An effective description of the instability of coherent states of gravitons in string theory

TL;DR

This paper investigates the instability of coherent graviton states in string theory using thermodynamic models, showing conditions for decoherence and implications for de Sitter space stability.

Contribution

It introduces a thermodynamic framework to analyze graviton state stability and links decoherence to de Sitter space instability in string theory.

Findings

Decoherence occurs under certain perturbations of coherent graviton states.

The system reaches thermodynamic equilibrium in a finite time.

Quantum-break time exceeds classical break-time, supporting Swampland conjectures.

Abstract

We study the dynamics of a coherent state of closed type II string gravitons within the framework of the Steepest Entropy Ascent Quantum Thermodynamics, an effective model where the quantum evolution is driven by a maximal increase of entropy. We find that by perturbing the pure coherent state of gravitons by the presence of other coherent fields in the string spectrum, there exists conditions upon which the system undergoes decoherence by reaching thermodynamical equilibrium. Following the proposal by Dvali, et al., this suggests the instability of the classical dS space. We identify the time scale it takes the system to reach equilibrium consisting of a mixed state of fields in the string spectrum and compare it with the quantum-break time. Also we find that in such final state the quantum-break time seems to be larger than the classical break-time, in agreement with the Swampland conjectures about the dS solution in string theory.