6 research outputs found
JT gravity from holographic reduction of 3D asymptotically flat spacetime
We attempt to understand the CFT structure underlying (2+1)D gravity in
flat spacetime via dimensional reduction. We observe that under superrotation,
the hyperbolic (and dS) slices of flat spacetime transform to
asymptotically (A)dS slices. We consider a wedge region bounded by two such
surfaces as End-of-the-World branes and employ Wedge holography to perform
holographic reduction. We show that once we consider fluctuating branes, the
localised theory on the branes is Jackiw-Teitelboim (JT) theory. Finally, using
the dual description of JT, we derive an 1D Schwarzian theory at the spatial
slice of null infinity. In this dual Celestial (nearly) CFT, the superrotation
mode of 3D plays the role of the Schwarzian derivative of the boundary time
reparametrization mode.Comment: 19 pages, 3 figure
Entropy of Flat Space Cosmologies from Celestial dual
We construct a one-dimensional dual theory that effectively describes the
sector of the (2+1)D flat gravity phase space near a Flat Space Cosmology (FSC)
saddle labeled by definite mass and angular momentum. This Schwarzian type
action describes the dynamics of the (Pseudo-) Goldstone Bosons of BMS
algebra on a circle as the symmetry is spontaneously and anomalously broken.
This 1D theory, living on the celestial circle, provides an explicit
construction of a celestial dual in (2+1)D. We use it to calculate the
semiclassical entropy of Flat Space Cosmologies and find perfect agreement with
existing literature.Comment: Typos correcte
Logarithmic corrections for near-extremal black holes
We present the computation of logarithmic corrections to near-extremal black
hole entropy from one-loop Euclidean gravity path integral around the
near-horizon geometry. We extract these corrections employing a suitably
modified heat kernel method, where the near-extremal near-horizon geometry is
treated as a perturbation around the extremal near-horizon geometry. Using this
method we compute the logarithmic corrections to non-rotating solutions in four
dimensional Einstein-Maxwell and supergravity theories.
We also discuss the limit that suitably recovers the extremal black hole
results.Comment: Minor revisions, references adde
JT gravity from holographic reduction of 3D asymptotically flat spacetime
Abstract We attempt to understand the CFT1 structure underlying (2+1)D gravity in flat spacetime via dimensional reduction. We observe that under superrotation, the hyperbolic (and dS2) slices of flat spacetime transform to asymptotically (A)dS2 slices. We consider a wedge region bounded by two such surfaces as End-of-the-World branes and employ Wedge holography to perform holographic reduction. We show that once we consider fluctuating branes, the localised theory on the branes is Jackiw-Teitelboim (JT) theory. Finally, using the dual description of JT, we derive an 1D Schwarzian theory at the spatial slice of null infinity. In this dual Celestial (nearly) CFT, the superrotation mode of 3D plays the role of the Schwarzian derivative of the boundary time reparametrization mode
Revisiting leading quantum corrections to near extremal black hole thermodynamics
Abstract Computing the 4D Euclidean path integral to one-loop order we find the large quantum corrections that govern the behavior of a spherically symmetric non-supersymmetric near-extremal black hole at very low temperature. These corrections appear from the near-horizon geometry of the near-extremal black hole. Using first-order perturbation theory we find that such corrections arise from the zero modes of the extremal background. In the logarithm of the partition function, these correspond to terms involving logarithm of temperature. Part of our result matches with the existing one in literature derived from an effective Schwarzian theory
Logarithmic corrections for near-extremal black holes
Abstract We present the computation of logarithmic corrections to near-extremal black hole entropy from one-loop Euclidean gravity path integral around the near-horizon geometry. We extract these corrections employing a suitably modified heat kernel method, where the near-extremal near-horizon geometry is treated as a perturbation around the extremal near-horizon geometry. Using this method we compute the logarithmic corrections to non-rotating solutions in four dimensional Einstein-Maxwell and N = 2, 4, 8 supergravity theories. We also discuss the limit that suitably recovers the extremal black hole results