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Related papers: Dark energy and the fitting problem

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We present a new model based on General Relativity in where a subtle change of curvature at late times is able to produce the observed Universe acceleration and an oscillating behavior in the effective equation of state. This model aims to…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-18 A. Esteban-Gutiérrez , Miguel A. García-Aspeitia , A. Hernández-Almada , Juan Magaña , V. Motta

We propose a cosmological model that makes a significant step toward solving the coincidence problem of the near similarity at the present of the dark energy and dark matter components. Our cosmology has the following properties: a) among…

Astrophysics · Physics 2008-11-26 Luca Amendola , Domenico Tocchini-Valentini

We discuss observational constrains coming from supernovae Ia imposed on the behaviour of the Randall-Sundrum models. In the case of dust matter on the brane, the difference between the best-fit Perlmutter model with a $\Lambda$-term and…

Astrophysics · Physics 2009-11-10 Wlodzimierz Godlowski , Marek Szydlowski

We present a model-independent null test of the late-time cosmological response to a reduced sound horizon, as typically required by early-universe solutions to the Hubble tension. In this approach, we phenomenologically impose a shorter…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-20 Tal Adi

A number of recent studies have found evidence for a tension between observations of large-scale structure (LSS) and the predictions of the standard model of cosmology with the cosmological parameters fit to the cosmic microwave background…

Improvements in the precision of the astrophysical flux scale are needed to answer fundamental scientific questions ranging from cosmology to stellar physics. The unexpected discovery that the expansion of the universe is accelerating was…

We introduce a theoretical framework to interpret the Hubble tension, based on the combination of a metric $f(R)$ gravity with a dynamical dark energy contribution. The modified gravity provides the non-minimally coupled scalar field…

General Relativity and Quantum Cosmology · Physics 2023-11-07 Giovanni Montani , Mariaveronica De Angelis , Flavio Bombacigno , Nakia Carlevaro

In this work, we assume the FRLW Universe which is filled with dark matter along with dark energy in the framework of Horava-Lifshitz (HL) gravity. The dark energy is considered as the Linear (Model I) and CPL (Model II) parametrizations of…

General Relativity and Quantum Cosmology · Physics 2024-02-07 Himanshu Chaudhary , Niyaz Uddin Molla , Madhur Khurana , Ujjal Debnath , G. Mustafa

As an increasing number of well measured type Ia supernovae (SNe Ia) become available, the statistical uncertainty on w has been reduced to the same size as the systematic uncertainty. The statistical error will decrease further in the near…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Ulrich Feindt , Marek Kowalski , Kerstin Paech

Bayesian model averaging is a procedure to obtain parameter constraints that account for the uncertainty about the correct cosmological model. We use recent cosmological observations and Bayesian model averaging to derive tight limits on…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-07 M. Vardanyan , R. Trotta , J. Silk

Observations provide increasingly strong evidence that the universe is accelerating. This revolutionary advance in cosmological observations confronts theoretical cosmology with a tremendous challenge, which it has so far failed to meet.…

Astrophysics · Physics 2008-11-26 Ruth Durrer , Roy Maartens

The concordance of the $\Lambda$CDM cosmological model in light of current observations has been the subject of an intense debate in recent months. The 2018 Planck Cosmic Microwave Background (CMB) temperature anisotropy power spectrum…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-02 Sunny Vagnozzi , Eleonora Di Valentino , Stefano Gariazzo , Alessandro Melchiorri , Olga Mena , Joseph Silk

In this paper we give a physical explanation to the accelerated expansion of the Universe, alleviating the tension between the discrepancy of Hubble constant measurements. By the Euler Cauchy stress principle, we identify a controversy on…

General Relativity and Quantum Cosmology · Physics 2021-02-17 C. Ortiz

The Schr\"odinger-Newton equation is a proposed model to explain the localization of macroscopic particles by suppressing quantum dispersion with the particle's own gravitational attraction. On cosmic scales, however, dark energy also acts…

General Relativity and Quantum Cosmology · Physics 2020-04-01 Kelvin , Kelvin Onggadinata , Matthew J. Lake , Tomasz Paterek

The discovery of accelerated Hubble expansion in the SNIa data and the observed power spectrum of the microwave background radiation provide an ample support for Dark energy and Dark matter. Except for the so far well-known facts that cold…

General Physics · Physics 2010-07-21 Balendra Kr. Dev Choudhury , Julie Saikia

We show that modelling the universe as a pre-geometric system with emergent quantum modes, and then constructing the classical limit, we obtain a new account of space and gravity that goes beyond Newtonian gravity even in the…

General Physics · Physics 2007-09-20 Reginald T Cahill

The paradigm of \Lambda CDM cosmology works impressively well and with the concept of inflation it explains the universe after the time of decoupling. However there are still a few concerns; after much effort there is no detection of dark…

General Physics · Physics 2017-03-22 B. Vlahovic

Recent supernovae of type Ia measurements and other astronomical observations suggest that our universe is in accelerating phase of evolution at the present epoch. While a dark energy of unknown form is usually proposed as the most feasible…

Astrophysics · Physics 2008-11-26 Andrzej Borowiec , Wlodzimierz Godlowski , Marek Szydlowski

Discoveries in the last few years have revolutionized our knowledge of the universe and our ideas of its ultimate fate. Measurements of the expansion of the universe show that it is not slowing down under normal gravity but accelerating due…

Astrophysics · Physics 2007-05-23 Eric V. Linder

A major quest in cosmology is the understanding of the nature of dark energy. It is now well known that a combination of cosmological probes is required to break the underlying degeneracies on cosmological parameters. In this paper, we…

Astrophysics · Physics 2009-11-11 Ch. Yeche , A. Ealet , A. Refregier , C. Tao , A. Tilquin , J. -M. Virey , D. Yvon
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