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相关论文: Constraints on running vacuum model with $H(z)$ an…

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We study a special running vacuum model (RVM) with $\Lambda = 3 \alpha H^2+3\beta H_0^4 H^{-2}+\Lambda_0$, where $\alpha$, $\beta$ and $\Lambda_0$ are the model parameters and $H$ is the Hubble one. This RVM has non-analytic background…

宇宙学与河外天体物理 · 物理学 2020-01-31 Chao-Qiang Geng , Chung-Chi Lee , Lu Yin

We investigate the power spectra of the CMB temperature and matter density in the running vacuum model (RVM) with the time-dependent cosmological constant of $\Lambda = 3 \nu H^2 + \Lambda_0$, where $H$ is the Hubble parameter. In this…

宇宙学与河外天体物理 · 物理学 2019-03-08 Jin-Jun Zhang , Chung-Chi Lee , Chao-Qiang Geng

We investigate the running cosmological constant model with dark energy linearly proportional to the Hubble parameter, $\Lambda = \sigma H + \Lambda_0$, in which the $\Lambda$CDM limit is recovered by taking $\sigma=0$. We derive the linear…

宇宙学与河外天体物理 · 物理学 2016-07-22 Chao-Qiang Geng , Chung-Chi Lee , Kaituo Zhang

We investigate observational constraints on the running vacuum model (RVM) of $\Lambda=3\nu (H^{2}+K/a^2)+c_0$ in the spatially curved universe, where $\nu$ is the model parameter, $K$ corresponds to the spatial curvature constant, and…

宇宙学与河外天体物理 · 物理学 2020-09-29 Chao-Qiang Geng , Yan-Ting Hsu , Lu Yin , Kaituo Zhang

In cosmology, phenomenologically motivated expressions for running vacuum are commonly parametrized as linear functions $\Lambda(H^2)$ or $\Lambda(R)$. Such kind of models assume an equation of state for vacuum given by $\,\overline…

宇宙学与河外天体物理 · 物理学 2017-08-30 E. L. D. Perico , D. A. Tamayo

A substantial body of phenomenological and theoretical work over the last few years strengthens the possibility that the vacuum energy density (VED) of the universe is dynamical, and in particular that it adopts the `running vacuum model'…

宇宙学与河外天体物理 · 物理学 2023-05-31 Joan Sola Peracaula , Adria Gomez-Valent , Javier de Cruz Perez , Cristian Moreno-Pulido

In this study, we consider three dark energy models in which $\Lambda$ is not constant, but has a dynamic nature that depends on the Hubble parameter $H$ and/or its time derivative $\dot{H}$. We analyze the generalized running vacuum model,…

宇宙学与河外天体物理 · 物理学 2022-01-05 Christine R. Farrugia , Joseph Sultana , Jurgen Mifsud

It is well-known that a constant $\Lambda$-term is a traditional building block of the concordance $\Lambda$CDM model. We show that this assumption is not necessarily the optimal one from the phenomenological point of view. The class of…

广义相对论与量子宇宙学 · 物理学 2016-05-23 Adrià Gómez-Valent , Joan Solà , Javier de Cruz Pérez

We use updated Hubble parameter and baryon acoustic oscillation data, as well as other lower-redshift Type Ia supernova, Mg II reverberation-measured quasar, quasar angular size, H II starburst galaxy, and Amati-correlated gamma-ray burst…

宇宙学与河外天体物理 · 物理学 2022-05-31 Shulei Cao , Bharat Ratra

The cosmological term, $\Lambda$, was introduced $104$ years ago by Einstein in his gravitational field equations. Whether $\Lambda$ is a rigid quantity or a dynamical variable in cosmology has been a matter of debate for many years,…

宇宙学与河外天体物理 · 物理学 2021-05-20 Joan Sola , Adria Gomez-Valent , Javier de Cruz Perez , Cristian Moreno-Pulido

We use all available baryon acoustic oscillation distance measurements and Hubble parameter data to constrain the cosmological constant $\Lambda$, dynamical dark energy, and spatial curvature in simple cosmological models. We find that the…

宇宙学与河外天体物理 · 物理学 2018-07-19 Joseph Ryan , Sanket Doshi , Bharat Ratra

For different gravitational models we consider limitations on their parameters coming from recent observational data for type Ia supernovae, baryon acoustic oscillations, and from 34 data points for the Hubble parameter $H(z)$ depending on…

广义相对论与量子宇宙学 · 物理学 2014-11-06 G. S. Sharov , E. G. Vorontsova

We examine the decay vacuum model with a parameter $\epsilon$ that indicates the vacuum energy decay rate. By constraining this model with cosmic microwave background radiation, baryon acoustic oscillation, type Ia supernovae and 30 H(z)…

宇宙学与河外天体物理 · 物理学 2018-01-04 Yang-Jie Yan , Deng Wang , Xin-He Meng

In this work, we present comprehensive observational constraints on the time-varying vacuum $\Lambda(t)$CDM cosmology using the latest baryon acoustic oscillation (BAO) data from Dark Energy Spectroscopic Instrument (DESI) Data Release 2…

宇宙学与河外天体物理 · 物理学 2026-03-05 Olga Avsajanishvili

Despite the outstanding achievements of modern cosmology, the classical dispute on the precise value of $H_0$, which is the first ever parameter of modern cosmology and one of the prime parameters in the field, still goes on and on after…

宇宙学与河外天体物理 · 物理学 2017-11-22 Joan Sola , Adria Gomez-Valent , Javier de Cruz Perez

Presently, we are facing a 3$\sigma$ tension in the most basic cosmological parameter -- the Hubble constant $H_0$. This tension arises when fitting the Lambda-cold-dark-matter model ($\Lambda$CDM) to the high-precision…

综合物理 · 物理学 2017-10-18 Steffen Hahn , Ralf Hofmann

We discuss the cosmological degeneracy between the Hubble parameter H(z), the age of the universe and cosmological parameters describing simple variations from the minimal LCDM model. We show that independent determinations of the Hubble…

天体物理学 · 物理学 2014-11-18 Daniel G. Figueroa , Licia Verde , Raul Jimenez

In this paper we compare data to theory. We use a compilation of the most recent cosmic microwave background (CMB) measurements to constrain Hubble's constant h, the baryon fraction Omega_b, and the cosmological constant lambda. We fit h-,…

天体物理学 · 物理学 2008-02-03 Charles H. Lineweaver , Domingos Barbosa , Alain Blanchard , James G. Bartlett

We derive for the first time the growth index of matter perturbations of the FLRW flat cosmological models in which the vacuum energy depends on redshift. A particularly well motivated model of this type is the so-called quantum field…

宇宙学与河外天体物理 · 物理学 2015-12-09 Spyros Basilakos , Joan Solà

We use 28 Hubble parameter, $H(z)$, measurements at intermediate redshifts $0.07 \leq z \leq 2.3$ to determine the present-day Hubble constant $H_0$ in four cosmological models. We measure $H_0 = 68.3^{ +2.7}_{ -2.6 }, 68.4^{ +2.9 }_{ -3.3…

宇宙学与河外天体物理 · 物理学 2017-01-26 Yun Chen , Suresh Kumar , Bharat Ratra
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