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Related papers: Halo models in modified gravity theories with self…

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We study the nonlinear growth of structure in nonlocal gravity models with the aid of N-body simulation and the spherical collapse and halo models. We focus on a model in which the inverse-squared of the d'Alembertian operator acts on the…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-25 Alexandre Barreira , Baojiu Li , Wojciech A. Hellwing , Carlton M. Baugh , Silvia Pascoli

We study and model the properties of galaxy clusters in the normal-branch Dvali-Gabadadze-Porrati (nDGP) model of gravity, which is representative of a wide class of theories which exhibit the Vainshtein screening mechanism. Using the first…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-03 Myles A. Mitchell , César Hernández-Aguayo , Christian Arnold , Baojiu Li

We study one of the simplest covariant modified-gravity models based on the Dvali-Gabadadze-Porrati (DGP) brane cosmology, a self-accelerating universe. In this model gravitational leakage into extra dimensions is responsible of late-time…

Astrophysics · Physics 2009-04-08 M. Sadegh Movahed , Marzieh Farhang , Sohrab Rahvar

We investigate self-gravitating equilibria of halos constituted by dark matter (DM) non-minimally coupled to gravity. In particular, we consider a theoretically motivated non-minimal coupling which may arise when the averaging/coherence…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-07 Giovanni Gandolfi , Andrea Lapi , Stefano Liberati

We compare N-body simulations of isolated galaxies performed in both frameworks of modified Newtonian dynamics (MOND) and Newtonian gravity with dark matter (DM). We have developed a multigrid code able to efficiently solve the modified…

Astrophysics · Physics 2009-11-13 O. Tiret , F. Combes

The braneworld model of Dvali, Gabadadze and Porrati (DGP) provides an intriguing modification of gravity at large distances and late times. By embedding a three-brane in an uncompactified extra dimension with separate Einstein-Hilbert…

Astrophysics · Physics 2007-05-23 Ignacy Sawicki , Sean M. Carroll

A scalar-tensor theory of gravity can be made not only to account for the current cosmic acceleration, but also to satisfy solar-system and laboratory constraints, by introducing a non-linear derivative interaction for the scalar field.…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Tsutomu Kobayashi , Hiroyuki Tashiro , Daichi Suzuki

We investigate the performance of semi-analytical modelling of large-scale structure in Galileon gravity cosmologies using results from N-body simulations. We focus on the Cubic and Quartic Galileon models that provide a reasonable fit to…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-05 Alexandre Barreira , Baojiu Li , Wojciech A. Hellwing , Lucas Lombriser , Carlton M. Baugh , Silvia Pascoli

The Galileon model is a modified gravity theory that may provide an explanation for the accelerated expansion of the Universe. This model does not suffer from instabilities or ghost problems (normally associated with higher-order derivative…

General Relativity and Quantum Cosmology · Physics 2013-07-02 J. Neveu , V. Ruhlmann-Kleider , A. Conley , N. Palanque-Delabrouille , P. Astier , J. Guy , E. Babichev

We study spherical collapse in the Quartic and Quintic Covariant Galileon gravity models within the framework of the excursion set formalism. We derive the nonlinear spherically symmetric equations in the quasi-static and weak-field limits,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-24 Alexandre Barreira , Baojiu Li , Carlton Baugh , Silvia Pascoli

We study the properties of dark matter haloes in a wide range of modified gravity models, namely, $f(R)$, DGP, and interacting dark energy models. We study the effects of modified gravity and dark energy on the internal properties of…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-15 Benjamin L'Huillier , Hans A. Winther , David F. Mota , Changbom Park , Juhan Kim

We investigate the effect of modified gravity on cluster abundance and the Sunyaev-Zel'dovich angular power spectrum. Our modified gravity is based on a phenomenological extension of the Dvali-Gabadadze-Porrati model which includes two free…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Tsutomu Kobayashi , Hiroyuki Tashiro

The generalised Proca (GP) theory is a modified gravity model in which the acceleration of the cosmic expansion rate can be explained by self interactions of a cosmological vector field. In this paper we study a particular sub-class of the…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-23 Christoph Becker , Alexander Eggemeier , Christopher T. Davies , Baojiu Li

We analyse modelling techniques for the large-scale structure formed in scalar-tensor theories of constant Brans-Dicke parameter which match the concordance model background expansion history and produce a chameleon suppression of the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-14 Lucas Lombriser , Kazuya Koyama , Baojiu Li

We build a spherical halo model for galaxies using a general scalar-tensor theory of gravity in its Newtonian limit. The scalar field is described by a time-independent Klein-Gordon equation with a source that is coupled to the standard…

Astrophysics of Galaxies · Physics 2009-03-24 Jorge L. Cervantes-Cota , Mario A. Rodriguez-Meza , Dario Nunez

We model the chameleon effect on cosmological statistics for the modified gravity f(R) model of cosmic acceleration. The chameleon effect, required to make the model compatible with local tests of gravity, reduces force enhancement as a…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-07 Yin Li , Wayne Hu

Modified gravity theories capable of genuine self-acceleration typically invoke a galileon scalar which mediates a long range force, but is screened by the Vainshtein mechanism on small scales. In such theories, non-relativistic stars carry…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Lam Hui , Alberto Nicolis

We summarize the present state of research on the darkon fuid as a model for the dark sector of the Universe. Nonrelativistic massless particles are introduced as a realization of the Galilei group in an enlarged phase space. The additional…

General Relativity and Quantum Cosmology · Physics 2016-11-04 P. C. Stichel , W. J. Zakrzewski

We conduct a Markov Chain Monte Carlo study of the Dvali-Gabadadze-Porrati (DGP) self-accelerating braneworld scenario given the cosmic microwave background (CMB) anisotropy, supernovae and Hubble constant data by implementing an effective…

Astrophysics · Physics 2010-04-21 Wenjuan Fang , Sheng Wang , Wayne Hu , Zoltan Haiman , Lam Hui , Morgan May

We investigate the density profiles and evolution of weakly self-interacting cold dark matter haloes using a numerical code based on the collisional Boltzmann equation. This approach is alternative to N-body techniques in following the…

Astrophysics · Physics 2012-07-07 C. Firmani , E. D'Onghia , G. Chincarini