Black Holes with Electroweak Hair

Area of Science:

• Theoretical physics
• Black hole physics
• Electroweak theory

Background:

• The study of black holes is a cornerstone of modern physics, with Reissner-Nordström (RN) black holes representing a fundamental class of charged, non-rotating solutions.
• The Weinberg-Salam theory unifies the electromagnetic and weak nuclear forces, providing a framework for understanding fundamental particle interactions.
• Hairy black holes, which possess additional properties beyond mass, charge, and angular momentum, challenge classical black hole uniqueness theorems and offer insights into quantum gravity.

Purpose of the Study:

• To construct static and axially symmetric magnetically charged hairy black holes within the gravity-coupled Weinberg-Salam theory.
• To investigate the properties and stability of these novel black hole solutions.
• To explore the physical implications of the electroweak condensate hair and its interaction with the black hole's magnetic field.

Main Methods:

• Construction of black hole solutions using the Einstein-Maxwell equations coupled with the Weinberg-Salam Lagrangian.
• Analysis of the asymptotic behavior and properties of the resulting spacetime geometries.
• Investigation of the stability and phase transitions of the hairy black hole solutions, particularly concerning their mass-to-charge ratio and horizon symmetry.

Main Results:

• Successful construction of static, axially symmetric, magnetically charged hairy black holes.
• Identification of two classes of black holes: large ones merging with the RN family and small, extremal ones with a ring-shaped electroweak condensate hair.
• Extremal solutions exhibit a mass below the total charge (M<|Q|) due to negative Zeeman energy, preventing decay into RN black holes.
• A phase transition occurs with increasing charge, altering the horizon symmetry from spherical to oblate.
• Planetary-sized black holes with approximately 11% of their mass stored in the hair were identified.

Conclusions:

• The constructed hairy black holes are stable and possess unique characteristics arising from the interplay between the black hole spacetime and the electroweak condensate.
• The mass-to-charge ratio and phase transitions indicate novel physical phenomena not observed in standard black hole solutions.
• These solutions, derived from a well-tested theory, are expected to have significant physical relevance and warrant further investigation.