English
Related papers

Related papers: The Simplest Exact Solutions in the LTB Model

200 papers

This pedagogic review aims to give a gentle introduction to an exactly solvable model, the Hatsugai-Kohmoto (HK) model, which has infinite-ranged interaction but conserves the center of mass. Although this model is invented in 1992,…

Strongly Correlated Electrons · Physics 2025-04-25 Miaomiao Zhao , Wei-Wei Yang , Yin Zhong

Some properties of cosmological models with matter creation are investigated in the framework of the Friedman-Robertson-Walker (FRW) line element. For adiabatic matter creation, as developed by Prigogine and coworkers, we derive a simple…

General Relativity and Quantum Cosmology · Physics 2009-10-28 J. A. S. Lima , A. S. M. Germano , L. R. W. Abramo

Hyperbolic balance laws with uncertain (random) parameters and inputs are ubiquitous in science and engineering. Quantification of uncertainty in predictions derived from such laws, and reduction of predictive uncertainty via data…

Statistics Theory · Mathematics 2021-04-28 Francesca Boso , Daniel M. Tartakovsky

In order to explore the generic properties of a backreaction model for explaining the accelerated expansion of the Universe, we exploit two metrics to describe the late time Universe. Since the standard FLRW metric cannot precisely describe…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-27 Shu-Lei Cao , Huan-Yu Teng , Hao-Ran Yu , Hao-Yi Wan , Tong-Jie Zhang

Recently, inhomogeneous generalisations of the Friedmann-Lemaitre-Robertson-Walker cosmological models have gained interest in the astrophysical community and are more often employed to study cosmological phenomena. However, in many papers…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-17 Krzysztof Bolejko , Marie-Noëlle Célérier , Andrzej Krasiński

In this paper, we investigate approximate solutions for nonlinear Fredholm integro-differential equations of fractional order. We present an operational Tau method by obtaining the Tau matrix representation. We solve a special class of…

Numerical Analysis · Mathematics 2017-12-13 A. Yousefi , E. Babolian , S. Javadi

Identification-robust hypothesis tests are commonly based on the continuous updating GMM objective function. When the number of moment conditions grows proportionally with the sample size, the large-dimensional weighting matrix prohibits…

Econometrics · Economics 2025-10-10 Tom Boot , Johannes W. Ligtenberg

We show that (1) the Einstein field equations with a perfect fluid source admit a nonlinear superposition of two distinct homogenous Friedman-Lemaitre-Robertson-Walker (FLRW) metrics as a solution, (2) the superposed solution is an…

General Relativity and Quantum Cosmology · Physics 2020-12-09 Metin Gurses , Yaghoub Heydarzade , Bayram Tekin

Lema\^{i}tre-Tolman-Bondi (LTB) solutions have traditionally been confined to systems with no pressure in which the gravity is due to massive dust, but the solutions are little changed in form if, as in cosmology, the pressure is uniform in…

General Relativity and Quantum Cosmology · Physics 2016-03-07 Donald Lynden-Bell , Jiří Bičák

This work aims to study the rates in the context of periodic homogenization of parabolic problems with large lower order terms (both drift and potential). We demonstrate that the solution is a product of three terms: (i) a function of time,…

Analysis of PDEs · Mathematics 2026-01-06 Kshitij Sinha

We test both the FLRW geometry and $\Lambda$CDM cosmology in a model independent way by reconstructing the Hubble function $H(z)$, the comoving distance $D(z)$ and the growth of structure $f\sigma_8(z)$ using the most recent data available.…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-18 Valerio Marra , Domenico Sapone

On exponentially expanding Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) spacetimes, there is a distinguished family of spatially homogeneous and isotropic solutions to the relativistic Euler equations with a linear equation of state of…

General Relativity and Quantum Cosmology · Physics 2025-04-01 Todd A. Oliynyk

We discuss metric perturbations of the relativistic diffusion equation around the homogeneous Juttner equilibrium of massless particles in a homogeneous expanding universe. The metric perturbation describes matter distribution and the…

General Relativity and Quantum Cosmology · Physics 2015-02-27 Z. Haba

This paper addresses the three concepts of \textit{ consistency, stability and convergence } in the context of compact finite volume schemes for systems of nonlinear hyperbolic conservation laws. The treatment utilizes the framework of…

Numerical Analysis · Mathematics 2020-03-17 Matania Ben-Artzi , Jiequan Li

In this thesis, two nonperturbative techniques, namely, similarity renormalization group (SRG) approach and light-front transverse lattice (LFTL) approach are studied in the the context of hadron bound state problem in light-front QCD. We…

High Energy Physics - Theory · Physics 2007-05-23 Dipankar Chakrabarti

By shifting the reference system for the local-density approximation (LDA) from the electron gas to other model systems one obtains a new class of density functionals, which by design account for the correlations present in the chosen…

Strongly Correlated Electrons · Physics 2009-11-07 N. A. Lima , M. F. Silva , L. N. Oliveira , K. Capelle

The time-translation symmetry of the conformal FLRW frame $\bar{g}=a^{-2}g$ allows reinterpretation of cosmological observation in the static space of a stationary universe, where constant matter density…

General Physics · Physics 2024-06-11 Herman Telkamp

The most general one dimensional reaction-diffusion model with nearest-neighbor interactions, which is exactly-solvable through the empty interval method, has been introduced. Assuming translationally-invariant initial conditions, the…

Condensed Matter · Physics 2009-11-07 M. Alimohammadi , M. Khorrami , A. Aghamohammadi

In the context of averaging an inhomogeneous cosmological model, we propose a natural measure identical to the Kullback-Leibler relative information entropy, which expresses the distinguishability of the local inhomogeneous density field…

General Relativity and Quantum Cosmology · Physics 2011-07-28 Masaaki Morita , Thomas Buchert , Akio Hosoya , Nan Li

The Hubbard model is investigated in the framework of lattice density functional theory (LDFT). The single-particle density matrix $\gamma_{ij}$ with respect the lattice sites is considered as the basic variable of the many-body problem. A…

Strongly Correlated Electrons · Physics 2009-11-10 R. Lopez-Sandoval , G. M. Pastor