Cosmology with exponential potentials

Kehagias, A; Kofinas, G

dc.contributor.author	Kehagias, A	en
dc.contributor.author	Kofinas, G	en
dc.date.accessioned	2014-03-01T01:20:04Z
dc.date.available	2014-03-01T01:20:04Z
dc.date.issued	2004	en
dc.identifier.issn	0264-9381	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/15832
dc.subject	Cosmological Constant	en
dc.subject	General Relativity	en
dc.subject	Initial Condition	en
dc.subject	Ordinary Differential Equation	en
dc.subject	Scalar Field	en
dc.subject	Structure Formation	en
dc.subject	First Order	en
dc.subject	Present Value	en
dc.subject	Robertson Walker	en
dc.subject.classification	Astronomy & Astrophysics	en
dc.subject.classification	Physics, Multidisciplinary	en
dc.subject.classification	Physics, Particles & Fields	en
dc.subject.other	SCALAR-FIELD COSMOLOGIES	en
dc.subject.other	POWER-LAW INFLATION	en
dc.subject.other	GRAVITY THEORIES	en
dc.subject.other	ACCELERATING COSMOLOGIES	en
dc.subject.other	SCALING SOLUTIONS	en
dc.subject.other	I MODELS	en
dc.subject.other	UNIVERSE	en
dc.subject.other	QUINTESSENCE	en
dc.subject.other	SUPERGRAVITY	en
dc.subject.other	SPACETIMES	en
dc.title	Cosmology with exponential potentials	en
heal.type	journalArticle	en
heal.identifier.primary	10.1088/0264-9381/21/16/003	en
heal.identifier.secondary	http://dx.doi.org/10.1088/0264-9381/21/16/003	en
heal.language	English	en
heal.publicationDate	2004	en
heal.abstract	We examine in the context of general relativity the dynamics of a spatially flat Robertson-Walker universe filled with a classical minimally coupled scalar field phi of exponential potential V(phi) similar to exp(-muphi) plus pressureless baryonic matter. This system is reduced to a first-order ordinary differential equation for Omega(phi) (w(phi)) or q(w(phi)), providing direct evidence on the acceleration/deceleration properties of the system. As a consequence, for positive potentials, passage into acceleration not at late times is generically a feature of the system for any value of mu, even when the late-times attractors are decelerating. Furthermore, the structure formation bound, together with the constraints Omega(m0) approximate to 0.25 - 0.3, -1 less than or equal to, w(phi0) less than or equal to, -0.6, provides, independently of initial conditions and other parameters, the necessary condition 0 < mu less than or similar to 1.6 root8piG(N), while the less conservative constraint -1 less than or equal to w(phi) less than or equal to -0.93 gives 0 < mu less than or equal to 0.7root8piG(N). Special solutions are found to possess intervals of acceleration. For the almost cosmological constant case wphi approximate to -1, the general relation Omega(phi)(wphi) is obtained. The generic (nonlinearized) late-times solution of the system in the plane (w(phi), Omega(phi)) or (w(phi), q) is also derived.	en
heal.publisher	IOP PUBLISHING LTD	en
heal.journalName	Classical and Quantum Gravity	en
dc.identifier.doi	10.1088/0264-9381/21/16/003	en
dc.identifier.isi	ISI:000223629500004	en
dc.identifier.volume	21	en
dc.identifier.issue	16	en
dc.identifier.spage	3871	en
dc.identifier.epage	3885	en