The Electric Charge of a Dirac Monopole at Nonzero Temperature

Abstract

We study the effect of nonzero temperature on the induced electric charge around a Dirac monopole. While at zero temperature the charge is known to be proportional to a CP violating $\theta$ parameter, we find that at high temperature the charge is proportional to sin $\theta$. Other features of the charge at nonzero temperature are discussed. We also compute the induced charge at nonzero temperature around an Aharonov-Bohm flux string in $2+1$ dimensions and compare the result with an index theorem, and also with the electron-monopole problem in $3+1$ dimensions.