Smooth Horizonless Geometries Deep Inside the Black-Hole Regime.

Area of Science:

• String Theory and Supergravity
• Quantum Gravity
• Black Hole Physics

Background:

• Supersymmetric rotating D1-D5-P black holes in five dimensions are key theoretical objects.
• Understanding the quantum nature of black hole horizons and singularities remains a major challenge.

Purpose of the Study:

• To construct horizonless supergravity solutions that precisely match the macroscopic properties of D1-D5-P black holes.
• To investigate the microstate structure of these black holes and resolve their singularities.

Main Methods:

• Construction of a new family of horizonless supergravity solutions.
• Comparison of these solutions with existing D1-D5-P black hole solutions.
• Identification of dual states in the N=(4,4) D1-D5 orbifold conformal field theory (CFT).

Main Results:

• The first family of horizonless supergravity solutions with identical mass, charges, and angular momenta to D1-D5-P black holes was successfully constructed.
• These solutions exhibit the characteristic near-horizon throat of black holes, but resolve the singularity into a smooth cap.
• Holographically dual states were identified within the N=(4,4) D1-D5 orbifold CFT, specifically within the states counted by the CFT elliptic genus.

Conclusions:

• The constructed geometries provide concrete examples of smooth microstate geometries for supersymmetric black holes.
• These findings offer a novel perspective on the resolution of black hole singularities and the holographic principle.
• The study bridges the gap between classical black hole solutions and their quantum microstate descriptions.