# Dynamics and entanglement in classical and quantum-classical systems: lessons for gravity (Prof. Viqar Husain, University of New Brunswick)

Motivated by quantum gravity, semiclassical theory, and quantum theory on a classical background, I will describe a study of three types of dynamics for an oscillator coupled to spins: quantum, quantum-classical, and spin dynamics on an oscillator “background.” I then apply a similar approach to cosmology, which is a hamiltonian proposal for a semiclassical Einstein equation. The main result of this application is a new (and unstable) semiclassical static universe characterized by discrete values of the curvature and cosmological constant.