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We use the latest compilation of observational H(z) measurements obtained with cosmic chronometers in the redshift range $0<z<2$ to place constraints on cosmological parameters. We consider the sample alone and in combination with other…

宇宙学与河外天体物理 · 物理学 2019-04-15 Michele Moresco , Raul Jimenez , Licia Verde , Andrea Cimatti , Lucia Pozzetti , Claudia Maraston , Daniel Thomas

In this work, we use a combined approach of Hubble parameter data together with redshift-space-distortion $(f\sigma_8)$ data, which together are used to reconstruct the teleparallel gravity (TG) Lagrangian via Gaussian processes (GP). The…

宇宙学与河外天体物理 · 物理学 2021-06-21 Jackson Levi Said , Jurgen Mifsud , Joseph Sultana , Kristian Zarb Adami

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 perform an observational data analysis on the $f(R,T)$ gravity with the aim of constraining the parameter space of the model. Five different models are considered and the 30 point $z-H(z)$ cosmic chronometer data is used in…

广义相对论与量子宇宙学 · 物理学 2021-05-24 Prabir Rudra , Kinsuk Giri

We discuss the problem of CMB spectrum corruption during Galactic emission removing. A new technique of spatial--frequency data reduction is proposed. The technique gives us a possibility to avoid a spatial harmonics nonorthogonality. The…

天体物理学 · 物理学 2007-05-23 A. A. Brukhanov , D. P. Skulachev , I. A. Strukov , T. V. Konkina

Astrometric precision and knowledge of the point spread function are key ingredients for a wide range of astrophysical studies including time-delay cosmography in which strongly lensed quasar systems are used to determine the Hubble…

天体物理仪器与方法 · 物理学 2021-09-22 Geoff C. -F. Chen , Tommaso Treu , Christopher D. Fassnacht , Sam Ragland , Thomas Schmidt , Sherry H. Suyu

Most cosmological data analysis today relies on the Friedmann-Lemaitre-Robertson-Walker (FLRW) metric, providing the basis of the current standard cosmological model. Within this framework, interesting tensions between our increasingly…

宇宙学与河外天体物理 · 物理学 2021-12-01 Hayley J. Macpherson , Asta Heinesen

In this paper, we use a newly compiled sample of ultra-compact structure in radio quasars and strong gravitational lensing systems with quasars acting as background sources to constrain six spatially flat and non-flat cosmological models…

宇宙学与河外天体物理 · 物理学 2022-12-07 Tonghua Liu , Shuo Cao , Xiaolei Li , Hao Zheng , Yuting Liu , Wuzheng Guo , Chenfa Zheng

We observe that the errors on the Hubble constant $H_0$, a universal parameter in any FLRW cosmology, can be larger in specific cosmological models than Gaussian Processes (GP) data reconstruction. We comment on the prior mean function and…

宇宙学与河外天体物理 · 物理学 2021-04-09 E. Ó Colgáin , M. M. Sheikh-Jabbari

Weak gravitational lensing has become a common tool to constrain the cosmological model. The majority of the methods to derive constraints on cosmological parameters use second-order statistics of the cosmic shear. Despite their success,…

宇宙学与河外天体物理 · 物理学 2015-06-04 Sandrine Pires , Adrienne Leonard , Jean-Luc Starck

We demonstrate that observations lacking reliable redshift information, such as photometric and radio continuum surveys, can produce robust measurements of cosmological parameters when empowered by clustering-based redshift estimation. This…

宇宙学与河外天体物理 · 物理学 2017-05-10 Ely D. Kovetz , Alvise Raccanelli , Mubdi Rahman

Hubble tension is a problem in one-dimensional (1D) posteriors, since local $H_0$ determinations are only sensitive to a single parameter. Projected 1D posteriors for $\Lambda$CDM cosmological parameters become more non-Gaussian with…

宇宙学与河外天体物理 · 物理学 2025-01-06 Eoin Ó Colgáin , Saeed Pourojaghi , M. M. Sheikh-Jabbari , Darragh Sherwin

We propose a strategy to infer the transition redshift $z_{da}$, which characterizes the passage through the universe decelerated to accelerated phases, in the framework $f(R)$ gravities. To this end, we numerically reconstruct $f(z)$, i.e.…

宇宙学与河外天体物理 · 物理学 2014-11-11 Salvatore Capozziello , Orlando Luongo

Constraints on the main cosmological parameters using CMB or large scale structure data are usually based on power-law assumption of the primordial power spectrum (PPS). However, in the absence of a preferred model for the early universe,…

宇宙学与河外天体物理 · 物理学 2013-08-14 Dhiraj Kumar Hazra , Arman Shafieloo , Tarun Souradeep

Large data-sets defined on the sphere arise in many fields. In particular, recent and forthcoming observations of the anisotropies of the cosmic microwave background (CMB) made on the celestial sphere contain approximately three and fifty…

天体物理仪器与方法 · 物理学 2011-08-22 J. D. McEwen , Y. Wiaux , D. M. Eyers

The errors of cosmological data generated from complex processes, such as the observational Hubble parameter data (OHD) and the Type Ia supernova (SN Ia) data, cannot be accurately modeled by simple analytical probability distributions,…

宇宙学与河外天体物理 · 物理学 2021-06-17 Yu-Chen Wang , Yuan-Bo Xie , Tong-Jie Zhang , Hui-Chao Huang , Tingting Zhang , Kun Liu

In the present article, we propose a very simple parametrization of the Hubble function without parametrizing the dark components of the Universe. One of the novelties of the parametrization is that it may include a wide variety of the…

宇宙学与河外天体物理 · 物理学 2025-08-12 Sivasish Paul , Raj Kumar Das , Supriya Pan

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

Strongly gravitational lensing systems (SGL) encodes cosmology information in source/lens distance ratios $\mathcal{D}_{\rm obs}=\mathcal{D}_{\rm ls}/\mathcal{D}_{\rm s}$, which can be used to precisely constrain cosmological parameters. In…

宇宙学与河外天体物理 · 物理学 2019-12-05 Tonghua Liu , Shuo Cao , Jia Zhang , Shuaibo Geng , Yuting Liu , Xuan Ji , Zong-Hong Zhu

We use Hubble parameter versus redshift data from Stern, et al(2010) and Gazta\~{n}aga, et al (2009) to place constraints on model parameters of constant and time-evolving dark energy cosmological models. These constraints are consistent…

宇宙学与河外天体物理 · 物理学 2013-07-12 Yun Chen , Bharat Ratra