Physics – High Energy Physics – High Energy Physics - Theory
Scientific paper
2008-06-11
JCAP 0810:032,2008
Physics
High Energy Physics
High Energy Physics - Theory
29 pages, 2 figure; v2: slightly extended to match JCAP version. v3: pre-factor corrected in (28)-(30); conclusions unchanged
Scientific paper
10.1088/1475-7516/2008/10/032
We investigate multi-field inflationary scenarios with fields that drop out of the model in a staggered fashion. This feature is natural in certain multi-field inflationary setups within string theory; for instance, it can manifest itself when fields are related to tachyons that condense, or inter-brane distances that become meaningless when branes annihilate. Considering a separable potential, and promoting the number of fields to a smooth time-dependent function, we derive the formalism to deal with these models at the background and perturbed level, providing general expressions for the scalar spectral index and the running. We recover known results of e.g. a dynamically relaxing cosmological constant in the appropriate limits. We further show that isocurvature perturbations are suppressed during inflation, so that perturbations are adiabatic and nearly Gaussian. The resulting setup might be interpreted as a novel type of warm inflation, readily implemented within string theory and without many of the shortcomings associated with warm inflation. To exemplify the applicability of the formalism we consider three concrete models: assisted inflation with exponential potentials as a simple toy model (a graceful exit becomes possible), inflation from multiple tachyons (a constant decay rate of the number of fields and negligible slow roll contributions turns out to be in good agreement with observations) and inflation from multiple M5-branes within M-theory (a narrow stacking of branes yields a consistent scenario).
Battefeld Diana
Battefeld Thorsten
Davis Anne--Christine
No associations
LandOfFree
Staggered Multi-Field Inflation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Staggered Multi-Field Inflation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Staggered Multi-Field Inflation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-689799