Quantum Gravity Seminar: Serena Giardino

Speaker: Serena Giardino (Max Planck Institute, Postdam)

Title: Mapping the landscape of gravity theories

Abstract: Given the plethora of modified gravity theories attempting to solve General Relativity's issues, it is useful to understand them through a unifying lens. A powerful idea for this purpose is given by the relationship between gravity and thermodynamics. It was found that both Einstein's equations and the equations of a modified theory can be derived as thermodynamical equations of state. This leads to identifying GR with an equilibrium state of gravity and modified gravity with a non-equilibrium one.  I will present a new approach to the thermodynamics of modified gravity that is inspired by these results but follows a starkly different path.

A precise description of the approach to equilibrium naturally emerges from using non-equilibrium thermodynamics on the effective imperfect fluid describing scalar-tensor gravity. Applications of this framework to cosmology and extensions to different classes of modified theories contribute to a new and unifying picture of the landscape of gravity theories that GR is embedded in.

Zoom Link: https://ucph-ku.zoom.us/j/9295289933?omn=67282578176