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Cosmic voids, the large underdense regions of our Universe, have emerged over the past decade as powerful cosmological laboratories: their simple dynamics, sensitivity to local gravitational effects and cosmic expansion, and ability to span…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-22 Sofia Contarini , Giovanni Verza , Alice Pisani

Numerical relativity is an essential tool for solving Einstein's equations of general relativity for dynamical systems characterized by high velocities and strong gravitational fields. The implementation of new algorithms that can solve…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Stuart L. Shapiro

Cosmographic approach, a Taylor expansion of the Hubble function, has been used as a model-independent method to investigate the evolution of the universe in the presence of cosmological data. Apart from possible technical problems like the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-04 Ahmad Mehrabi , Mehdi Rezaei

The purpose of this work is to review, clarify, and critically analyse modern mathematical cosmology. The emphasis is upon mathematical objects and structures, rather than numerical computations. This paper concentrates on general…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Gordon McCabe

We study observational constraints on the non-metricity $f(Q)$-gravity which reproduces an exact $\Lambda$CDM background expansion history while modifying the evolution of linear perturbations. To this purpose we use Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-29 Luís Atayde , Noemi Frusciante

This study explores the impact of cosmic curvature on structure formation through general relativistic first-order perturbation theory. We analyze continuity and Euler equations, incorporating cosmic curvature into Einstein equations.…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-29 Bikash R. Dinda

We determine cosmological and evolutionary parameters from the 3CR K-band Hubble diagram and K-band number counts, assuming that the galaxies in question undergo pure luminosity evolution. Separately the two data sets are highly degenerate…

Astrophysics · Physics 2009-11-07 J. C. Jackson , Marina Dodgson

We explore the cosmological consequences of a modified cosmology inspired by string T-duality. We incorporate the zero-point length correction, $l_0$, into the gravitational potential and derive the modified Friedmann equations via…

General Relativity and Quantum Cosmology · Physics 2026-05-29 G. G. Luciano , A. Paliathanasis , A. Sheykhi

We numerically determine the cosmological branch of the free function in a nonlocal metric-based modification of gravity which provides a relativistic generalization of Milgrom's Modified Newtonian Dynamics. We are able to reproduce the…

General Relativity and Quantum Cosmology · Physics 2016-11-11 M. Kim , M. H. Rahat , M. Sayeb , L. Tan , R. P. Woodard , B. Xu

In this year, in which we celebrate 100 years of the cosmological term, $\Lambda$, in Einstein's gravitational field equations, we are still facing the crucial question whether $\Lambda$ is truly a fundamental constant or a mildly evolving…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-27 Joan Sola , Adria Gomez-Valent , Javier de Cruz Perez

The search for the physical mechanism underlying the observational evidence for the acceleration of the recent universe is a compelling goal of modern fundamental cosmology. Here we quantitatively study a class of homogeneous and isotropic…

Cosmology and Nongalactic Astrophysics · Physics 2022-04-19 E. -A. Kolonia , C. J. A. P. Martins

We investigate in detail some popular cosmological models in light of the latest observational data, including the Union2.1 supernovae compilation, the baryon acoustic oscillation measurements from the WiggleZ Dark Energy Survey, the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Ke Shi , Yongfeng Huang , Tan Lu

Combining cosmological probes has consolidated the standard cosmological model with percent precision, but some tensions have recently emerged when certain parameters are estimated from the local or primordial Universe. The origin of this…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-16 Fabrizio Cogato , Michele Moresco , Lorenzo Amati , Andrea Cimatti

Cosmography is a phenomenological and relatively model-independent approach to cosmology, where physical quantities are expanded as a Taylor series in the cosmological redshift, or in related variables. Here we apply this methodology to…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-08 C. J. A. P. Martins , F. P. S. A. Ferreira , P. V. Marto

A numerical approach is considered for spherically symmetric spacetimes that generalize Lemaitre-Tolman-Bondi dust solutions to nonzero pressure ("LTB spacetimes"). We introduce quasi-local (QL) variables that are covariant LTB objects…

General Relativity and Quantum Cosmology · Physics 2010-05-12 Roberto A. Sussman

The standard model of cosmology ($\Lambda$CDM) is facing a serious crisis caused by the inconsistencies in the measurements of some fundamental cosmological parameters (Hubble constant $H_{0}$ and cosmic curvature parameter $\Omega_{k}$ for…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-05 Savita Gahlaut

Gravitational lensing information from the two and higher point statistics of the CMB temperature and polarization fields are intrinsically correlated because they are lensed by the same realization of structure between last scattering and…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-01 Pavel Motloch , Wayne Hu , Aurélien Benoit-Lévy

Cosmological probes pose an inverse problem where the measurement result is obtained through observations, and the objective is to infer values of model parameters which characterize the underlying physical system -- our Universe. Modern…

Instrumentation and Methods for Astrophysics · Physics 2019-05-21 Timur Takhtaganov , Zarija Lukic , Juliane Mueller , Dmitriy Morozov

We use covariant and first-order formalism techniques to study the properties of general relativistic cosmology in three dimensions. The covariant approach provides an irreducible decomposition of the relativistic equations, which allows…

General Relativity and Quantum Cosmology · Physics 2009-11-11 John D. Barrow , Douglas J. Shaw , Christos G. Tsagas

In this investigation, we perform an observational statistical analysis in the theory of $ f(R, L_m) $ gravity. The proposed theoretical model is based on the Ricci scalar's non-linear contribution. We use a distinct parameterization for…

General Relativity and Quantum Cosmology · Physics 2024-08-30 J. K. Singh , Shaily , Akanksha Singh , Harshna Balhara , Joao R. L. Santos
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