Hyperbolic scaling of the small-exponent limit in magnetic nonlinear electrodynamics

Abstract

A magnetic spacetime can approach Schwarzschild while its electromagnetic characteristics remain singular in the same parameter limit. We study this separation in fractional-power nonlinear electrodynamics as the exponent tends to zero with asymptotic mass, magnetic charge and nonlinear coupling independently fixed. The extraordinary polarization admits a common physical time direction only outside a boundary that grows as the inverse fourth root of the exponent. On this radial scale, the lapse tends to unity but the constitutive angular response retains a nondegenerate barrier and finite scaled critical data. An exact representation of the exterior electromagnetic energy yields complete second-order corrections to the orbit and impact, separating mass and charge contributions and their distinct cancellations. Constraining the mass to equal the electromagnetic self-energy preserves the leading critical constants while changing the approach from fourth-root to square-root corrections. Returning rays remain inside the admissible exterior and define a limiting scattering function with a calculated logarithmic strong-deflection coefficient. In the weak regime, constitutive bending decays as the inverse fourth power of scaled impact, whereas finite mass supplies a slower inverse-impact tail. We determine their competition scale, its accessibility above the critical impact, and the accuracy of the two-term approximation. Independent energy, orbit and scattering calculations check the expansions and resolve their parameter-dependent convergence. The analysis shows how a nearly vacuum background can support a distinct exterior optical limit through the nonlinear constitutive response.