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Related papers: Constrainting Cosmic Quintessence

200 papers

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 in the light of the cosmological constant problem. Cosmological…

Astrophysics · Physics 2009-11-07 Michael Doran , Christof Wetterich

A novel approach to quintessential inflation model building is studied, within the framework of $\alpha$-attractors, motivated by supergravity theories. Inflationary observables are in excellent agreement with the latest CMB observations,…

General Relativity and Quantum Cosmology · Physics 2017-06-23 Konstantinos Dimopoulos , Charlotte Owen

In this talk we present a model of the universe in which dark energy is modelled explicitely with both a dynamical quintessence field and a cosmological constant. Our results confirm the possibility of a collapsing universe (for a given…

Astrophysics · Physics 2007-05-23 Rolando Cardenas , Tame Gonzalez , Osmel Martin , Israel Quiros

We study the possibility that large scale cosmological perturbations have been generated during the domination and decay of a massive particle species whose mass depends on the expectation value of a light scalar field. We discuss the…

Astrophysics · Physics 2009-11-10 Filippo Vernizzi

We examine the possibility of achieving quintessential inflation, where the same field serves as both inflaton and quintessence, in the context of a five-dimensional braneworld. Braneworld cosmology provides an appropriate environment as it…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-22 Mafalda Dias , Andrew R Liddle

We study the robustness of the quintessence tracking scenario in the context of more general cosmological models that derive from high-energy physics. We consider the effects of inclusion of multiple scalar fields, corrections to the Hubble…

Astrophysics · Physics 2009-11-07 Greg Huey , Reza Tavakol

We investigate two classes of models of quintessential inflation, based upon canonical as well as noncanonical scalar fields. In particular, introducing potentials steeper than the standard exponential, we construct models that can give…

General Relativity and Quantum Cosmology · Physics 2015-07-17 Chao-Qiang Geng , Md. Wali Hossain , R. Myrzakulov , M. Sami , Emmanuel N. Saridakis

Quintessential inflation unifies inflation and late time acceleration by a single scalar field. Such a scenario, with canonical and non-canonical scalar fields, has been discussed . The scalar field behaves as an inflaton field during…

General Relativity and Quantum Cosmology · Physics 2018-01-11 Md. Wali Hossain

If the inflaton and the quintessence fields are identified, the background geometry evolves through a stiff epoch undershooting the expansion rate of a radiation-dominated plasma. For some classes of inflationary potentials this scenario is…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Massimo Giovannini

Recent data point in the direction of a $\Lambda$ dominated universe. We briefly review ``Quintessence'' as a model for a dynamical cosmological term and analyse the role of Susy QCD as a possible particle physics candidate. The multiscalar…

High Energy Physics - Phenomenology · Physics 2011-08-05 Francesca Rosati

An extremely light ($m_{\phi} \ll 10^{-33} {\rm eV}$), slowly-varying scalar field $\phi $ (quintessence) with a potential energy density as large as 60% of the critical density has been proposed as the origin of the accelerated expansion…

High Energy Physics - Phenomenology · Physics 2009-10-31 R. Horvat

We construct a model of quintessential inflation in Palatini $R^2$ gravity employing a scalar field with a simple exponential potential and coupled to gravity with a running non-minimal coupling. At early times, the field acts as the…

General Relativity and Quantum Cosmology · Physics 2022-11-03 Konstantinos Dimopoulos , Alexandros Karam , Samuel Sánchez López , Eemeli Tomberg

It is shown that the accelerated expansion of the universe in the framework of the relativistic theory of gravitation can be achieved by the introduction of the quintessential term in the energy-momentum tensor. The value of the minimum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. L. Kalashnikov

We study the nonlinear realization of supersymmetry in a dynamical/cosmological background in which derivative terms like kinetic terms are finite. Starting from linearly realized theories, we integrate out heavy modes without neglecting…

High Energy Physics - Theory · Physics 2022-02-24 Shuntaro Aoki , Takahiro Terada

The quintessence field coupled to the cosmic neutrino background (CNB) has been widely discussed as an alternative mechanism to address the coincidence problem. As it is well known, it is possible to extend such models to obtain…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-01 Zurab Kepuladze , Michael Maziashvili

We investigate a cosmological model in which dark energy, represented by a quintessential scalar field, is directly coupled to a dark-matter perfect fluid. We are interested in solutions of cosmological relevance, namely those for which a…

General Relativity and Quantum Cosmology · Physics 2022-12-07 Robertus Potting , Paulo M. Sá

Recently, a novel class of models for inflation has been found in which the inflationary dynamics is driven solely by (non-canonical) kinetic terms rather than by potential terms. As an obvious extension, we show that a scalar field with…

Astrophysics · Physics 2008-11-26 Takeshi Chiba , Takahiro Okabe , Masahide Yamaguchi

We perform a cosmological analysis in which we allow the primordial power spectrum of scalar perturbations to assume a shape that is different with respect to the usual power-law, arising from the simplest models of cosmological inflation.…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-22 Stefano Gariazzo

The evolution of the quintessence field during a phase of chaotic inflation is studied. The inflaton and the quintesssence field are described in a supergravity framework where the coupling between the inflaton and quintessence is induced…

Astrophysics · Physics 2008-11-26 Philippe Brax , Jerome Martin

We consider the question of deriving initial conditions for scalar fields in driving both an early and late quintessence phase. The dark energy field presents an unresolved uniformity problem. Further difficulties with initial conditions…

General Relativity and Quantum Cosmology · Physics 2012-12-20 D. H. Coule