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相关论文: Running vacuum model versus $\Lambda$CDM -- a Baye…

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We employ the Planck 2013 CMB temperature anisotropy and lensing data, and baryon acoustic oscillation (BAO) data to constrain a phenomenological $w$CDM model, where dark matter and dark energy interact. We assume time-dependent equation of…

宇宙学与河外天体物理 · 物理学 2015-07-15 Jussi Valiviita , Elina Palmgren

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…

宇宙学与河外天体物理 · 物理学 2012-06-07 M. Vardanyan , R. Trotta , J. Silk

We present a cosmological model constituted by three perfect fluids, cold dark matter, vacuum energy and radiation, which interacting with each other lead to an equivalent model of three self-preserved fluids that can be identified with the…

广义相对论与量子宇宙学 · 物理学 2018-01-25 Mónica Forte

Decaying vacuum models are a class of models that incorporate the vacuum energy density as a time-evolving entity that has the potential to explain the entire evolutionary history of the universe in a single framework. A general solution to…

广义相对论与量子宇宙学 · 物理学 2021-03-30 Sarath N , Titus K. Mathew

Within the Friedmann-Lema\^itre-Robertson-Walker (FLRW) framework, the Hubble constant $H_0$ is an integration constant. Thus, consistency of the model demands observational constancy of $H_0$. We demonstrate redshift evolution of best fit…

宇宙学与河外天体物理 · 物理学 2024-03-28 Mohammad Malekjani , Ruairí Mc Conville , Eoin Ó Colgáin , Saeed Pourojaghi , M. M. Sheikh-Jabbari

In this paper bulk viscosity is introduced to describe the effects of cosmic non-perfect fluid on the cosmos evolution and to build the unified dark energy (DE) with (dark) matter models. Also we derive a general relation between the bulk…

宇宙学与河外天体物理 · 物理学 2009-10-14 X. H. Meng , X. Dou

In a spatially flat Friedmann-Lema\^{i}tre-Robertson-Walker universe, we investigate a unified cosmic fluid scenario endowed with bulk viscosity in which the coefficient of the bulk viscosity has a power law evolution. The power law in the…

宇宙学与河外天体物理 · 物理学 2019-11-20 Weiqiang Yang , Supriya Pan , Eleonora Di Valentino , Andronikos Paliathanasis , Jianbo Lu

In this paper, we study several models and parameterizations of dynamical dark energy (DE) that have been studied already in the past, in conjunction with the recently proposed model $w$XCDM, the running vacuum model (RVM) with and without…

宇宙学与河外天体物理 · 物理学 2026-03-03 Javier de Cruz Pérez , Adrià Gómez-Valent , Joan Solà Peracaula

We propose a revised formulation of General Relativity for cosmological settings, in which the Einstein constant varies with the energy density of the Universe. We demonstrate that this modification has only phenomenological impact of…

广义相对论与量子宇宙学 · 物理学 2025-08-28 Giovanni Montani , Giulia Maniccia , Elisa Fazzari , Alessandro Melchiorri

Bayesian statistics and Markov Chain Monte Carlo (MCMC) algorithms have found their place in the field of Cosmology. They have become important mathematical and numerical tools, especially in parameter estimation and model comparison. In…

宇宙学与河外天体物理 · 物理学 2021-07-02 Luis E. Padilla , Luis O. Tellez , Luis A. Escamilla , J. Alberto Vazquez

Recent measurements of baryon acoustic oscillations (BAO) by the Dark Energy Spectroscopic Instrument (DESI) suggest a preference for a dynamic dark energy model over a cosmological constant. This conclusion emerges from the combination of…

宇宙学与河外天体物理 · 物理学 2024-07-15 Guanlin Liu , Yu Wang , Wen Zhao

Next year we will celebrate 100 years of the cosmological term, $\Lambda$, in Einstein's gravitational field equations, also 50 years since the cosmological constant problem was first formulated by Zeldovich, and almost about two decades of…

宇宙学与河外天体物理 · 物理学 2016-12-14 Joan Sola

First principles microphysics models are essential to the design and analysis of high energy density physics experiments. Using experimental data to investigate the underlying physics is also essential, particularly when simulations and…

等离子体物理 · 物理学 2013-06-04 Jim A Gaffney , Dan Clark , Vijay Sonnad , Stephen B Libby

The $\Lambda$CDM model has long served as the cornerstone of modern cosmology, offering an elegant and successful framework for interpreting a wide range of cosmological observations. However, the rise of high-precision datasets has…

宇宙学与河外天体物理 · 物理学 2025-10-01 Manish Yadav , Archana Dixit , Anirudh Pradhan , M S Barak

The latest improvements in the scale and calibration of Type Ia supernovae catalogues allow us to constrain the specific nature and evolution of dark energy through its effect on the expansion history of the universe. We present the results…

宇宙学与河外天体物理 · 物理学 2023-12-05 Toby Lovick , Suhail Dhawan , Will Handley

The $\Lambda$CDM cosmolgical model has long been regarded as highly successful in accurately describing a wide range of astronomical observations. However, numerous observational findings have also provided hints of discrepancies from the…

宇宙学与河外天体物理 · 物理学 2025-12-01 Yupeng Yang

We study the matter density fluctuations in the running cosmological constant (RCC) model using linear perturbations in the longitudinal gauge. Using this observable we calculate the growth rate of structures and the matter power spectrum,…

宇宙学与河外天体物理 · 物理学 2015-03-13 A. M. Velasquez-Toribio

It is well known that estimating cosmological parameters from cosmic microwave background (CMB) data alone results in a significant degeneracy between the total neutrino mass and several other cosmological parameters, especially the Hubble…

宇宙学与河外天体物理 · 物理学 2018-03-28 Will Sutherland

We constrain the basic comological parameters using the first observations by the Very Small Array (VSA) in its extended configuration, together with existing cosmic microwave background data and other cosmological observations. We estimate…

We generalize the previously proposed running vacuum energy model by including a term proportional to \dot{H}, in addition to the existing H^2 term. We show that the added degree of freedom is very constrained if both low redshift and high…

广义相对论与量子宇宙学 · 物理学 2013-05-30 Spyros Basilakos , David Polarski , Joan Sola