Phenomenology of magnetic black holes with electroweak-symmetric coronas

Abstract

Magnetically charged black holes (MBHs) are interesting solutions of the Standard Model and general relativity. They may possess a “hairy” electroweak-symmetric corona outside the event horizon, which speeds up their Hawking radiation and leads them to become nearly extremal on short timescales. Their masses could range from the Planck scale up to the Earth mass. We study various methods to search for primordially produced MBHs and estimate the upper limits on their abundance. We revisit the Parker bound on magnetic monopoles and show that it can be extended by several orders of magnitude using the large-scale coherent magnetic fields in Andromeda. This sets a mass-independent constraint that MBHs have an abundance less than 4 × 10−4 times that of dark matter. MBHs can also be captured in astrophysical systems like the Sun, the Earth, or neutron stars. There, they can become non-extremal either from merging with an oppositely charged MBH or absorbing nucleons. The resulting Hawking radiation can be detected as neutri- nos, photons, or heat. High-energy neutrino searches in particular can set a stronger bound than the Parker bound for some MBH masses, down to an abundance 10−7 of dark matter.

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

“…Magnetic charges, if they exist in the early Universe, will provide a hitherto unexplored window to probe fundamental physics in the Standard Model of particle physics and beyond. Though no evidence of magnetic charges has been found yet [1,2], magnetically charged black holes have attracted much attention not only in theoretical study but also in recent astronomical observations [3][4][5]. Recently, spectacular properties of magnetic charged black holes have been extensively discussed in [3].…”

“…It is shown there that the magnetic field near the horizon of a magnetic black hole could be strong enough to restore the electroweak symmetry. The phenomenology of low-mass magnetic black holes, which can have electroweak-symmetric coronas outside of the event horizon, has been comprehensively studied in [4]. Potential astrophysical signatures for magnetically charged black holes have also been investigated in [5].…”

Hairy magnetic and dyonic black holes in the Standard Model

“…The black hole horizon continues shrinking and T keeps increasing. During this period, the Hawking radiation is dominated by the 2d one (the ground state of charged fermions in the monopole background behaves as 2d modes) with the radiated power as [14,17] GeV, this period of evaporation is longer than the Big Bang nucleosynthesis (BBN) time O(1 s). The black hole evaporation could leave observational imprints on the light-element abundance [27].…”

“…Hairy magnetic black holes can be probed using a variety of astrophysical or directdetection methods. Motion of hMBHs in the galactic magnetic fields lead to the Parker bound on abundance of MBHs: f * < 4 × 10 −4 , where f * is the MBH abundance as the total fraction of dark matter abudance [17,45]. Similar to the magnetic monopole, MBHs can also be probed by direct-detection searches through MACRO and ancient Mica [17].…”

“…In our study, we will consider the magnetic charge Q = 2 case with a spherically symmetric configuration for the whole system. We want to emphasize that the existence of hairy magnetic and dyonic black holes only depends on the known SM and general relativity, although their abundance in the current Universe is subject to the early-universe formation mechanism and various phenomenological constraints [17].…”