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Thomas Tappeiner

Publications and source records attributed to Thomas Tappeiner.

3 recordsLinked to original sources

Quantum gravity around ultracold black holes from DSSYK

We propose a quantum description of the ultracold Reissner-Nordstr\"om de Sitter black hole via a specific flat space limit of the double-scaled SYK model. Fluctuations in this regime reduce to flat JT gravity, which is ill-behaved as a quantum system. We show that including the first subleading correction to the dilaton potential breaks the leading order Hagedorn degeneracy but does not resolve the structural problem. Finally, we leverage the gauged description of the sine dilaton gravity model to propose a novel quantization of the near-horizon dynamics of ultracold black holes. This leads to a new proposal for the partition function where states in the asymptotics of the spectrum are suppressed dynamically, and features of a discretized spacetime arise. We obtain a non-perturbative low temperature behavior of the partition function, which is quite different than the cold and Nariai physics. Our result can be interpreted as a dynamical way to enforce cosmic censorship on the quantum system.

hep-th

Fiducial observers and the thermal atmosphere in the black hole quantum throat

We propose a construction of fiducial observers in the throat region of near-extremal black holes within the framework of JT quantum gravity, leading to a notion of local observers in a highly quantum regime of the gravitational field. The construction is based on an earlier proposal for light-ray anchoring to the asymptotic boundary and is uniquely fixed at the semiclassical level by demanding that the notion of time translations for an observer at the asymptotic boundary of JT gravity should be extended into the bulk as the flow of a conformal isometry. Since conformal isometries are a necessary condition for geometric modular flow, our construction is amenable as a candidate geometric gravitational dressing that may be interpreted via the modular crossed product, potentially connecting our choice of dressing with recent developments on the literature on local observables in quantum gravity. Taking this definition beyond the semiclassical regime, we compute quantum gravitational wormhole contributions to the black hole thermal atmosphere, directly producing a finite thermal entropy and leading to a quantum description of the stretched horizon in this model.

hep-th

Quantum group origins of edge states in double-scaled SYK

Double-scaled SYK (DSSYK) is known to have an underlying quantum group theoretical description. We precisely pinpoint the quantum group structure, improving upon earlier work in the literature. This allows us to utilize this framework for bulk gravitational applications. We explain bulk discretization in DSSYK from the underlying irreducibility of the representations. We derive trumpet and brane amplitudes using character insertions of the quantum group, simplifying earlier calculations. Most importantly, we factorize the bulk Hilbert space dual to DSSYK in the quantum group description using a complete set of edge degrees of freedom living at a bulk entangling surface. An analogous treatment for $\mathcal{N}=1$ DSSYK is provided in the same quantum group theoretical framework.

hep-th