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As evidenced by a great number of works, it is common practice to assume that the Universe is flat. However, the majority of studies which make use of observational data to constrain the curvature density parameter are premised on the…

广义相对论与量子宇宙学 · 物理学 2019-07-18 Christine R. Farrugia , Joseph Sultana

We revisit a cosmological model where dark matter (DM) and dark energy (DE) follow barotropic equations of state, allowing deviations from the standard $\Lambda$CDM framework (i.e. $w_{dm} \neq 0$, $w_{de} \neq -1$), considering both flat…

宇宙学与河外天体物理 · 物理学 2025-11-24 Dorian Araya , Cristian Castillo , Genly Leon , Juan Magaña , Angie Barr Domínguez , Miguel A. García-Aspeitia

We constrain two non-flat time-evolving dark energy cosmological models by using Hubble parameter data, Type Ia supernova apparent magnitude measurements, and baryonic acoustic oscillation peak length scale observations. The inclusion of…

宇宙学与河外天体物理 · 物理学 2017-03-22 Omer Farooq , Data Mania , Bharat Ratra

We analyse some open debates in cosmology in light of the most updated quasar (QSO) sample, covering a wide redshift range up to $z\sim7.5$, combined with type Ia supernovae (SNe) and baryon acoustic oscillations (BAO). Indeed, extending…

宇宙学与河外天体物理 · 物理学 2022-08-04 G. Bargiacchi , M. Benetti , S. Capozziello , E. Lusso , G. Risaliti , M. Signorini

This study explores the impact of cosmic curvature on structure formation through general relativistic first-order perturbation theory. We analyze continuity and Euler equations, incorporating cosmic curvature into Einstein equations.…

宇宙学与河外天体物理 · 物理学 2025-05-29 Bikash R. Dinda

In this paper we consider the effects of adding curvature in extended cosmologies involving a free-to-vary neutrino sector and different parametrizations of Dark Energy (DE). We make use of the Planck 2018 cosmic microwave background…

宇宙学与河外天体物理 · 物理学 2023-03-29 Weiqiang Yang , William Giarè , Supriya Pan , Eleonora Di Valentino , Alessandro Melchiorri , Joseph Silk

When using distance measurements to probe spatial curvature, the geometric degeneracy between curvature and dark energy in the distance-redshift relation typically requires either making strong assumptions about the dark energy evolution or…

宇宙学与河外天体物理 · 物理学 2009-12-14 Michael J. Mortonson

The $\Lambda$CDM framework offers a remarkably good description of our universe with a very small number of free parameters, which can be determined with high accuracy from currently available data. However, this does not mean that the…

宇宙学与河外天体物理 · 物理学 2015-07-22 Yves Zolnierowski , Alain Blanchard

The results of joint analyses of available cosmological data have motivated an important debate about a possible detection of a non-zero spatial curvature. If confirmed, such a result would imply a change in our present understanding of…

宇宙学与河外天体物理 · 物理学 2021-12-08 Javier E. Gonzalez , Micol Benetti , Rodrigo von Marttens , Jailson Alcaniz

We carry out an independent re-analysis of the Dark Energy Spectroscopic Instrument (DESI) public dataset, focusing on extensions to the standard cosmological model, $\Lambda$CDM. Utilizing the dataset and Effective Field Theory (EFT)-based…

宇宙学与河外天体物理 · 物理学 2026-04-15 Anton Chudaykin , Mikhail M. Ivanov , Oliver H. E. Philcox

The current expansion of the Universe has been observed to be accelerating, and the widely accepted spatially-flat concordance model of general relativistic cosmology attributes this phenomenon to a constant dark energy, a cosmological…

宇宙学与河外天体物理 · 物理学 2023-04-13 Shulei Cao

Observations conducted over the last few decades show that the expansion of the Universe is accelerating. In the standard model of cosmology, this accelerated expansion is attributed to a dark energy in the form of a cosmological constant.…

宇宙学与河外天体物理 · 物理学 2021-04-22 Joseph Ryan

Measurements of the current expansion rate of the Universe, $H_0$, using standard candles, disagree with those derived from observations of the Cosmic Microwave Background (CMB). This discrepancy, known as the Hubble tension, is substantial…

宇宙学与河外天体物理 · 物理学 2024-02-05 Sergio Torres-Arzayus

We discuss the constraints on the time-varying equation of state for dark energy and the curvature of the universe using observations of type Ia supernovae from Riess et al. and the most recent Supernova Legacy Survey (SNLS), the baryon…

天体物理学 · 物理学 2009-11-13 Kazuhide Ichikawa , Tomo Takahashi

We investigate the relationship between the cosmic curvature and the model of dark energy (hereafter DE) with the recent Type Ia supernovae (hereafter SNe Ia) data, i.e., the Pantheon sample including 1048 SNe Ia with $0.01 < z < 2.3$. We…

宇宙学与河外天体物理 · 物理学 2020-10-09 Chao Gao , Yun Chen , Jie Zheng

In this analysis we apply a model-independent framework to test the flat $\Lambda$CDM cosmology using simulated SNIa data from the upcoming Legacy Survey of Space and Time (LSST) and combined with simulated Dark Energy Spectroscopic…

宇宙学与河外天体物理 · 物理学 2025-05-19 Benjamin L'Huillier , Ayan Mitra , Arman Shafieloo , Ryan E. Keeley , Hanwool Koo

The expansion rate of the Universe changes with time, initially slowing (decelerating) when the universe was matter dominated, because of the mutual gravitational attraction of all the matter in it, and more recently speeding up…

宇宙学与河外天体物理 · 物理学 2013-09-17 Muhammad Omer Farooq

We show that the assumption of a flat universe induces critically large errors in reconstructing the dark energy equation of state at z>~0.9 even if the true cosmic curvature is very small, O(1%) or less. The spuriously reconstructed w(z)…

天体物理学 · 物理学 2008-11-26 Chris Clarkson , Marina Cortes , Bruce A. Bassett

Observation of thousands of type Ia supernovae should offer the most direct approach to probe the dark energy content of the universe. This will be undertaken by future large ground-based surveys followed by a space mission (SNAP/JDEM). We…

天体物理学 · 物理学 2009-11-10 J. -M. Virey , P. Taxil , A. Tilquin , A. Ealet , D. Fouchez , C. Tao

In a previous paper, we proposed a heterotic dark energy model, called $\Lambda$HDE, in which dark energy is composed of two components: cosmological constant (CC) and holographic dark energy (HDE). The aim of this work is to give a more…

宇宙学与河外天体物理 · 物理学 2017-02-17 Shuang Wang , Sixiang Wen , Lanjun Zhou , Miao Li
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