ACP Seminar (Astronomy - Cosmology - Particle Physics)

Speaker: Federico Urban (UBC)
Title: The cosmological constant as a manifestation of the conformal anomaly
Date (JST): Thu, Feb 26, 2009, 13:30 - 14:30
Place: Seminar Room at IPMU Prefab. B
Related File: 7.swf
Abstract: It has been recently proposed that the solution to the cosmological vacuum energy puzzle must be sought after in the infrared sector of the effective theory of gravity, where the impact of the trace anomaly is seen to be the most relevant. This is best enginnered with the help of two auxiliary fields which, via the specification of their macroscopic boundary conditions --in contrast to ultraviolet cutoffs, are capable of describing a diversity of quantum vacuum states. Our investigation aims at finding a realistic cosmological solution which interprets the observed cosmological constant as a well defined deficit in the zero point energy density of the Universe, due to a phase transition of some sort which rearranges the properties of the quantum state, thereby requiring a counter-adjustment of the initial vacuum.