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Related papers: Deformed Matter Bounce with Dark Energy Epoch

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We study the dynamics of the Bianchi I universe in modified loop quantum cosmology (mLQC-I) and uncover a robust mechanism for isotropization: the shear is dynamically suppressed after the bounce and decays rapidly in the quantum…

General Relativity and Quantum Cosmology · Physics 2026-05-26 Wen-Cong Gan , Leila L. Graef , Rudnei O. Ramos , Gustavo S. Vicente , Anzhong Wang

The ekpyrotic and cyclic universe scenarios have revived the idea that the density perturbations apparent in today's universe could have been generated in a `pre-singularity' epoch before the big bang. These scenarios provide explicit…

High Energy Physics - Theory · Physics 2009-11-07 Christopher Gordon , Neil Turok

We extend the scalar-tensor reconstruction techniques for classical cosmology frameworks, in the context of loop quantum cosmology. After presenting in some detail how the equations are generalized in the loop quantum cosmology case, we…

General Relativity and Quantum Cosmology · Physics 2016-08-24 V. K. Oikonomou

We investigate a bounce realization in the framework of higher order curvature in $ f(R,T) $ modified theory of gravity. We perform a detailed analysis of the cosmological parameters to explain the contraction phase, the bounce phase, and…

General Relativity and Quantum Cosmology · Physics 2023-07-19 J. K. Singh , Shaily , Akanksha Singh , Aroonkumar Beesham , Hamid Shabani

We outline a dynamical dark energy scenario whose signatures may be simultaneously tested by astronomical observations and laboratory experiments. The dark energy is a field with slightly sub-gravitational couplings to matter, a logarithmic…

Astrophysics · Physics 2009-06-23 Nemanja Kaloper

Our universe is observed to be accelerating due to the dominant dark energy with negative pressure. The dark energy equation of state (w) holds a key to understanding the ultimate fate of the universe. The cosmic voids behave like bubbles…

Astrophysics · Physics 2011-02-11 Jounghun Lee , Daeseong Park

A finite vacuum energy density implies the existence of a UV scale for gravitational modes. This gives a phenomenological scale to the dynamical equations governing the cosmological expansion that must satisfy constraints consistent with…

Astrophysics · Physics 2007-05-23 James Lindesay

The fate of our universe is an unceasing topic of cosmology and the human being. The discovery of the current accelerated expansion of the universe significantly changed our view of the fate of the universe. Recently, some interesting…

General Relativity and Quantum Cosmology · Physics 2012-10-11 Hao Wei , Long-Fei Wang , Xiao-Jiao Guo

We aim at the construction of dark energy models without exotic matter but with a phantom-like equation of state (an effective phantom phase). The first model we consider is decaying vacuum cosmology where the fluctuations of the vacuum are…

High Energy Physics - Theory · Physics 2009-09-17 Emilio Elizalde , Shin'ichi Nojiri , Sergei D. Odintsov , Peng Wang

As one of the fundamental unknowns of our Universe, the mass of dark matter remains to be a topic of great interest. We consider the possibility of a time-variation of the dark matter mass. We study the cosmological constraints on a model…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-01 Amlan Chakraborty , Anirban Das , Subinoy Das , Shiv K. Sethi

The standard model of cosmology assumes a homogeneous and isotropic universe that undergoes a period of exponential expansion very early on, named inflation. This stretches quantum fluctuations from the onset of inflation to cosmological…

General Relativity and Quantum Cosmology · Physics 2024-10-22 Rita B. Neves

We investigate the background dynamics when dark energy is coupled to dark matter in the universe described by Einstein cosmology and Loop Quantum Cosmology. We introduce a new general form of dark sector coupling, which presents us a more…

General Relativity and Quantum Cosmology · Physics 2008-12-18 Songbai Chen , Bin Wang , Jiliang Jing

Expansion dynamics of the Universe is one of the important subjects in modern cosmology. The dark energy equation of state determines this dynamics so that the Universe is in an accelerating phase. However, the dark matter can also affect…

General Relativity and Quantum Cosmology · Physics 2025-10-08 Zeinab Rezaei

Considering that the universe is filled with the nonrelativistic matter and dark energy and each component is respectively satisfied with its conservation condition in the absence of their interaction, we give the change rate of the…

Astrophysics · Physics 2007-05-23 Wei Wang , Yuanxing Gui , Ying Shao

We study the possibility to describe dark matter in a model of the universe with two scale factors and a non-standard Poisson bracket structure characterized by the deformation parameter \kappa. The dark matter evolution is analyzed in the…

High Energy Physics - Phenomenology · Physics 2023-08-16 Carlos Maldonado , Fernando Mendez

Here, creation of the universe is obtained only from gravity sector. The dynamical universe begins with two basic ingredients (i) vacuum energy, also called dark energy (as vacuum energy is not observed) and (ii) background radiation. These…

High Energy Physics - Theory · Physics 2007-05-23 S. K. Srivastava

By studying the present cosmological data, particularly on CMB, SNeIA and LSS, we find that the future fate of the universe, for simple linear models of the dark energy equation-of-state, can vary between the extremes of (I) a divergence of…

Astrophysics · Physics 2009-11-10 Paul H. Frampton

In the context of a homogeneous and isotropic universe, we consider the degeneracy condition at the background level between two scenarios in which processes out of equilibrium are possible; this consideration allows us to deviate from the…

General Relativity and Quantum Cosmology · Physics 2025-03-05 Gilberto Aguilar-Pérez , Ana A. Avilez-López , Miguel Cruz

A $\Lambda$CDM model with dark matter that decays into inert relativistic energy on a timescale longer than the Hubble time will produce an expansion history that can be misinterpreted as stable dark matter with time-varying dark energy. We…

Cosmology and Nongalactic Astrophysics · Physics 2010-08-27 Sourish Dutta , Robert J. Scherrer

We develop the general program of the unification of matter-dominated era with acceleration epoch for scalar-tensor theory or dark fluid. The general reconstruction of single scalar-tensor theory is fulfilled. The explicit form of scalar…

High Energy Physics - Theory · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov , Hrvoje Stefancic