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Related papers: Exploring the Growth-Index ($\gamma$) Tension with…

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Can new cosmic physics be uncovered through tensions amongst datasets? Tensions in parameter determinations amongst different types of cosmological observation, especially the `Hubble tension' between probes of the expansion rate, have been…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-24 Marina Cortês , Andrew R. Liddle

We consider a new cosmological model (called $\tilde\Lambda$CDM) in which the vacuum energy interacts with matter and radiation, and test this model using the current cosmological observations. Using the CMB+BAO+SN (CBS) dataset to…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-01 Li-Yang Gao , She-Sheng Xue , Xin Zhang

We place tight constraints on the growth index $\gamma$ by using the recent growth history results of 2dFGRS, SDSS-LRG, VIMOS-VLT deep Survey (VVDS) and {\em WiggleZ} datasets. In particular, we investigate several parametrizations of the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Spyros Basilakos , Athina Pouri

On the basis of a previously established scalar-tensor extension of the $\Lambda$CDM model we develop an effective fluid approach for the matter growth function. This extended $\Lambda$CDM (henceforth $e_{\Phi}\Lambda$CDM) cosmology takes…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-01 W. Zimdahl , H. E. S. Velten , W. C. Algoner

Recent weak lensing surveys have revealed that the direct measurement of the parameter combination $S_8\equiv\sigma_8(\Omega_m/0.3)^{0.5}$ -- where $\sigma_8$ is a measure of the amplitude of matter fluctuations on 8 $h^{-1}$Mpc scales --…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-23 Guillermo Franco Abellán , Riccardo Murgia , Vivian Poulin , Julien Lavalle

Given the persistence of various tensions in the "Cosmic Concordance" -- such as the "Hubble Tension", and possible departures from LambdaCDM time evolution -- seen from combinations of complementary data sets (e.g., Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-19 Brett Bochner , Aiden Jin

Measurements of weak gravitational lensing at low redshifts ($z\lesssim 0.5-1$), quantified by the parameter $S_8$, favor weaker matter clustering than that expected from the standard $\Lambda$CDM cosmological model with parameters…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-12 Vivian Poulin , José Luis Bernal , Ely Kovetz , Marc Kamionkowski

The parameter $S_8$, a key probe of cosmic structure growth, exhibits a persistent $\sim3\sigma$ tension between high-redshift measurements from cosmic microwave background (CMB) anisotropies and low-redshift weak gravitational lensing…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-11 Jin Qin , Xue-Bing Wu , Yuming Fu , Haojie Xu , Yuxuan Pang , Yun-Hao Zhang , Pengjie Zhang

The discrepancy between Planck data and direct measurements of the current expansion rate $H_0$ and the matter fluctuation amplitude $S_8$ has become one of the most intriguing puzzles in cosmology nowadays. The $H_0$ tension has reached…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-28 Safae Dahmani , Amine Bouali , Imad El Bojaddaini , Ahmed Errahmani , Taoufik Ouali

The current discrepancy between the CMB and weak lensing measurements of the amplitude of matter fluctuations, the so-called $S_8$ tension, has attracted a great deal of recent attention, as it may show a crack in the $\Lambda$CDM model of…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-12 Pedro Carrilho , Chiara Moretti , Maria Tsedrik

The cosmological constant $\Lambda$ and cold dark matter (CDM) model ($\Lambda\text{CDM}$) is one of the pillars of modern cosmology and is widely used as the de facto theoretical model by current and forthcoming surveys. As the nature of…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-08 Rubén Arjona , Alessandro Melchiorri , Savvas Nesseris

This study investigates the potential of a cosmological model termed $\Lambda w$DM, in which a cosmological constant play the role of dark energy and dark matter is barotropic and has a constant equation of state parameter ($w_{\rm dm}$),…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-02 Yan-Hong Yao , Jian-Qi Liu

We apply a new model for the spherically averaged correlation function at large pair separations to the measurement of the clustering of luminous red galaxies (LRGs) made from the SDSS by Cabre and Gaztanaga(2009). Our model takes into…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Ariel G. Sanchez , M. Crocce , A. Cabre , C. M. Baugh , E. Gaztanaga

The observational success and simplicity of the $\Lambda$CDM model, and the explicit analytic perturbations thereof, set the standard for any alternative cosmology. It therefore serves as a comparison ground and as a test case for methods…

General Relativity and Quantum Cosmology · Physics 2019-10-02 Artur Alho , Claes Uggla , John Wainwright

The $\Gamma$ growth model is an effective parameterization employed across various scientific disciplines and scales to depict growth. It has been demonstrated that the cosmic star formation rate density (CSFRD) can also be described…

Recent measurements of the Cosmic Microwave Background (CMB) by the Planck Collaboration have produced arguably the most powerful observational evidence in support of the standard model of cosmology, i.e. the spatially flat $\Lambda$CDM…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-10 S. Grandis , D. Rapetti , A. Saro , J. J. Mohr , J. P. Dietrich

Tensions between several cosmic observations were found recently, such as the inconsistent values of $H_{0}$ (or $\sigma_{8}$) were indicated by the different cosmic observations. Introducing the massive neutrinos in $\Lambda$CDM could…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-04 Jianbo Lu , Molin Liu , Yabo Wu , Yan Wang , Weiqiang Yang

We use recently published redshift space distortion measurements of the cosmological growth rate, f sigma_8(z), to examine whether the linear evolution of perturbations in the R_h=ct cosmology is consistent with the observed development of…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-21 Fulvio Melia

The mismatch between the locally measured expansion rate of the universe and the one inferred from the cosmic microwave background measurements by Planck in the context of the standard $\Lambda$CDM, known as the Hubble tension, has become…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-11 Karsten Jedamzik , Levon Pogosian , Gong-Bo Zhao

We measure the small-scale clustering of the Data Release 16 extended Baryon Oscillation Spectroscopic Survey Luminous Red Galaxy sample, corrected for fibre-collisions using Pairwise Inverse Probability weights, which give unbiased…

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