PIRSA:10060017  ( MP4 Medium Res , MP3 , PDF ) Which Format?
A comment on gravitational waves and the scale of supersymmetry breaking
Speaker(s): Alexander Westphal
Abstract: It has been suggested, by Kallosh and Linde, that a generic bound on inflation in string theory keeps the Hubble scale of inflation $H$ smaller than the gravitino mass, $m_{3/2}$. Given that models with low-energy supersymmetry have $m_{3/2}$ smaller than a TeV, this is a severe constraint, and would suggest that one is forced to choose between high-scale inflation and low-scale supersymmetry. The bound arises by considering possible decompactification instabilities of the extra (compactified) dimensions of string theory, during the inflationary epoch. I explain the arguments that give rise to such a bound, and describe recent work with T. He and A. Westphal exhibiting large-field chaotic inflation models in string-inspired supergravities that have $H >> m_{3/2}$ but avoid decompactification. I conclude that even within the framework of string theory, high-scale inflation and low-energy supersymmetry may well be compatible.
Date: 16/06/2010 - 3:45 pm
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