Inflationary thermal Krylov complexity

Abstract

This work explores thermal Krylov complexity and thermal K-entropy of primordial perturbations under three comoving momentum correction frameworks, including canonical scalar field inflation (standard inflation), non-trivial sound speed, and the modified dispersion relations. Adopting the thermal field double state purification, we derive the thermal wave function and obtain the evolutions of effective temperature and squeezed angle, and further compare the quantum information dynamics of closed and open thermal quantum systems. The numerical results indicate that comoving momentum suppresses the growth of Krylov observables in standard inflation. In the non-trivial sound speed model, larger correction strength enhances their oscillatory behaviors, while the ultraviolet correction in the modified dispersion relation model induces stage-dependent oscillations. By analyzing the Lanczos coefficient and dissipation strength, we find that system dissipation suppresses quantum coherent oscillations. Continuous oscillations only emerge for larger non-trivial sound speed, whereas modified dispersion relations yield monotonic evolution. These distinct signatures provide effective quantum information probes for discriminating quantum gravity corrections in inflationary cosmology.

Comments: 46 pages, 14 figures, the whole paper was totally rewritten