2014/11/17 by Anupam Mazumdar, Mazumdar, Anupam, Pramod Shukla +1
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Relativity and Gravitational Theory
paper · pdf · doi:10.48550/arxiv.1411.4636
openalex publication_date 2014/11/17 · openalex created_date 2016/07/22 · openalex updated_date 2026/07/28
By demanding the validity of an effective field theory description during inflation, in this note we derive some peculiar inequalities among the three interesting stringy and cosmological parameters, namely the tensor-to-scalar ratio (r), the string coupling (gs) and the compactification volume (\cal V). In deriving these inequalities, we explicitly demand that the inflationary scale and the Hubble parameter during inflation are well below the Kaluza-Klein (KK) mass scale, string scale, and the four dimensional Planck mass. For the inflationary models developed within the framework of type IIB orientifold comapctification, we investigate the regions of parameters space spanned by the three parameters (r, gs, \cal V) by satisfying our inequalities, and we find that the same can reduce the size of available parameter space quite significantly. Moreover, we comment on obtaining further constraints on the parameters by comparing gravitino mass (m3/2) with the Hubble scale (H), which also provides a lower bound on tensor-to-scalar ratio (r), for the cases when m3/2