Black holes with conical infinity in gravitational caloric theory

Abstract: Whether gravitational caloric theory admits spherical black-hole solutions beyond Schwarzschild remains open. A well-defined black-hole solution requires both a regular horizon and a nonsingular exterior extending to infinity. To investigate this question, we cast the vacuum equations for a purely radial caloric field in a general static spherically symmetric metric into a three-dimensional autonomous system, which facilitates the global classification of solutions. We show that the regular asymptotic geometry can be Minkowski or conical, with the latter requiring a specific relation between the model parameters. Within this parameter slice, Schwarzschild is the only asymptotically flat black hole, whereas non-Schwarzschild black holes with conical infinity exist. These black holes can remain arbitrarily close to Schwarzschild from the near-horizon region to the conventional weak-field region (e.g., Solar System scales), yet retain an order-unity solid-angle deficit or excess at infinity. The asymptotic solid angle depends on a single model parameter and is independent of the caloric field amplitude. At fixed locally inferred mass, the caloric amplitude sets the conical transition scale, with weaker fields shifting the transition outward. We derive the local metric corrections and use the resulting periapsis shift to formulate an orbital test of the transition scale.