jueves, 16 de agosto de 2012

Quantum Mechanics, Gravity, and the Multiverse

(Submitted on 11 May 2012 (v1), last revised 30 Jul 2012 (this version, v2))

The discovery of accelerating expansion of the universe has led us to take the dramatic view that our universe may be one of the many universes in which low energy physical laws take different forms: the multiverse. I explain why/how this view is supported both observationally and theoretically, especially by string theory and eternal inflation. I then describe how quantum mechanics plays a crucial role in understanding the multiverse, even at the largest distance scales. The resulting picture leads to a revolutionary change of our view of spacetime and gravity, and completely unifies the paradigm of the eternally inflating multiverse with the many worlds interpretation of quantum mechanics. The picture also provides a solution to a long-standing problem in eternal inflation, called the measure problem, which I briefly describe.

Comments:	18 pages, 6 figures. An article published in the Astronomical Review, based on talks given by the author at various institutions. v2: a note added
Subjects:	High Energy Physics - Theory (hep-th); Cosmology and Extragalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); Quantum Physics (quant-ph)
Journal reference:	AstRv. 7, 36 (2012)
Report number:	UCB-PTH-12/04
Cite as:	arXiv:1205.2675v2 [hep-th]