2025/10/07 by Bernardo Araneda, Maciej Dunajski, Araneda, Bernardo +1
Engineering · Mathematics · #Characterization and Applications of Magnetic Nanoparticles #Differential Geometry (math.DG) #FOS: Mathematics #FOS: Physical sciences #Gas Dynamics and Kinetic Theory #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th)
paper · pdf · doi:10.48550/arxiv.2510.06458
openalex publication_date 2025/10/07 · openalex created_date 2025/10/18 · openalex updated_date 2026/07/31
We disprove the Euclidean Einstein--Maxwell Black Hole Uniqueness Conjecture, and thus demonstrate that the semi-classical properties of coupled gravitational and electromagnetic fields are more subtle than expected from Lorentzian general relativity, where the Kerr-Newman family of metrics yields the most general stationary and asymptotically flat black holes with a single event horizon. This is achieved by an explicit construction of a new three--parameter family of asymptotically flat Einstein--Maxwell instantons. These solutions are toric, regular, and free of conical and orbifold singularities on the manifold M=\CP2∖ S1. In the case of vanishing charge, these instantons reduce to the Chen--Teo Ricci flat instantons.