Black Holes and the Strong CP Problem
General Relativity and Quantum Cosmology
2015-03-17 v2 High Energy Physics - Theory
Abstract
The strong CP problem is that SU(3) gauge field instantons naturally induce a CP violating term in the QCD Lagrangian which is constrained by experiment to be very small for no obvious reason. We show that this problem disappears if one assumes the existence of at least one black hole somewhere in the universe. The argument is reminiscent of Dirac's argument for the quantization of charge, in which the existence of one monople anywhere in the universe suffices to require the quantization of electric charge everywhere.
Cite
@article{arxiv.1005.1097,
title = {Black Holes and the Strong CP Problem},
author = {John Swain},
journal= {arXiv preprint arXiv:1005.1097},
year = {2015}
}
Comments
Small corrections/additions made plus added references and discussion of theta terms for electromagnetism and gravity in topologically more complicated spacetimes