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We present a simple model which generates cosmological anisotropies on top of standard FLRW geometry. This is in some sense reminiscent of the mean field approximation, where the mean field cosmological model under consideration would be…

General Relativity and Quantum Cosmology · Physics 2024-09-25 Bum-Hoon Lee , Hochoel Lee , Wonwoo Lee , Nils A. Nilsson , Somyadip Thakur

We perform a data-driven test of the FLRW metric and the flatness of the Universe, independently of any Dark Energy model, and in light of the latest DESI DR2 results. We use Pantheon+ and DESY5 SNIa data to reconstruct the distance…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-29 Cléa Millard , Benjamin L'Huillier , Marian Douspis

Any Dark Energy (DE) or Modified Gravity (MG) model that deviates from a cosmological constant requires a consistent treatment of its perturbations, which can be described in terms of an effective entropy perturbation and an anisotropic…

Cosmology and Nongalactic Astrophysics · Physics 2015-02-26 Bjoern Soergel , Tommaso Giannantonio , Jochen Weller , Richard A. Battye

Inspired by an exponential $f(R)$ gravity model studied in the literature, in this work we introduce a new and viable $f(Q)$ gravity model, which can be represented as a perturbation of $\Lambda$CDM. Typically, within the realm of $f(Q)$…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-31 A. Oliveros , Mario A. Acero

Non-linear evolution of density fluctuations yields secondary anisotropies in the cosmic microwave background (CMB), which are correlated with the same density fluctuations that can be measured by weak lensing (WL) surveys. We study the…

We present simulation-based cosmological $w$CDM inference using Dark Energy Survey Year 3 weak-lensing maps, via neural data compression of weak-lensing map summary statistics: power spectra, peak counts, and direct map-level…

Cosmography is a useful tool to constrain cosmological models, in particular dark energy models. In the case of modified theories of gravity, where the equations of motion are generally quite complicated, cosmography can contribute to…

General Relativity and Quantum Cosmology · Physics 2010-12-23 Mariam Bouhmadi-Lopez , Salvatore Capozziello , Vincenzo F. Cardone

We observe that the errors on the Hubble constant $H_0$, a universal parameter in any FLRW cosmology, can be larger in specific cosmological models than Gaussian Processes (GP) data reconstruction. We comment on the prior mean function and…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-09 E. Ó Colgáin , M. M. Sheikh-Jabbari

We investigate and update observational constraints on cosmological parameters within the $\Lambda$CDM and dynamical dark energy frameworks, using a new compilation of the transverse (or 2D) BAO data, measurements that provide a relatively…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-30 Miguel A. Sabogal , Rafael C. Nunes , Felipe Avila , Armando Bernui

We present a unified Bayesian assessment of model comparison and data-set consistency for LCDM (cold dark matter plus a cosmological constant) and minimal extensions (neutrino mass, spatial curvature, constant or evolving dark energy) using…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-09 Lukas Tobias Hergt , Sophie Henrot-Versillé , Matthieu Tristram , Douglas Scott

We apply a new model for the spherically averaged correlation function at large pair separations to the measurement of the clustering of luminous red galaxies (LRGs) made from the SDSS by Cabre and Gaztanaga(2009). Our model takes into…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Ariel G. Sanchez , M. Crocce , A. Cabre , C. M. Baugh , E. Gaztanaga

In this work we present a nonparametric approach, which works on minimal assumptions, to reconstruct the cosmic expansion of the Universe. We propose to combine a locally weighted scatterplot smoothing method and a simulation-extrapolation…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-20 Ariadna Montiel , Ruth Lazkoz , Irene Sendra , Celia Escamilla-Rivera , Vincenzo Salzano

This study explores the compatibility of Covariant Extrinsic Gravity (CEG) with current cosmological observations. We employ the chi-square statistic and Markov Chain Monte Carlo (MCMC) methods to fit the FLRW and Bianchi type-I and V brane…

General Relativity and Quantum Cosmology · Physics 2024-07-23 R. Jalalzadeh , S. Jalalzadeh , B. Malekolkalami , Z. Davari

We explore the possible advantages of extending the $\Lambda$CDM model by more realistic backgrounds compared to its spatially flat RW spacetime assumption, while preserving the underpinning physics; in particular, by simultaneously…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-05 Ozgur Akarsu , Eleonora Di Valentino , Suresh Kumar , Maya Ozyigit , Shivani Sharma

We investigate a relativistic cosmological model with background rotation, sourced by a non-perfect fluid with anisotropic stress. A modified version of the CLASS Boltzmann code is employed to perform Monte Carlo Markov Chain analyses…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-16 Micol Benetti , David A. Cook , Saulo Carneiro

We use cosmography to present constraints on the kinematics of the Universe without postulating any underlying theoretical model a priori. To this end, we use a Markov Chain Monte Carlo analysis to perform comparisons to the supernova Ia…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-18 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

In spatially extended systems, it is common to find latent variables that are hard, or even impossible, to measure with acceptable precision, but are crucially important for the proper description of the dynamics. This substantially…

Numerical Analysis · Computer Science 2019-08-28 Patrick A. K. Reinbold , Roman O. Grigoriev

In this paper, we explore power law solution of FLRW universe model that is associated with a variable cosmological term $\Lambda(t)$ as a linear function of $\frac{\ddot{a}}{a}, (\frac{\dot{a}}{a})^2$ and $\rho$. The model parameters were…

General Physics · Physics 2025-04-28 G. K. Goswami , Anirudh Pradhan

We present a new, model-independent approach for measuring non-Gaussianity of the Cosmic Microwave Background (CMB) anisotropy pattern. Our approach is based on the empirical distribution function of the normalized spherical harmonic…

Astrophysics · Physics 2011-05-10 Frode K. Hansen , Domenico Marinucci , Paolo Natoli , Nicola Vittorio

We present cosmological constraints for the flat $\Lambda$CDM model, including the sum of neutrino masses, by performing a multi-probe analysis of a total of 13 tomographic auto- and cross-angular power spectra. This is achieved by…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-11 Raphael Sgier , Christiane Lorenz , Alexandre Refregier , Janis Fluri , Dominik Zürcher , Federica Tarsitano