Research output: Contribution to journal › Article › peer-review
Gravity as an ensemble and the moment problem. / Janssen, Oliver; Mirbabayi, Mehrdad; Zograf, Peter.
In: Journal of High Energy Physics, Vol. 2021, No. 6, 184, 06.2021.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Gravity as an ensemble and the moment problem
AU - Janssen, Oliver
AU - Mirbabayi, Mehrdad
AU - Zograf, Peter
N1 - Publisher Copyright: © 2021, The Author(s).
PY - 2021/6
Y1 - 2021/6
N2 - If a bulk gravitational path integral can be identified with an average of partition functions over an ensemble of boundary quantum theories, then a corresponding moment problem can be solved. We review existence and uniqueness criteria for the Stieltjes moment problem, which include an infinite set of positivity conditions. The existence criteria are useful to rule out an ensemble interpretation of a theory of gravity, or to indicate incompleteness of the gravitational data. We illustrate this in a particular class of 2D gravities including variants of the CGHS model and JT supergravity. The uniqueness criterion is relevant for an unambiguous determination of quantities such as log Z(β) ¯ or the quenched free energy. We prove in JT gravity that perturbation theory, both in the coupling which suppresses higher-genus surfaces and in the temperature, fails when the number of boundaries is taken to infinity. Since this asymptotic data is necessary for the uniqueness problem, the question cannot be settled without a nonperturbative completion of the theory.
AB - If a bulk gravitational path integral can be identified with an average of partition functions over an ensemble of boundary quantum theories, then a corresponding moment problem can be solved. We review existence and uniqueness criteria for the Stieltjes moment problem, which include an infinite set of positivity conditions. The existence criteria are useful to rule out an ensemble interpretation of a theory of gravity, or to indicate incompleteness of the gravitational data. We illustrate this in a particular class of 2D gravities including variants of the CGHS model and JT supergravity. The uniqueness criterion is relevant for an unambiguous determination of quantities such as log Z(β) ¯ or the quenched free energy. We prove in JT gravity that perturbation theory, both in the coupling which suppresses higher-genus surfaces and in the temperature, fails when the number of boundaries is taken to infinity. Since this asymptotic data is necessary for the uniqueness problem, the question cannot be settled without a nonperturbative completion of the theory.
KW - 2D Gravity
KW - Models of Quantum Gravity
UR - http://www.scopus.com/inward/record.url?scp=85109111728&partnerID=8YFLogxK
U2 - 10.1007/JHEP06(2021)184
DO - 10.1007/JHEP06(2021)184
M3 - Article
AN - SCOPUS:85109111728
VL - 2021
JO - Journal of High Energy Physics
JF - Journal of High Energy Physics
SN - 1126-6708
IS - 6
M1 - 184
ER -
ID: 98426342