Relevance of "on" and "off" transitions in quantum pair production experiments

TL;DR

This paper investigates how 'on' and 'off' transitions in analog gravity experiments affect particle production spectra, emphasizing the importance of transition effects in interpreting results, especially in cosmological simulations versus Schwinger effect experiments.

Contribution

It highlights the significant impact of transition periods on particle spectra in analog gravity experiments and clarifies their differing roles in cosmological versus Schwinger effect simulations.

Findings

Transition effects dominate spectra in analog gravity experiments.

Transition effects are less significant in Schwinger effect experiments.

Careful interpretation is required for experimental outcomes involving transitions.

Abstract

Analog gravity experiments, such as those realized in Bose-Einstein condensates, often aim at simulating cosmological pair production due to the dynamical expansion of the Universe. However, these experiments have a start and an end, which introduces unavoidable transitions out of and into static regimes that alter the intended expansion profile. We show that the resulting particle spectra can be overwhelmingly dominated by these transition periods, which calls for a careful interpretation of experimental outcomes. In prospective Schwinger effect experiments, by contrast, transition effects do not dominate particle production, and such a reinterpretation may not be necessary.