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Related papers: Bianchi type I cosmology with scalar and spinor fi…

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We consider an interacting system of massless scalar and electromagnetic field, with the Lagrangian explicitly depending on the electromagnetic potentials, i.e., interaction with broken gauge invariance. The Lagrangian for interaction is…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Yu. P. Rybakov , G. N. Shikin , Yu. A. Popov , Bijan Saha

A Bianchi type-I cosmological model in the presence of a magnetic flux along a cosmic string is investigated. A nonlinear spinor field is used to simulate the cosmological cloud of strings. It is shown that the spinor field simulation offer…

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

Einstein's field equations with variable gravitational and cosmological ``constant'' are considered in presence of perfect fluid for Bianchi type-I spacetime. Consequences of the four cases of the phenomenological decay of $\Lambda$ have…

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. P. Singh , A. Pradhan , A. K. Singh

We investigate in detail the qualitative behaviour of the class of Bianchi type B spatially homogeneous cosmological models in which the matter content is composed of two non-interacting components; the first component is described by a…

General Relativity and Quantum Cosmology · Physics 2014-11-17 A. P. Billyard , A. A. Coley , R. J. van den Hoogen , J. Ibanez , I. Olasagasti

The flat anisotropic model of the early Universe is considered. Two interacting scalar fields with special form of potential energy are a source of matter fields. Analytic solutions for inflationary and scalaron stages are found. It is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Vladimir Folomeev

The important role of scalar field in cosmology was noticed by a number of authors. Due to the fact that the scalar field possesses zero spin, it was basically considered in isotropic cosmological models. If considered in an anisotropic…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Yu. P. Rybakov , G. N. Shikin , Yu. A. Popov , Bijan Saha

In this paper, we investigate a non-canonical scalar field model in the background dynamics of anisotropic Locally Rotationally Symmetric (LRS) Bianchi type I universe where gravity is coupled minimally to scalar field which is taken as…

General Relativity and Quantum Cosmology · Physics 2023-11-17 Sujoy Bhanja , Goutam Mandal , Abdulla Al Mamon , Sujay Kr. Biswas

Evolution of an anisotropic universe described by a Bianchi type I (BI) model in presence of nonlinear spinor field has been studied by us recently in a series of papers. On offer the Bianchi models, those are both inhomogeneous and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Bijan Saha

The nature of cosmological solutions for a homogeneous, anisotropic Universe given by a Bianchi type-I (BI) model in the presence of a Cosmological constant $\Lambda$ is investigated by taking into account dissipative process due to…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Bijan Saha , V. Rikhvitsky

Within the scope of $f(R,\,T)$ gravity we have studied the interacting scalar and electromagnetic fields in a Bianchi type I universe. It was found that if the study is confined to the case $f(R,\,T) = R + \lambda f(T)$, the system is…

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

A self-consistent system of nonlinear spinor and Bianchi type-V anisotropic gravitational fields are investigated. It is found that the presence of nontrivial non-diagonal components of the energy-momentum tensor of the spinor field imposes…

General Relativity and Quantum Cosmology · Physics 2016-02-19 Bijan Saha

LRS Bianchi type-I models have been studied in the cosmological theory based on Lyra's geometry. A new class of exact solutions has been obtained by considering a time dependent displacement field for variable deceleration parameter models…

General Relativity and Quantum Cosmology · Physics 2010-05-28 Anirudh Pradhan , D. S. Chauhan

We consider a system of nonlinear spinor and scalar fields with minimal coupling in general relativity. The nonlinearity in the spinor field Lagrangian is given by an arbitrary function of the invariants generated from the bilinear spinor…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Bijan Saha , G. N. Shikin

In this paper the dynamics of free gauge fields in Bianchi type I-VII$_{h}$ space-times is investigated. The general equations for a matter sector consisting of a $p$-form field strength ($p\,\in\,\{1,3\}$), a cosmological constant…

General Relativity and Quantum Cosmology · Physics 2018-04-10 Ben David Normann , Sigbjørn Hervik , Angelo Ricciardone , Mikjel Thorsrud

Recently a new Lagrangian framework was introduced to describe interactions between scalar fields and relativistic perfect fluids. This allows two consistent generalizations of coupled quintessence models: non-vanishing pressures and a new…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Tomi S. Koivisto , Emmanuel N. Saridakis , Nicola Tamanini

In many cases a scalar field can lead to accelerated expansion in cosmological models. This paper contains mathematical results on this subject particularly on type I Bianchi space-time. In this paper, global existence to the coupled…

Analysis of PDEs · Mathematics 2017-03-07 Alexis Nangue

We consider an anisotropic cosmological model based on the locally rotational Bianchi I spacetime, incorporating a scalar field and a non-zero cosmological interaction term. The framework of averaging theory is employed to study the…

General Relativity and Quantum Cosmology · Physics 2025-08-06 Alfredo D. Millano , Genly Leon , Andronikos Paliathanasis

We present the case of time-varying cosmological term $\Lambda(t)$. The main idea arises by proposing that as in the cosmological constant case, the scalar potential is identified as $ V(\phi)=2\Lambda$, with $\Lambda$ a constant, this…

General Physics · Physics 2019-11-21 J. Socorro , M. D'oleire , Luis O. Pimentel

Within the scope of a Bianchi type-I (BI) cosmological model we study the interacting system of spinor and electromagnetic fields and its role in the evolution of the Universe. In some earlier studies it was found that in case of a pure…

General Relativity and Quantum Cosmology · Physics 2023-07-21 Bijan Saha

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