Statistical coupling constants from hidden sector entanglement

TL;DR

This work argues that string-theory-inspired extra sectors entangle with the visible sector via moduli, so that the visible couplings are not fixed constants but drawn from a quantum statistical ensemble after tracing out the hidden degrees of freedom. Through both a concrete coupled-oscillator example and a field-theory generalization, it shows that this entanglement induces an irreducible variance in observed couplings, with the variance amplified by the number of hidden sectors or by strong modulus-hidden mixing. The authors develop a covariant, density-matrix framework to describe couplings and their correlators, discuss how experimental measurements sample this distribution, and identify observable signatures that extend the reach of experiments in energy and precision. The work highlights a new open-system perspective on stringy couplings and outlines pathways for using variance in couplings as a probe of hidden sectors and quantum-gravity-inspired physics.

Abstract

String theory predicts that the couplings of Nature descend from dynamical fields. All known string-motivated particle physics models also come with a wide range of possible extra sectors. It is common to posit that such moduli are frozen to a background value, and that extra sectors can be nearly completely decoupled. Performing a partial trace over all sectors other than the visible sector generically puts the visible sector in a mixed state, with coupling constants drawn from a quantum statistical ensemble. An observable consequence of this entanglement between visible and extra sectors is that the reported values of couplings will appear to have an irreducible variance. Including this variance in fits to experimental data gives an important additional parameter that can be used to distinguish this scenario from the case where couplings are treated as fixed parameters. There is a consequent interplay between energy range and precision of an experiment that allows an extended reach for new physics.

Figures (1)

• Figure 1: Depiction of the many QFT sectors of a string compactification. Performing a partial trace over the complement of the visible sector yields an effective density matrix for the visible sector couplings.