TY - JOUR
T1 - Halo models in modified gravity theories with self-accelerated expansion
AU - Narikawa, Tatsuya
AU - Kimura, Rampei
AU - Yano, Tatsunosuke
AU - Yamamoto, Kazuhiro
N1 - Funding Information:
We thank anonymous referee for useful comments which helped improve the original manuscript. This work was supported by Japan Society for Promotion of Science (JSPS) Grants-in-Aid for Scientific Research (Nos. 21540270, 21244033). This work was also supported by JSPS Core-to-Core Program “International Research Network for Dark Energy.” TN and RA acknowledge support by a research assistant program of Hiroshima University. This work was supported in part by a Grant-in-Aid for JSPS Fellows (TN).
PY - 2011/11/25
Y1 - 2011/11/25
N2 - 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.
AB - 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.
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U2 - 10.1142/S0218271811020421
DO - 10.1142/S0218271811020421
M3 - Article
AN - SCOPUS:82655168146
VL - 20
SP - 2383
EP - 2397
JO - International Journal of Modern Physics D
JF - International Journal of Modern Physics D
SN - 0218-2718
IS - 12
ER -