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相关论文: Recovering $\Lambda$CDM Model From a Cosmographic …

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We compile a list of 28 independent measurements of the Hubble parameter between redshifts 0.07 < z < 2.3 and use this to place constraints on model parameters of constant and time-evolving dark energy cosmologies. These H(z) measurements…

宇宙学与河外天体物理 · 物理学 2015-06-12 Omer Farooq , Bharat Ratra

Given the persistence of various tensions in the "Cosmic Concordance" -- such as the "Hubble Tension", and possible departures from LambdaCDM time evolution -- seen from combinations of complementary data sets (e.g., Cosmic Microwave…

宇宙学与河外天体物理 · 物理学 2026-02-19 Brett Bochner , Aiden Jin

The simplest cosmological model ($\Lambda$CDM) is well-known to suffer from the Hubble tension, namely an almost $5 \sigma$ discrepancy between the (model-based) early-time determination of the Hubble constant $H_0$ and its late-time (and…

宇宙学与河外天体物理 · 物理学 2023-10-06 Darshan Kumar , Debajyoti Choudhury , Debottam Nandi

Cosmic chronometers offer a model-independent way to trace the expansion history of the Universe via the dating of passively evolving objects. This enables testing the validity of cosmological models without concrete assumptions of their…

Using comoving distance $d_c$ and angular diameter distance $d_A$, we recalculate parameters describing kinematical state of the universe, still combining the kinematical model of universe but not relying on dynamical equations for gravity.…

宇宙学与河外天体物理 · 物理学 2021-05-27 Hai Huang , Long Huang

In this work, we investigate a cosmological scenario with a time-dependent cosmological constant $\Lambda$(t) within the spatially flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) framework. Here we study a power-law $\Lambda(t)$CDM model…

广义相对论与量子宇宙学 · 物理学 2025-10-28 Archana Dixit , Manish Yadav , Anirudh Pradhan , M. S. Barak

In this study, we construct a theoretical framework based on the generalized Hubble parameter form which may arise within the particle creation, viscous and $f(R)$ gravity theory. The Hubble parameter is scrutinized for its compatibility…

广义相对论与量子宇宙学 · 物理学 2025-03-11 G. P. Singh , Romanshu Garg , Ashutosh Singh

Accurately measuring the Hubble parameter is vital for understanding the expansion history and properties of the universe. In this paper, we propose a new method that supplements the covariance between redshift pairs to improve the…

宇宙学与河外天体物理 · 物理学 2024-01-23 Jian-Chen Zhang , Yu Hu , Kang Jiao , Hong-Feng Wang , Yuan-Bo Xie , Bo Yu , Li-Li Zhao , Tong-Jie Zhang

We study the late-time cosmology in $f(R, G)=R+\alpha R^{2}+\beta e^{\gamma G}$, using a logarithmic parametrization of the deceleration parameter $q(z)=q_{0}+q_{1}sin[log(1+z)]$. The Hubble parameter $H(z)$ is reconstructed and model…

广义相对论与量子宇宙学 · 物理学 2025-06-10 Amit Samaddar , S. Surendra Singh

Observational constraints are considered on a $w_{log}$CDM model of the dark energy equation of state, $w_{d}(z) = w_{0} + w_{a}\left( \frac{\ln(2+z)}{1+z} - \ln 2 \right)$, using the most recent cosmological datasets including DESI Baryon…

综合物理 · 物理学 2026-03-10 Saurabh Verma , Archana Dixit , Anirudh Pradhan , M. S. Barak

We study observational constraints on the cosmographic functions up to the fourth derivative of the scale factor with respect to cosmic time, i.e., the so-called snap function, using the non-parametric method of Gaussian Processes. As…

宇宙学与河外天体物理 · 物理学 2022-05-18 A. M. Velasquez-Toribio , J. C. Fabris

The standard relation between the cosmological redshift and cosmic scale factor underlies cosmological inference from virtually all kinds of cosmological observations, leading to the emergence of the LambdaCDM cosmological model. This…

宇宙学与河外天体物理 · 物理学 2019-08-08 Radosław Wojtak , Francisco Prada

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 study cosmological evolution in a flat FLRW spacetime in the context of modified STEGR gravity or $f(Q)$, using an exponential two-parameter model which represents a smooth perturbative expansion around the $\Lambda$CDM model. The…

广义相对论与量子宇宙学 · 物理学 2025-04-15 Ivan R. Vasquez , A. Oliveros

In this paper, linear first order expansion of deceleration parameter $q(z)=q_0+q_1(1-a)$ ($M_1$), constant jerk $j=j_0$ ($M_2$) and third order expansion of luminosity distance ($M_3$) are confronted with cosmic observations: SCP 307 SN…

宇宙学与河外天体物理 · 物理学 2009-07-24 Lixin Xu , Wenbo Li , Jianbo Lu

The standard cosmographic approach consists in performing a series expansion of a cosmological observable around $z=0$ and then using the data to constrain the cosmographic (or kinematic) parameters at present time. Such a procedure works…

宇宙学与河外天体物理 · 物理学 2018-08-01 C. Rodrigues Filho , Edésio M. Barboza

In the paper, we present an accelerating cosmological model in $f(R,\mathcal{L}_{m})$ gravity with the parameter constrained through the cosmological data sets. At the beginning, we have employed a functional form of $f(R,\mathcal{L}_{m})…

广义相对论与量子宇宙学 · 物理学 2025-01-10 Y. Kalpana Devi , S. A. Narawade , B. Mishra

We use cosmography to present constraints on the kinematics of the Universe without postulating any underlying theoretical model a priori. To this end, we use a Markov Chain Monte Carlo analysis to perform comparisons to the supernova Ia…

宇宙学与河外天体物理 · 物理学 2013-01-18 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

Taking into consideration of Kaniadakis entropy associated with the apparent horizon of Friedmann-Robertson-Walker (FRW) Universe and using the gravity-thermodynamics conjecture, a new cosmological scenarios emerges based on corrected…

广义相对论与量子宇宙学 · 物理学 2023-09-29 Amin Salehi

In this study, we have explored a transitioning cosmological model of universe's expansion in $f(R,\mathcal{L}_{m})$ gravity. The quadratic type of equation of state parameter in the form $\omega=-1 + \alpha (1 + z) + \beta (1 + z)^2$,…

广义相对论与量子宇宙学 · 物理学 2025-04-16 Vinod Kumar Bhardwaj , Saibal Ray