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How to tame your (black hole) saddles: Lessons from the Lorentzian Gravitational Path Integral

4 Pith papers cite this work. Polarity classification is still indexing.

4 Pith papers citing it
abstract

We resolve a puzzle associated with the spherically-symmetric sector of the AdS$_4$ Einstein-Maxwell partition function with inverse temperature $\beta$. Since charge is quantized, the semiclassical limit of the partition function is expected to be given by a sum over complex black hole solutions obtained by shifting the associated chemical potential $\mu$ by $\frac{2\pi i n}{e \beta}$ in terms of the relevant charge quantum $e$. However, the sum over all such saddles turns out to diverge at any finite value of $\beta$. We therefore consider a definition of this partition function as an integral over a space of metrics that are real and of Lorentz-signature up to the presence of certain conical singularities. A Picard-Lefshetz analysis shows that only a finite subset of the above saddles contribute to our integral at finite $\beta$, and thus that the sum over such saddles converges. The low temperature limit is nonetheless associated with a convergent sum over all saddles that (as $\beta \rightarrow \infty$) approach the usual large real Euclidean black holes. We also analyze the analogous partition function for the (uncharged) BTZ black hole in the ensemble defined by fixing an angular velocity $\Omega$ up to shifts by $\frac{2\pi i m}{s \beta}$, where $s=\frac{1}{2}$ or $s=1$ depending on the presence of absence of fermionic states. In this case, at all $\beta$ we find that all saddles contribute and that the sum over saddles converges. We also comment briefly on the apparent lack of utility of the so-called KSW condition in our context.

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hep-th 4

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2026 4

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representative citing papers

The yes boundaries wavefunctions of the universe

hep-th · 2026-04-11 · conditional · novelty 6.5

A constrained product of two dressed one-sided dS quantum systems yields a holographic dual whose top-band TFD and lower tall states capture the future wedge and overlapping causal wedges.

Complex BPS Black Holes in AdS$_3\times S^3$

hep-th · 2026-05-27 · unverdicted · novelty 6.0

Constructs complex BTZ x S3 saddles for the supersymmetric index in AdS3 x S3 supergravity, matching supersymmetry requirements through two-center 4D solutions with complex charges and 6D black strings.

citing papers explorer

Showing 4 of 4 citing papers.

  • The yes boundaries wavefunctions of the universe hep-th · 2026-04-11 · conditional · none · ref 114 · internal anchor

    A constrained product of two dressed one-sided dS quantum systems yields a holographic dual whose top-band TFD and lower tall states capture the future wedge and overlapping causal wedges.

  • Wormholes as red herrings: reflection positivity and the reconstruction of unitary quantum field theories hep-th · 2026-07-01 · unverdicted · none · ref 109 · internal anchor

    Unitary QFTs are determined up to unitary isomorphism by closed-manifold partition functions; every reflection-positive partition function comes from a unitary QFT, so spatial wormholes do not break Hilbert-space factorization once the full charged spectrum is included.

  • Index saddle for the D1-D5-P black string and its decoupling limit hep-th · 2026-06-25 · conditional · none · ref 47 · internal anchor

    A six-dimensional gravitational index saddle for the D1-D5-P black string is built and decoupled to a BTZ×S^3 saddle for the D1-D5 CFT index.

  • Complex BPS Black Holes in AdS$_3\times S^3$ hep-th · 2026-05-27 · unverdicted · none · ref 43 · internal anchor

    Constructs complex BTZ x S3 saddles for the supersymmetric index in AdS3 x S3 supergravity, matching supersymmetry requirements through two-center 4D solutions with complex charges and 6D black strings.