中文
相关论文

相关论文: Noncommutative effects in Bianchi I cosmology with…

200 篇论文

In this work, we will explore the effects of non-commutativity in fractional classical and quantum schemes using the anisotropicc Bianchi Type I cosmological model coupled to a scalar field in the K-essence formalism. We introduce…

广义相对论与量子宇宙学 · 物理学 2024-05-28 J. Socorro , J. Juan Rosales , Leonel Toledo-Sesma

We present the classical solutions to the Einstein field equations derived using the WKB-like and Hamilton procedures. The investigation is carried out in the commutative and noncommutative scenario for the Bianchi type I cosmological model…

广义相对论与量子宇宙学 · 物理学 2009-11-13 C. Ortiz , E. Mena-Barboza , M. Sabido , J. Socorro

Understanding the early evolution of the universe requires models that incorporate possible quantum and anisotropic effects in its dynamics. In this work, we analyze the dynamical evolution of locally rotationally symmetric anisotropic…

广义相对论与量子宇宙学 · 物理学 2025-10-13 G. Oliveira-Neto , Y. Soncco Apaza

We study the effects of noncommutativity, in the form of a Lie-algebraically deformed Poisson commutation relations, on the evolution of a Bianchi type I cosmological model with a positive cosmological constant. The phase space variables…

广义相对论与量子宇宙学 · 物理学 2015-05-20 Babak Vakili , Nima Khosravi

Making use of the $1 + 3$ covariant formalism, we show explicitly the effect that nonmetricity has on the dynamics of the universe. Then, using the Dynamical System Approach, we analyze the evolution of Bianchi type-I cosmologies within the…

广义相对论与量子宇宙学 · 物理学 2022-11-16 Fabrizio Esposito , Sante Carloni , Stefano Vignolo

Using the ADM formalism in the minisuperspace, we obtain the commutative and noncommutative exact classical solutions and exact wave function to the Wheeler-DeWitt equation with an arbitrary factor ordering, for the anisotropic Bianchi type…

广义相对论与量子宇宙学 · 物理学 2015-05-14 J. Socorro , Luis O. Pimentel , C. Ortiz , M. Aguero

The cosmological singularities of the Bianchi I universe are analyzed in the setting of loop geometry underlying the loop quantum cosmology. We solve the Hamiltonian constraint of the theory and find the Lie algebra of elementary…

广义相对论与量子宇宙学 · 物理学 2014-11-20 Piotr Dzierzak , Wlodzimierz Piechocki

The dynamics of cosmological anisotropies is investigated for Bianchi type I universe filled by a relativistic matter represented by the reduced relativistic gas model (RRG), with equation of state interpolating between radiation and…

广义相对论与量子宇宙学 · 物理学 2019-08-20 Simpliciano Castardelli dos Reis , Ilya L. Shapiro

The dynamics of the Bianchi IX cosmological model with minimally coupled massive real scalar field is studied. The possibility of non-singular transition from contraction to expansion is shown. A set of initial conditions that lead to…

广义相对论与量子宇宙学 · 物理学 2007-05-23 A. V. Toporensky , V. O. Ustiansky

The effects of noncommutativity in the phase-space of the classical and quantum cosmology of Bianchi models are investigated. Exact solutions in both commutative and noncommutative cases are presented and compared. Further, the Noether…

广义相对论与量子宇宙学 · 物理学 2008-11-26 B. Vakili , N. Khosravi , H. R. Sepangi

The dynamics and evolution of Bianchi type I space-times is considered in the framework of the four-dimensional truncation of a reduced theory obtained from the N=2,D=5 supergravity. The general solution of the gravitational field equations…

高能物理 - 理论 · 物理学 2009-10-31 Chiang-Mei Chen , T. Harko , M. K. Mak

A Bianchi type-I cosmological model in the presence of a magnetic flux along a cosmological string is considered. The first objective of this study is to investigate Einstein equations using a tractable assumption usually accepted in the…

广义相对论与量子宇宙学 · 物理学 2015-06-03 Victor Rikhvitsky , Bijan Saha , Mihai Visinescu

We study the dynamics of the Bianchi~I cosmological model in the presence of both polymer quantization effects and an exponential deformation of the Poisson algebra. Starting from the Hamiltonian formulation, we derive the polymer-deformed…

广义相对论与量子宇宙学 · 物理学 2025-10-09 Babak Vakili

In this work we carry out a noncommutative analysis of several Friedmann-Robert-Walker models, coupled to different types of perfect fluids and in the presence of a cosmological constant. The classical field equations are modified, by the…

高能物理 - 理论 · 物理学 2015-06-03 E. M. C. Abreu , M. V. Marcial , A. C. R. Mendes , W. Oliveira , G. Oliveira-Neto

In this article, we propose an anisotropic Bianchi-I type cosmological model in non-conservative Unimodular Gravity ($\mathrm{NUG}$). We show that simply using the Bianchi-I type metric does not resolve a striking characteristic of the…

广义相对论与量子宇宙学 · 物理学 2025-11-26 Marcelo H. Alvarenga , Júlio C. Fabris

Dynamical systems methods are used to study the evolution of the Bianchi I model with a scalar field. We show that inclusion of the non-minimal coupling term between the scalar field and the curvature changes evolution of the model compared…

广义相对论与量子宇宙学 · 物理学 2013-10-09 Orest Hrycyna , Marek Szydlowski

The non-diagonal Bianchi models are studied in the loop framework for their classical and quantum formulation. The expressions of the Ashtekar-Barbero-Immirzi variables and their properties are found to provide a loop quantization of these…

广义相对论与量子宇宙学 · 物理学 2023-06-19 Matteo Bruno , Giovanni Montani

Loop quantum cosmology, the symmetry reduction of quantum geometry for the study of various cosmological situations, leads to a difference equation for its quantum evolution equation. To ensure that solutions of this equation act in the…

广义相对论与量子宇宙学 · 物理学 2009-11-11 Daniel Cartin , Gaurav Khanna

Cosmic Microwave Background anomalies suggest that the Universe is slightly anisotropic, so a Cosmological Model that does not satisfy the Cosmological Principle is necessary. Anisotropic Bianchi models have been studied given that they…

广义相对论与量子宇宙学 · 物理学 2017-02-07 Ericsson López , Mario Llerena

The "improved dynamics" of loop quantum cosmology is extended to include anisotropies of the Bianchi I model. As in the isotropic case, a massless scalar field serves as a relational time parameter. However, the extension is non-trivial…

广义相对论与量子宇宙学 · 物理学 2010-04-14 Abhay Ashtekar , Edward Wilson-Ewing
‹ 上一页 1 2 3 10 下一页 ›