As one of the most powerful probes of cosmological structure formation, the abundance of massive galaxy clusters is a sensitive probe of modifications to gravity on cosmological scales. In this paper, we present results from N-body simulations of a general class of fðRÞ models, which self-consistently solve the nonlinear field equation for the enhanced forces. Within this class we vary the ampl...

Gravity is nearly a universal constant in the cusp of an NFW galaxy halo. Inside this external field an isothermal gas sphere will collapse and trigger a starburst if above a critical central pressure. Thus formed spheroidal stellar systems have Sersic-profile and satisfy the Faber-Jackson relation. The process is consistent with observed starbursts. We also recover the MBH −σ∗ relation, if the...

Adrenalectomized dogs maintained on desoxycorticosterone acetate developed a fatal circulatory collapse when given normal dog plasma. They showed general restlessness, a rapid fall in blood pressure and cardiac index, a decline in central venous pressure and general prostration. Most dogs developed a bloody diarrhea and a minority showed edematous swelling of the face with itching. Animals with...

Clusters of galaxies form by gravitational collapse and accretion of subgroups under the influence of gravity. Analyses of the gas thermal structure within clusters obtained from X-ray observations reveals us the underlying dark matter structure and dynamics, provided that the baryonic physics is well understood. We use hydrodynamical N-body simulations of galaxy clusters evolving in cosmologic...

We investigate how braneworld gravity affects gravitational collapse and black hole formation by studying Oppenheimer-Snyder-like collapse on a Randall-Sundrum type brane. Without making any assumptions about the bulk, we show that the exterior spacetime on the brane is non-static. In the special case where there is no matter but only collapsing Weyl " dark radiation " , a static black hole may...