Spherical collapse in modified gravity with the Birkhoff theorem
نویسندگان
چکیده
منابع مشابه
Spherical collapse in modified gravity with the Birkhoff-theorem
We study structure formation in a phenomenological model of modified gravity which interpolates between ΛCDM and phenomenological DGP-gravity. Generalisation of spherical collapse by using the Birkhoff-theorem along with the modified growth equation shows that the overdensity for spherical collapse δc in these models is significantly lowered compared to ΛCDM, leading to enhanced number densitie...
متن کاملSpherical Collapse and Cluster Counts in Modified Gravity Models
Modifications to the gravitational potential affect the nonlinear gravitational evolution of large scale structures in the Universe. To illustrate some generic features of such changes, we study the evolution of spherically symmetric perturbations when the modification is of Yukawa type; this is nontrivial, because we should not and do not assume that Birkhoff ’s theorem applies. We then show h...
متن کاملThe Birkhoff theorem for topologically massive gravity
We derive the general Σ2×S solution of topologically massive gravity in vacuum and in presence of a cosmological constant. The field equations reduce to three-dimensional Einstein equations and the solution has constant Ricci tensor. We briefly discuss the emergence of non-Ricci flat solutions when spin is introduced. Pac(s) numbers: 04.50.+h, 04.20.Cv, 04.20.Jb Keyword(s): Alternative theories...
متن کاملSpherical Collapse in ƒ(R) Gravity
We use one-dimensional numerical simulations to study spherical collapse in the ƒ(R) gravity models. We include the nonlinear self-coupling of the scalar field in the theory and use a relaxation scheme to follow the collapse. We find an unusual enhancement in density near the virial radius which may provide observable tests of gravity. We also use the estimated collapse time to calculate the cr...
متن کاملSpherical Collapse and the Halo Model in Braneworld Gravity
Fabian Schmidt, Wayne Hu, and Marcos Lima Theoretical Astrophysics, California Institute of Technology M/C 350-17, Pasadena, California 91125-0001, USA Department of Astronomy and Astrophysics, Kavli Institute for Cosmological Physics, and Enrico Fermi Institute, The University of Chicago, Chicago, Illinois 60637-1433, USA Department of Physics and Astronomy, University of Pennsylvania, Philade...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 2008
ISSN: 0035-8711
DOI: 10.1111/j.1365-2966.2008.12841.x