What Happens Due to the Baby Universe Effect in Jackiw–Teitelboim Gravity? Analysis of Correlation Functions and Einstein–Rosen Bridge Length at Late Time Using Three Approaches
Year: 2025
Type: article
Abstract: We analyze the correlation function in Jackiw–Teitelboim gravity using three approaches: by summing over all geodesics connecting boundary operators, integrating over the region of moduli space determined by the “no-shortcut condition,” and using the formula for the universal spectral density correlation in the $\tau$-scaling limit. We find that the behaviors of the three results coincide at late times: they all exhibit a “ramp” instead of permanent decay. Using the third approach we also confirm that the “plateau” appears after $T_H=2\pi e^{S_0}\widehat{\rho }_0(E)$. Overall, our results are consistent with the spectral form factor analysis. We also calculate the Einstein–Rosen bridge length $\langle \ell (T) \rangle$ using the three approaches and find that the results are in good agreement with each other. We also find that the $\langle \ell (T) \rangle$ grows as a cubic function in $T$ due to the contribution from geometry including one observable baby universe, and converges to a constant after $T=T_H$. For the geometry with one baby universe, we compute the size $\langle b(T) \rangle$ of the baby universe and find that it is of the same order as $\langle \ell (T) \rangle$. This result is consistent with the baby universe emission mechanism previously claimed.
DOI: 10.1093/ptep/ptaf073
Author: Masayoshi Sato
Institution: National Defense Academy of Japan
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $979
OpenAlex ID: W4410360288