Atlantic General Relativity 2024

Session

Session 2.2

19 Jun 2024, 11:00

307 (Tilley Hall, University of New Brunswick)

16. Motivating semiclassical gravity: a classical-quantum approximation for bipartite quantum systems

Irfan Javed (University of New Brunswick)

19/06/2024, 11:00

Oral

We derive a “classical-quantum” approximation scheme for a broad class of bipartite quantum systems from fully quantum dynamics. In this approximation, one subsystem evolves via classical equations of motion with quantum corrections, and the other subsystem evolves quantum mechanically with equations of motion informed by the evolving classical degrees of freedom. Using perturbation theory, we...

24. Entanglement in quantum cosmology

Sanjeev Seahra

19/06/2024, 11:30

Oral

We investigate the quantum entanglement between spacetime geometry and matter during a quantum cosmological bounce and a subsequent possible inflationary period. We find that entanglement entropy does not monotonically increase in the early universe and is therefore not an "arrow of time", and that the emergence of a (semi-)classical inflating universe from a quantum gravity era is not...

18. Semiclassical Gravity on Effective Backgrounds

Muhammad Muzammil (University of New Brunswick)

19/06/2024, 12:00

Oral

We study the classical-quantum (CQ) hybrid dynamics of homogeneous cosmology from a Hamiltonian perspective where the classical gravitational phase space variables and matter state evolve self-consistently with full backreaction. We compare numerically the classical and CQ dynamics for isotropic and anisotropic models, including quantum scalar-field induced corrections to the Kasner exponents....