Small Black Holes on Cylinders
Troels Harmark
TL;DR
This work provides the complete metric for small neutral, static black holes on a cylinder $\mathbb{R}^{d-1}\times S^1$ by employing the Harmark–Huhans ansatz in the small-mass limit, and uses it to derive first-order corrections to thermodynamics, revealing deviations from $(d+1)$-dimensional Schwarzschild behavior. A Newtonian, near-field analysis yields leading corrections to the metric away from the hole, while a change of coordinates clarifies the near-horizon structure and yields a closed-form description of the full small-hole solution in terms of a function $G(\tilde{\rho})$ with parameter $w$. The results show a nonzero leading relative binding energy $n$ and provide a concrete $(M,n)$ phase-diagram piece for $d=5$, highlighting how black holes on cylinders differ from their flat-space counterparts and informing the black-hole/black-string transition picture. The analysis supports locality of small black holes in locally flat regions and demonstrates the continued relevance of the proposed ansatz for non-maximally symmetric backgrounds, while opening avenues for higher-order corrections and broader phase-structure investigations.
Abstract
We find the metric of small black holes on cylinders, i.e. neutral and static black holes with a small mass in d-dimensional Minkowski-space times a circle. The metric is found using an ansatz for black holes on cylinders proposed in hep-th/0204047. We use the new metric to compute corrections to the thermodynamics which is seen to deviate from that of the (d+1)-dimensional Schwarzschild black hole. Moreover, we compute the leading correction to the relative binding energy which is found to be non-zero. We discuss the consequences of these results for the general understanding of black holes and we connect the results to the phase structure of black holes and strings on cylinders.
