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| {{for|other forms of quintessence|Quintessence (disambiguation)}}
| | If you are reading this, then you are at least thinking about home improvement. Wonderful idea! However, quite a bit of hard work goes into improving your home properly. Do you have an idea of what to do? If not, you need to read the following pieces of advice.<br><br>If you prefer an inexpensive type of flooring, you will prefer vinyl over stone or ceramic tile. Vinyl has several things going for it. It is durable, installs easily with an adhesive backing, Should you loved this informative article and you want to receive more information with regards to home renovations ideas [[http://www.homeimprovementdaily.com homeimprovementdaily.com]] i implore you to visit the site. and resists water damage. Vinyl flooring comes in two varieties: separate tiles for small areas and large sheets for bigger areas.<br><br>Whenever your roof needs redoing, you should insert white tile. If not white, then ensure it is light colored. Light colors deflect the heat from the sun away from the house. This ensures you're not spending a lot on air conditioning.<br><br>Use a wet sponge on your drywall installation. Rather than sanding the seams in your drywall, sponge them. Using a wet sponge can do as good of a job as sanding can. The good thing is that using a sponge spares you the dust that you get with sanding.<br><br>If your home renovation project involves work in the bathroom or kitchen, make sure to shut off the water. You'll need to find the main shut-off in your home before you start any work that involves your plumbing. This step will help you prevent a flood.<br><br>When hiring a contractor, be sure to keep good records and always sign a clearly stated contract. Don't make any assumptions that your contractor will do so. Keep a file of all invoices and contracts associated with your project. Such records can help both you and the contractor stay organized and focused.<br><br>If you are looking for a simple improvement to your home then head to the store and grab some paint. It makes for an amazing visual change. A brand new coat of paint can also make your home more attractive to those that may be buying it if you put it up for sale.<br><br>Make sure that any landscaping projects you tackle are ones that will complement the style of your home and neighborhood. A new garden or outside dining area that goes well with your home's style will improve the entire look of your property, but things that clash will offer the appearance of insufficient planning and end up looking outright unattractive.<br><br>Always make sure the power is turned off when working near an electrical area. If you don't cut the power to the area you're working on, you could touch live wires. This will certainly injure you, and it could kill you.<br><br>Do you know about "age-in-place" techniques? This method factors in the age of the homeowner to determine which improvements will provide the most for your home improvement dollar. No matter if you are improving your forever home or just working on a property you are likely to sell, these types of design decisions can enhance the value and utility of your house.<br><br>Reading the helpful advice above will better prepare you for any home improvement project you have in mind. These insights may also help you decide whether you can go it alone, or if your project needs the expertise of an outside party. |
| {{For|theories and defunct or classical concepts named after the synonym "Aether"|Aether (disambiguation)}}
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| In [[physics]], '''quintessence''' is a [[hypothesis|hypothetical]] form of [[dark energy]] postulated as an explanation of observations of an [[accelerating universe]]. It has been proposed by some physicists to be a [[fifth force|fifth fundamental force]]. Quintessence differs from the [[cosmological constant]] explanation of dark energy in that it is dynamic, changing over time, unlike the cosmological constant which always stays constant. It is suggested{{whom|date=April 2013}} that quintessence can be either attractive or repulsive depending on the ratio of its kinetic and potential energy. Specifically, it is thought that quintessence became repulsive about ten billion years ago (the universe is approximately 13.8 billion years old).<ref>Christopher Wanjek; "Quintessence, accelerating the Universe?"; http://www.astronomytoday.com/cosmology/quintessence.html</ref>
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| == Scalar field ==
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| Quintessence is a [[scalar field]] with an [[Equation of State (Cosmology)|equation of state]] where ''w''<sub>''q''</sub>, the ratio of pressure ''p''<sub>''q''</sub> and density <math>\rho</math><sub>''q''</sub>, is given by the potential energy <math>V(Q)</math> and a kinetic term:
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| :<math>w_q=p_q/\rho_q=\frac{\frac{1}{2}\dot{Q}^2-V(Q)}{\frac{1}{2}\dot{Q}^2+V(Q)}</math>
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| Hence, Quintessence is dynamic, and generally has a density and ''w''<sub>''q''</sub> parameter that varies with time. By contrast, a cosmological constant is static, with a fixed energy density and ''w''<sub>''q''</sub> = −1.
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| == Tracker behavior ==
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| Many models of quintessence have a ''tracker'' behavior, which according to [[Paul Steinhardt]] ''et al.'' (1999) partly solves the [[Cosmological_constant#Cosmological_constant_problem|cosmological constant problem]].<ref name="Zlatev">{{cite journal
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| | last1=Zlatev |first1=I.
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| |last2=Wang |first2=L.
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| |last3=Steinhardt |first3=P.
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| | title=Quintessence, Cosmic Coincidence, and the Cosmological Constant
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| | journal=[[Physical Review Letters]]
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| | year=1999
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| | volume=82
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| |issue=5
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| | pages=896–899
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| | doi=10.1103/PhysRevLett.82.896
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| |bibcode=1999PhRvL..82..896Z
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| |arxiv = astro-ph/9807002 }}</ref> In these models, the quintessence field has a density which closely tracks (but is less than) the radiation density until [[Timeline_of_the_Big_Bang#Matter_domination|matter-radiation equality]], which triggers quintessence to start having characteristics similar to [[dark energy]], eventually dominating the universe. This naturally sets the low [[energy scale|scale]] of the [[dark energy]].<ref name="Steinhardt1999">{{cite journal
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| | last3=Zlatev |first3=I.
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| |last2=Wang |first2=L.
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| |last1=Steinhardt |first1=P.
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| | title=Cosmological tracking solutions
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| | journal=[[Physical Review D]]
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| | year=1999
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| | volume=59
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| |issue=12
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| | pages=123504
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| | doi=10.1103/PhysRevD.59.123504
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| |bibcode=1999PhRvD..59l3504S
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| |arxiv = astro-ph/9812313 }}</ref> When comparing the predicted [[metric expansion of space|expansion rate]] of the universe as given by the tracker solutions with cosmological data, a main feature of tracker solutions is that one needs four parameters to properly describe the behavior of their [[equation of state (cosmology)|equation of state]],<ref name="Linden2008">{{cite journal
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| | last1=Linden |first1=Sebastian
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| |last2=Virey |first2=Jean-Marc
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| | title=Test of the Chevallier-Polarski-Linder parametrization for rapid dark energy equation of state transitions
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| | journal=[[Physical Review D]]
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| | year=2008
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| | volume=78
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| |issue=2
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| | pages=023526
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| | doi=10.1103/PhysRevD.78.023526
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| |bibcode=2008PhRvD..78b3526L
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| |arxiv = 0804.0389 }}</ref><ref name="Ferramacho2010">{{cite journal
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| | last1=Ferramacho |first1=L.
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| |last2=Blanchard |first2=A.
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| |last3=Zolnierowsky | first3=Y.
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| |last4=Riazuelo | first4=A.
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| | title=Constraints on dark energy evolution
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| | journal=[[Astronomy & Astrophysics|A&A]]
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| | year=2010
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| | volume=514
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| | pages=A20
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| | doi=10.1051/0004-6361/200913271
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| |bibcode=2010A&A...514A..20F
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| |arxiv = 0909.1703 }}</ref> whereas it has been shown that at most a two-parameter model can optimally be constrained by mid-term future data (horizon 2015-2020).<ref name="LindererHuterer2005">{{cite journal
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| | last1=Linder |first1=Eric V.
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| |last2=Huterer |first2=Dragan
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| | title=How many cosmological parameters
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| | journal=[[Physical Review D]]
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| | year=2005
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| | volume=72
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| |issue=4
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| | pages=043509
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| | doi=10.1103/PhysRevD.72.043509
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| |bibcode=2005PhRvD..72d3509L
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| |arxiv = astro-ph/0505330 }}</ref>
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| == Specific models ==
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| Some special cases of quintessence are [[phantom energy]], in which ''w''<sub>''q''</sub> < −1,<ref name="Caldwell2002">{{cite journal
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| | last1=Caldwell |first1=R. R.
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| | title=A phantom menace? Cosmological consequences of a dark energy component with super-negative equation of state
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| | journal=[[Physics Letters B]]
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| | year=2002
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| | volume=545
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| |issue=1-2
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| | pages=23–29
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| | doi=10.1016/S0370-2693(02)02589-3
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| |bibcode=2002PhLB..545...23C
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| |arxiv = astro-ph/9908168 }}</ref> and [[k-essence]] (short for [[kinetic quintessence]]), which has a non-standard form of [[kinetic energy]]. If this type of energy were to exist, it would cause a [[big rip]] in the universe due to the growing energy density of dark energy which would cause the expansion of the universe to increase at a faster-than-exponential rate.
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| == Quintom scenario ==
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| In 2004, when scientists fit the evolution of dark energy with the cosmological data, they found that the equation of state had possibly crossed the [[cosmological constant boundary]] (w=-1) from above to below. A proven [[no-go theorem]]{{which|date=April 2013}} indicates this situation, called the [[Quintom scenario]], requires at least two degrees of freedom for dark energy models.<ref name="Hu2005">{{cite journal
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| | last1=Hu |first1=Wayne
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| | title=Crossing the phantom divide: Dark energy internal degrees of freedom
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| | journal=[[Physical Review D]]
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| | year=2005
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| | volume=71
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| |issue=4
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| | pages=047301
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| | doi=10.1103/PhysRevD.71.047301
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| |bibcode=2005PhRvD..71d7301H
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| |arxiv = astro-ph/0410680 }}</ref>
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| == Terminology ==
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| The name comes from the [[Classical element#Classical elements in Greece|classical elements]] in ancient Greece. The [[Aether (classical element)|aether]], a pure "fifth element" (''quinta essentia'' in Latin), was thought to fill the Universe beyond Earth. Similarly, modern quintessence would be the fifth known contribution to the overall mass-energy content of the Universe. (The other four in the modern interpretation, different from the ancient ideas, are: [[Baryon|baryonic matter]]; radiation – photons and the highly relativistic [[neutrinos]], which may be considered [[hot dark matter]]; [[cold dark matter]]; and the term due to spatial curvature – loosely, [[gravitation]]al [[self-energy]].)
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| == References ==
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| {{Reflist|2}}
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| ===Further reading===
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| * {{Cite journal |author=Ostriker JP, Steinhardt P |title=The Quintessential Universe |journal=Scientific American |volume=284 |number=1 |date=January 2001 |pages=46–53}}
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| == External links ==
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| * [http://www.astro.uni-bonn.de/~webiaef/outreach/posters/darkenergy/ Dark Energy dominates the Universe] (recently unavailable link, outreach poster from [[University of Bonn]])
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| * [http://www.astro.uni-bonn.de/~kilbinge/de/index.shtml/ Dark Energy dominates the Universe]
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| * [http://www.astronomytoday.com/cosmology/quintessence.html/ Quintessence Accelerating the Universe]
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| * [http://physicsworld.com/cws/article/print/402 Quintessence]
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| * [http://xstructure.inr.ac.ru/x-bin/theme3.py?level=1&index1=-328030 Quintessence model on arxiv.org]
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| {{Expert-subject|physics|date=April 2009|reason=Unclear phrasing in [[#Tracker behavior]] and [[#Quintom scenario]]}}
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| {{DEFAULTSORT:Quintessence (Physics)}}
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| [[Category:Physical cosmology]]
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If you are reading this, then you are at least thinking about home improvement. Wonderful idea! However, quite a bit of hard work goes into improving your home properly. Do you have an idea of what to do? If not, you need to read the following pieces of advice.
If you prefer an inexpensive type of flooring, you will prefer vinyl over stone or ceramic tile. Vinyl has several things going for it. It is durable, installs easily with an adhesive backing, Should you loved this informative article and you want to receive more information with regards to home renovations ideas [homeimprovementdaily.com] i implore you to visit the site. and resists water damage. Vinyl flooring comes in two varieties: separate tiles for small areas and large sheets for bigger areas.
Whenever your roof needs redoing, you should insert white tile. If not white, then ensure it is light colored. Light colors deflect the heat from the sun away from the house. This ensures you're not spending a lot on air conditioning.
Use a wet sponge on your drywall installation. Rather than sanding the seams in your drywall, sponge them. Using a wet sponge can do as good of a job as sanding can. The good thing is that using a sponge spares you the dust that you get with sanding.
If your home renovation project involves work in the bathroom or kitchen, make sure to shut off the water. You'll need to find the main shut-off in your home before you start any work that involves your plumbing. This step will help you prevent a flood.
When hiring a contractor, be sure to keep good records and always sign a clearly stated contract. Don't make any assumptions that your contractor will do so. Keep a file of all invoices and contracts associated with your project. Such records can help both you and the contractor stay organized and focused.
If you are looking for a simple improvement to your home then head to the store and grab some paint. It makes for an amazing visual change. A brand new coat of paint can also make your home more attractive to those that may be buying it if you put it up for sale.
Make sure that any landscaping projects you tackle are ones that will complement the style of your home and neighborhood. A new garden or outside dining area that goes well with your home's style will improve the entire look of your property, but things that clash will offer the appearance of insufficient planning and end up looking outright unattractive.
Always make sure the power is turned off when working near an electrical area. If you don't cut the power to the area you're working on, you could touch live wires. This will certainly injure you, and it could kill you.
Do you know about "age-in-place" techniques? This method factors in the age of the homeowner to determine which improvements will provide the most for your home improvement dollar. No matter if you are improving your forever home or just working on a property you are likely to sell, these types of design decisions can enhance the value and utility of your house.
Reading the helpful advice above will better prepare you for any home improvement project you have in mind. These insights may also help you decide whether you can go it alone, or if your project needs the expertise of an outside party.