Halo models in modified gravity theories with self-accelerated expansion

Tatsuya Narikawa, Rampei Kimura, Tatsunosuke Yano, Kazuhiro Yamamoto

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

We investigate the structure of halos in the sDGP (self-accelerating branch of the Dvali-Gavadadze-Porrati braneworld gravity) model and the Galileon modified gravity model on the basis of the static and spherically symmetric solutions of the collisionless Boltzmann equation, which reduce to the singular isothermal sphere model and the King model in the limit of Newtonian gravity. The common feature of these halos is that the density of a halo in the outer region is larger (smaller) in the sDGP (Galileon) model, respectively, in comparison with Newtonian gravity. This comes from the suppression (enhancement) of the effective gravity at large distance in the sDGP (Galileon) model, respectively. However, the difference between these modified gravity models and Newtonian gravity only appears outside the halo due to the Vainshtein mechanism, which makes it difficult to distinguish between them. We also discuss the case in which the halo density profile is fixed independently of the gravity model for comparison between our results and previous work.

Original languageEnglish
Pages (from-to)2383-2397
Number of pages15
JournalInternational Journal of Modern Physics D
Volume20
Issue number12
DOIs
Publication statusPublished - 2011 Nov 25

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Keywords

  • Cosmology
  • galaxies
  • halos

ASJC Scopus subject areas

  • Mathematical Physics
  • Astronomy and Astrophysics
  • Space and Planetary Science

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