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Despite the fact that the $\Lambda$CDM model has been highly successful over the last few decades in providing an accurate fit to a broad range of cosmological and astrophysical observations, different intriguing tensions and anomalies…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-05 Pietro Ghedini , Rasmi Hajjar , Olga Mena

By integration of generalized BSBM and Brans-Dicke cosmological models, in this article, we investigate the theoretical framework of fine structure constant variation and current cosmic acceleration. We first develop a mathematical…

General Relativity and Quantum Cosmology · Physics 2015-06-11 H. Farajollahi , A. Salehi

We propose a new non-minimally coupled quintessence model to account for the late-time dark energy dynamics indicated by recent DESI measurements. Within this framework, the quintessence density begins to decrease only when it starts to…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-10 Jia-Qi Wang , Rong-Gen Cai , Zong-Kuan Guo , Yun-He Li , Shao-Jiang Wang , Xin Zhang

Models in which dark energy interacts with dark matter have been proposed in the literature to help explain why dark energy should only come to dominate in recent times. In this paper, we present a dynamical framework to calculate…

Astrophysics · Physics 2009-03-12 Sirichai Chongchitnan

We analyze the consistency of different astronomical data of the variation in the fine-structure constant obtained with KECK and VLT. We tested the consistency using the Student test and confidence intervals. We splited the data sets in to…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-27 Lucila Kraiselburd , Susana J. Landau , Claudio Simeone

The star formation rate (SFR) in high redshift galaxies is expected to be time-variable due to competing physical processes. Such stochastic variability might boost the luminosity of galaxies, possibly explaining the over-abundance seen at…

Astrophysics of Galaxies · Physics 2023-09-06 A. Pallottini , A. Ferrara

Recent observations of high-redshift Type Ia supernovae have placed stringent constraints on the cosmological constant $\Lambda$. We explore the implications of these SNe observations for cosmological models in which a classically evolving…

Astrophysics · Physics 2009-10-30 Joshua A. Frieman , Ioav Waga

In the context of a spatially flat $\Lambda(t)$CDM cosmology, we investigate interacting dark energy (IDE) scenarios characterized by phenomenological interaction terms proportional to the Hubble expansion rate and the dark energy density.…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-13 A. A. Escobal , H. A. P. Macedo , J. F. Jesus , R. C. Nunes , J. A. S. Lima

We investigate a phenomenological non-gravitational coupling between dark energy and dark matter, where the interaction in the dark sector is parameterized as an energy transfer either from dark matter to dark energy or the opposite. The…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-11 Riccardo Murgia , Stefano Gariazzo , Nicolao Fornengo

We explore the dynamics of cosmological models with two coupled dark components with energy densities $\rho_A$ and $\rho_B$. We assume that the coupling is of the form $Q=Hq(\rho_A,\rho_B)$, so that the dynamics of the two components turns…

Astrophysics · Physics 2009-02-23 Claudia Quercellini , Marco Bruni , Amedeo Balbi , Davide Pietrobon

This conference proceedings paper provides a short summary of the constraints presented by Menci et al. (2020) and Menci et al. (2022) to dynamical dark energy models. Dynamical dark energy (DDE) models have been proposed to address several…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-11 Paola Santini , Nicola Menci , Marco Castellano

The possible interaction between the dark components of the Universe (dark matter and dark energy) stands as an attractive alternative to the standard $\Lambda$CDM cosmological model. In this work, we present a novel analysis of three…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-18 F. Villalobos , J. Magana , T. Verdugo

When the 2dF QSO Redshift Survey (2QZ) is complete, a powerful geometric test for the cosmological constant will be available. By comparing the clustering along and across the line of sight and modelling the effects of peculiar velocities…

Astrophysics · Physics 2009-11-06 P. J. Outram , Fiona Hoyle , T. Shanks , B. J. Boyle , S. M. Croom , N. S. Loaring , L. Miller , R. J. Smith

Recent observations of Type Ia supernova at high redshifts establish that the dark energy component of the universe has (a probably constant) ratio between pressure and energy density $w=p/\rho=-1.02(^{+0.13}_{-0.19})$. The conventional…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Edgard Gunzig , Alberto Saa

A sufficiently light scalar field slowly evolving in a potential can account for the dark energy that presently dominates the universe. This quintessence field is expected to couple directly to matter components, unless some symmetry of a…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-09 Ewan R. M. Tarrant , Carsten van de Bruck , Edmund J. Copeland , Anne M. Green

Changes in the values of the fundamental constants mu, the proton to electron mass ratio, and alpha, the fine structure constant due to rolling scalar fields have been discussed both in the context of cosmology and in new physics such as…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Rodger I. Thompson

Within the context of mass-varying neutrinos, we construct a cosmological model that has a phase transition in the electromagnetic fine structure constant \alpha at a redshift of 0.5. The model accommodates hints of a time variable \alpha…

High Energy Physics - Phenomenology · Physics 2008-11-26 L. Anchordoqui , V. Barger , H. Goldberg , D. Marfatia

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

Detecting dark energy dynamics is the main quest of current dark energy research. Addressing the issue demands a fully consistent analysis of CMB, large scale structure and SN-Ia data with multi-parameter freedom valid for all redshifts.…

Astrophysics · Physics 2008-11-26 P. S. Corasaniti , M. Kunz , D. Parkinson , E. J. Copeland , B. A. Bassett

The predicted present-day amplitude of matter fluctuations based on cosmic microwave background (CMB) anisotropy data has sometimes been found discrepant with more direct measurements of late-time structure. This has motivated many…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-14 Alex Laguë , Fiona McCarthy , Mathew Madhavacheril , J. Colin Hill , Frank J. Qu
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