Speaker
Dr
Alfredo Urbano
(CERN)
Description
It is commonly believed that no global symmetries can exist in a consistent theory of quantum gravity.
This "folk argument" can be put on more solid and quantitative ground by explicitly constructing non-perturbative gravitational instanton solutions.
In this talk, I will review such solutions in the case of an axion field minimally coupled to Einstein gravity. I will discuss both theoretical and phenomenological implications, with a special focus on the case of the QCD axion.
Primary author
Dr
Alfredo Urbano
(CERN)
