English

Mock modularity at work, or black holes in a forest

High Energy Physics - Theory 2025-07-14 v2 General Relativity and Quantum Cosmology Mathematical Physics Algebraic Geometry math.MP Number Theory

Abstract

Mock modular forms, first invented by Ramanujan, provide a beautiful generalization of the usual modular forms. In recent years, it was found that they capture generating functions of the number of microstates of BPS black holes appearing in compactifications of string theory with 8 and 16 supercharges. This review describes these results and their applications which range from the actual computation of these generating functions for both compact and non-compact compactification manifolds (encoding, respectively, Donaldson-Thomas and Vafa-Witten topological invariants) to the construction of new non-commutative structures on moduli spaces of Calabi-Yau threefolds.

Cite

@article{arxiv.2505.02572,
  title  = {Mock modularity at work, or black holes in a forest},
  author = {Sergei Alexandrov},
  journal= {arXiv preprint arXiv:2505.02572},
  year   = {2025}
}

Comments

invited review for "Entropy"; 2 figures added and typos corrected

R2 v1 2026-06-28T23:21:22.645Z