Cosmological simulations of normal-branch braneworld gravity
- Theoretical Astrophysics, California Institute of Technology M/C 350-17, Pasadena, California 91125-0001 (United States)
We introduce a cosmological model based on the normal branch of Dvali-Gabadadze-Porrati (DGP) braneworld gravity with a smooth dark energy component on the brane. The expansion history in this model is identical to {lambda}CDM, thus evading all geometric constraints on the DGP crossover scale r{sub c}. This well-defined model can serve as a first approximation to more general braneworld models whose cosmological solutions have not been obtained yet. We study the formation of large-scale structure in this model in the linear and nonlinear regime using N-body simulations for different values of r{sub c}. The simulations use the code presented in 25 and solve the full nonlinear equation for the brane-bending mode in conjunction with the usual gravitational dynamics. The brane-bending mode is attractive rather than repulsive in the DGP normal branch, hence the sign of the modified gravity effects is reversed compared to those presented in 25. We compare the simulation results with those of ordinary {lambda}CDM simulations run using the same code and initial conditions. We find that the matter power spectrum in this model shows a characteristic enhancement peaking at k{approx}0.7h/Mpc. We also find that the abundance of massive halos is significantly enhanced. Other results presented here include the density profiles of dark matter halos, and signatures of the brane-bending mode self-interactions (Vainshtein mechanism) in the simulations. Independently of the expansion history, these results can be used to place constraints on the DGP model and future generalizations through their effects on the growth of cosmological structure.
- OSTI ID:
- 21313538
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 80, Issue 12; Other Information: DOI: 10.1103/PhysRevD.80.123003; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
Similar Records
Spherical collapse and the halo model in braneworld gravity
Self-Consistent Cosmological Simulations of DGP Braneworld Gravity