Information content of nonautonomous free fields in curved space-time

Abstract

We show that it is possible to quantify the information content of a nonautonomous free field state in curved space-time. A covariance matrix is defined and it is shown that, for symmetric Gaussian field states, the matrix is connected to the entropy of the state. This connection is maintained throughout a quadratic nonautonomous (including possible phase transitions) evolution. Although particle-antiparticle correlations are dynamically generated, the evolution is isoentropic. If the current standard cosmological model for the inflationary period is correct, in absence of decoherence such correlations will be preserved, and could potentially lead to observable effects, allowing for a test of the model.

Entanglement of self-interacting scalar fields in an expanding spacetime

“…Even though experimental evidences show that primordial perturbations have undergone quantum-to-classical transition by some decoherence mechanism, some quantum correlations could in principle linger, in the case of weakly interacting fields, and encode information about the evolution of the universe [13,14]. The theoretical framework to study such phenomena is quantum field theory in curved backgrounds [1,2,[15][16][17][18][19]. As quantum technologies progress, the effects of gravity and motion on quantum correlations need to be accounted for in high-precision measurements such as Unruh temperatures [20], detection of gravity waves using Bose-Einstein condensates [21], Schwarzschild parameters of the Earth [22], etc.…”