Spherical Collapse in the Symmetron Model

4th Young Researcher Meeting, Trieste 2013

Taddei, Laura^1

Physics Department, University of Parma, Viale G.P. Usberti 7/A, 43100 Parma, Italy^1

关键词: Critical value;    Density perturbation;    High-density environment;    Linear density;    Nonlinear evolutions;    Reflection symmetry;    Scalar field models;    Spherical collapse;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/470/1/012006/pdf
DOI  :  10.1088/1742-6596/470/1/012006

来源: IOP

【 摘 要 】

The Symmetron model is a scalar field model for dark energy in which the scalar field is coupled to matter and is invariant under a reflection symmetry φ → -φ. The coupling of the symmetron to matter is such that the symmetry is exact in high density environments and spontaneously broken when the density drops below a critical value. We study the nonlinear evolution of density perturbations using the spherical collapse model. We calculate the extrapolated linear density contrast δcwhich is a fundamental quantity to obtain the halo-mass function for this model.