2007/05/31 by G. Lazarides, Achilleas Vamvasakis, A. Vamvasakis
Mathematics · Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Gauge (firearms) #Gauge group #Gauge theory #Grand Unified Theory #Inflation (cosmology) #Mathematical analysis #Mathematical physics #Mathematics #Maxima and minima #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum mechanics #Spectral index #Standard Model (mathematical formulation) #Supergravity #Superpotential #Supersymmetry #Theoretical physics #Yukawa potential #astro-ph #hep-ph
paper · pdf · doi:10.1103/physrevd.76.083507
published as Phys.Rev.D76:083507,2007 · 15 pages including 5 figures, uses Revtex, version to appear in PRD
arxiv created 2007/09/26 · openalex publication_date 2007/10/09 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We consider the extension of the supersymmetric Pati-Salam model which solves the b-quark mass problem of supersymmetric grand unified models with exact Yukawa unification and universal boundary conditions and leads to the so-called new shifted hybrid inflationary scenario. We show that this model can also lead to a new version of smooth hybrid inflation based only on renormalizable interactions provided that a particular parameter of its superpotential is somewhat small. The potential possesses valleys of minima with classical inclination, which can be used as inflationary paths. The model is consistent with the fitting of the three-year Wilkinson microwave anisotropy probe data by the standard power-law cosmological model with cold dark matter and a cosmological constant. In particular, the spectral index turns out to be adequately small so that it is compatible with the data. Moreover, the Pati-Salam gauge group is broken to the standard model gauge group during inflation and, thus, no monopoles are formed at the end of inflation. Supergravity corrections based on a nonminimal K"ahler potential with a convenient choice of a sign keep the spectral index comfortably within the allowed range without generating maxima and minima of the potential on the inflationary path. So, unnatural restrictions on the initial conditions for inflation can be avoided.