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相关论文: Pressure in Lema\^{i}tre-Tolman-Bondi solutions an…

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We find new, simple cosmological solutions with flat, open, and closed spatial geometries, contrary to the previous wisdom that only the open model is allowed. The metric and the St\"{u}ckelberg fields are given explicitly, showing…

高能物理 - 理论 · 物理学 2015-06-05 Tsutomu Kobayashi , Masaru Siino , Masahide Yamaguchi , Daisuke Yoshida

We derive a class of non-static inhomogeneous dust solutions in f(R) gravity described by the Lemaitre-Tolman-Bondi (LTB) metric. The field equations are fully integrated for all parameter subcases and compared with analogous subcases of…

广义相对论与量子宇宙学 · 物理学 2017-11-28 Roberto A Sussman , Luisa G Jaime

We construct the Lema\^itre-Tolman-Bondi (LTB) dust universe whose distance-redshift relation is equivalent to that in the concordance $\Lambda$ cold dark matter ($\Lambda$CDM) cosmological model. In our model, the density distribution and…

天体物理学 · 物理学 2009-08-18 Chul-Moon Yoo , Tomohiro Kai , Ken-ichi Nakao

We analyze inhomogeneous cosmological models in the local Universe, described by the Lema\^itre-Tolman-Bondi (LTB) metric and developed using linear perturbation theory on a homogeneous and isotropic Universe background. Focusing on the…

广义相对论与量子宇宙学 · 物理学 2024-05-16 Tiziano Schiavone , Giovanni Montani

A perfect fluid, spatially flat cosmology in a $f(T)$ model, derived from a recently proposed general Born-Infeld type theory of gravity is studied. Four dimensional cosmological solutions are obtained assuming the equation of state…

广义相对论与量子宇宙学 · 物理学 2014-12-04 Soumya Jana

Lemaitre-Tolman-Bondi models as specific spherically symmetric solutions of general relativity simplify in their reduced form some of the mathematical ingredients of black hole or cosmological applications. The conditions imposed in…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Martin Bojowald , Tomohiro Harada , Rakesh Tibrewala

The Lema\'itre-Toman-Bondi (LTB) models have reported to suffer from incompatibility with cosmological observations and fine-tuning of the observer's location. Further analysis of these issues indicates that they could be resolved by models…

宇宙学与河外天体物理 · 物理学 2016-01-21 Peter Sundell , Iiro Vilja

We review a subset of the current tensions affecting the standard $\Lambda$CDM cosmological model, emphasizing the role of chronic systematics and significance inflation in shaping their interpretation. As a unifying framework, we consider…

宇宙学与河外天体物理 · 物理学 2026-02-02 Valerio Marra

In this paper we explore the possibility to find exact solutions for Teleparallel Gravity (TG) of the type of spherically symmetric Lema\^\i tre-Tolman-Bondi (LTB) dust models. We apply to the LTB metric the formalism of Teleparallel…

广义相对论与量子宇宙学 · 物理学 2022-03-28 Sebastián Nájera , Aram Aguilar , Geovanny A. Rave-Franco , Celia Escamilla-Rivera , Roberto A. Sussman

In this work we have obtained the set of new exact solutions of the Einstein equations that generalize the known Lemaitre-Tolman-Bondi solution for the certain case of nonzero pressure under zero spatial curvature. These solutions are…

广义相对论与量子宇宙学 · 物理学 2016-11-29 E. Kopteva , P. Jaluvkova , Z. Stuchlik

We examine a large class of inhomogeneous spherically symmetric spacetimes that generalize the Lemaitre-Tolman-Bondi dust solutions to nonzero pressure ("LTB spacetimes"). Local covariant LTB objects can be expressed as perturbations of…

广义相对论与量子宇宙学 · 物理学 2010-05-12 Roberto A. Sussman

The approximate homogeneity of spatial sections of the Universe is well supported observationally, but the inhomogeneity of the spatial sections is even better supported. Here, we consider the implications of inhomogeneity in dust models…

宇宙学与河外天体物理 · 物理学 2015-03-20 Boudewijn F. Roukema , Vincent Blanloeil , Jan J. Ostrowski

We describe Lema\^{i}tre-Tolman-Bondi cosmological models where an anisotropic pressures is considered. By using recent astronomical observations coming from supernova of Ia types we constraint the values of the parameters that characterize…

宇宙学与河外天体物理 · 物理学 2012-11-19 Sergio del Campo , Victor H. Cardenas , Ramon Herrera

We assume a one-to-one correspondence between comoving coordinates and the cosmic rest frame in a spherically symmetric inhomogeneous universe. This strongly restricts the solutions of Einstein's equations: (i) The pressure must be zero.…

综合物理 · 物理学 2018-05-29 Günter Scharf

Current observations suggest that our Universe is not incompatible with a small positive spatial curvature that can be associated with rest frames having a "closed" standard topology. We examine a toy model generalisation of the…

广义相对论与量子宇宙学 · 物理学 2018-07-09 Sebastián Nájera , Roberto A. Sussman

Conditions for smooth cosmological models are set out and applied to inhomogeneous spherically symmetric models constructed by matching together different Lemaitre-Tolman-Bondi solutions to the Einstein field equations. As an illustration…

广义相对论与量子宇宙学 · 物理学 2015-06-25 D. R. Matravers , N. P. Humphreys

As an alternative to dark energy it has been suggested that we may be at the center of an inhomogeneous isotropic universe described by a Lemaitre-Tolman-Bondi (LTB) solution of Einstein's field equations. In order to test such an…

宇宙学与河外天体物理 · 物理学 2014-11-20 Antonio Enea Romano

We argue that more cosmological solutions in massive gravity can be obtained if the metric tensor and the tensor $\Sigma_{\mu\nu}$ defined by St\"{u}ckelberg fields take the homogeneous and isotropic form. The standard cosmology with matter…

广义相对论与量子宇宙学 · 物理学 2015-06-05 Yungui Gong

The character of the central density profile in the Lema\^{i}tre-Tolman (LT) solutions plays a fundamental role in their application as cosmological models. This same character is studied here for these solutions used to model complete…

广义相对论与量子宇宙学 · 物理学 2015-06-24 Kayll Lake

It is the common consensus that the expansion of a universe always slows down if the gravity provided by the energy sources therein is attractive and accordingly one needs to invoke dark energy as a source of anti-gravity for understanding…

天体物理学 · 物理学 2008-11-26 Chia-Hsun Chuang , Je-An Gu , W-Y. P. Hwang
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