English
Related papers

Related papers: Bouncing Galileon Cosmologies

200 papers

We present a unified framework for non-singular bouncing cosmologies in modified gravity, combining $f(R,G,T)$ geometry with quintom scalar dynamics in a flat FLRW universe. While single-field models achieve phantom divide line (PDL)…

General Relativity and Quantum Cosmology · Physics 2025-12-30 Farzad Milani

We examine non-singular bounce cosmology within the framework of a phantom scalar field coupled to the Gauss-Bonnet term in both non-viscous and bulk-viscous cases. Using the scale factor ansatz…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-07 Khandro K. Chokyi , Surajit Chattopadhyay

An extremely fast exponential expansion of the Universe is typical for the stable version of the inflationary model, based on the anomaly-induced action of gravity. The total amount of exponential $e$-folds could be very large, before the…

High Energy Physics - Theory · Physics 2021-08-05 Wagno Cesar e Silva , Ilya L. Shapiro

In this paper we study the dynamics of {\it orthogonal spatially homogeneous} Bianchi cosmologies in $R^n$-gravity. We construct a compact state space by dividing the state space into different sectors. We perform a detailed analysis of the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Naureen Goheer , Jannie A. Leach , Peter K. S. Dunsby

Ho\v{r}ava-Lifshitz gravity is a potentially UV complete theory with important implications for the very early universe. In particular, in the presence of spatial curvature it is possible to obtain a non-singular bouncing cosmology. The…

High Energy Physics - Theory · Physics 2015-05-14 Xian Gao , Yi Wang , Wei Xue , Robert Brandenberger

The theory of inflation is one of the fundamental and revolutionary developments of modern cosmology that became able to explain many issues of early universe in the context of the standard cosmological model (SCM). However, the initial…

General Relativity and Quantum Cosmology · Physics 2018-05-23 Jaume de Haro , Supriya Pan

String-inspired cosmologies, whereby a non-singular curvature bounce is induced by a general-covariant, $T$-duality-invariant, non-local dilaton potential, are used to study numerically how inhomogeneities evolve and to compare the outcome…

High Energy Physics - Theory · Physics 2010-04-05 M. Gasperini , M. Giovannini , G. Veneziano

We consider a bouncing Universe model which explains the flatness of the primordial scalar spectrum via complex scalar field that rolls down its negative quartic potential and dominates in the Universe. We show that in this model, there…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Sergey Mironov

We study the transfer of cosmological perturbations through a nonsingular cosmological bounce in a special model in which the parameters of the bounce and the equation of state of matter are chosen such as to allow for an exact calculation…

High Energy Physics - Theory · Physics 2008-07-30 Stephon Alexander , Tirthabir Biswas , Robert H. Brandenberger

In quantum cosmology, one has to select a specific wave function solution of the quantum state equations under consideration in order to obtain concrete results. The simplest choices have been already explored, in different frameworks,…

General Relativity and Quantum Cosmology · Physics 2021-09-06 P. C. M. Delgado , N. Pinto-Neto

We construct a class of viable bouncing models that are conformally related to cosmological inflation. There are three main difficulties in constructing such a model: (i) A stable (attractor) solution, (ii) A non-singular bounce, and (iii)…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-25 Debottam Nandi

In this article, we explore the homogeneous and isotropic flat Friedmann-Robertson-Walker (FRW) model in Chameleon cosmology. By considering a non-minimal coupling between the scalar field and matter, we present a non-singular bouncing…

General Relativity and Quantum Cosmology · Physics 2022-12-06 Ashutosh Singh , Anirudh Pradhan

We show that every Galileon theory admits a dual formulation as a Galileon theory with new operator coefficients. In n dimensions a free scalar field in Minkowski spacetime is dual to a (n+1)-th order Galileon theory which exhibits the…

High Energy Physics - Theory · Physics 2014-05-07 Claudia de Rham , Matteo Fasiello , Andrew J. Tolley

We explore the dynamics of FLRW cosmologies which consist of dark matter, radiation and dark energy with a quadratic equation of state. Standard cosmological singularities arise due to energy conditions which are violated by dark energy,…

General Relativity and Quantum Cosmology · Physics 2023-05-19 Molly Burkmar , Marco Bruni

A nonsingular emergent universe cosmology can be realized by a nonconventional spinor field as first developed in \cite{Cai:2012yf}. We study the mechanisms of generating scale-invariant primordial power spectrum of curvature perturbation…

High Energy Physics - Theory · Physics 2014-03-11 Yi-Fu Cai , Youping Wan , Xinmin Zhang

As an alternative to the paradigm of slow roll inflation, we propose an extended scenario of the matter bounce cosmology in which the Universe has experienced a quasi-matter contracting phase with a variable background equation of state…

General Relativity and Quantum Cosmology · Physics 2015-09-04 Jaume de Haro , Yi-Fu Cai

In this paper, a bouncing cosmological scenario is studied in the background of a flat FLRW model with a specific parametrized hyperbolic form of scale factor $ a $ in terms of $ t $, where $ \lambda $ is taken as the model parameter. This…

General Relativity and Quantum Cosmology · Physics 2022-08-12 J. K. Singh , Shaily , Kazuharu Bamba

A quantum cosmological bouncing model may exhibit an ambiguity stemming from the nonclassical nature of the background evolution: two classically equivalent theories can produce two qualitatively different potentials sourcing the…

General Relativity and Quantum Cosmology · Physics 2024-03-25 Jaime de Cabo Martin , Przemysław Małkiewicz , Patrick Peter

We study the dynamics of the homogeneous and isotropic cosmological background in the recently proposed ``quantum phenomenological gravitational dynamics'', characterised by logarithmic corrections to the Bekenstein entropy. We show that…

General Relativity and Quantum Cosmology · Physics 2023-07-21 Marco de Cesare , Giulia Gubitosi

We revisit the cosmological dynamics of the cubic Galileon model in light of the recently proposed model-independent analyses of the Pantheon supernova data. At the background level, it is shown to be compatible with data and preferred over…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-01 Suddhasattwa Brahma , Md. Wali Hossain