Eliminating the η-problem in SUGRA hybrid inflation with vector backreaction
- Consortium for Fundamental Physics, Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom)
- Physics Division, School of Technology, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece)
It is shown that, when the inflaton field modulates the gauge kinetic function of the gauge fields in supergravity realisations of inflation, the dynamic backreaction leads to a new inflationary attractor solution, in which the inflaton's variation suffers additional impedance. As a result, slow-roll inflation can naturally occur along directions of the scalar potential which would be too steep and curved to support it otherwise. This provides a generic solution to the infamous eta-problem of inflation in supergravity. Moreover, it is shown that, in the new inflationary attractor, the spectral index of the generated curvature perturbations is kept mildly red despite eta of order unity. The above findings are applied to a model of hybrid inflation in supergravity with a generic Kähler potential. The spectral index of the generated curvature perturbations is found to be 0.97–0.98, in excellent agreement with observations. The gauge field can play the role of the vector curvaton after inflation but observable statistical anisotropy requires substantial tuning of the gauge coupling.
- OSTI ID:
- 22279744
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2012, Issue 02; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
Similar Records
Gravity waves from non-minimal quadratic inflation
Gravity waves from non-minimal quadratic inflation