Stable solutions of inflation driven by vector fields

Dec 30, 2016
20 pages
Published in:
  • JCAP 03 (2017) 058
  • Published: Mar 29, 2017
e-Print:

Citations per year

2015201820212024202502468
Abstract: (arXiv)
Many models of inflation driven by vector fields alone have been known to be plagued by pathological behaviors, namely ghost and/or gradient instabilities. In this work, we seek a new class of vector-driven inflationary models that evade all of the mentioned instabilities. We build our analysis on the Generalized Proca Theory with an extension to three vector fields to realize isotropic expansion. We obtain the conditions required for quasi de-Sitter solutions to be an attractor analogous to the standard slow-roll one and those for their stability at the level of linearized perturbations. Identifying the remedy to the existing unstable models, we provide a simple example and explicitly show its stability. This significantly broadens our knowledge on vector inflationary scenarios, reviving potential phenomenological interests for this class of models.
Note:
  • 16 pages plus references; v2 matches JCAP published version, 17 pages plus references, Section IV.E added on attractor condition against background anisotropy
  • inflation: model
  • perturbation: linear
  • stability
  • slow-roll approximation
  • attractor
  • de Sitter
  • ghost
  • Proca
  • field theory: vector
  • O(3)