2025/06/07 by Fateme Shojaei Arani, Brahim Lamine, Arani, Fateme Shojaei +5
Physics and Astronomy · #Cosmology and Gravitation Theories #Pulsars and Gravitational Waves Research #Statistical Mechanics and Entropy
paper · pdf · doi:10.48550/arxiv.2506.06922
The interaction between quantum gravitational waves (GWs) and electromagnetic (EM) fields is investigated within the open quantum system formalism, where GWs are considered as a heat bath reservoir occupying a generic state ρgws. Following the quantum Langevin equations, it turns out that the correlations of the Langevin noise operator associated with the GW background directly determine the statistical properties of the EM phasor ϕ(t). We apply this formalism to the background of inflationary-generated primordial gravitational waves (PGW). Since this background has an astronomically large correlation time, of the order of the Hubble time H0-1, we show that it leads to a non-Markovian dynamics of the EM field, which causes memory effects. As a result of the Gaussianity of PGW, it turns out that the EM phasor goes through a stochastic process, which is a manifestation of the fluctuation-dissipation in EM-GW system. The variance of the EM phase smears out as Δ2φ(t)= Δ2φ0+ 4(t/τc)4, where the characteristic time scale τc is associated with the diffusion rate caused by PGWs. The specific quartic growth of the phase noise is thus attributed to the two-mode squeezed nature of PGWs, which is inherently different from the phase diffusion induced by vacuum fluctuations of spacetime or a thermal heat bath of gravitons.