Energy-Momentum squared gravity (EMSG)

محمود روشن  (گروه فیزیک دانشکده علوم دانشگاه فردوسی مشهد)

Abstract:  In this talk I review a covariant generalization of Einstein’s general relativity which allows the existence of a term proportional to T_{\alpha\beta} T^{\alpha\beta} in the action functional of the theory ( T_{\alpha\beta} is the energy-momentum tensor). This simple generalization leads to interesting consequences in the early universe. Applying this theory to a homogeneous and isotropic spacetime, we find that there is a maximum energy density ρ_{max}, and correspondingly a minimum length a_{min}, in the thermal history of the universe. This means that there is a bounce at early times, and this theory avoids the existence of an early-time singularity. Also I review the possible consequences of this theory in the dynamics of compact objects like Neutron stars. More specifically I discuss the mass-radius relation for Neutron stars in this model.

The talk is based on the following paper:Roshan and Shojai PRD 2016: 10.1103/PhysRevD.94. 044002

یکشنبه 20 فروردین ماه 1396، ساعت 15:00

دانشکده فیزیک، طبقه اول کلاس فیزیک 3