Large Nc deconfinement transition in the presence of a magnetic field

We investigate the effect of a homogeneous magnetic field on the thermal deconfinement transition of QCD in the large N_c limit. First we discuss how the critical temperature decreases due to the inclusion of N _fN_c flavors of massless quarks in comparison to the pure glue case. Then we study the equivalent correction in the presence of an external Abelian magnetic field. To leading order in N_f/N _c, the deconfinement critical temperature decreases with the magnetic field if the flavor contribution to the pressure behaves paramagnetically, with a sufficiently large magnetization as to overcome any possible magnetic effects in the string tension. Finally, we discuss the effects from a finite quark mass and its competition with magnetic effects.