TPPC weekly seminar (in-person): Sravan Kumar - Unitary QFT in curved spacetime and its implications for black holes and cosmology

Wednesday 2 Apr 2025, 12:30 → 14:30 Europe/London

In this talk, we present how the recent proposal of direct-sum quantum field theory (DQFT) in curved spacetime offers unitarity and observer complementarity. We discuss, in particular, quantum aspects of the de Sitter Universe and Schwarzschild black hole. We demonstrate that one can have Hawking radiation with pure states without firewalls. Furthermore, we illustrate the way DQFT ideas can be traced back to the initial thoughts by Einstein and Rosen in 1935, Schrodinger in 1956, and 't Hooft in 2016. We comment on a concrete path to resolve the black hole information paradox. Finally, we show compelling evidence for DQFT with the treatment of inflationary quantum fluctuations (called Direct-sum inflation) in explaining large-scale (parity-asymmetric) features of the cosmic microwave background (CMB). Direct-sum inflation uncovers the interplay between gravity and quantum mechanics, fitting the CMB data 650 times better than standard inflationary quantum fluctuations.