Vacuum Energy Decay from a q-Bubble

Abstract

We consider a finite-size spherical bubble with a nonequilibrium value of the q-field, where the bubble is immersed in an infinite vacuum with the constant equilibrium value q0 for the q-field (this q0 has already cancelled an initial cosmological constant). Numerical results are presented for the time evolution of such a q-bubble with gravity turned off and with gravity turned on. For small enough bubbles and a q-field energy scale sufficiently below the gravitational energy scale EPlanck, the vacuum energy of the q-bubble is found to disperse completely. For large enough bubbles and a finite value of EPlanck, the vacuum energy of the q-bubble disperses only partially and there occurs gravitational collapse near the bubble center.