Running spectral index as a probe of physics at high scales
Dec, 2005
33 pages
Published in:
- JCAP 03 (2006) 001
e-Print:
- hep-ph/0601134 [hep-ph]
Report number:
- IFT-UAM-CSIC-05-51
View in:
Citations per year
Abstract:
The WMAP results on the scalar spectral index n and its running with scale, though preliminary, open a very interesting window to physics at very high energies. We address the problem of finding inflaton potentials well motivated by particle physics which can accomodate WMAP data. We make a model independent analysis of a large class of models: those with flat tree-level potential lifted by radiative corrections, which cause the slow rolling of the inflaton and the running of n. This includes typical hybrid inflation models. In the small-coupling regime the predictions for the size and running of n are remarkably neat, e.g. -dn/dln k=(n-1)^2 << 1, and n does not cross n=1, contrary to WMAP indications. On the other hand, n can run significantly if the couplings are stronger but at the price of having a small number of e-folds, Ne. We also examine the effect of mass thresholds crossed during inflation. Finally, we show that the presence of non-renormalizable operators for the inflaton, suppressed by a mass scale above the inflationary range, is able to give both dn/dln k ~ O(-0.05) and Ne ~ 50.- inflation: hybrid
- cosmic background radiation
- inflaton: potential
- operator: nonrenormalizable
- coupling constant
- mass: threshold
- energy: threshold
- power spectrum: scalar
- numerical calculations: interpretation of experiments
References(36)
Figures(0)