Modified electron trajectory due to axion dark matter background

Abstract

It is well known that the coupling of the axion-like particle with the photon modifies Maxwell equations. One of the main consequences of these modifications is the conversion of axions into photons. Little has been said about the effect of the modified electromagnetic fields by the axion-like particles background on the trajectory of charged particles. In this note, we show that the trajectory of an electron can be significantly altered in this modified axion-electrodynamics. As a representative example, with current values of the dark matter density and the magnetic field strength on Earth, it is shown that an axion-like particle with a mass $\mu_a\sim 10^{-15}$eV will change the trajectory of an electron by several kilometers. Other scenarios are briefly mentioned.