Explore an in-depth lecture on ab initio quantum chemistry approaches to nonequilibrium interactions in molecules and materials. Delve into advanced topics including correlated photon-molecule interactions, molecular strong coupling with ab initio QED, and quasiparticle descriptions of non-perturbative interactions. Examine ground and excited-state energies of mixed photon-quantum matter systems, modification of intermolecular interactions in cavities, and polaritonics in the presence of cavity loss. Investigate master equation approaches to open quantum system dynamics, correlated light-matter interactions, and the control of magnon-polaritons in cuprate parent compounds. Gain insights into cavity control, nonequilibrium dynamics, and quantum materials through this comprehensive presentation by Harvard University's Prineha Narang at IPAM's Advancing Quantum Mechanics with Mathematics and Statistics Tutorials.