Nordita Astrophysics seminars

Galaxy clusters and cosmic voids in modified gravity scenarios

by Sveva Castello (University of Torino, Uppsala University, and Nordita)

The so-called 'cosmic web', comprising cosmic voids and galaxy clusters, has been proven extremely sensitive to deviations from General Relativity. This could be further investigated by future large-scale surveys, such as with the European Space Agency satellite Euclid. We constrain the parameter |fR0| from f(R) gravity by considering the Euclid survey specifications to predict the observed numbers of voids and clusters in bins of redshift, mass and, only for voids, density contrast. From these values, we compute the Fisher matrix for three values of |fR0| (10-4, 10-6 and 10-8) by assuming a flat Universe with a component that mimics the cosmological constant. The probability density functions are obtained for |fR0| and seven other parameters from the fiducial model considered (ns, h, Ωb, Ωm, σ8, w0 and wa).