Saswat Sarangi (ISCAP, Columbia University)


String theorists have become increasingly convinced of the existence of a landscape of string theory vacua. The number of vacua is probably infinite. It is natural to ask if there is any selection principle that picks up a particular set of vacua as more likely for the universe to begin its life in. The wavefuntion of the universe is one possible selection principle. There exist two possible choices for the wavefunction depending on the boundary condition imposed at the origin of the universe - the Hartle Hawking (HH) wavefunction, and the Linde-Vilenkin wavefunction (LV). Both of them aim at describing the creation of a deSitter universe from "nothing". However, a naive use of either wavefunction leads to absurd results. We propose a possible modification of the wavefunction that leads to a "modified wavefunction" for the universe and which is devoid of the problems with the HH and the LV wavefunctions. The application of this modified wavefunction to KKLT and KKLMMT type vacua suggests that the universe prefers to begin its life in an inflationary phase with an inflationary scale that is favored by the WMAP data.



16 09 2005, ISCAP Seminar Room Pupin 908, 2:00 pm