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dS$\boldsymbol{_2}$ as excitation of AdS$\boldsymbol{_2}$

by Florian Ecker, Daniel Grumiller, Robert McNees

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Submission summary

Authors (as registered SciPost users): Daniel Grumiller · Robert McNees
Submission information
Preprint Link:  (pdf)
Date accepted: 2022-10-14
Date submitted: 2022-09-02 21:45
Submitted by: McNees, Robert
Submitted to: SciPost Physics
Ontological classification
Academic field: Physics
  • Gravitation, Cosmology and Astroparticle Physics
  • High-Energy Physics - Theory
Approach: Theoretical


We introduce a family of 2D dilaton gravity models with state-dependent constant curvature so that dS$_2$ emerges as an excitation of AdS$_2$. Curiously, the strong coupling region corresponds to the asymptotic region geometrically. Apart from these key differences, many features resemble the Almheiri--Polchinski model. We discuss perturbative and non-perturbative thermodynamical stability, bubble nucleation through matter shockwaves, and semiclassical backreaction effects. In some of these models, we find that low temperatures are dominated by AdS$_2$ but high temperatures are dominated by dS$_2$, concurrent with a recent proposal by Susskind.

Published as SciPost Phys. 13, 119 (2022)

Author comments upon resubmission

This is a resubmission, after responding to comments and questions from referees.

List of changes

There have been two updates (v2 and v3) since the initial submission. The updates include changes in response to previous referee comments. The changes, by version, are as follows:

Version 2
- Section 6, First paragraph: "...This is distinct from other constructions that yield a state-dependent cos- mological constant, at the price of introducing extra gauge fields [46–53]. It also differs from the “centaur geometry” studied in [54], which interpolates between AdS in the UV and dS2 in the IR. Unlike the centaur geometries, solutions in our model have constant curvature, whose value and sign are state-dependent."

- Section 6, Third to last paragraph: "In this paper we took an intrinsically 2D perspective. However, from the viewpoint of dimensional reduction a linear coupling of the matter field to the dilaton is required. Therefore, it could be rewarding to generalize our discussion to non-minimal coupling in (93). Another possible generalization is to relax the assumption of staticity in our treatment of backreaction. This would accommodate time dependent configurations such as the shockwaves in [55]."

- Section 6, Penultimate paragraph: "We conclude with an intriguing observation, and additional prospects for future re- search. ..."

- Added the following references:
[54] D. Anninos and D. Hofman, Infrared Realization of dS2 in AdS2, Class.Quant.Grav. 35, 085003 (2018), doi:10.1088/1361-6382/aab143, 1703.04622.

[56] T. J. Hollowood and S. P. Kumar, Islands and Page Curves for Evaporating Black Holes in JT Gravity, JHEP 08, 094 (2020), doi:10.1007/JHEP08(2020)094, 2004. 14944.

Version 3
- Comment added after Eq. (91) explaining that bubble nucleation only increases the curvature, as a result of the averaged null energy condition.
- Made a small clarifying edit in the conclusion, replacing "concrete" with "possible."
- Added reference [55] in the Discussion
[55] D. Anninos, D. A. Galante and D. M. Hofman, De Sitter horizons & holographic liquids, JHEP 07, 038 (2019), doi:10.1007/JHEP07(2019)038, 1811.08153.

Reports on this Submission

Anonymous Report 2 on 2022-9-27 (Invited Report)


I appreciate the answers gave by the authors and the changes in the manuscript, so I am happy to suggest the manuscript for publication in SciPost.

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Anonymous Report 1 on 2022-9-8 (Invited Report)


I wrote report 1 and I am satisfied with the answers and changes of the authors.

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