Probing nonlinear electrodynamics in slowly rotating spacetimes through neutrino astrophysics

Understand

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 (generalizations of the Maxwellian electromagnetism).
• We firstly solve Einstein field equations minimally coupled to an arbitrary (current-free) nonlinear Lagrangian of electrodynamics (NLED) in the slow rotation regime $a\ll M$ (black hole's mass), up to first order in $a/M$.
• We then make use of the robust and self-contained Born-Infeld Lagrangian in order to compare and contrast the physical properties of such NLED spacetime with its Maxwellian counterpart (a slowly rotating Kerr-Newman spacetime), especially focusing on the astrophysics of both neutrino flavor oscillations ($\nu_e \rightarrow \nu_\mu, \nu_\tau$) and spin-flip ($\nu_l \rightarrow \nu_r$, "$l$" stands for "left" and "$r$" stands for "right", change of neutrino handedness) mass level-crossings, the equivalent to gyroscopic precessions.