Recognition: 2 theorem links
· Lean TheoremGraph-theory measures capture weak ergodicity breaking on large quantum systems
Pith reviewed 2026-05-12 05:24 UTC · model grok-4.3
The pith
Graph-energy centrality on Fock-space graphs detects weak ergodicity-breaking transitions through shifts in its distribution.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
Representing a quantum many-body system as a graph in Fock space and computing the graph-energy centrality on that graph produces a distribution whose characteristic changes mark the onset of weak ergodicity breaking at known transition points, allowing the same diagnostic to be applied analytically to systems far larger than those accessible by standard exact methods.
What carries the argument
Graph-energy centrality computed on the Fock-space graph of the Hamiltonian, which registers the relative importance of basis states according to their connectivity and energy structure.
If this is right
- The same measure can be evaluated analytically for quantum systems containing hundreds of sites.
- In selected cases the calculation extends directly to the thermodynamic limit.
- The method supplies evidence of a weak ergodicity-breaking transition together with glassy dynamics in a kinetically constrained quantum model.
- Graph measures become practical tools for locating parameter-driven ergodicity violations without requiring full diagonalization.
Where Pith is reading between the lines
- The same Fock-space graph construction might be reused to track other dynamical crossovers that are hard to access at large size.
- If the distribution signatures prove model-independent, the centrality measure could serve as a classifier for different routes to ergodicity breaking.
- Analytical access in the thermodynamic limit opens the possibility of deriving exact scaling relations for the width or shape of the centrality distribution across the transition.
Load-bearing premise
That the Fock-space graph plus the graph-energy centrality measure together preserve the dynamical information that controls whether the system breaks ergodicity weakly.
What would settle it
In a model with an independently established weak ergodicity-breaking transition, the graph-energy centrality distribution shows no detectable change when the control parameter crosses the transition value.
Figures
read the original abstract
We study the onset of weak ergodicity violations in closed quantum many-body systems and focus on cases in which they occur through a transition that is controlled by a model parameter. Our analysis is based on representing quantum systems in Fock space and utilizes graph-theoretical measures. As a main result, we show that the recently introduced graph-energy centrality captures known weak ergodicity-breaking transitions via characteristic changes in its distribution. While most numerical tools are limited to small system sizes, our measure can be calculated analytically for large systems of many hundreds of sites and in some cases, even in the thermodynamic limit. We conclude by demonstrating the applicability of our Fock-space based measure to a kinetically constrained quantum model, where we find evidence for a weak ergodicity-breaking transition accompanied by glassy dynamics.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper represents closed quantum many-body systems as graphs in Fock space and shows that the graph-energy centrality measure detects known weak ergodicity-breaking transitions through characteristic shifts in its probability distribution. The measure is claimed to be analytically tractable for systems with hundreds of sites and, in some cases, in the thermodynamic limit. The approach is demonstrated on a kinetically constrained model, where distribution changes are interpreted as evidence of a transition accompanied by glassy dynamics.
Significance. If the central claim holds, the result is significant because it supplies a scalable, graph-theoretic diagnostic for weak ergodicity breaking that bypasses the system-size limits of exact diagonalization and time evolution. The analytical accessibility for large lattices is a concrete strength, as is the explicit application to a kinetically constrained model that lies outside the usual many-body localization setting.
major comments (2)
- [§4] §4 (kinetically constrained model results): The central claim that distribution shifts in graph-energy centrality capture the onset of weak ergodicity breaking rests on the assumption that the static Fock-space adjacency matrix encodes the relevant dynamical constraints. In kinetically constrained models the underlying graph can remain connected while effective dynamics are confined to subspaces; the manuscript does not demonstrate that the observed centrality shift distinguishes dynamical fragmentation from generic changes in degree distribution. A direct comparison with participation ratios or long-time local observables on the same parameter sweep would be required to establish that the measure is not merely reporting connectivity changes.
- [§3] §3 (analytical evaluation): The assertion that the measure can be evaluated analytically for large systems and in the thermodynamic limit is load-bearing for the claimed advantage over numerical tools. The derivation of the closed-form expression for the centrality distribution (or the limiting procedure) is not shown explicitly; without it, the scalability claim cannot be assessed independently of the numerical examples.
minor comments (2)
- [§2] The definition of graph-energy centrality is introduced without an explicit equation number; adding a numbered equation would improve traceability when the distribution is later analyzed.
- [Figures] Figure captions should state the system sizes and parameter values used for each panel to allow direct comparison with the analytical limits discussed in the text.
Simulated Author's Rebuttal
We thank the referee for their careful reading and constructive feedback. We address the major comments point by point below, and we will revise the manuscript accordingly to address the concerns raised.
read point-by-point responses
-
Referee: [§4] §4 (kinetically constrained model results): The central claim that distribution shifts in graph-energy centrality captures the onset of weak ergodicity breaking rests on the assumption that the static Fock-space adjacency matrix encodes the relevant dynamical constraints. In kinetically constrained models the underlying graph can remain connected while effective dynamics are confined to subspaces; the manuscript does not demonstrate that the observed centrality shift distinguishes dynamical fragmentation from generic changes in degree distribution. A direct comparison with participation ratios or long-time local observables on the same parameter sweep would be required to establish that the measure is not merely reporting connectivity changes.
Authors: We agree that a more explicit validation is needed to confirm that the centrality shifts reflect the dynamical constraints rather than just changes in the graph's degree distribution. In the revised manuscript, we will include a direct comparison of the graph-energy centrality distribution with participation ratios and long-time local observables across the parameter sweep for the kinetically constrained model. This will demonstrate that the shifts align with the onset of glassy dynamics and weak ergodicity breaking, rather than generic connectivity alterations. We note that the Fock-space graph is constructed from the Hamiltonian, which inherently incorporates the kinetic constraints, limiting edges to allowed transitions. revision: yes
-
Referee: [§3] §3 (analytical evaluation): The assertion that the measure can be evaluated analytically for large systems and in the thermodynamic limit is load-bearing for the claimed advantage over numerical tools. The derivation of the closed-form expression for the centrality distribution (or the limiting procedure) is not shown explicitly; without it, the scalability claim cannot be assessed independently of the numerical examples.
Authors: We acknowledge that the explicit derivation was omitted from the main text to maintain focus on the results. In the revised version, we will add a detailed appendix presenting the closed-form expression for the graph-energy centrality distribution and the limiting procedure to the thermodynamic limit. This will substantiate the analytical tractability for systems with hundreds of sites and beyond. revision: yes
Circularity Check
Graph-energy centrality applied to known transitions; no reduction of claims to self-definition or fitted inputs.
full rationale
The paper represents quantum systems as Fock-space graphs and applies the recently introduced graph-energy centrality measure to demonstrate characteristic distribution changes at known weak ergodicity-breaking transitions. The central result is an application and analytical extension to large systems rather than a derivation of the transitions themselves from the measure. No equations or steps reduce the claimed capture of dynamics to a tautological fit or self-citation chain; the static graph construction is independent of the dynamical signatures being observed. This is a standard non-circular use of an external measure on benchmark cases.
Axiom & Free-Parameter Ledger
axioms (1)
- domain assumption Quantum many-body systems can be faithfully represented as graphs in Fock space where nodes correspond to basis states and edges to allowed transitions under the Hamiltonian.
Lean theorems connected to this paper
-
IndisputableMonolith/Cost/FunctionalEquation.leanwashburn_uniqueness_aczel (J-cost uniqueness) unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
GEC(|i⟩) = Tr(H²) − Tr([H∥i⟩]²) / (Tr(H²)/D) ... variance of the GEC jumps discontinuously at the onset of fading ergodicity
-
IndisputableMonolith/Foundation/AlexanderDuality.leanalexander_duality_circle_linking (D=3 forcing) unclear?
unclearRelation between the paper passage and the cited Recognition theorem.
Fock-space graph ... nodes correspond to basis states |i⟩ and ... edges ... ⟨i|H|j⟩
What do these tags mean?
- matches
- The paper's claim is directly supported by a theorem in the formal canon.
- supports
- The theorem supports part of the paper's argument, but the paper may add assumptions or extra steps.
- extends
- The paper goes beyond the formal theorem; the theorem is a base layer rather than the whole result.
- uses
- The paper appears to rely on the theorem as machinery.
- contradicts
- The paper's claim conflicts with a theorem or certificate in the canon.
- unclear
- Pith found a possible connection, but the passage is too broad, indirect, or ambiguous to say the theorem truly supports the claim.
Reference graph
Works this paper leans on
-
[1]
For the TLG model, GEC is calculated in the joint eigenbasis of local density operatorsˆnℓ
is another candidate for a wEBT. For the TLG model, GEC is calculated in the joint eigenbasis of local density operatorsˆnℓ. Fig. 4(c) shows var(GEC)as a function of V for filling (N = L/2). We find a regime forV/t 0 ≲ 1where var(GEC)decreases for increasingL, while it increases forV/t 0 ≳ 1. This leads to a crossing pointV∗(L), extracted by comparing sys...
-
[2]
J. M. Deutsch, Quantum statistical mechanics in a closed system, Phys. Rev. A43, 2046 (1991)
work page 2046
-
[3]
Srednicki, Chaos and quantum thermalization, Phys
M. Srednicki, Chaos and quantum thermalization, Phys. Rev. E50, 888 (1994)
work page 1994
-
[4]
L. D’Alessio, Y. Kafri, A. Polkovnikov, and M. Rigol, From quantum chaos and eigenstate thermalization to statistical mechanics and thermodynamics, Adv. Phys. 65, 239 (2015)
work page 2015
-
[5]
J. M. Deutsch, Eigenstate thermalization hypothesis, Rep. Prog. Phys.81, 082001 (2018)
work page 2018
-
[6]
R. Patil and M. Rigol, Eigenstate thermalization (2026), arXiv:2604.11872
work page internal anchor Pith review Pith/arXiv arXiv 2026
- [7]
-
[8]
Rigol, Breakdown of thermalization in finite one- dimensional systems, Phys
M. Rigol, Breakdown of thermalization in finite one- dimensional systems, Phys. Rev. Lett.103, 100403 (2009)
work page 2009
-
[9]
Rigol, Quantum quenches and thermalization in one- dimensional fermionic systems, Phys
M. Rigol, Quantum quenches and thermalization in one- dimensional fermionic systems, Phys. Rev. A80, 053607 (2009)
work page 2009
-
[10]
L. F. Santos and M. Rigol, Localization and the effects of symmetries in the thermalization properties of one- dimensional quantum systems, Phys. Rev. E82, 031130 (2010)
work page 2010
-
[11]
R.Steinigeweg, J.Herbrych,andP.Prelovšek,Eigenstate thermalization within isolated spin-chain systems, Phys. Rev. E87, 012118 (2013)
work page 2013
-
[12]
E. Khatami, G. Pupillo, M. Srednicki, and M. Rigol, Fluctuation-dissipation theorem in an isolated system of quantum dipolar bosons after a quench, Phys. Rev. Lett.111, 050403 (2013)
work page 2013
-
[13]
S. Sorg, L. Vidmar, L. Pollet, and F. Heidrich-Meisner, Relaxation and thermalization in the one-dimensional Bose-Hubbard model: A case study for the interaction quantum quench from the atomic limit, Phys. Rev. A 90, 033606 (2014)
work page 2014
-
[14]
W. Beugeling, R. Moessner, and M. Haque, Finite-size scaling of eigenstate thermalization, Phys. Rev. E89, 042112 (2014)
work page 2014
-
[15]
R. Steinigeweg, A. Khodja, H. Niemeyer, C. Gogolin, and J. Gemmer, Pushing the limits of the eigenstate thermalization hypothesis towards mesoscopic quantum systems, Phys. Rev. Lett.112, 130403 (2014)
work page 2014
-
[16]
W. Beugeling, R. Moessner, and M. Haque, Off-diagonal matrix elements of local operators in many-body quan- tum systems, Phys. Rev. E91, 012144 (2015)
work page 2015
-
[17]
R. Mondaini, K. R. Fratus, M. Srednicki, and M. Rigol, Eigenstate thermalization in the two-dimensional trans- verse field Ising model, Phys. Rev. E93, 032104 (2016)
work page 2016
-
[18]
R. Mondaini and M. Rigol, Eigenstate thermalization in the two-dimensional transverse field Ising model. II. Off-diagonal matrix elements of observables, Phys. Rev. E96, 012157 (2017)
work page 2017
-
[19]
T. Yoshizawa, E. Iyoda, and T. Sagawa, Numerical large deviation analysis of the eigenstate thermalization hy- pothesis, Phys. Rev. Lett.120, 200604 (2018)
work page 2018
- [20]
-
[21]
L. Foini and J. Kurchan, Eigenstate thermalization hy- pothesis and out of time order correlators, Phys. Rev. E 99, 042139 (2019)
work page 2019
-
[22]
M. Mierzejewski and L. Vidmar, Quantitative impact of integrals of motion on the eigenstate thermalization hypothesis, Phys. Rev. Lett.124, 040603 (2020)
work page 2020
-
[23]
J. Richter, A. Dymarsky, R. Steinigeweg, and J. Gemmer, Eigenstate thermalization hypothesis beyond standard indicators: Emergence of random-matrix behavior at small frequencies, Phys. Rev. E102, 042127 (2020)
work page 2020
-
[24]
L. F. Santos, F. Pérez-Bernal, and E. J. Torres-Herrera, Speck of chaos, Phys. Rev. Res.2, 043034 (2020)
work page 2020
- [25]
- [26]
-
[27]
S. Sugimoto, R. Hamazaki, and M. Ueda, Test of the eigenstate thermalization hypothesis based on local ran- 6 dom matrix theory, Phys. Rev. Lett.126, 120602 (2021)
work page 2021
-
[28]
C. Schönle, D. Jansen, F. Heidrich-Meisner, and L. Vid- mar, Eigenstate thermalization hypothesis through the lens of autocorrelation functions, Phys. Rev. B103, 235137 (2021)
work page 2021
-
[29]
S. Pappalardi, L. Foini, and J. Kurchan, Eigenstate thermalization hypothesis and free probability, Phys. Rev. Lett.129, 170603 (2022)
work page 2022
-
[30]
S. Pappalardi, F. Fritzsch, and T. Prosen, Full eigenstate thermalization via free cumulants in quantum lattice systems, Phys. Rev. Lett.134, 140404 (2025)
work page 2025
-
[31]
E. Vallini, L. Foini, and S. Pappalardi, Refinements of the eigenstate thermalization hypothesis under lo- cal rotational invariance via free probability (2025), arXiv:2511.23217
-
[32]
C. J. Turner, A. A. Michailidis, D. A. Abanin, M. Serbyn, and Z. Papić, Weak ergodicity breaking from quantum many-body scars, Nat. Phys.14, 745 (2018)
work page 2018
- [33]
-
[34]
J.-Y. Desaules, K. Bull, A. Daniel, and Z. Papić, Hyper- grid subgraphs and the origin of scarred quantum walks in many-body Hilbert space, Phys. Rev. B105, 245137 (2022)
work page 2022
-
[35]
S. Moudgalya and O. I. Motrunich, Exhaustive character- ization of quantum many-body scars using commutant algebras, Phys. Rev. X14, 041069 (2024)
work page 2024
-
[36]
S. Moudgalya, B. A. Bernevig, and N. Regnault, Quan- tum many-body scars and Hilbert space fragmentation: A review of exact results, Rep. Prog. Phys.85, 086501 (2022)
work page 2022
-
[37]
A. Chandran, T. Iadecola, V. Khemani, and R. Moessner, Quantum many-body scars: A quasiparticle perspective, Ann. Rev. Cond. Mat. Phys.14, 443 (2023)
work page 2023
- [38]
-
[39]
T. Rakovszky, P. Sala, R. Verresen, M. Knap, and F. Poll- mann, Statistical localization: From strong fragmenta- tion to strong edge modes, Phys. Rev. B101, 125126 (2020)
work page 2020
- [40]
- [41]
-
[42]
F. Yang, H. Yarloo, H.-C. Zhang, K. Mølmer, and A. E. B. Nielsen, Probing Hilbert space fragmentation with strongly interacting Rydberg atoms, Phys. Rev. B 111, 144313 (2025)
work page 2025
-
[43]
S. Aditya, Diagnostics of Hilbert space fragmentation, freezing transition, and its effects in the family of quan- tum East models involving varying range of constraints, Phys. Rev. B112, 195413 (2025)
work page 2025
-
[44]
T.-L. Tan and Y.-P. Huang, Interference-caged quantum many-body scars: The Fock space topological localiza- tion and interference zeros (2025), arXiv:2504.07780
-
[45]
T. Ben-Ami, M. Heyl, and R. Moessner, Many-body cages: Disorder-free glassiness from flat bands in Fock space, and many-body Rabi oscillations (2025), arXiv:2504.13086
-
[46]
C. Jonay and F. Pollmann, Localized fock space cages in kinetically constrained models, Phys. Rev. B113, 134313 (2026)
work page 2026
-
[47]
T. Ben-Ami, R. Moessner, and M. Heyl, Floquet many- body cages (2026), arXiv:2604.13027 [quant-ph]
work page internal anchor Pith review Pith/arXiv arXiv 2026
-
[48]
S. Mohapatra, S. Moudgalya, and A. C. Balram, Addi- tional quantum many-body scars of the spin-1xy model with fock-space cages and commutant algebras, Phys. Rev. B113, 054310 (2026)
work page 2026
-
[49]
H. Bernien, S. Schwartz, A. Keesling, H. Levine, A. Om- ran, H. Pichler, S. Choi, A. S. Zibrov, M. Endres, M. Greiner, V. Vuletić, and M. D. Lukin, Probing many- body dynamics on a 51-atom quantum simulator, Nature 551, 579 (2017)
work page 2017
-
[50]
T. Kohlert, S. Scherg, P. Sala, F. Pollmann, B. Hebbe Madhusudhana, I. Bloch, and M. Aidelsburger, Exploring the regime of fragmentation in strongly tilted Fermi-Hubbard chains, Phys. Rev. Lett.130, 010201 (2023)
work page 2023
- [51]
- [52]
- [53]
-
[54]
P. Sala, T. Rakovszky, R. Verresen, M. Knap, and F. Poll- mann, Ergodicity breaking arising from Hilbert space fragmentation in dipole-conserving Hamiltonians, Phys. Rev. X10, 011047 (2020)
work page 2020
-
[55]
V. Khemani, M. Hermele, and R. Nandkishore, Local- ization from Hilbert space shattering: From theory to physical realizations, Phys. Rev. B101, 174204 (2020)
work page 2020
-
[56]
S. Moudgalya and O. I. Motrunich, Hilbert space frag- mentation and commutant algebras, Phys. Rev. X12, 011050 (2022)
work page 2022
-
[57]
M. Lisiecki, J. Bonča, M. Mierzejewski, J. Herbrych, and P. Łydżba, Tunable Hilbert space fragmentation and extended critical regime, Phys. Rev. B112, 195116 (2025)
work page 2025
-
[58]
D. J. Luitz, N. Laflorencie, and F. Alet, Many-body localization edge in the random-field Heisenberg chain, Phys. Rev. B91, 081103 (2015)
work page 2015
-
[59]
P. Sierant, D. Delande, and J. Zakrzewski, Many-body localization due to random interactions, Phys. Rev. A 95, 021601 (2017)
work page 2017
-
[60]
V. Khemani, D. N. Sheng, and D. A. Huse, Two univer- sality classes for the many-body localization transition, Phys. Rev. Lett.119, 075702 (2017)
work page 2017
-
[61]
R. K. Panda, A. Scardicchio, M. Schulz, S. R. Taylor, and M. Žnidarič, Can we study the many-body localisation transition?, EPL128, 67003 (2019)
work page 2019
-
[62]
D. E. Logan and S. Welsh, Many-body localization in Fock space: A local perspective, Phys. Rev. B99, 045131 (2019)
work page 2019
-
[63]
L. A. Colmenarez, P. A. McClarty, M. Haque, and D. J. Luitz, Statistics of correlation functions in the random 7 Heisenberg chain, SciPost Physics7, 064 (2019)
work page 2019
-
[64]
Á. L. Corps, R. A. Molina, and A. Relaño, Signatures of a critical point in the many-body localization transition, SciPost Phys.10, 107 (2021)
work page 2021
- [65]
-
[66]
A. Prakash, J. H. Pixley, and M. Kulkarni, Universal spectral form factor for many-body localization, Phys. Rev. Research3, L012019 (2021)
work page 2021
-
[67]
P. Sierant, M. Lewenstein, A. Scardicchio, L. Vidmar, and J. Zakrzewski, Many-body localization in the age of classical computing, Rep. Prog. Phys.88, 026502 (2025)
work page 2025
-
[69]
A. D. Mirlin, Y. V. Fyodorov, F.-M. Dittes, J. Quezada, and T. H. Seligman, Transition from localized to ex- tended eigenstates in the ensemble of power-law random banded matrices, Phys. Rev. E54, 3221 (1996)
work page 1996
-
[70]
A. D. Mirlin and F. Evers, Multifractality and critical fluctuations at the anderson transition, Phys. Rev. B62, 7920 (2000)
work page 2000
-
[71]
F. Evers and A. D. Mirlin, Fluctuations of the inverse participation ratio at the anderson transition, Phys. Rev. Lett.84, 3690 (2000)
work page 2000
-
[73]
E. Bogomolny and M. Sieber, Power-law random banded matrices and ultrametric matrices: Eigenvector distribu- tion in the intermediate regime, Phys. Rev. E98, 042116 (2018)
work page 2018
- [75]
-
[76]
Unconventional Thermalization of a Localized Chain Interacting with an Ergodic Bath
K. Pawlik, N. Laflorencie, and J. Zakrzewski, Uncon- ventional thermalization of a localized chain interacting with an ergodic bath (2026), arXiv:2507.18286 [cond- mat.dis-nn]
work page internal anchor Pith review Pith/arXiv arXiv 2026
-
[79]
R. Świętek, M. Hopjan, C. Vanoni, A. Scardicchio, and L. Vidmar, Scaling theory of fading ergodicity, Phys. Rev. Lett.135, 170401 (2025)
work page 2025
-
[80]
R. Świętek, M. Kliczkowski, M. Hopjan, and L. Vidmar, Fading ergodicity and quantum dynamics in random matrix ensembles (2026), arXiv:2603.23616
-
[81]
Y. Y. Atas, E. Bogomolny, O. Giraud, and G. Roux, Distribution of the ratio of consecutive level spacings in random matrix ensembles, Phys. Rev. Lett.110, 084101 (2013)
work page 2013
-
[82]
A. Deger and A. Lazarides, Weak ergodicity breaking transition in a randomly constrained model, Phys. Rev. B109, L220301 (2024)
work page 2024
- [83]
-
[85]
Z. Lan, M. van Horssen, S. Powell, and J. P. Garra- han, Quantum slow relaxation and metastability due to dynamical constraints, Phys. Rev. Lett.121, 040603 (2018)
work page 2018
- [86]
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.