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Inflation has long been the accepted paradigm for understanding the early universe. Most models of inflation have a scalar field acting as the inflaton particle which decays after inflation during a process called reheating into standard…

General Relativity and Quantum Cosmology · Physics 2018-11-30 Abhass Kumar

We consider a polymer quantization of a free massless scalar field in a homogeneous and isotropic cosmological spacetime. This quantization method assumes that field translations are fundamentally discrete, and is related to but distinct…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-27 Golam Mortuza Hossain , Viqar Husain , Sanjeev S. Seahra

In this paper, we investigate the evolution of the early universe within an emergent fractional cosmological framework. The underlying formulation is conceptually rooted in generalized measure constructions, closely related to fractal…

General Relativity and Quantum Cosmology · Physics 2026-04-16 S. M. M. Rasouli

To seek for a singularity free model universe from a perfect fluid scalar-metric cosmology, we work in the "\emph{Emergent Cosmology}" (EC) paradigm which is a non-singular alternative for cosmological inflation. By using two methods…

General Relativity and Quantum Cosmology · Physics 2018-06-26 Mohsen Khodadi , Kourosh Nozari

The gravitational clustering of collisionless particles in an expanding universe is modelled using some simple physical ideas. I show that it is indeed possible to understand the nonlinear clustering in terms of three well defined regimes:…

Astrophysics · Physics 2016-06-08 T. Padmanabhan

We investigate cosmology with complex scalar field. It is shown that such models can describe two stages of inflation and the oscillatory regime. Thus we don't need both quintessence and $\Lambda$-term. It is enough to have single complex…

High Energy Physics - Theory · Physics 2007-05-23 A. V. Yurov

For a universe containing cosmological constant together with uniform arrangements of magnetic fields, strings, or domain walls, exact solutions to the Einstein equations are shown to lead to a universe with ellipsoidal expansion. The…

High Energy Physics - Phenomenology · Physics 2009-11-10 Arjun Berera , Roman V. Buniy , Thomas W. Kephart

A self-consistent system of interaction nonlinear spinor and scalar fields within the scope of a BI cosmological model filled with perfect fluid is considered. The role of spinor field in the evolution of the Universe is studied. It is…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha

The four-form field recently considered by Hawking and Turok couples naturally to a charged membrane, across which the effective cosmological constant has a discontinuity. We present instantons for the creation of an open inflationary…

High Energy Physics - Theory · Physics 2009-10-31 Raphael Bousso , Andrew Chamblin

Assuming a cellular structure for the space-time, we propose a model in which the expansion of the universe is understood as a decrumpling process, much like the one we know from polymeric surfaces. The dimension of space is then a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. Khorrami , M. Mansouri , M. Mohazzab

Matrix theory is a proposed non-perturbative definition of superstring theory in which space is emergent. We begin a study of cosmology in the context of matrix theory. Specifically, we show that matrix theory can lead to an emergent…

High Energy Physics - Theory · Physics 2022-03-30 Suddhasattwa Brahma , Robert Brandenberger , Samuel Laliberte

Here we formulate scenario of emergent universe from particle creation mechanism in spatially flat braneworld models. We consider an isotropic and homogeneous universe in Braneworld cosmology and universe is considered as a non-equilibrium…

General Relativity and Quantum Cosmology · Physics 2016-01-20 Jibitesh Dutta , Sourav Haldar , Subenoy Chakraborty

In order to bypass the big bang singularity, we develop an emergent universe scenario within a covariant extension of General Relativity known as \emph{"Energy-Momentum Squared Gravity"}. The extra terms of the model emerge in the high…

General Relativity and Quantum Cosmology · Physics 2022-04-05 Mohsen Khodadi , Alireza Allahyari , Salvatore Capozziello

Within the scope of isotropic FRW cosmological model the role of nonlinear spinor field in the evolution of the Universe is studied. It is found that unlike in anisotropic cosmological models in the present case the spinor field does not…

General Relativity and Quantum Cosmology · Physics 2016-07-27 Bijan Saha

Emergent scenario of cosmic evolution is a topic of great interest in recent cosmology, especially because it describes a non-singular origin of the Universe unlike the Big-Bang models. This types of cosmic evolution pattern have already…

General Relativity and Quantum Cosmology · Physics 2023-09-01 Subhayan Maity , Sujayita Bakra

Different characteristic of matter influencing the evolution of the Universe has been simulated by means of a nonlinear spinor field. We have considered two cases where the spinor field nonlinearity occurs either as a result of self-action…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha

We propose the application of the chiral cosmological model (CCM) for the Einstein--Gauss--Bonnet (EGB) theory of gravitation with the aim of finding new models of the Emergent Universe (EmU) scenario. We analysed the EmU supported by two…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Sergey V. Chervon , Sunil D. Maharaj , Aroonkumar Beesham ans Aleksandr Kubasov

We investigate the emergent universe scenario in the presence of interacting fluids. The non-linear equation of state (EoS) considered in the general theory of relativity for obtaining emergent universe is effectively a cosmological model…

General Relativity and Quantum Cosmology · Physics 2015-05-20 B. C. Paul , A. S. Majumdar

A model for the Universe is proposed whose constituents are: (a) a dark energy field modeled by a fermionic field non-minimally coupled with the gravitational field, (b) a matter field which consists of pressureless baryonic and dark matter…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. O. Ribas , F. P. Devecchi , G. M. Kremer

In this paper, we have assumed a flat Friedmann-Lemaitr\'e-Robertson-Walker universe endowed with a general form of dissipation. The source of dissipation is considered to be a bulk viscous pressure $\Pi$ which leads to an adiabatic…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Subhajit Saha