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相关论文: The Cardassian expansion revisited: constraints fr…

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Deriving the expansion history of the Universe is a major goal of modern cosmology. To date, the most accurate measurements have been obtained with Type Ia Supernovae and Baryon Acoustic Oscillations, providing evidence for the existence of…

In this paper, we propose a modified scale factor (MSF) that allows us to explore the accelerating expansion of the universe without invoking the traditional dark-energy model, as described in the Lambda cold dark matter ($\Lambda$CDM)…

宇宙学与河外天体物理 · 物理学 2024-12-10 Goratamang Gaedie , Shambel Sahlu , Amare Abebe

The expectation of explaining cosmological observations without requiring new energy sources is forsooth worthy of investigation. In this letter, a new kind of Cardassian models, called exponential Cardassian models, for the late-time…

天体物理学 · 物理学 2009-11-13 Dao-jun Liu , Chang-bo Sun , Xin-zhou Li

We study the accelerated expansion phase of the universe by using the {\textit{kinematic approach}}. In particular, the deceleration parameter $q$ is parametrized in a model-independent way. Considering a generalized parametrization for…

广义相对论与量子宇宙学 · 物理学 2018-10-22 Abdulla Al Mamon , Kazuharu Bamba

We compile an updated list of 38 measurements of the Hubble parameter $H(z)$ between redshifts $0.07 \leq z \leq 2.36$ and use them to place constraints on model parameters of constant and time-varying dark energy cosmological models, both…

宇宙学与河外天体物理 · 物理学 2017-01-25 Omer Farooq , Foram Madiyar , Sara Crandall , Bharat Ratra

This study investigates the accelerated cosmic expansion within the Ho\v{r}ava-Lifshitz Model. To constrain the cosmological parameters of this model, we incorporate 17 Baryon Acoustic Oscillation points, 31 Cosmic Chronometer points, 40…

宇宙学与河外天体物理 · 物理学 2024-08-16 Himanshu Chaudhary , Ujjal Debnath , Shibesh Kumar Jas Pacif , Niyaz Uddin Molla , G. Mustafa , S. K. Maurya

In this paper, we use a set of observational $H(z)$ data (OHD) to constrain the $\Lambda$CDM cosmology. This data set can be derived from the differential ages of the passively evolving galaxies. Meanwhile, the $\mathcal {A}$-parameter,…

天体物理学 · 物理学 2014-11-18 Hui Lin , Cheng Hao , Xiao Wang , Qiang Yuan , Ze-Long Yi , Tong-Jie Zhang , Bao-Quan Wang

In `entropic cosmology', instead of a cosmological constant $\Lambda$, an extra driving term is added to the Friedmann equation and the acceleration equation, taking into account the entropy and the temperature on the horizon of the…

宇宙学与河外天体物理 · 物理学 2013-03-14 Nobuyoshi Komatsu , Shigeo Kimura

This paper is a review on the observational Hubble parameter data that have gained increasing attention in recent years for their illuminating power on the dark side of the universe --- the dark matter, dark energy, and the dark age.…

宇宙学与河外天体物理 · 物理学 2015-03-17 Tong-Jie Zhang , Cong Ma , Tian Lan

We investigate whether the current Hubble parameter $H(z)$ measurements could help improve the constraints on dark energy on the basis of the mainstream cosmological probes including the type Ia supernovae (SN) observation, the cosmic…

宇宙学与河外天体物理 · 物理学 2019-05-16 Yan Liu , Rui-Yun Guo , Jing-Fei Zhang , Xin Zhang

In this study, we investigate the late-time accelerated expansion of the universe within the framework of non-minimally coupled $f(Q,L_m)$ gravity, where $Q$ is the non-metricity scalar and $L_m$ is the matter Lagrangian. We derive modified…

广义相对论与量子宇宙学 · 物理学 2025-07-08 Yash B. Ingole , K. V. Somwanshi , S. R. Bhoyar , S. N. Bayaskar

We investigate late-time cosmology in the context of modified $f(Q,L_m)$ gravity, considering a non-linear model$ f(Q,L_m) = \alpha Q + \beta L_m^n + \lambda$ where, $\alpha$, $\beta$, $\lambda$, and $n$ are some free parameters. The…

广义相对论与量子宇宙学 · 物理学 2026-01-16 Rajdeep Mazumdar , Kalyan Malakar , Kalyan Bhuyan

In the paper, we consider two models in which dark energy is coupled with either dust matter or dark matter, and discuss the conditions that allow more time for structure formation to take place at high redshifts. These models are expected…

宇宙学与河外天体物理 · 物理学 2021-03-08 Shulei Cao , Tong-Jie Zhang , Xinya Wang , Tingting Zhang

We use 21 Hubble parameter versus redshift data points, from Gazta\~{n}aga et al. (2009), Stern et al. (2010), and Moresco et al. (2012), to place constraints on model parameters of constant and time-evolving dark energy cosmologies. This…

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

This paper introduces a novel cosmological model aimed at probing the accelerated expansion of the late Universe through a unique parametrization of the deceleration parameter. We aim to constrain key cosmic parameters by integrating recent…

广义相对论与量子宇宙学 · 物理学 2024-08-14 Himanshu Chaudhary , Ujjal Debnath , G. Mustafa , S. K. Maurya , Farruh Atamurotov

In this paper, a well-motivated parametrization of the Hubble parameter ($H$% ) is revisited that renders two models of dark energy showing some intriguing features of the late-time accelerating Universe. A general quintessence field is…

广义相对论与量子宇宙学 · 物理学 2023-09-19 Amine Bouali , Himanshu Chaudhary , Amritansh Mehrotra , S. K. J. Pacif

The current tension between early- and late-Universe measurements of the Hubble constant ($H_0$), along with the still elusive nature of dark matter and dark energy, calls for model-independent probes of the Universe's expansion history.…

Using the absolute ages of passively evolving galaxies observed at different redshifts, one can obtain the differential ages, the derivative of redshift $z$ with respect to the cosmic time $t$ (i.e. ${\rm d} z/{\rm d}t$). Thus, the Hubble…

天体物理学 · 物理学 2008-11-26 Ze-Long Yi , Tong-Jie Zhang

The measurements of the CMB have determined the cosmological parameters with high accuracy, and the observation of the flatness of space have contributed to the status of the concordance $\Lambda$CDM model. However, the cosmological…

宇宙学与河外天体物理 · 物理学 2024-12-06 Horst Foidl , Tanja Rindler-Daller

The evolution of the Hubble parameter $H(z)$ with redshift $z$ is estimated from the Pantheon+ data of Type Ia supernovae, for the $\Lambda$CDM model and the three special cases of the eternal coasting (EC) cosmological model with three…

宇宙学与河外天体物理 · 物理学 2024-12-23 Ardra Edathandel Sasi , Moncy Vilavinal John