2008/12/31 by Claudio Caviezel, Paul Koerber, Simon Kors +5 · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Coset #Cosmology and Gravitation Theories #De Sitter universe #Dilaton #Inflation (cosmology) #Manifold (fluid mechanics) #Noncommutative and Quantum Gravity Theories #Supergravity #Tachyon #Type (biology) #hep-th
paper · pdf · doi:10.1088/1126-6708/2009/04/010
published as JHEP 0904:010,2009 · LaTeX, 22 pages plus appendix; v2: references added, minor changes
arxiv created 2009/01/09 · openalex publication_date 2009/04/02 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study cosmological properties of type IIA compactifications on orientifolds of SU(3)-structure manifolds with non-vanishing geometric flux. These compactifications give rise to effective 4D N=1 supergravity theories that do not fall under some recently-proven no-go theorems against de Sitter vacua and slow-roll inflation. Focusing on a well-understood class of models based on coset spaces, however, we can use a refined no-go theorem that rules out de Sitter vacua and slow-roll inflation in all but one case. The refined no-go theorem uses the dilaton and a specific linear combination of the Kaehler moduli, which is different from the overall volume modulus. It puts a lower bound on the first slow-roll parameter: epsilon>=2. The only case not ruled out is the manifold SU(2)x SU(2), for which we indeed find critical points with epsilon numerically zero. However, all the points we could find have a tachyon corresponding to an eta-parameter eta<= -2.4.