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Related papers: CLASH-VLT: The Fifth Force in Chameleon Gravity fr…

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The chameleon gravity model postulates the existence of a scalar field that couples with matter to mediate a fifth force. If it exists, this fifth force would influence the hot X-ray emitting gas filling the potential wells of galaxy…

We perform a maximum likelihood kinematic analysis of the two dynamically relaxed galaxy clusters MACS J1206.2-0847 at $z=0.44$ and RXC J2248.7-4431 at $z=0.35$ to determine the total mass profile in modified gravity models, using a…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-01 L. Pizzuti , B. Sartoris , L. Amendola , S. Borgani , A. Biviano , K. Umetsu , A. Mercurio , P. Rosati , I. Balestra , G. B. Caminha , M. Girardi , C. Grillo , M. Nonino

We study the radial total mass profiles of nine massive galaxy clusters ($M_\mathrm{200c}>5\times10^{14}$ M$_\odot$) in the redshift range $0.2 < z < 0.9$. These clusters were observed as part of the CLASH, HFF, BUFFALO, and CLASH-VLT…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-25 Enrico Maraboli , Claudio Grillo , Pietro Bergamini , Carlo Giocoli

The chameleon screening mechanism has been constrained many a time using dynamic and kinematic galaxy cluster observables. Current constraints are, however, insensitive to different mass components within galaxy clusters and have been…

We use high-precision kinematic and lensing measurements of the total mass profile of the dynamically relaxed galaxy cluster MACS J1206.2-0847 at $z=0.44$ to estimate the value of the ratio $\eta=\Psi/\Phi$ between the two scalar potentials…

We investigate the anisotropic stress parameter, $\eta=\Psi/\Phi$, defined as the ratio of the gravitational potentials in the linearly perturbed Friedmann-Lema\^itre Robertson-Walker metric, as a probe of deviations from general relativity…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-23 L. Pizzuti , A. Biviano , K. Umetsu , E. Agostoni , A. Autorino , A. M. Pombo , A. Mercurio , M. D'Addona

We use two new hydrodynamical simulations of $\Lambda$CDM and $f(R)$ gravity to test the methodology used by Wilcox et al. 2015 (W15) in constraining the effects of a fifth force on the profiles of clusters of galaxies. We construct…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-07 Harry Wilcox , Robert C. Nichol , Gong-bo Zhao , David Bacon , Kazuya Koyama , A. Kathy Romer

We present a comprehensive analysis of strong-lensing, weak-lensing shear and magnification data for a sample of 16 X-ray-regular and 4 high-magnification galaxy clusters selected from the CLASH survey. Our analysis combines constraints…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 Keiichi Umetsu , Adi Zitrin , Daniel Gruen , Julian Merten , Megan Donahue , Marc Postman

We present a joint analysis of Chandra X-ray observations, Bolocam thermal Sunyaev-Zel'dovich (SZ) effect observations, Hubble Space Telescope (HST) strong lensing data, and HST and Subaru Suprime-Cam weak lensing data. The multiwavelength…

In the context of Chameleon gravity, we present a semi-analytical solution of the chameleon field profile in accurately modelled galaxy cluster's mass components, namely: the stellar mass of the Brightest Cluster Galaxy (BCG), the baryonic…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-04 Lorenzo Pizzuti , Valentina Amatori , Alexandre M. Pombo , Sandeep Haridasu

We propose a novel method to test the gravitational interactions in the outskirts of galaxy clusters. When gravity is modified, this is typically accompanied by the introduction of an additional scalar degree of freedom, which mediates an…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-20 Ayumu Terukina , Lucas Lombriser , Kazuhiro Yamamoto , David Bacon , Kazuya Koyama , Robert C. Nichol

We constrain the Chameleon \textit{screening} mechanism in galaxy clusters, essentially obtaining limits on the coupling strength $\beta$ and the asymptotic value of the field $\phi_{\infty}$. For this purpose, we utilized a collection of…

Cosmology and Nongalactic Astrophysics · Physics 2023-08-16 Yacer Boumechta , Balakrishna S. Haridasu , Lorenzo Pizzuti , Minahil Adil Butt , Carlo Baccigalupi , Andrea Lapi

We determine the concentration-mass relation of 19 X-ray selected galaxy clusters from the CLASH survey in theories of gravity that directly modify the lensing potential. We model the clusters as NFW haloes and fit their lensing signal, in…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-03 Alexandre Barreira , Baojiu Li , Elise Jennings , Julian Merten , Lindsay King , Carlton Baugh , Silvia Pascoli

We carry out a detailed strong lensing analysis of a sub-sample of eight galaxy clusters of the CLASH survey, in the redshift range of $ z_{\rm cluster} = [0.23-0.59]$, using extensive spectroscopic information, primarily MUSE archival data…

We present a new determination of the concentration-mass relation for galaxy clusters based on our comprehensive lensing analysis of 19 X-ray selected galaxy clusters from the Cluster Lensing and Supernova Survey with Hubble (CLASH). Our…

We present a detailed mass reconstruction and a novel study on the substructure properties in the core of the CLASH and Frontier Fields galaxy cluster MACS J0416.1-2403. We show and employ our extensive spectroscopic data set taken with the…

In this work we will test an alternative model of gravity belonging to the large family of galileon models. It is characterized by an intrinsic breaking of the Vainshtein mechanism inside large astrophysical objects, thus having possibly…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-05 Vincenzo Salzano , David F. Mota , Salvatore Capozziello , Megan Donahue

We present a novel fitting formula for the halo concentration enhancement in chameleon $f(R)$ gravity relative to General Relativity (GR). The formula is derived by employing a large set of $N$-body simulations of the Hu-Sawicki $f(R)$…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-04 Myles A. Mitchell , Christian Arnold , Jian-hua He , Baojiu Li

Extensions of the standard models of particle physics and cosmology often lead to long-range fifth forces with properties dependent on gravitational environment. Fifth forces on astrophysical scales are best studied in the cosmic web where…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-26 Harry Desmond , Pedro G Ferreira , Guilhem Lavaux , Jens Jasche
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