Linear Growth of Holographic Time-like Entanglement Entropy and Kasner exponents
Pith reviewed 2026-06-26 14:06 UTC · model grok-4.3
The pith
A critical extremal surface inside the event horizon governs the late-time linear growth of holographic time-like entanglement entropy.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
By assuming Kasner geometry near the space-like singularity and using the null energy condition, a critical extremal surface A_c inside the event horizon completely governs the late-time linear growth of the TEE. Numerical results indicate that the vacuum Schwarzschild-AdS sets an upper bound on the real part growth rate and lower bound on the imaginary part, proven under dominant energy condition in static planar symmetric cases.
What carries the argument
The critical extremal surface A_c inside the event horizon that sets the coefficient of the linear growth term in the piece-wise extremal surface prescription for TEE.
If this is right
- The late-time behavior of TEE is tightly constrained by the geometry of black hole interiors.
- The real-part growth rate is bounded above by the Schwarzschild-AdS value in static planar symmetric spacetimes under the dominant energy condition.
- The imaginary-part growth rate is bounded below by the Schwarzschild-AdS value in the same class of spacetimes.
- The bounds are conjectured to hold more generally beyond the proven planar static case.
Where Pith is reading between the lines
- Kasner exponents may enter the explicit linear coefficient of TEE growth once the interior geometry is fixed.
- If the prescription remains valid, similar interior surfaces could control late-time growth for other time-like boundary observables.
- The result suggests that time-like entanglement may serve as a probe of near-singularity physics even when direct access is impossible.
- Violations of the null or dominant energy conditions could alter the dominance of A_c and therefore change the growth bounds.
Load-bearing premise
The piece-wise extremal surfaces prescription correctly computes holographic time-like entanglement entropy and the near-singularity region is described by Kasner geometry.
What would settle it
A counter-example black hole spacetime in which the late-time TEE growth rate deviates from the value fixed by any single critical surface inside the horizon would falsify the governing role of A_c.
read the original abstract
The holographic time-like entanglement entropy (TEE) extends entanglement to time-like boundary subregions. While its definitive holographic dictionary remains debated, one concrete proposal utilizes piece-wise extremal surfaces. In this work, we adopt this geometric prescription as an exploratory framework to holographically investigate the late-time ($\tau_0\to \infty$) growth of TEE in asymptotically AdS black holes with a space-like singularity and no inner horizon. By assuming a Kasner geometry near the space-like singularity and using null energy condition, we analytically show that a critical extremal surface $\mathcal{A}_c$ inside the event horizon completely governs the late-time linear growth of the TEE. This result suggests that the late-time behavior of TEE is tightly constrained by the geometry of black hole interiors. Using numerical results from Einstein-scalar theory, we find a robust behavior: the vacuum Schwarzschild-AdS geometry sets an upper bound on the growth rate of the real part and a lower bound on the imaginary part. We prove these bounds in static planar symmetric case under dominant energy condition and conjecture that it should be true in more general cases.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript adopts the piece-wise extremal surface prescription for holographic time-like entanglement entropy (TEE) as an exploratory framework and analytically demonstrates that a critical extremal surface A_c inside the event horizon governs the late-time linear growth of TEE in asymptotically AdS black holes with space-like singularities. This is shown by assuming Kasner geometry near the singularity together with the null energy condition. Numerical solutions in Einstein-scalar theory indicate that the vacuum Schwarzschild-AdS geometry supplies an upper bound on the real-part growth rate and a lower bound on the imaginary-part growth rate; these bounds are proven for static planar symmetric cases under the dominant energy condition, with a conjecture for generality.
Significance. If the adopted TEE prescription holds, the result supplies analytic control linking black-hole interior geometry (via Kasner exponents) to late-time TEE growth rates, together with concrete bounds that are at least partially proven. The combination of analytic derivation under stated assumptions and numerical checks in a concrete theory constitutes a clear strength, though the exploratory framing limits the immediate scope.
major comments (2)
- [Abstract] Abstract and § on analytic derivation: the identification of A_c as completely governing late-time growth, and the derived bounds on Re/Im rates, are obtained entirely within the piece-wise extremal surface ansatz. The abstract explicitly flags this dictionary as debated and adopted only exploratorily; if an alternative prescription applies, the central claim does not transfer.
- [Proof of bounds (static planar case)] Section containing the DEC proof and conjecture: the upper/lower bounds on growth rates are proven only in the static planar symmetric case under the dominant energy condition. The extension to more general cases is stated as a conjecture without an outline of a proof strategy or additional evidence, which is load-bearing for the 'robust behavior' claim.
minor comments (2)
- [Analytic section] The definition of the critical surface A_c and its relation to the Kasner exponents should be stated with an explicit equation or diagram for clarity.
- [Introduction] A brief reference list entry or footnote on the status of the piece-wise TEE prescription would help readers locate the debate.
Simulated Author's Rebuttal
We thank the referee for the careful reading and constructive comments. We respond to the major comments point by point below.
read point-by-point responses
-
Referee: [Abstract] Abstract and § on analytic derivation: the identification of A_c as completely governing late-time growth, and the derived bounds on Re/Im rates, are obtained entirely within the piece-wise extremal surface ansatz. The abstract explicitly flags this dictionary as debated and adopted only exploratorily; if an alternative prescription applies, the central claim does not transfer.
Authors: We agree that the identification of the critical surface A_c and the derived bounds are obtained within the piece-wise extremal surface prescription. The abstract and introduction already emphasize that this is an exploratory framework adopted because the definitive holographic dictionary for TEE remains debated. All central claims are therefore conditional on this prescription, as stated. revision: no
-
Referee: [Proof of bounds (static planar case)] Section containing the DEC proof and conjecture: the upper/lower bounds on growth rates are proven only in the static planar symmetric case under the dominant energy condition. The extension to more general cases is stated as a conjecture without an outline of a proof strategy or additional evidence, which is load-bearing for the 'robust behavior' claim.
Authors: The referee correctly notes that the analytic proof applies only to the static planar symmetric case under the dominant energy condition. The conjecture for generality is supported by the numerical evidence in Einstein-scalar theory, but we acknowledge that no explicit proof strategy for the general case is outlined. This remains a conjecture. revision: partial
Circularity Check
No significant circularity; central claims derived from external conditions and stated assumptions
full rationale
The paper adopts the piece-wise extremal surface prescription explicitly as an 'exploratory framework' because the dictionary 'remains debated,' rather than deriving or fitting it internally. Analytic control of late-time TEE growth by A_c follows from the Kasner near-singularity assumption plus the null energy condition (NEC); bounds on growth rates are proven under the dominant energy condition (DEC) for the static planar case and verified numerically in Einstein-scalar theory. No derivation step reduces by construction to a fitted input, self-citation chain, or redefinition of the target quantity. The result is therefore self-contained against the stated external benchmarks and assumptions.
Axiom & Free-Parameter Ledger
axioms (2)
- domain assumption Null energy condition
- domain assumption Dominant energy condition
Reference graph
Works this paper leans on
-
[1]
Maldacena,The LargeNlimit of superconformal field theories and supergravity,Adv
J.M. Maldacena,The LargeNlimit of superconformal field theories and supergravity,Adv. Theor. Math. Phys.2(1998) 231 [hep-th/9711200]
Pith/arXiv arXiv 1998
-
[2]
S.S. Gubser, I.R. Klebanov and A.M. Polyakov,Gauge theory correlators from noncritical string theory,Phys. Lett. B428(1998) 105 [hep-th/9802109]
Pith/arXiv arXiv 1998
-
[3]
Witten,Anti de Sitter space and holography,Adv
E. Witten,Anti de Sitter space and holography,Adv. Theor. Math. Phys.2(1998) 253 [hep-th/9802150]
Pith/arXiv arXiv 1998
-
[4]
Maldacena,Eternal black holes in anti-de Sitter,JHEP04(2003) 021 [hep-th/0106112]
J.M. Maldacena,Eternal black holes in anti-de Sitter,JHEP04(2003) 021 [hep-th/0106112]
Pith/arXiv arXiv 2003
-
[5]
J. Maldacena and L. Susskind,Cool horizons for entangled black holes,Fortsch. Phys.61 (2013) 781 [1306.0533]. – 31 –
Pith/arXiv arXiv 2013
-
[6]
Van Raamsdonk,Building up spacetime with quantum entanglement,Gen
M. Van Raamsdonk,Building up spacetime with quantum entanglement,Gen. Rel. Grav.42 (2010) 2323 [1005.3035]
arXiv 2010
-
[7]
S. Ryu and T. Takayanagi,Holographic derivation of entanglement entropy from AdS/CFT, Phys. Rev. Lett.96(2006) 181602 [hep-th/0603001]
Pith/arXiv arXiv 2006
-
[8]
V.E. Hubeny, M. Rangamani and T. Takayanagi,A Covariant holographic entanglement entropy proposal,JHEP07(2007) 062 [0705.0016]
Pith/arXiv arXiv 2007
-
[9]
P. Calabrese and J.L. Cardy,Evolution of entanglement entropy in one-dimensional systems, J. Stat. Mech.0504(2005) P04010 [cond-mat/0503393]
Pith/arXiv arXiv 2005
-
[10]
W.W. Ho and D.A. Abanin,Entanglement dynamics in quantum many-body systems,Phys. Rev. B95(2017) 094302 [1508.03784]
Pith/arXiv arXiv 2017
-
[11]
T. Hartman and J. Maldacena,Time Evolution of Entanglement Entropy from Black Hole Interiors,JHEP05(2013) 014 [1303.1080]
Pith/arXiv arXiv 2013
-
[12]
Z. Li and R.-Q. Yang,Upper bounds of holographic entanglement entropy growth rate for thermofield double states,JHEP10(2022) 072 [2205.15154]
arXiv 2022
-
[13]
S.J. Olson and T.C. Ralph,Extraction of timelike entanglement from the quantum vacuum, Phys. Rev. A85(2012) 012306 [1101.2565]
Pith/arXiv arXiv 2012
-
[14]
P. Wang, H. Wu and H. Yang,Fix the dual geometries ofT¯Tdeformed CFT 2 and highly excited states of CFT2,Eur. Phys. J. C80(2020) 1117 [1811.07758]
arXiv 2020
-
[15]
K. Doi, J. Harper, A. Mollabashi, T. Takayanagi and Y. Taki,Pseudoentropy in dS/CFT and Timelike Entanglement Entropy,Phys. Rev. Lett.130(2023) 031601 [2210.09457]
arXiv 2023
-
[16]
X. Jiang and H. Yang,Timelike entanglement entropy revisited,Phys. Rev. D113(2026) 106021 [2503.19342]
Pith/arXiv arXiv 2026
-
[17]
A. Milekhin, Z. Adamska and J. Preskill,Observable and computable entanglement in time, 2502.12240
-
[18]
X. Gong, W.-z. Guo and J. Xu,Entanglement measures for causally connected subregions and holography,Phys. Rev. D113(2026) 106009 [2508.05158]
arXiv 2026
-
[19]
W.-z. Guo, S. He and T. Liu,Entanglement of General Subregions in Time-Dependent States,2512.19955
-
[20]
W.-z. Guo, S. He and Y.-X. Zhang,Relation between time- and spacelike entanglement entropy,Phys. Rev. D112(2025) 086020 [2402.00268]
arXiv 2025
-
[21]
J. Xu and W.-z. Guo,Imaginary part of timelike entanglement entropy,JHEP02(2025) 094 [2410.22684]
arXiv 2025
- [22]
-
[23]
C. Nunez and D. Roychowdhury,Timelike entanglement entropy: A top-down approach, Phys. Rev. D112(2025) 026030 [2505.20388]
arXiv 2025
-
[24]
C. Nunez and D. Roychowdhury,Holographic timelike entanglement across dimensions, JHEP11(2025) 100 [2508.13266]
arXiv 2025
-
[25]
P.-Z. He and H.-Q. Zhang,Holographic timelike entanglement entropy from Rindler method*, Chin. Phys. C48(2024) 115113 [2307.09803]. – 32 –
arXiv 2024
-
[26]
Q. Wen, M. Xu and H. Zhong,Timelike and gravitational anomalous entanglement from the inner horizon,SciPost Phys.18(2025) 204 [2412.21058]
arXiv 2025
-
[27]
M. Afrasiar, J.K. Basak and D. Giataganas,Timelike entanglement entropy and phase transitions in non-conformal theories,JHEP07(2024) 243 [2404.01393]
arXiv 2024
-
[28]
M. Afrasiar, J.K. Basak and D. Giataganas,Holographic timelike entanglement entropy in non-relativistic theories,JHEP05(2025) 205 [2411.18514]
arXiv 2025
-
[29]
M. Afrasiar, J.K. Basak and K.-Y. Kim,Aspects of holographic timelike entanglement entropy in black hole backgrounds,2512.21327
- [30]
- [31]
- [32]
- [33]
-
[34]
K. Doi, J. Harper, A. Mollabashi, T. Takayanagi and Y. Taki,Timelike entanglement entropy,JHEP05(2023) 052 [2302.11695]
arXiv 2023
-
[35]
H. Bohra and A. Sivaramakrishnan,Composite AdS geodesics for CFT correlators and timelike entanglement entropy,2511.22168
-
[36]
Z.-H. Li and R.-Q. Yang,Black Hole Interior and Time-like Entanglement Entropy, 2601.18319
-
[37]
B. Liu, H. Chen and B. Lian,Entanglement entropy of free fermions in timelike slices,Phys. Rev. B110(2024) 144306 [2210.03134]
arXiv 2024
-
[38]
W.-z. Guo, S. He and Y.-X. Zhang,On the real-time evolution of pseudo-entropy in 2d CFTs,JHEP09(2022) 094 [2206.11818]
arXiv 2022
-
[39]
F. Omidi,Pseudo Rényi Entanglement Entropies For an Excited State and Its Time Evolution in a 2D CFT,2309.04112
- [40]
- [41]
-
[42]
G. Katoch, D. Sarkar and B. Sen,Entanglement inequalities for timelike intervals within dynamical holography,2604.11158
-
[43]
D. Carmi, S. Chapman, H. Marrochio, R.C. Myers and S. Sugishita,On the Time Dependence of Holographic Complexity,JHEP11(2017) 188 [1709.10184]
Pith/arXiv arXiv 2017
-
[44]
Yang,Upper bound on cross sections inside black holes and complexity growth rate, Phys
R.-Q. Yang,Upper bound on cross sections inside black holes and complexity growth rate, Phys. Rev. D102(2020) 106001 [1911.12561]
arXiv 2020
-
[45]
Y.-S. An, L. Li, F.-G. Yang and R.-Q. Yang,Interior structure and complexity growth rate of holographic superconductor from M-theory,JHEP08(2022) 133 [2205.02442]. – 33 –
arXiv 2022
- [46]
-
[47]
D.Z. Freedman, S.S. Gubser, K. Pilch and N.P. Warner,Renormalization group flows from holography supersymmetry and a c theorem,Adv. Theor. Math. Phys.3(1999) 363 [hep-th/9904017]
Pith/arXiv arXiv 1999
-
[48]
R.C. Myers and A. Sinha,Seeing a c-theorem with holography,Phys. Rev. D82(2010) 046006 [1006.1263]
Pith/arXiv arXiv 2010
-
[49]
M. Headrick and T. Takayanagi,A Holographic proof of the strong subadditivity of entanglement entropy,Phys. Rev. D76(2007) 106013 [0704.3719]
Pith/arXiv arXiv 2007
-
[50]
A.C. Wall,Maximin Surfaces, and the Strong Subadditivity of the Covariant Holographic Entanglement Entropy,Class. Quant. Grav.31(2014) 225007 [1211.3494]
Pith/arXiv arXiv 2014
- [51]
-
[52]
Belinski and I.M
V.A. Belinski and I.M. Khalatnikov,Effect of Scalar and Vector Fields on the Nature of the Cosmological Singularity,Sov. Phys. JETP36(1973) 591
1973
-
[53]
Kasner,Geometrical theorems on Einstein’s cosmological equations,Am
E. Kasner,Geometrical theorems on Einstein’s cosmological equations,Am. J. Math.43 (1921) 217
1921
-
[54]
R.-G. Cai, L. Li and R.-Q. Yang,No Inner-Horizon Theorem for Black Holes with Charged Scalar Hairs,JHEP03(2021) 263 [2009.05520]
arXiv 2021
-
[55]
S.A. Hartnoll, G.T. Horowitz, J. Kruthoff and J.E. Santos,Diving into a holographic superconductor,SciPost Phys.10(2021) 009 [2008.12786]
arXiv 2021
- [56]
-
[57]
Z.-Q. Zhao, Z.-Y. Nie, X.-K. Zhang, Y.-S. An, J.-F. Zhang and X. Zhang,Interior structure of black holes with nonlinear terms,Eur. Phys. J. C86(2026) 447 [2512.24893]
Pith/arXiv arXiv 2026
-
[58]
Z.-Q. Zhao, Z.-Y. Nie, S.-W. Wei, J.-F. Zhang and X. Zhang,Interior geometry of black holes as a probe of first-order phase transition,2604.01818
-
[59]
Z.-X. Zhao, L. Zhao and S. He,Timelike entanglement entropy in higher curvature gravity, JHEP12(2025) 156 [2509.04181]
arXiv 2025
-
[60]
N. Grandi and I. Salazar Landea,Diving inside a hairy black hole,JHEP05(2021) 152 [2102.02707]
arXiv 2021
-
[61]
Li,On Thermodynamics of AdS Black Holes with Scalar Hair,Phys
L. Li,On Thermodynamics of AdS Black Holes with Scalar Hair,Phys. Lett. B815(2021) 136123 [2008.05597]
arXiv 2021
-
[62]
I.R. Klebanov and E. Witten,AdS / CFT correspondence and symmetry breaking,Nucl. Phys. B556(1999) 89 [hep-th/9905104]
Pith/arXiv arXiv 1999
-
[63]
Lloyd,Ultimate physical limits to computation,Nature406(2000) 1047 [quant-ph/9908043]
S. Lloyd,Ultimate physical limits to computation,Nature406(2000) 1047 [quant-ph/9908043]
Pith/arXiv arXiv 2000
-
[64]
A.R. Brown, D.A. Roberts, L. Susskind, B. Swingle and Y. Zhao,Holographic Complexity Equals Bulk Action?,Phys. Rev. Lett.116(2016) 191301 [1509.07876]. – 34 –
Pith/arXiv arXiv 2016
-
[65]
A.R. Brown, D.A. Roberts, L. Susskind, B. Swingle and Y. Zhao,Complexity, action, and black holes,Phys. Rev. D93(2016) 086006 [1512.04993]
Pith/arXiv arXiv 2016
-
[66]
L. Lehner, R.C. Myers, E. Poisson and R.D. Sorkin,Gravitational action with null boundaries,Phys. Rev. D94(2016) 084046 [1609.00207]
Pith/arXiv arXiv 2016
-
[67]
R.-G. Cai, S.-M. Ruan, S.-J. Wang, R.-Q. Yang and R.-H. Peng,Action growth for AdS black holes,JHEP09(2016) 161 [1606.08307]
Pith/arXiv arXiv 2016
-
[68]
Yang,Strong energy condition and complexity growth bound in holography,Phys
R.-Q. Yang,Strong energy condition and complexity growth bound in holography,Phys. Rev. D95(2017) 086017 [1610.05090]
Pith/arXiv arXiv 2017
-
[69]
Alishahiha,Timelike Holographic Complexity,2510.25700
M. Alishahiha,Timelike Holographic Complexity,2510.25700
-
[70]
T. Anegawa and K. Tamaoka,Black hole singularity and timelike entanglement,JHEP10 (2024) 182 [2406.10968]
arXiv 2024
-
[71]
T. Mädler and J. Winicour,Bondi-Sachs Formalism,Scholarpedia11(2016) 33528 [1609.01731]. – 35 –
Pith/arXiv arXiv 2016
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.