge \lambda_2 \ge \cdots \ge \lambda_{n}</math>. It is known that all these eigenvalues are in [−''d'', ''d'']. | |||
Because ''G'' is regular, the uniform distribution <math>u\in\R^n</math> with <math>u_i=1/n</math> for all ''i'' = 1, ..., ''n'' is the [[stationary distribution]] of ''G''. That is, we have ''Au'' = ''du'', and ''u'' is an eigenvector of ''A'' with eigenvalue λ<sub>1</sub> = ''d'', where ''d'' is the [[degree (graph theory)|degree]] of the vertices of ''G''. The ''[[spectral gap]]'' of ''G'' is defined to be ''d''−λ<sub>2</sub>, and it measures the spectral expansion of the graph ''G''.<ref>This definition of the spectral gap is from Section 2.3 in {{harvtxt|Hoory|Linial|Widgerson|2006}}</ref> | |||
It is known that λ<sub>''n''</sub> = −''d'' if and only if ''G'' is bipartite. In many contexts, for example in the [[expander mixing lemma]], it is necessary to bound from below not only the gap between λ<sub>1</sub> and λ<sub>2</sub>, but also the gap between λ<sub>1</sub> and the second-largest eigenvalue in absolute value: | |||
:<math>\lambda=\max\{|\lambda_2|, |\lambda_{n}|\}</math>. | |||
Since this is the largest eigenvalue corresponding to an eigenvector orthogonal to ''u'', it can be equivalently defined using the [[Rayleigh quotient]]: | |||
:<math>\lambda=\max_{0\neq v\perp u} \frac{\|Av\|_2}{\|v\|_2},</math> | |||
where | |||
:<math>\|v\|_2=\left(\sum_{i=1}^n v_i^2\right)^{1/2}</math> | |||
is the [[2-norm]] of the vector <math>v\in\R^n</math>. | |||
The normalized versions of these definitions are also widely used and more convenient in stating some results. Here one considers the matrix <math>\tfrac{1}{d} A</math>, which is the [[Markov transition matrix]] of the graph ''G''. Its eigenvalues are between −1 and 1. For not necessarily regular graphs, the spectrum of a graph can be defined similarly using the eigenvalues of the [[Laplacian matrix]]. For directed graphs, one considers the [[singular values]] of the adjacency matrix ''A'', which are equal to the roots of the eigenvalues of the symmetric matrix ''A<sup>T</sup>A''. | |||
==Relationships between different expansion properties== | |||
The expansion parameters defined above are related to each other. In particular, for any ''d''-regular graph ''G'', | |||
:<math>h_{\text{out}}(G) \le h(G) \le d \cdot h_{\text{out}}(G).</math> | |||
Consequently, for constant degree graphs, vertex and edge expansion are qualitatively the same. | |||
===Cheeger inequalities=== | |||
When ''G'' is ''d''-regular, there is a relationship between ''h''(''G'') and the spectral gap ''d'' − λ<sub>2</sub> of ''G''. An inequality due to Tanner and independently [[Noga Alon|Alon]] and [[Vitali Milman|Milman]]{{Sfn|Alon|Spencer|2011}} states that<ref>Theorem 2.4 in {{harvtxt|Hoory|Linial|Widgerson|2006}}</ref> | |||
: <math>\tfrac{1}{2}(d - \lambda_2) \le h(G) \le \sqrt{2d(d - \lambda_2)}.</math> | |||
This inequality is closely related to the [[Cheeger bound]] for [[Markov chains]] and can be seen as a discrete version of [[Cheeger_constant#Cheeger.27s_inequality|Cheeger's inequality]] in [[Riemannian geometry]]. | |||
Similar connections between vertex isoperimetric numbers and the spectral gap have also been studied:<ref>See Theorem 1 and p.156, l.1 in {{harvtxt|Bobkov|Houdré|Tetali|2000}}. Note that λ<sub>2</sub> there corresponds to 2(''d'' − λ<sub>2</sub>) of the current article (see p.153, l.5)</ref> | |||
: <math>h_{\text{out}}(G)\le \left(\sqrt{4 (d-\lambda_2)} + 1\right)^2 -1</math> | |||
: <math>h_{\text{in}}(G) \le \sqrt{8(d-\lambda_2)}.</math> | |||
Asymptotically speaking, the quantities <math>\frac{h^2}{d}</math>, <math>h_{\text{out}}</math>, and <math>h_{\text{in}}^2</math> are all bounded above by the spectral gap <math>O(d-\lambda_2)</math>. | |||
==Constructions== | |||
There are three general strategies for constructing families of expander graphs.<ref>see, e.g., {{harvtxt|Yehudayoff|2012}}</ref> The first strategy is algebraic and group-theoretic, the second strategy is analytic and uses [[additive combinatorics]], and the third strategy is combinatorial and uses the [[zig-zag product|zig-zag]] and related graphs products. | |||
===Margulis-Gabber-Galil=== | |||
[[Abstract algebra|Algebraic]] constructions based on [[Cayley graph]]s are known for various variants of expander graphs. The following construction is due to Margulis and has been analysed by Gabber and Galil.<ref>see, e.g., p.9 of {{harvtxt|Goldreich|2011}}</ref> For every natural number ''n'', one considers the graph ''G<sub>n</sub>'' with the vertex set <math>\mathbb Z_n \times \mathbb Z_n</math>, where <math>\mathbb Z_n=\mathbb Z/n\mathbb Z</math>: For every vertex <math>(x,y)\in\mathbb Z_n \times \mathbb Z_n</math>, its eight adjacent vertices are | |||
:<math>(x \pm 2y,y), (x \pm (2y+1),y), (x,y \pm 2x), (x,y \pm (2x+1)).</math> | |||
Then the following holds: | |||
<blockquote>'''Theorem.''' For all ''n'', the graph ''G<sub>n</sub>'' has second-largest eigenvalue <math>\lambda(G)\leq 5 \sqrt{2}</math>.</blockquote> | |||
===Ramanujan graphs=== | |||
{{main|Ramanujan graph}} | |||
By a theorem of Alon and Boppana, all large enough ''d''-regular graphs satisfy <math>\lambda \ge 2\sqrt{d-1} - o(1)</math>, where λ is the second largest eigenvalue in absolute value.<ref>Theorem 2.7 of {{harvtxt|Hoory|Linial|Widgerson|2006}}</ref> [[Ramanujan graph]]s are ''d''-regular graphs for which this bound is tight. That is, they satisfy <math>\lambda \le 2\sqrt{d-1}</math>.<ref>Definition 5.11 of {{harvtxt|Hoory|Linial|Widgerson|2006}}</ref> Hence Ramanujan graphs have an asymptotically smallest possible λ. They are also excellent spectral expanders. | |||
[[Alexander Lubotzky|Lubotzky]], Phillips, and Sarnak (1988), Margulis (1988), and Morgenstern (1994) show how Ramanujan graphs can be constructed explicitly.<ref>Theorem 5.12 of {{harvtxt|Hoory|Linial|Widgerson|2006}}</ref> By a theorem of Friedman (2003), [[Random regular graph|random d-regular graphs]] on ''n'' vertices are almost Ramanujan, that is, they satisfy | |||
:<math>\lambda \le 2\sqrt{d-1}+\epsilon</math> | |||
with probability <math>1-o(1)</math> as ''n'' → ∞ tends to infinity.<ref>Theorem 7.10 of {{harvtxt|Hoory|Linial|Widgerson|2006}}</ref> | |||
==Applications and useful properties== | |||
The original motivation for expanders is to build economical robust networks (phone or computer): an expander with bounded valence is precisely an asymptotic robust graph with number of edges growing linearly with size (number of vertices), for all subsets. | |||
Expander graphs have found extensive applications in [[computer science]], in designing [[algorithm]]s, [[Expander code|error correcting codes]], [[Extractor (mathematics)|extractors]], [[pseudorandom generator]]s, [[sorting network]]s ({{harvtxt|Ajtai|Komlós|Szemerédi|1983}}) and robust [[computer network]]s. They have also been used in proofs of many important results in [[computational complexity theory]], such as [[SL (complexity)|SL]]=[[L (complexity)|L]] ({{harvtxt|Reingold|2008}}) and the [[PCP theorem]] ({{harvtxt|Dinur|2007}}). In [[cryptography]], expander graphs are used to construct [[hash function]]s. | |||
The following are some properties of expander graphs that have proven useful in many areas. | |||
===Expander mixing lemma=== | |||
{{Main|Expander mixing lemma}} | |||
The expander mixing lemma states that, for any two subsets of the vertices ''S'', ''T'' ⊆ ''V'', the number of edges between ''S'' and ''T'' is approximately what you would expect in a random ''d''-regular graph. The approximation is better, the smaller <math>\lambda=\max\{|\lambda_2|,|\lambda_n|\}</math> is. In a random ''d''-regular graph, as well as in an [[Erdős–Rényi model|Erdős–Rényi random graph]] with edge probability ''d''/''n'', we expect <math>\tfrac{d}{n} \cdot |S| \cdot |T|</math> edges between ''S'' and ''T''. | |||
More formally, let ''E''(''S'', ''T'') denote the number of edges between ''S'' and ''T''. If the two sets are not disjoint, edges in their intersection are counted twice, that is, | |||
:<math>E(S,T)=2|E(G[S\cap T])| + E(S\setminus T,T) + E(S,T\setminus S)</math>. | |||
Then the expander mixing lemma says that the following inequality holds: | |||
:<math>\left|E(S, T) - \frac{d \cdot |S| \cdot |T|}{n}\right| \leq d\lambda \sqrt{|S| \cdot |T|},</math> | |||
where λ is the absolute value of the '''normalized''' second largest eigenvalue. | |||
===Expander walk sampling=== | |||
{{Main|Expander walk sampling}} | |||
The [[Chernoff bound]] states that, when sampling many independent samples from a random variables in the range [−1, 1], with high probability the average of our samples is close to the expectation of the random variable. The expander walk sampling lemma, due to {{harvtxt|Ajtai|Komlós|Szemerédi|1987}} and {{harvtxt|Gillman|1998}}, states that this also holds true when sampling from a walk on an expander graph. This is particularly useful in the theory of [[derandomization]], since sampling according to an expander walk uses many fewer random bits than sampling independently. | |||
==See also== | |||
*[[Algebraic connectivity]] | |||
*[[Zig-zag product]] | |||
==Notes== | |||
{{Reflist|colwidth=25em}} | |||
==References== | |||
{{Refbegin|colwidth=25em}} | |||
'''Textbooks and surveys''' | |||
* {{cite book|title=The Probabilistic Method|first1=N.|last1=Alon|author1-link=Noga Alon|first2=Joel H.|last2=Spencer|author2-link=Joel Spencer|publisher=John Wiley & Sons|year=2011|edition=3rd|chapter=9.2. Eigenvalues and Expanders|ref=harv}} | |||
* {{Citation | last=Chung |first=Fan R. K. | title=Spectral Graph Theory | series=CBMS Regional Conference Series in Mathematics | volume=92 | publisher=[[American Mathematical Society]] | year=1997 | isbn=0-8218-0315-8}} | |||
* {{Citation | first1=Guiliana |last1=Davidoff | first2=Peter | last2=Sarnak | first3=Alain | last3=Valette | title=Elementary number theory, group theory and Ramanujan graphs | publisher=[[Cambridge University Press]] | series=LMS student texts | volume=55 | year=2003 | isbn=0-521-53143-8}} | |||
* {{Citation | first1=Shlomo | last1=Hoory | first2=Nathan | last2=Linial | author2-link = Nati Linial | first3=Avi | last3=Widgerson | author3-link = Avi Wigderson | title=Expander graphs and their applications | journal= Bulletin (New series) of the American Mathematical Society | volume=43 | issue=4 | pages=439–561 | url=http://www.cs.huji.ac.il/~nati/PAPERS/expander_survey.pdf | year=2006 | doi = 10.1090/S0273-0979-06-01126-8}} | |||
* {{Citation | first1=Mike |last1=Krebs | first2=Anthony | last2=Shaheen | title=Expander families and Cayley graphs: A beginner's guide | publisher=Oxford University Press | year=2011 | isbn=0-19-976711-4}} | |||
'''Research articles''' | |||
* {{Citation|last1=Ajtai|first1=M.|author1-link=Miklós Ajtai|last2=Komlós|first2=J.|author2-link=János Komlós (mathematician)|last3=Szemerédi|first3=E.|author3-link=Endre Szemerédi|chapter=An O(n log n) sorting network|title=Proceedings of the 15th Annual ACM Symposium on Theory of Computing|pages=1–9|year=1983|doi=10.1145/800061.808726|isbn=0-89791-099-0}} | |||
* {{Citation | |||
| first1=M. | last1=Ajtai | |||
| first2=J. | last2=Komlós | |||
| first3=E. | last3=Szemerédi | |||
| chapter=Deterministic simulation in LOGSPACE | |||
| title=Proceedings of the 19th Annual ACM Symposium on Theory of Computing | |||
| pages=132–140 | |||
| year=1987 | |||
| work=ACM | |||
| doi=10.1145/28395.28410 | |||
| isbn=0-89791-221-7 | |||
}} | |||
* {{cite doi|10.1109/SFCS.2002.1181884}} | |||
* {{Citation | |||
|last1=Bobkov|first1=S. | |||
|last2=Houdré|first2=C. | |||
|last3=Tetali|first3=P. | |||
|title=λ<sub>∞</sub>, vertex isoperimetry and concentration|journal=Combinatorica|volume=20|issue=2|year=2000|doi=10.1007/s004930070018|pages = 153–172}}. | |||
* {{Citation|last=Dinur|first=Irit|title=The PCP theorem by gap amplification|journal=Journal of the ACM|volume=54|issue=3|year=2007|doi=10.1145/1236457.1236459|pages=12}}. | |||
* {{Citation | |||
| first=D. | last=Gillman | |||
| title=A Chernoff Bound for Random Walks on Expander Graphs | |||
| journal=SIAM Journal on Computing | |||
| volume=27 | |||
| issue=4, | |||
| pages=1203–1220 | |||
| year=1998 | |||
| publisher=Society for Industrial and Applied Mathematics | |||
| doi=10.1137/S0097539794268765 | |||
}} | |||
* {{Citation | |||
| first=Oded | |||
| last=Goldreich | |||
| title=Basic Facts about Expander Graphs | |||
| journal = Studies in Complexity and Cryptography | |||
| year = 2011 | |||
| pages = 451–464 | |||
| doi = 10.1007/978-3-642-22670-0_30 | |||
| ref=harv | |||
}} | |||
* {{Citation|first=Omer|last=Reingold|authorlink=Omer Reingold|title=Undirected connectivity in log-space|journal=[[Journal of the ACM]]|year=2008| | |||
volume=55|issue=4|pages=Article 17, 24 pages|doi=10.1145/1391289.1391291 | |||
}} | |||
* {{Citation | |||
|first=Amir | |||
|last=Yehudayoff | |||
|title=Proving expansion in three steps | |||
|journal=[[ACM SIGACT News]] | |||
|year=2012 | |||
|volume=43 | |||
|issue=3 | |||
|pages=67–84 | |||
|doi=10.1145/2421096.2421115 | |||
|ref=harv | |||
}} | |||
{{Refend}} | |||
== External links == | |||
* [http://www.ams.org/notices/200407/what-is.pdf Brief introduction in Notices of the American Mathematical Society] | |||
* [http://michaelnielsen.org/blog/archive/notes/expander_graphs.pdf Introductory paper by Michael Nielsen] | |||
* [http://www.math.ias.edu/~boaz/ExpanderCourse/ Lecture notes from a course on expanders (by Nati Linial and Avi Wigderson)] | |||
* [http://ttic.uchicago.edu/~prahladh/teaching/spring05/index.html Lecture notes from a course on expanders (by Prahladh Harsha)] | |||
*[http://www.yann-ollivier.org/specgraph/specgraph.html Definition and application of spectral gap] | |||
{{DEFAULTSORT:Expander Graph}} | |||
[[Category:Graph families]] |
Revision as of 00:04, 17 September 2013
In combinatorics, an expander graph is a sparse graph that has strong connectivity properties, quantified using vertex, edge or spectral expansion as described below. Expander constructions have spawned research in pure and applied mathematics, with several applications to complexity theory, design of robust computer networks, and the theory of error-correcting codes.[1]
Definitions
Intuitively, an expander is a finite, undirected multigraph in which every subset of the vertices "that is not too large" has a "large" boundary. Different formalisations of these notions give rise to different notions of expanders: edge expanders, vertex expanders, and spectral expanders, as defined below.
A disconnected graph is not an expander, since the boundary of a connected component is empty. Every connected graph is an expander; however, different connected graphs have different expansion parameters. The complete graph has the best expansion property, but it has largest possible degree. Informally, a graph is a good expander if it has low degree and high expansion parameters.
Edge expansion
The edge expansion (also isoperimetric number or Cheeger constant) h(G) of a graph G on n vertices is defined as
where the minimum is over all nonempty sets S of at most n/2 vertices and ∂(S) is the edge boundary of S, i.e., the set of edges with exactly one endpoint in S.[2]
Vertex expansion
The vertex isoperimetric number (also vertex expansion or magnification) of a graph G is defined as
where is the outer boundary of S, i.e., the set of vertices in with at least one neighbor in S.[3] In a variant of this definition (called unique neighbor expansion) is replaced by the set of vertices in V with exactly one neighbor in S.[4]
The vertex isoperimetric number of a graph G is defined as
where is the inner boundary of S, i.e., the set of vertices in S with at least one neighbor in .[3]
Spectral expansion
When G is d-regular, a linear algebraic definition of expansion is possible based on the eigenvalues of the adjacency matrix A = A(G) of G, where is the number of edges between vertices i and j.[5] Because A is symmetric, the spectral theorem implies that A has n real-valued eigenvalues . It is known that all these eigenvalues are in [−d, d].
Because G is regular, the uniform distribution with for all i = 1, ..., n is the stationary distribution of G. That is, we have Au = du, and u is an eigenvector of A with eigenvalue λ1 = d, where d is the degree of the vertices of G. The spectral gap of G is defined to be d−λ2, and it measures the spectral expansion of the graph G.[6]
It is known that λn = −d if and only if G is bipartite. In many contexts, for example in the expander mixing lemma, it is necessary to bound from below not only the gap between λ1 and λ2, but also the gap between λ1 and the second-largest eigenvalue in absolute value:
Since this is the largest eigenvalue corresponding to an eigenvector orthogonal to u, it can be equivalently defined using the Rayleigh quotient:
where
is the 2-norm of the vector .
The normalized versions of these definitions are also widely used and more convenient in stating some results. Here one considers the matrix , which is the Markov transition matrix of the graph G. Its eigenvalues are between −1 and 1. For not necessarily regular graphs, the spectrum of a graph can be defined similarly using the eigenvalues of the Laplacian matrix. For directed graphs, one considers the singular values of the adjacency matrix A, which are equal to the roots of the eigenvalues of the symmetric matrix ATA.
Relationships between different expansion properties
The expansion parameters defined above are related to each other. In particular, for any d-regular graph G,
Consequently, for constant degree graphs, vertex and edge expansion are qualitatively the same.
Cheeger inequalities
When G is d-regular, there is a relationship between h(G) and the spectral gap d − λ2 of G. An inequality due to Tanner and independently Alon and MilmanTemplate:Sfn states that[7]
This inequality is closely related to the Cheeger bound for Markov chains and can be seen as a discrete version of Cheeger's inequality in Riemannian geometry.
Similar connections between vertex isoperimetric numbers and the spectral gap have also been studied:[8]
Asymptotically speaking, the quantities , , and are all bounded above by the spectral gap .
Constructions
There are three general strategies for constructing families of expander graphs.[9] The first strategy is algebraic and group-theoretic, the second strategy is analytic and uses additive combinatorics, and the third strategy is combinatorial and uses the zig-zag and related graphs products.
Margulis-Gabber-Galil
Algebraic constructions based on Cayley graphs are known for various variants of expander graphs. The following construction is due to Margulis and has been analysed by Gabber and Galil.[10] For every natural number n, one considers the graph Gn with the vertex set , where : For every vertex , its eight adjacent vertices are
Then the following holds:
Theorem. For all n, the graph Gn has second-largest eigenvalue
.
Ramanujan graphs
Mining Engineer (Excluding Oil ) Truman from Alma, loves to spend time knotting, largest property developers in singapore developers in singapore and stamp collecting. Recently had a family visit to Urnes Stave Church. By a theorem of Alon and Boppana, all large enough d-regular graphs satisfy , where λ is the second largest eigenvalue in absolute value.[11] Ramanujan graphs are d-regular graphs for which this bound is tight. That is, they satisfy .[12] Hence Ramanujan graphs have an asymptotically smallest possible λ. They are also excellent spectral expanders.
Lubotzky, Phillips, and Sarnak (1988), Margulis (1988), and Morgenstern (1994) show how Ramanujan graphs can be constructed explicitly.[13] By a theorem of Friedman (2003), random d-regular graphs on n vertices are almost Ramanujan, that is, they satisfy
with probability as n → ∞ tends to infinity.[14]
Applications and useful properties
The original motivation for expanders is to build economical robust networks (phone or computer): an expander with bounded valence is precisely an asymptotic robust graph with number of edges growing linearly with size (number of vertices), for all subsets.
Expander graphs have found extensive applications in computer science, in designing algorithms, error correcting codes, extractors, pseudorandom generators, sorting networks (Template:Harvtxt) and robust computer networks. They have also been used in proofs of many important results in computational complexity theory, such as SL=L (Template:Harvtxt) and the PCP theorem (Template:Harvtxt). In cryptography, expander graphs are used to construct hash functions.
The following are some properties of expander graphs that have proven useful in many areas.
Expander mixing lemma
Mining Engineer (Excluding Oil ) Truman from Alma, loves to spend time knotting, largest property developers in singapore developers in singapore and stamp collecting. Recently had a family visit to Urnes Stave Church. The expander mixing lemma states that, for any two subsets of the vertices S, T ⊆ V, the number of edges between S and T is approximately what you would expect in a random d-regular graph. The approximation is better, the smaller is. In a random d-regular graph, as well as in an Erdős–Rényi random graph with edge probability d/n, we expect edges between S and T.
More formally, let E(S, T) denote the number of edges between S and T. If the two sets are not disjoint, edges in their intersection are counted twice, that is,
Then the expander mixing lemma says that the following inequality holds:
where λ is the absolute value of the normalized second largest eigenvalue.
Expander walk sampling
Mining Engineer (Excluding Oil ) Truman from Alma, loves to spend time knotting, largest property developers in singapore developers in singapore and stamp collecting. Recently had a family visit to Urnes Stave Church. The Chernoff bound states that, when sampling many independent samples from a random variables in the range [−1, 1], with high probability the average of our samples is close to the expectation of the random variable. The expander walk sampling lemma, due to Template:Harvtxt and Template:Harvtxt, states that this also holds true when sampling from a walk on an expander graph. This is particularly useful in the theory of derandomization, since sampling according to an expander walk uses many fewer random bits than sampling independently.
See also
Notes
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References
Template:Refbegin Textbooks and surveys
- 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.
My blog: http://www.primaboinca.com/view_profile.php?userid=5889534 - Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010 - Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010 - Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010 - Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010
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- Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010 - Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010 - Template:Cite doi
- Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010. - Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010. - Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010 - Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010 - Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010 - Many property agents need to declare for the PIC grant in Singapore. However, not all of them know find out how to do the correct process for getting this PIC scheme from the IRAS. There are a number of steps that you need to do before your software can be approved.
Naturally, you will have to pay a safety deposit and that is usually one month rent for annually of the settlement. That is the place your good religion deposit will likely be taken into account and will kind part or all of your security deposit. Anticipate to have a proportionate amount deducted out of your deposit if something is discovered to be damaged if you move out. It's best to you'll want to test the inventory drawn up by the owner, which can detail all objects in the property and their condition. If you happen to fail to notice any harm not already mentioned within the inventory before transferring in, you danger having to pay for it yourself.
In case you are in search of an actual estate or Singapore property agent on-line, you simply should belief your intuition. It's because you do not know which agent is nice and which agent will not be. Carry out research on several brokers by looking out the internet. As soon as if you end up positive that a selected agent is dependable and reliable, you can choose to utilize his partnerise in finding you a home in Singapore. Most of the time, a property agent is taken into account to be good if he or she locations the contact data on his website. This may mean that the agent does not mind you calling them and asking them any questions relating to new properties in singapore in Singapore. After chatting with them you too can see them in their office after taking an appointment.
Have handed an trade examination i.e Widespread Examination for House Brokers (CEHA) or Actual Property Agency (REA) examination, or equal; Exclusive brokers are extra keen to share listing information thus making certain the widest doable coverage inside the real estate community via Multiple Listings and Networking. Accepting a severe provide is simpler since your agent is totally conscious of all advertising activity related with your property. This reduces your having to check with a number of agents for some other offers. Price control is easily achieved. Paint work in good restore-discuss with your Property Marketing consultant if main works are still to be done. Softening in residential property prices proceed, led by 2.8 per cent decline within the index for Remainder of Central Region
Once you place down the one per cent choice price to carry down a non-public property, it's important to accept its situation as it is whenever you move in – faulty air-con, choked rest room and all. Get round this by asking your agent to incorporate a ultimate inspection clause within the possibility-to-buy letter. HDB flat patrons routinely take pleasure in this security net. "There's a ultimate inspection of the property two days before the completion of all HDB transactions. If the air-con is defective, you can request the seller to repair it," says Kelvin.
15.6.1 As the agent is an intermediary, generally, as soon as the principal and third party are introduced right into a contractual relationship, the agent drops out of the image, subject to any problems with remuneration or indemnification that he could have against the principal, and extra exceptionally, against the third occasion. Generally, agents are entitled to be indemnified for all liabilities reasonably incurred within the execution of the brokers´ authority.
To achieve the very best outcomes, you must be always updated on market situations, including past transaction information and reliable projections. You could review and examine comparable homes that are currently available in the market, especially these which have been sold or not bought up to now six months. You'll be able to see a pattern of such report by clicking here It's essential to defend yourself in opposition to unscrupulous patrons. They are often very skilled in using highly unethical and manipulative techniques to try and lure you into a lure. That you must also protect your self, your loved ones, and personal belongings as you'll be serving many strangers in your home. Sign a listing itemizing of all of the objects provided by the proprietor, together with their situation. HSR Prime Recruiter 2010
External links
- Brief introduction in Notices of the American Mathematical Society
- Introductory paper by Michael Nielsen
- Lecture notes from a course on expanders (by Nati Linial and Avi Wigderson)
- Lecture notes from a course on expanders (by Prahladh Harsha)
- Definition and application of spectral gap
- ↑ Template:Harvtxt
- ↑ Definition 2.1 in Template:Harvtxt
- ↑ 3.0 3.1 Template:Harvtxt
- ↑ Template:Harvtxt
- ↑ cf. Section 2.3 in Template:Harvtxt
- ↑ This definition of the spectral gap is from Section 2.3 in Template:Harvtxt
- ↑ Theorem 2.4 in Template:Harvtxt
- ↑ See Theorem 1 and p.156, l.1 in Template:Harvtxt. Note that λ2 there corresponds to 2(d − λ2) of the current article (see p.153, l.5)
- ↑ see, e.g., Template:Harvtxt
- ↑ see, e.g., p.9 of Template:Harvtxt
- ↑ Theorem 2.7 of Template:Harvtxt
- ↑ Definition 5.11 of Template:Harvtxt
- ↑ Theorem 5.12 of Template:Harvtxt
- ↑ Theorem 7.10 of Template:Harvtxt