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Related papers: Beyond $\Lambda$CDM with a Logistic RG-like Flow o…

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We investigate deviations from $\Lambda$CDM by independently parameterizing modifications in the background evolution and the growth of structures. The background is characterized by two parameters, $A$ and $B$, which reduce to…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-08 Shibendu Gupta Choudhury , Purba Mukherjee , Anjan Ananda Sen

We explore the late time cosmological dynamics of the Universe within the framework of $f(Q,\mathcal{L}_{m})$ gravity by considering the specific form $f(Q, \mathcal{L}_m)=-Q+2\mathcal{L}_m+\gamma$. To describe the cosmic pressure…

General Relativity and Quantum Cosmology · Physics 2025-08-08 Amit Samaddar , S. Surendra Singh

The evolution of the configuration entropy of the mass distribution in the Universe is known to be governed by the growth rate of density perturbations and the expansion rate of the Universe. We consider the $\Lambda$CDM model and a set of…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-31 Biswajit Das , Biswajit Pandey

Recent astronomical observations of SNIa, CMB, as well as BAO in the Sloan Digital Sky Survey, suggest that the current Universe has entered a stage of an accelerated expansion with the transition redshift at $z \simeq 0.5$. While the…

Astrophysics · Physics 2010-11-11 Aleksandra Kurek , Marek Szydlowski

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

In this study, we investigate deviations from the Planck-$\Lambda$CDM model in the late universe ($z \lesssim 2.5$) using the Gaussian Processes method, with minimal assumptions. Our goal is to understand where exploring new physics in the…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-18 Miguel A. Sabogal , Özgür Akarsu , Alexander Bonilla , Eleonora Di Valentino , Rafael C. Nunes

[abridged] We propose a model of the Universe (dubbed $\eta$CDM) featuring a stochastic evolution of the cosmological quantities, that is meant to render small deviations from homogeneity/isotropy on scales of $30-50\, h^{-1}$ Mpc at late…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-30 Andrea Lapi , Lumen Boco , Marcos M. Cueli , Balakrishna S. Haridasu , Tommaso Ronconi , Carlo Baccigalupi , Luigi Danese

Observations of gamma-ray bursts up to $z\sim 9$ are best suited to study the possible evolution of the Universe equation of state at intermediate redshifts. We apply the Combo-relation to a sample of 174 gamma ray bursts to investigate…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 M. Muccino , L. Izzo , O. Luongo , K. Boshkayev , L. Amati , M. Della Valle , G. B. Pisani , E. Zaninoni

For the first time, we reconstruct the dark energy equation of the state parameter $w$ from the combination of background and perturbation observations, specifically combining the Hubble parameter data from cosmic chronometer observations…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-15 Bikash R. Dinda , Narayan Banerjee

We investigate several phenomenological dark energy parameterizations using a joint analysis of late-time cosmological observations, including cosmic-chromatometer measurements of the Hubble parameter, DESI DR2 baryon acoustic oscillation…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 Chanchal Kumari , Dinesh Kumar

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

The cosmographic approach is gaining considerable interest as a model-independent technique able to describe the late expansion of the universe. Indeed, given only the observational assumption of the cosmological principle, it allows to…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-11 Micol Benetti , Salvatore Capozziello

We consider spherically symmetric inhomogeneous dust models with a positive cosmological constant, $\Lambda$, given by the Lemaitre-Tolman-Bondi metric. These configurations provide a simple but useful generalization of the Lambda-CDM model…

General Relativity and Quantum Cosmology · Physics 2015-03-14 Roberto A. Sussman , German Izquierdo

We use low-redshift background cosmology data to place quantitative constraints on three separate modified gravity models, each of which aims to explain the low-redshift acceleration through a different physical mechanism. The Lifshitz…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 S. R. Pinto , A. M. Cabral , C. J. A. P. Martins

We present a generalized phenomenological parameterization of the deceleration parameter $q(z)$ that incorporates an effective radiative component (ERC) in addition to a localized late-time contribution. The proposed framework extends…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-28 Tomás Verdugo , Alberto Hernández-Almada , Miguel A. García-Aspeitia , Juan Magaña , Verónica Motta

Combining Supernovae, Baryon Acoustic Oscillations and Redshift-Space Distortions data from the next generation of (Stage-IV) cosmological surveys, we aim to reconstruct the expansion history up to large redshifts using forward-modeling of…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-29 R. Calderón , B. L'Huillier , D. Polarski , A. Shafieloo , A. A. Starobinsky

We analyse various low-redshift cosmological data from Type-Ia Supernova, Baryon Acoustic Oscillations, Time-Delay measurements using Strong-Lensing, $H(z)$ measurements using Cosmic Chronometers and growth measurements from large scale…

Cosmology and Nongalactic Astrophysics · Physics 2019-11-06 Koushik Dutta , Anirban Roy , Ruchika , Anjan A Sen , M. M. Sheikh-Jabbari

We investigate the universe's evolution within the framework of Rastall gravity, which is an extension of the standard $\Lambda$CDM model. Utilizing a linear parametrization of the Equation of State (EoS) in a…

General Relativity and Quantum Cosmology · Physics 2024-10-17 J. K. Singh , Akanksha Singh , Shaily , Sushant G. Ghosh , Sunil D. Maharaj

Astrophysical observations have put unprecedentedly tight constraints on cosmological theories. The $\Lambda$CDM model, mathematically simple and fits observational data-sets well, is preferred for explaining the behavior of universe. But…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Qiang Zhang , Guang Yang , Qixiang Zou , Xinhe Meng , Keji Shen

This paper introduces a novel cosmological model aimed at probing the accelerated expansion of the late Universe through a unique parametrization of the deceleration parameter. We aim to constrain key cosmic parameters by integrating recent…

General Relativity and Quantum Cosmology · Physics 2024-08-14 Himanshu Chaudhary , Ujjal Debnath , G. Mustafa , S. K. Maurya , Farruh Atamurotov