Toshifumi Noumi, Kobe University

Mon, 12/10/2018 - 2:10pm
Pupin Hall Theory Center, 8th Floor


"Weak Gravity Conjecture from Unitarity and Causality"

The Weak Gravity Conjecture, motivated by string theory and black hole thought experiments, states that gravity is the weakest force. In particular, it claims that there exist theoretical bounds on the charge-to-mass ratio and the axion decay constant in quantum gravity, which provides theoretical constraints on models of inflation and dark matter for example. In this talk, I will first review the Weak Gravity Conjecture and its phenomenological implications. I will then introduce our recent work providing its strong evidence based on unitarity and causality.

About the speaker

Noumi's research interests focus on cosmology and its connection to fundamental physics. Recent developments in observational experiments have revealed phenomenological aspects of cosmology in an impressive way. In particular they strongly suggest the new paradigms such as cosmic inflation, dark matter and dark energy. Fundamental physics such as particle physics and string theory will play a crucial role in clarifying the mechanism of these phenomena. At the same time, the observational data will provide a probe for high energy frontier. By focusing on such a connection, Noumi's goal is to contribute in the deepening of our understanding of the universe and developing the fundamental theory. 

Recently, Noumi is focusing on cosmic inflation in particular. He is exploring a way to probe high energy physics using inflation. Noumi is also interested in developing theoretical framework for cosmology based on recent developments in particle physics and string theory.

More details can be found here.