English
Related papers

Related papers: Testing Screening Mechanisms with Mass Profiles of…

200 papers

Modified gravitational forces in models that seek to explain cosmic acceleration without dark energy typically predict deviations in the abundance of massive dark matter halos. We conduct the first, simulation calibrated, cluster abundance…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-06 Fabian Schmidt , Alexey Vikhlinin , Wayne Hu

Galaxy clusters are one of the most powerful probes to study extensions of General Relativity and the Standard Cosmological Model. Upcoming surveys like the Vera Rubin Observatory's Legacy Survey of Space and Time are expected to…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-19 Markus Michael Rau , Florian Kéruzoré , Nesar Ramachandra , Lindsey Bleem

In theories of modified gravity with the chameleon screening mechanism, the strength of the fifth force depends on environment. This induces an environment dependence of structure formation, which differs from $\Lambda$CDM. We show that…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-06 Joaquin Armijo , Yan-Chuan Cai , Nelson Padilla , Baojiu Li , John A. Peacock

We present a machine learning approach for estimating galaxy cluster masses, trained using both Chandra and eROSITA mock X-ray observations of 2,041 clusters from the Magneticum simulations. We train a random forest regressor, an ensemble…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-14 Sheridan B. Green , Michelle Ntampaka , Daisuke Nagai , Lorenzo Lovisari , Klaus Dolag , Dominique Eckert , John A. ZuHone

We establish new constraints on $f(T)$ gravity models by using cosmological data. In particular, we investigate the restrictions given by the gas mass fraction measurements of galaxy clusters and transversal BAO data. Both data sets are…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-28 F. B. M. dos Santos , J. E. Gonzalez , R. Silva

A key uncertainty in interpreting observations of bimodal merging galaxy clusters is the unknown angle between the subcluster separation vector and the plane of the sky. We present a new method for constraining this key parameter. We find…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-14 David Wittman , B Hunter Cornell , Jayke Nguyen

Light unaffiliated mass clumps (LUMCs), i.e. dark matter (DM) components without any stellar counterparts, have been reported in strong lensing mass reconstructions of MACS 0416, both on galaxy and galaxy cluster scales. On galaxy cluster…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-05 Marceau Limousin , Derek Perera , Gregor Rihtarsic , Liliya L. R. Williams , Jori Liesenborgs

We propose a novel methodology for feature screening in clustering massive datasets, in which both the number of features and the number of observations can potentially be very large. Taking advantage of a fusion penalization based convex…

Methodology · Statistics 2017-10-05 Trambak Banerjee , Gourab Mukherjee , Peter Radchenko

Scalar fields are crucial components in high energy physics and extensions of General Relativity. The fact they are not observed in the solar system may be due to a mechanism which screens their presence in high dense regions. We show how…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-04 Claudio Llinares , David F. Mota

Modified theories of gravity provide us with a unique opportunity to generate innovative tests of gravity. In Chameleon f(R) gravity, the gravitational potential differs from the weak-field limit of general relativity (GR) in a mass…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-26 Alejo Stark , Christopher J. Miller , Nicholas Kern , Daniel Gifford , Gong-Bo Zhao , Baojiu Li , Kazuya Koyama , Robert C. Nichol

Modified gravity models require a screening mechanism to be able to evade the stringent constraints from local gravity experiments and, at the same time, give rise to observable astrophysical and cosmological signatures. Such screened…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-04 Max Gronke , David F. Mota , Hans A. Winther

We implement an adaptation of the COLA approach, a hybrid scheme that combines Lagrangian perturbation theory with an N-body approach, to model non-linear collapse in chameleon and symmetron modified gravity models. Gravitational screening…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-30 Georgios Valogiannis , Rachel Bean

Two methods for mass profiles reconstruction in disc-like galaxies are presented in this work, the first is done with the fit of the rotation curve based on the data of circular velocity which are obtained observationally in a stars system,…

Astrophysics of Galaxies · Physics 2021-04-22 Itamar López , Leonardo Castañeda

We present a new galaxy survey simulation package, which combines the power of Markov Chain Monte Carlo (MCMC) sampling with a robust and adaptable model of galaxy evolution. The aim of this code is to aid in the characterization and study…

Instrumentation and Methods for Astrophysics · Physics 2016-11-25 Noah Kurinsky , Anna Sajina

We report weak-lensing masses for 51 of the most X-ray luminous galaxy clusters known. This cluster sample, introduced earlier in this series of papers, spans redshifts 0.15 < z_cl < 0.7, and is well suited to calibrate mass proxies for…

Chameleon fields may modify gravity on cluster scales while recovering general relativity locally. This article reviews signatures of chameleon modifications in the nonlinear cosmological structure, comparing different techniques to model…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-06 Lucas Lombriser

We present a perturbative treatment of nonlinear galaxy clustering in the context of the cubic Galileon modified gravity model, in terms of 2nd order Lagrangian Perturbation theory and an extension of ellipsoidal collapse that includes…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-14 Yanling Song , Chiara Moretti , Pierluigi Monaco , Bin Hu

In this paper we introduce a new public Einstein-Boltzmann solver, \texttt{MGCLASS II}, built as a modification to the publicly available \texttt{CLASS} code, that allows to obtain cosmological observables for Modified Gravity theories. It…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-28 Ziad Sakr , Matteo Martinelli

In this work, we update the unsupervised machine learning (UML) step by proposing an algorithm based on ConvNeXt large model coding to improve the efficiency of unlabeled galaxy morphology classifications. The method can be summarized into…

Astrophysics of Galaxies · Physics 2025-01-03 Guanwen Fang , Yao Dai , Zesen Lin , Chichun Zhou , Jie Song , Yizhou Gu , Xiaotong Guo , Anqi Mao , Xu Kong

The knowledge of the redshift of multiple images in cluster-lenses allows to determine precisely the total projected mass within the Einstein radius. The observation of various multiple images in a same cluster is opening new possibilities…

Astrophysics · Physics 2007-05-23 G. Golse , J. -P. Kneib , G. Soucail