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Markov Chain Monte Carlo (MCMC) techniques are now widely used for cosmological parameter estimation. Chains are generated to sample the posterior probability distribution obtained following the Bayesian approach. An important issue is how…

The aim of this analysis was to determine whether or not the given error bars truly represented the dispersion of values in a historical compilation of two cosmological parameters: the amplitude of mass fluctuations ($\sigma_8$) and…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-11 Timothy Faerber , Martin Lopez-Corredoira

In this work we use cosmography to alleviate the degeneracy among cosmological models, proposing a way to parameterize matter and dark energy in terms of cosmokinematics quantities. The recipe of using cosmography allows to expand…

General Relativity and Quantum Cosmology · Physics 2015-12-23 Orlando Luongo , Giovanni Battista Pisani , Antonio Troisi

Galaxy clusters have their unique advantages for cosmology. Here we collect a new sample of 10 lensing galaxy clusters with X-ray observations to constrain cosmological parameters.The redshifts of lensing clusters lie between 0.1 and 0.6,…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Heng Yu , Zong-Hong Zhu

Relations connecting gamma ray burst quantities can be used to constrain cosmographic parameters of the Hubble law at medium-high redshifts. We consider a sample of 27 gamma ray bursts to construct the luminosity distance to redshift…

Astrophysics · Physics 2010-01-09 S. Capozziello , L. Izzo

In this work we present the first results from a new ray-tracing tool to calculate cosmological distances in the context of fully nonlinear general relativity. We use this tool to study the ability of the general cosmographic representation…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-15 Hayley J. Macpherson

We develop estimators of agreement and disagreement between correlated cosmological data sets. These account for data correlations when computing the significance of both tensions and excess confirmation while remaining statistically…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-27 Marco Raveri , Georgios Zacharegkas , Wayne Hu

Quasars have recently been used as an absolute distance indicator, extending the Hubble diagram to high redshift to reveal a deviation from the expansion history predicted for the standard, $\Lambda$CDM cosmology. Here we show that the…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-14 Lorenzo Speri , Nicola Tamanini , Robert R. Caldwell , Jonathan R. Gair , Benjamin Wang

We consider multicriteria problems of evaluating absolute ratings (scores, priorities, weights) of given alternatives for making decisions, which are compared in pairs under several criteria. Given matrices of pairwise comparisons of…

Optimization and Control · Mathematics 2026-01-27 Nikolai Krivulin

Upcoming galaxy surveys will allow us to probe the growth of the cosmic large-scale structure with improved sensitivity compared to current missions, and will also map larger areas of the sky. This means that in addition to the increased…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-31 Matteo Martinelli , Roohi Dalal , Fereshteh Majidi , Yashar Akrami , Stefano Camera , Elena Sellentin

In the near future, observations of the cosmic microwave background (CMB) anisotropies will provide accurate determinations of many fundamental cosmological parameters. In this paper, we analyse degeneracies among cosmological parameters to…

Astrophysics · Physics 2009-10-30 G. Efstathiou , J. R. Bond

We present a numerical framework to study the cosmological background evolution in $f(R)$ gravity by employing a \textit{spectral Chebyshev collocation approach}. Unlike standard integration methods such as Runge--Kutta that often encounter…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-21 Akshay Rana

Control of systematic uncertainties in the use of Type Ia supernovae as standardized distance indicators can be achieved through contrasting subsets of observationally-characterized, like supernovae. Essentially, like supernovae at…

Astrophysics · Physics 2009-01-21 Eric V. Linder

Future microwave sky surveys will have the sensitivity to detect the kinematic Sunyaev-Zeldovich signal from moving galaxy clusters, thus providing a direct measurement of their line-of-sight peculiar velocity. We show that cluster peculiar…

Astrophysics · Physics 2009-11-11 Suman Bhattacharya , Arthur Kosowsky

According to the Cosmological Principle, the matter distribution on very large scales should have a kinematic dipole that is aligned with that of the CMB. We determine the dipole anisotropy in the number counts of two all-sky surveys of…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-11 C. A. P. Bengaly , R. Maartens , M. G. Santos

Tensions between cosmological parameters derived through different channels can be a genuine signature of new physics that $\Lambda$CDM as the standard model is not able to reproduce, in particular in the missing consistency between…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-20 Benedikt Schosser , Pedro Riba Mello , Miguel Quartin , Bjoern Malte Schaefer

The goal of the present paper is to assess the usefulness of quasars as cosmological distance indicators. We calibrate, in a model-independent way, the non-linear relation between X-ray and UV emission to derive quasar luminosity distances.…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-12 Ariadna Montiel , Sofia Samario-Nava , Juan Carlos Hidalgo , Jose Ignacio Cabrera

We present a new algorithm for finding isolated zeros of a system of real-valued functions in a bounded interval in $\mathbb{R}^n$. It uses the Chebyshev proxy method combined with a mixture of subdivision, reduction methods, and…

We estimate how clustering in large-scale redshift surveys can constrain various cosmological parameters. Depth and sky coverage of modern redshift surveys are greater than ever, opening new possibilities for statistical analysis. We have…

Astrophysics · Physics 2009-11-07 Takahiko Matsubara , Alexander S. Szalay

In this paper, we study the power-law $f(T)$ model using Hubble diagrams of type Ia supernovae (SNIa), quasars (QSOs), Gamma Ray Bursts (GRBs) and the measurements from baryonic acoustic oscillations (BAO) in the framework of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-14 M. Sabiee , M. Malekjani , D. Mohammad Zadeh Jassur
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