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56
Exponential Quintessence and the End of Acceleration
, 2001
"... Recent observations indicate that the universe’s expansion has been accelerating of late. But recent theoretical work has highlighted the difficulty of squaring acceleration with the underlying assumptions of string theory, disfavoring most models of quintessence. because they predict eternal accele ..."
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acceleration. We show that one of the simplest and most motivated quintessence models described by an exponential potential can produce the acceleration needed to explain the data while also predicting only a finite period of acceleration, consistent with theoretical paradigms. This model is no more tuned than
Extended quintessence with an exponential coupling
 JCAP
, 2005
"... Abstract. We study a class of extended quintessence cosmologies where the scalar field playing the role of the dark energy is exponentially coupled to the Ricci scalar. We find that the dynamics induced by the effective gravitational potential in the KleinGordon equation dominates the motion of the ..."
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Cited by 4 (0 self)
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Abstract. We study a class of extended quintessence cosmologies where the scalar field playing the role of the dark energy is exponentially coupled to the Ricci scalar. We find that the dynamics induced by the effective gravitational potential in the KleinGordon equation dominates the motion
An alternative to quintessence
 Phys. Lett
"... We consider a FRW cosmological model with an exotic fluid known as Chaplygin gas. We show that the resulting evolution of the universe is not in disagreement with the current observation of cosmic acceleration. The model predict an increasing value for the effective cosmological constant. The discov ..."
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Cited by 26 (0 self)
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. The discovery that the expansion of the universe is accelerating [1] has promoted the search for new types of matter that can behave like a cosmological constant [2, 3] by combining positive energy density and negative pressure. This type of matter is often called ”quintessence”. Since in a variety
Quintessence Cosmologies with a Double Exponential Potential 1
, 2004
"... We use phase space methods to investigate closed, flat, and open FriedmannRobertsonWalker cosmologies with a scalar potential given by the sum of two exponential terms. The form of the potential is motivated by the dimensional reduction of Mtheory with nontrivial fourform flux on a maximally sy ..."
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Cited by 7 (0 self)
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We use phase space methods to investigate closed, flat, and open FriedmannRobertsonWalker cosmologies with a scalar potential given by the sum of two exponential terms. The form of the potential is motivated by the dimensional reduction of Mtheory with nontrivial fourform flux on a maximally
Gauge Invariant Perturbation Analysis for Quintessence with an Exponential Potential
, 2001
"... Gauge invariant adiabatic perturbations in the cosmology of a scalar field ϕ(x, t) gravitationally coupled to a perfect fluid (radiation or matter) are investigated. The potential of the scalar field is of exponential form. This model recently has received much attention in the context of ‘quintesse ..."
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Gauge invariant adiabatic perturbations in the cosmology of a scalar field ϕ(x, t) gravitationally coupled to a perfect fluid (radiation or matter) are investigated. The potential of the scalar field is of exponential form. This model recently has received much attention in the context
Fine Tuning in Quintessence Models with Exponential Potentials
, 2002
"... Preprint typeset in JHEP style HYPER VERSION astroph/0206194 ..."
Quintessence and the transition to an accelerating universe
, 2004
"... The implications of seven popular models of quintessence based on supergravity or M/string theory for the transition from a decelerating to an accelerating universe are explored. All seven potentials can mimic the ΛCDM model at low redshifts 0 � z � 5. However, for a natural range of initial values ..."
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Cited by 3 (3 self)
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The implications of seven popular models of quintessence based on supergravity or M/string theory for the transition from a decelerating to an accelerating universe are explored. All seven potentials can mimic the ΛCDM model at low redshifts 0 � z � 5. However, for a natural range of initial values
Quintessence with Hybrid Potential
, 2013
"... I present the numerical solution of equations of the evolution of a universe containing background fluids (radiation, dark matter and baryonic matter), plus a scalar matter field with a hybrid potential that is a combination of exponential potential and powerlaw potential. The plot of the evolution ..."
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I present the numerical solution of equations of the evolution of a universe containing background fluids (radiation, dark matter and baryonic matter), plus a scalar matter field with a hybrid potential that is a combination of exponential potential and powerlaw potential. The plot
Quintessence – the Dark Energy in the Universe?
, 2001
"... Quintessence – the energy density of a slowly evolving scalar field – may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea and indicate observational tests which may distinguish quintessence from a cosmological constant. The idea of quintessence or ..."
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Cited by 1 (0 self)
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Quintessence – the energy density of a slowly evolving scalar field – may constitute a dynamical form of the homogeneous dark energy in the universe. We review the basic idea and indicate observational tests which may distinguish quintessence from a cosmological constant. The idea of quintessence
Results 1  10
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56