ISGC 240904 talk by Dr. Suddhasattwa Brahma - University of Edinburgh

Title: Entanglement and dissipation of quantum origins of structure
Abstract:
A profound prediction of the standard model of cosmology is that primordial quantum fluctuations are responsible for large-scale structure formation in the universe. However, our knowledge of the early universe is incomplete, and we must treat inflation as an open quantum system and derive, in a systematic manner, quantum corrections to cosmological observables due to interactions with unobservable environments. For instance, the "cosmological horizon" is an example of a spacetime boundary that restricts our observable degrees of freedom while still allowing energy and information to flow across it into hidden sectors. Borrowing techniques from Quantum Information Theory, I will show how an Open Effective Field Theory formalism can incorporate non-unitary effects in cosmology and describe dissipation and decoherence of primordial fluctuations. I will also highlight new insights this approach provides regarding quantum entanglement in the early universe, and emphasize how the out-of-equilibrium nature of gravitational systems necessarily result in non-Markovian dynamics.
Speaker: Suddhasattwa Brahma - Higgs Centre for Theoretical Physics, University of Edinburgh, England
Date and Time: September 4th, 2024 - 12pm GMT