Stimulated creation of quanta during inflation and the observable universe

TL;DR

This paper explores how stimulated quantum creation during inflation influences the primordial spectrum, potentially preserving information about the universe's initial state and affecting observable non-Gaussianities in the CMB and galaxy distribution.

Contribution

It introduces the role of stimulated creation of quanta in inflation, showing it preserves initial state information in primordial inhomogeneities, unlike previous models.

Findings

Stimulated creation affects the primordial spectrum.

Initial state information can be imprinted in non-Gaussianities.

Non-Gaussianities reveal details about early universe quantum states.

Abstract

Inflation provides a natural mechanism to account for the origin of cosmic structures. The generation of primordial inhomogeneities during inflation can be understood via the spontaneous creation of quanta from the vacuum. We show that when the corresponding {\it stimulated} creation of quanta is considered, the characteristics of the state of the universe at the onset of inflation are not diluted by the inflationary expansion and can be imprinted in the spectrum of primordial inhomogeneities. The non-gaussianities (particularly in the so-called squeezed configuration) in the cosmic microwave background and galaxy distribution can then tell us about the state of the universe that existed at the time when quantum field theory in curved spacetime first emerged as a plausible effective theory.