Neutrino physics in slowly rotating black hole spacetime and nonlinear electrodynamics
Huge electromagnetic fields are known to be present during the late stages of the dynamics of supernovae. Thus, when dealing with electrodynamics in this context, the possibility may arise to probe nonlinear theories. The Einstein field equations minimally coupled to an arbitrary nonlinear Lagrangian of electrodynamics are solved in the regime of slow rotation, i.e. $a << M$ (black hole's mass), up to first order in $a/M$. We use Born-Infeld Lagrangian to compare the obtained results with Maxwellian counterpart. We focus on the astrophysics of neutrino flavor oscillations ($ν_e\toν_{μ, τ}$) and spin-flip ($ν_L\toν_R$), as well as on the computation of that the electron fraction $Y_e$, hence the r-processes, which may significantly differ with respect to the standard electrodynamics.