Gravitational condensate stars & dark energy

by Emil Mottola

Friday 20 Nov 2009, 11:30 → 12:30 Europe/Zurich

Univ. de Geneve, Auditoire 234, 24 quai E. Ansermet, CH-1211 Genève 4

Quantum effects in the vicinity of black hole event horizons suggest that backreaction is important in gravitational collapse. In particular, a quantum phase transition in which the local value of the vacuum energy or cosmological `constant' changes can prevent a true event horizon from forming at all. This suggests a completely non-singular final state of gravitational collapse in which the classical black hole event horizon is replaced by a thin shell of ultrarelativistic matter, and the interior is a vacuum condensate with dark energy eq. of the state, p=-rho. A condensate star has a modest entropy does not emit Hawking quanta, and suffers from no black hole information paradox. The cosmological dark energy of the Universe may then just be a finite volume effect associated with boundary conditions on the Hubble horizon.