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The Hubble tension between the $\Lambda$CDM-model-dependent prediction of the current expansion rate $H_0$ using Planck data and direct, model-independent measurements in the local universe from the SH0ES collaboration disagree at…

宇宙学与河外天体物理 · 物理学 2020-07-14 Kanhaiya L. Pandey , Tanvi Karwal , Subinoy Das

On the basis of a previously established scalar-tensor extension of the $\Lambda$CDM model we develop an effective fluid approach for the matter growth function. This extended $\Lambda$CDM (henceforth $e_{\Phi}\Lambda$CDM) cosmology takes…

宇宙学与河外天体物理 · 物理学 2019-05-01 W. Zimdahl , H. E. S. Velten , W. C. Algoner

The growth index of matter fluctuations is computed for ten distinct accelerating cosmological models and confronted to the latest growth rate data via a two-step process. First, we implement a joint statistical analysis in order to place…

宇宙学与河外天体物理 · 物理学 2017-01-03 Spyros Basilakos , Savvas Nesseris

We investigate a non-parametric Bayesian method for reconstructing the primordial power spectrum (PPS) of scalar perturbations using temperature and polarisation data from the {\em Planck}, ACT, and SPT CMB experiments. This reconstruction…

宇宙学与河外天体物理 · 物理学 2025-07-30 Antonio Raffaelli , Mario Ballardini

Until recently the study of the gravitational field of dark matter was primarily concerned with its local effects on the motion of stars in galaxies and galaxy clusters. On the other hand, the WMAP experiment has shown that the…

广义相对论与量子宇宙学 · 物理学 2010-04-30 M. D. Maia , A. J. S. Capistrano , D. Muller

The use of Gaussian Processes with a measurement of the cosmic expansion rate based solely on the observation of cosmic chronometers provides a completely cosmology-independent reconstruction of the Hubble constant H(z) suitable for testing…

宇宙学与河外天体物理 · 物理学 2018-09-21 Fulvio Melia , Manoj K. Yennapureddy

We investigate a cosmological scenario in which the dark matter particles can be created during the evolution of the Universe. By regarding the Universe as an open thermodynamic system and using non-equilibrium thermodynamics, we examine…

宇宙学与河外天体物理 · 物理学 2022-09-20 Z. Safari , K. Rezazadeh , B. Malekolkalami

The Universe consists of a variety of objects that formed at different epochs, leading to variations in the formation time which represents the time elapsed from the onset of structure formation until the formation time of a particular…

宇宙学与河外天体物理 · 物理学 2025-10-01 Agripino Sousa-Neto , Maria Aldinêz Dantas , Javier E. González , Joel C. Carvalho , Jailson Alcaniz

The equation of state (EoS) of dark energy plays an important role in the evolution of the universe and arouses great interests in recent years. With the progress on observational technique, precise constraint on the EoS of dark energy…

广义相对论与量子宇宙学 · 物理学 2019-08-19 Hai-Nan Lin , Xin Li , Li Tang

We investigate the prospects for determining the accelerating history of the Universe from upcoming measurements of the expansion rate $H(z)$. In our analyses, we use Monte Carlo simulations based on $w$CDM models to generate samples with…

宇宙学与河外天体物理 · 物理学 2012-04-22 J. C. Carvalho , J. S. Alcaniz

We introduce a cosmological model based on the normal branch of DGP braneworld gravity with a smooth dark energy component on the brane. The expansion history in this model is identical to LambdaCDM, thus evading all geometric constraints…

宇宙学与河外天体物理 · 物理学 2018-08-02 Fabian Schmidt

We consider gravity mediated by non-metricity, with vanishing curvature and torsion. The gravitational action, including an arbitrary function of the non-metric scalar, is investigated in view of characterizing the dark energy effects. In…

广义相对论与量子宇宙学 · 物理学 2022-07-13 Salvatore Capozziello , Rocco D'Agostino

A class of well-behaved modified gravity models with long enough matter domination epoch and a late-time accelerated expansion is confronted with SNIa, CMB, SDSS, BAO and H(z) galaxy ages data, as well as current measurements of the linear…

宇宙学与河外天体物理 · 物理学 2010-11-09 Z. Girones , A. Marchetti , O. Mena , C. Pena-Garay , N. Rius

Over the last decade, much attention has been given to the study of modified gravity theories to find a more natural explanation for the late-time acceleration of the Universe. Particular attention has focused on the so-called $f(R)$ dark…

广义相对论与量子宇宙学 · 物理学 2024-08-09 Kelly MacDevette , Jess Worsley , Peter Dunsby , Saikat Chakraborty

We study the growth of linear matter density perturbations in a modified gravity approach of scalar field couplings with metric and torsion. In the equivalent scalar-tensor formulation, the matter fields in the Einstein frame interact as…

广义相对论与量子宇宙学 · 物理学 2021-02-03 Mohit Kumar Sharma , Sourav Sur

We present an efficient numerical algorithm for evolving self-gravitating systems of dark-matter particles that leverages the assumption of spherical symmetry to reduce the nominally six-dimensional phase space to three dimensions. It can…

星系天体物理 · 物理学 2025-04-22 Marc Kamionkowski , Kris R. Sigurdson

We study the evolution of cosmological perturbations around a homogeneous and isotropic background in the framework of the non-minimal torsion-matter coupling extension of $f(T)$ gravity. We are concerned with the effects of the non-minimal…

广义相对论与量子宇宙学 · 物理学 2018-10-09 Manuel Gonzalez-Espinoza , Giovanni Otalora , Joel Saavedra , Nelson Videla

It has been recently shown that cosmological models with scale-dependent primordial non-Gaussianities (sPNG) could provide a possible path to solve current cosmic tensions. Moreover, it has been pointed out that some of these models might…

宇宙学与河外天体物理 · 物理学 2025-01-08 Clément Stahl , Benoit Famaey , Rodrigo Ibata , Katarina Kraljic , Fabien Castillo

We take into account redshift-space distortion measurements to investigate the growth of cosmological large-scale structures within the framework of modified symmetric teleparallel $f(Q)$ gravity. After comparing the predictions of the…

广义相对论与量子宇宙学 · 物理学 2025-03-20 Shambel Sahlu , Álvaro de la Cruz-Dombriz , Amare Abebe

We use a suite of high-resolution $N$-body simulations and state-of-the-art perturbation theory to improve the code halofit, which predicts the nonlinear matter power spectrum. We restrict attention to parameters in the vicinity of the…

宇宙学与河外天体物理 · 物理学 2019-04-09 Robert E. Smith , Raul E. Angulo