Monopoles, Dyons and Theta Term in Dirac-Born-Infeld Theory

Phys.Rev. D60 (1999) 125002 We present dyon solutions to an SU(2) Dirac-Born-Infeld (DBI) gauge theory coupled to a Higgs triplet. We consider different non-Abelian extensions of the DBI action and study the resulting solutions numerically, comparing them with the standard Julia-Zee dyons. We discuss the existence of a critical value of $\beta$, the Born-Infeld absolute field parameter, below which the solution ceases to exist. We also analyse the effect of modifying the DBI action so as to include the analogous of the $\theta$ term, showing that Witten formula for the dyon charge also holds in DBI theories.