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The redshift drift provides a kinematic test of the cosmic expansion history through the slow time variation of the redshift of comoving sources. Motivated by the expected Sandage-Loeb measurements from future facilities, we investigate the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-06 Anna Chiara Alfano , Orlando Luongo

This cosmological model is a study of modified $f(Q,T)$ theory of gravity which was recently proposed by Xu {\it et al.} (Eur. Phys. J. C {\bf 79}, 708 (2019)). In this theory of gravity, the action contains an arbitrary function $f(Q,T)$…

General Physics · Physics 2021-09-03 Anirudh Pradhan , Archana Dixit

In this paper, by considering an absorption probability independent of photon wavelength, we show that current type Ia supernovae (SNe Ia) and gamma ray burst (GRBs) observations plus high-redshift measurements of the cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-07 R. F. L. Holanda , S. H. Pereira , Deepak Jain

Understanding the evolution of dark energy poses a significant challenge in modern cosmology, as it is responsible for the universe's accelerated expansion. In this study, we focus on a specific $f(T)$ cosmological model and analyze its…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-14 A. Zhadyranova , M. Koussour , S. Bekkhozhayev , V. Zhumabekova , J. Rayimbaev

Measurements of the cosmic redshift drift - the change in redshift of a source over time - will enable independent detection of cosmological expansion thanks to the immense precision soon reached by new facilities such as the Square…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-16 Sofie Marie Koksbang , Asta Heinesen , Hayley J. Macpherson

Redshift drift effect, an observational probe that indenpendent of cosmological models, presents unique applications in specific cosmological epoch. By quantifying redshift drift signal , researchers can determine the rate of the Universe's…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-22 Jiangang Kang , Guangyuan Song , Tong Jie Zhang , Ming Zhu

We investigate the redshift evolution of the matter density parameter, $\Omega_m(z)$, using galaxy cluster gas mass fraction measurements combined with cosmic chronometer $H(z)$ data and type Ia supernova luminosity distances. Our approach…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-30 R. F. L. Holanda , J. F. Jesus , Z. C. Santana , R. C. Nunes

We propose a new model for regression and dependence analysis when addressing spatial data with possibly heavy tails and an asymmetric marginal distribution. We first propose a stationary process with $t$ marginals obtained through scale…

Statistics Theory · Mathematics 2019-12-20 M. Bevilacqua , C. Caamaño , R. B. Arellano Valle , V. Morales-Onñate

Accurate estimation of the Hubble constant, and other cosmological parameters, from distances measured by cosmic gravitational wave sirens requires sufficient allowance for the dark energy evolution. We demonstrate how model independent…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-17 Ryan E. Keeley , Arman Shafieloo , Benjamin L'Huillier , Eric V. Linder

The empirical correlation between the H$\beta$ luminosity ($L$) and the ionized gas velocity dispersion ($\sigma$) in HII starburst galaxies (HIIGs) provides a foundation for using them as cosmological standard candles. A key unresolved…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-22 Jiaze Gao , Yun Chen , Lixin Xu

The redshift of all cosmological sources drifts by a systematic velocity of order a few m/s over a century due to the deceleration of the Universe. The specific functional dependence of the predicted velocity shift on the source redshift…

Astrophysics · Physics 2011-02-11 Abraham Loeb

We study the dark energy equation of state as a function of redshift in a non-parametric way, without imposing any {\it a priori} $w(z)$ (ratio of pressure over energy density) functional form. As a check of the method, we test our scheme…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-05 Sergey Postnikov , Maria Giovanna Dainotti , Xavier Hernandez , Salvatore Capozziello

The cosmological redshift drift promises to be the first observable directly measuring the evolution of the cosmic expansion rate and should be detectable with upcoming surveys by the Square Kilometre Array and the Extremely Large…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-13 Alexander Oestreicher , Chris Clarkson , Julian Adamek , Sofie Marie Koksbang

We propose, and constrain with the latest observational data, three model-independent parametrizations of the cosmic deceleration parameter $q(z)$. They are well behaved and stay finite at all redshifts. We construct them by fixing the…

General Relativity and Quantum Cosmology · Physics 2012-10-16 Sergio del Campo , Ivan Duran , Ramon Herrera , Diego Pavon

In this work we extend our earlier phenomenological model for a gravitational phase transition (GPT) and its generalization to early times by letting the modifications in the linearly-perturbed Einstein equations be scale-dependent. These…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-27 Marzieh Farhang , Nima Khosravi

This work uses hierarchical logistic Gaussian processes to infer true redshift distributions of samples of galaxies, through their cross-correlations with spatially overlapping spectroscopic samples. We demonstrate that this method can…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-30 Markus Michael Rau , Simon Wilson , Rachel Mandelbaum

We propose a computational procedure for identifying convection in heat transfer dynamics. The procedure is based on a Gaussian process latent force model, consisting of a white-box component (i.e., known physics) for the conduction and…

Systems and Control · Electrical Eng. & Systems 2024-07-10 Wouter M. Kouw , Caspar Gruijthuijsen , Lennart Blanken , Enzo Evers , Timothy Rogers

The accelerated expansion of the universe has been widely confirmed, posing challenges to the standard $\Lambda$CDM model, particularly the cosmological coincidence problem. This has motivated the exploration of modified gravity theories,…

General Relativity and Quantum Cosmology · Physics 2025-01-03 Gaurav N. Gadbail , Sanjay Mandal , P. K. Sahoo , Kazuharu Bamba

Most cosmological constraints on modified gravity are obtained assuming that the cosmic evolution was standard $\Lambda$CDM in the past and that the present matter density and power spectrum normalization are the same as in a $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Laura Taddei , Luca Amendola

Cosmic opacity may vary spatially due to the inhomogeneous distribution of dust, its grain properties, and the efficiency of photon attenuation. In this work, we present a model independent method to investigate the variation of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-29 Savita Gahlaut , Meetu Luthra