Informal Pizza Seminar

Inflation with a stringy minimal length, reworked<

Subodh Patil

Humboldt Universitat

We revisit the formulation of scalar field theories on de Sitter backgrounds subject to the generalized uncertainty principle (GUP)-- readily though of as arising from having strings as our only probes of geometry. We review (and critique) previous attempts to write down low energy effective field theories which represent the GUP, after which we uncover a new representation, which unlike previous studies, readily permits exact analytical solutions for the mode functions of a scalar field on de Sitter backgrounds, whilst avoiding certain ordering ambiguities. We show that scalar fields cannot be quantized on de Sitter backgrounds with a Hubble scale larger than the string scale, implying a sensibly stringy (as opposed to Planckian) cutoff on the scale of inflation resulting from the GUP. We analytically compute (H l_s)2 corrections to the correlation functions and comment on their physical interpretation. We also comment on future prospects of observing such corrections in the charitable circumstance that our universe is described by a very weakly coupled string theory.