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It has recently been argued that the Hubble tension may call for a combination of both pre- and post-recombination new physics. Motivated by these considerations, we provide one of the first concrete case studies aimed at constructing such…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-02 Yo Toda , William Giarè , Emre Özülker , Eleonora Di Valentino , Sunny Vagnozzi

We derive an observational constraint on a spherical inhomogeneity of the void centered at our position from the angular power spectrum of the cosmic microwave background(CMB) and local measurements of the Hubble parameter. The late time…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-04 Masato Tokutake , Kiyotomo Ichiki , Chul-Moon Yoo

Extensions to the $\Lambda\textrm{CDM}$ model prior to recombination can modify the growth of perturbations around radiation-matter equality, leaving a distinct signature in the matter power spectrum. Upcoming large-scale structure surveys…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-09 Raphaël Kou , Antony Lewis

Observations of the cosmic microwave background (CMB) together with weak lensing measurements of the clustering of large scale cosmological structures and local measurements of the Hubble constant pose a challenge to the standard…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-08 Marco Raveri , Wayne Hu , Timothy Hoffman , Lian-Tao Wang

An accurate determination of the Hubble constant remains a puzzle in observational cosmology. The possibility of a new physics has emerged with a significant tension between the current expansion rate of our Universe measured from the…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 R. F. L. Holanda , G. Pordeus-da-Silva , S. H. Pereira

The standard $\Lambda$CDM model of cosmology is largely successful in describing many observations, including precise measurements of the Cosmic Microwave Background (CMB) radiation. However, some intriguing anomalies remain currently…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-13 William Giarè

The cosmic microwave background (CMB) offers a unique window into the early universe, providing insights into cosmological parameters like the Hubble constant. Recent precise measurements of the CMB by experiments like Planck seem to point…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-26 Pablo Lemos , Paul Shah

A simple and minimal extension of the standard cosmological $\Lambda$CDM model in which dark matter experiences an additional long-range scalar interaction is demonstrated to alleviate the long lasting Hubble-tension while letting…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-08 Cyril Pitrou , Jean-Philippe Uzan

The current Hubble constant tension is usually presented by comparing constraints on $H_0$ only. However, the post-recombination background cosmic evolution is determined by two parameters in the standard $\Lambda$CDM model, the Hubble…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-09 Weikang Lin , Katherine J. Mack , Liqiang Hou

(abridged)Cosmological observational programs often compare their data not only with $\Lambda$CDM, but also with extensions applying dynamical models of dark energy (DDE), with a time-dependent equation of state (EoS) parameter $w$. We…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-13 Horst Foidl , Tanja Rindler-Daller

We investigate whether the two cosmological discrepancies on the Hubble constant ($H_0$) and the matter fluctuation parameter ($\sigma_8$) are suggesting and compatible with the existence of an additional one on the matter density. Knowing…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-23 Ziad Sakr

We investigate constraints on some key cosmological parameters by confronting metastable dark energy models with different combinations of the most recent cosmological observations. Along with the standard $\Lambda$CDM model, two…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-14 Xiaolei Li , Arman Shafieloo , Varun Sahni , Alexei A. Starobinsky

Direct measurements of Hubble parameters $H(z)$ are very useful for cosmological model parameters inference. Based on them, Sahni, Shafieloo and Starobinski introduced a two-point diagnostic $Omh^2(z_i, z_j)$ as an interesting tool for…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-24 Xiaogang Zheng , Marek Biesiada , Xuheng Ding , Shuo Cao , Sixuan Zhang , Zong-Hong Zhu

We present a new Hubble parameterization method and employ observational data from Hubble, Pantheon, and Baryon Acoustic Oscillations to constrain model parameters. The proposed method is thoroughly validated against these datasets,…

General Relativity and Quantum Cosmology · Physics 2024-09-18 Tong-Yu He , Jia-Jun Yin , Zhen-Yu Wang , Zhan-Wen Han , Rong-Jia Yang

The possibility of determining cosmological parameters on the basis of a wide set of observational data including the Abell-ACO cluster power spectrum and mass function, peculiar velocities of galaxies, the distribution of Ly-$\alpha$…

Astrophysics · Physics 2007-05-23 B. Novosyadlyj , R. Durrer , S. Gottloeber , V. N. Lukash , S. Apunevych

Recently, cosmology has seen a surge in alternative models that purport to solve the discrepancy between the values of the Hubble constant $H_0$ as measured by cosmological microwave background anisotropies and local supernovae,…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-01 Jonas El Gammal , Sven Günther , Emil Brinch Holm , Andreas Nygaard

Persistent tension between low-redshift observations and the Cosmic Microwave Background radiation (CMB), in terms of two fundamental distance scales set by the sound horizon $r_d$ and the Hubble constant $H_0$, suggests new physics beyond…

The Hubble tension between the $\Lambda$CDM-model-dependent prediction of the current expansion rate $H_0$ using Planck data and direct, model-independent measurements in the local universe from the SH0ES collaboration disagree at…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-14 Kanhaiya L. Pandey , Tanvi Karwal , Subinoy Das

In this work we investigate, through a Bayesian study, the ability of a local low matter density $\Omega_{\rm M}$, in discrepancy with the value usually inferred from the CMB angular power spectrum, to accommodate observations from local…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-16 Ziad Sakr

We present the idea that replacing the cosmological constant $\Lambda$ in the $\Lambda$CDM model by a distribution of walls, with very low tension compared to what one would expect from new physics, could help explaining the tension in the…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-13 Colin D. Froggatt , Holger Bech Nielsen