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We construct data-driven solutions to the Hubble tension which are perturbative modifications to the fiducial $\Lambda$CDM cosmology, using the Fisher bias formalism. Taking as proof of principle the case of a time-varying electron mass and…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Nanoom Lee , Yacine Ali-Haïmoud , Nils Schöneberg , Vivian Poulin

We propose a non-parametric method of smoothing supernova data over redshift using a Gaussian kernel in order to reconstruct important cosmological quantities including H(z) and w(z) in a model independent manner. This method is shown to be…

Astrophysics · Physics 2009-11-24 Arman Shafieloo , Ujjaini Alam , Varun Sahni , Alexei A. Starobinsky

The $\Lambda$CDM model is the current standard model in cosmology thanks to its ability to reproduce the observations. Its first observational evidence appeared from the type Ia supernovae (SNIa) Hubble diagram. However, there has been some…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-01 Isaac Tutusaus , Brahim Lamine , Alain Blanchard

A higher value of Hubble constant has been obtained from measurements with nearby Type Ia supernovae, than that obtained at much higher redshift. With the peculiar motions of their hosts, we find that the matter content at such low redshift…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-25 Shuang-Nan Zhang , Yin-Zhe Ma

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,…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-14 Dhiraj Kumar Hazra , Arman Shafieloo , Tarun Souradeep

In this work, we discuss model-independent reconstruction of the expansion history of the late Universe. We use Gaussian Process Regression (GPR) to reconstruct the evolution of various cosmological parameters such as Hubble parameter…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-05 Joseph P Johnson , H. K. Jassal

Using the relation between distance modulus $(m - M)$ and redshift $z$, deduced from Friedman- Robertson-Walker (FRW) metric and assuming different values of deceleration parameter $q_0$. We constrained the Hubble parameter $h$. The…

General Physics · Physics 2016-06-03 C. C. Onuchukwu , A. C. Ezeribe

We present up-to-date constraints on a generic Higgs parameter space. An accurate assessment of these exclusions must take into account statistical, and potentially signal, fluctuations in the data currently taken at the LHC. For this, we…

High Energy Physics - Phenomenology · Physics 2015-06-04 Aleksandr Azatov , Roberto Contino , Jamison Galloway

The bias in the determination of the Hubble parameter and the Hubble constant in the modern Universe is discussed. It could appear due to statistical processing of data on galaxies redshifts and estimated distances based on some statistical…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-22 S. L. Parnovsky

In the present work we describe a model-independent method of developing a plot of scale factor versus lookback time from the usual Hubble diagram of modulus data against redshift. This is the first plot of this type. We follow the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Harry I. Ringermacher , Lawrence R. Mead

We present a generalized phenomenological parameterization of the deceleration parameter $q(z)$ that incorporates an effective radiative component (ERC) in addition to a localized late-time contribution. The proposed framework extends…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-28 Tomás Verdugo , Alberto Hernández-Almada , Miguel A. García-Aspeitia , Juan Magaña , Verónica Motta

Decaying Dark Energy models modify the background evolution of the most common observables, such as the Hubble function, the luminosity distance and the Cosmic Microwave Background temperature-redshift scaling relation. We use the most…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Ivan de Martino

In this paper, we present a model-independent approach to calibrate the largest quasar sample. Calibrating quasar samples is essentially constraining the parameters of the linear relation between the $\log$ of the ultraviolet (UV) and X-ray…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-11 Xiaolei Li , Ryan E. Keeley , Arman Shafieloo , Xiaogang Zheng , Shuo Cao , Marek Biesiada , Zong-Hong Zhu

An observational program focused on the high redshift ($2<z<6$) Universe has the opportunity to dramatically improve over upcoming LSS and CMB surveys on measurements of both the standard cosmological model and its extensions. Using a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-04 Noah Sailer , Emanuele Castorina , Simone Ferraro , Martin White

The release of the fourth Gravitational Wave Transient Catalog (GWTC-4.0) by the LIGO-Virgo-KAGRA collaboration includes more than 200 compact binary coalescence (CBC) candidates that can be used to probe the cosmic expansion. The…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-18 Grégoire Pierra , Alberto Colombo , Simone Mastrogiovanni

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.…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-27 Hai Huang , Long Huang

Considering a well-motivated $f(R)$ modified-gravity model, in which an exponential function of the curvature is included, in this paper we implement a statistical data analysis to set constraints on the parameters of the model, taking into…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-01 Mario A. Acero , A. Oliveros

This paper aims to put constraints on the transition redshift $z_t$, which determines the onset of cosmic acceleration, in cosmological-model independent frameworks. In order to perform our analyses, we consider a flat universe and {assume}…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-31 J. F. Jesus , R. F. L. Holanda , S. H. Pereira

We propose a model-independent way to determine the cosmic curvature using the Hubble parameter $H(z)$ measured with cosmic chronometers and the comoving distance $D(z)$ inferred from HII galaxies. We employ Gaussian processes to smooth the…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-18 Jing Zheng , Fulvio Melia , Tong-Jie Zhang

We present a novel approach to photometric redshifts, one that merges the advantages of both the template fitting and empirical fitting algorithms, without any of their disadvantages. This technique derives a set of templates, describing…

Astrophysics · Physics 2009-10-31 I. Csabai , A. J. Connolly , A. S. Szalay , T. Budavari
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