Magnetically charged black holes from non-linear electrodynamics and the Event Horizon Telescope

Abstract

Non-linear electrodynamics (NLED) theories are well-motivated extensions of QED in the strong field regime, and have long been studied in the search for regular black hole (BH) solutions. We consider two well-studied and well-motivated NLED models coupled to General Relativity: the Euler-Heisenberg model and the Bronnikov model. After carefully accounting for the effective geometry induced by the NLED corrections, we determine the shadows of BHs within these two models. We then compare these to the shadow of the supermassive BH M87* recently imaged by the Event Horizon Telescope collaboration. In doing so, we are able to extract upper limits on the black hole magnetic charge, thus providing novel constraints on fundamental physics from this new extraordinary probe.

Gravitational and electromagnetic radiation from binary black holes with electric and magnetic charges: Circular orbits on a cone

“…A similar expression holds for the rate of the energy loss. In the first case of e = 0, the φ has the period of 2π and thus, the period for the one revolution is T 1 = 2π/ φ in (13). In the second case of e = 0 and sin θ = l/n, the orbits returns to the initial position after φ revolves n-times and r nutates l-times, which give the period T 2 = 2nπ/ φ in (15).…”

“…Compared to Schwarzschild black holes, charged black holes have rich phenomena. Recently, charged black holes have been discussed extensively [9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25]. Binary black holes with charges emit not only gravitational radiation but also electromagnetic radiation.…”

The Weak Gravity Conjecture Requires the Existence of Exotic AdS Black Holes

“…We will discuss the case in which an asymptotically AdS 4 black hole rotates and is magnetically charged [38], since this case currently attracts considerable attention, from both the observational [39][40][41][42][43] (see [44,45] for reviews) and theoretical [46][47][48]37] points of view. The magnetic case is particularly interesting to us because such a black hole is expected to be, generically, approximately extremal [47], and extremal black holes are of course the ones of most interest in connection with the WGC 4 .…”

Investigating strong gravitational lensing with black hole metrics modified with an additional term

“…When the parameters are properly chosen, horizons may exist. If µ > 0.1 and 0 < q ≤ 0.25, A(r) = 0 has only one positive root representing the event horizon, and if 0 < µ ≤ 0.1 and 0 < q ≤ 0.25, A(r) = 0 has three positive roots, whose largest one is the event horizon [32]. For example, we have plotted A(r) in Fig.…”