Black holes with electroweak hair

by Mikhail Volkov

Wednesday 2 Apr 2025, 11:30 → 12:30 Europe/Zurich

4/2-011 - TH common room (CERN)

We construct static and axially symmetric magnetically charged
hairy black holes in the gravity-coupled Weinberg-Salam theory. 
Large black holes merge with the Reissner-Nordstr\"om (RN) family,
while the small ones are extremal and support a hair in the form of
a ring-shaped electroweak condensate carrying superconducting
W-currents and up to $22\%$ of the total magnetic charge.
The extremal solutions are asymptotically  RN with a  mass {\it below}
the total charge, $M<|Q|$,  due to the negative Zeeman energy of the
condensate interacting with the black hole magnetic field. Therefore,
they cannot decay into RN black holes. As their charge increases,
they show a phase transition when the horizon symmetry changes from
spherical to oblate. At this point they  have the mass typical for  planetary
size black holes of which $\approx 11\%$ are stored in the hair. Being obtained
within a well-tested  theory, our solutions are expected to  be  physically relevant.

Based on https://doi.org/10.1103/PhysRevLett.133.171402