Semiclassical relativistic stars

Understand

We present strong evidence that semiclassical gravity can give place to self-consistent ultracompact stars beyond the Buchdahl limit.

• We integrate the semiclassical equations of (spherically symmetric) stellar equilibrium for a constant-density classical fluid.
• The semiclassical contribution is modelled by a quantum massless scalar field in the only static vacuum state compatible with asymptotic flatness (Boulware vacuum).
• The Renormalized Stress-Energy Tensor (RSET) is firstly approximated by the analytic Polyakov approximation.