REVIEW 1 major objections 3 minor 2 cited by
Locality and Heating in Periodically Driven, Power-law Interacting Systems
T0 review · 1 major / 3 minor · reviewed 2026-08-14 · deepseek-v4-flash
Pith's one-line read Periodically driven power-law interacting systems heat up only after a time exponentially long in the drive frequency: for α>D under linear response, and for α>2D for generic drives.
desk verdict Solid advance on heating times for power-law Floquet systems; the main results hold up, but the conjectured tight Lieb-Robinson bound in Sec. V is too strong at short times and should be repaired. read the letter →
The pith
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
The reading
What carries the argument
The argument is carried by two constructions. In Section IV, heating is quantified through the dissipative response function $\sigma(\omega)=\sum_{i,j}\sigma_{ij}(\omega)$: diagonal entries are exponentially small by an eigenstate argument, and off-diagonal entries are bounded using a Lieb-Robinson bound with a logarithmic light cone for $\alpha>D$, yielding Eq. (29). In Section V, a periodic unitary $Q(t)=e^{\Omega(t)}$ is chosen order by order in the period $T$; the transformed Hamiltonian splits into a time-independent effective Hamiltonian $H_*$ (itself power-law with exponent $\alpha$) and a residual drive whose local norm is exponentially small in the frequency $\omega_*\propto 1/T$. Lieb-Robinson bounds—logarithmic cones for $\alpha>D$, algebraic cones for $\alpha>2D$—then control how much the residual drive can affect a local observable, producing the heating-time estimates.
What would settle it
Run a finite-size simulation of a one-dimensional spin chain with $1/r^{\alpha}$ couplings ($1<\alpha<2$), start it in a thermal state of $H_0$, apply a weak cosine drive of frequency $\omega$, and measure the steady-state energy absorption rate; if the rate decays polynomially rather than exponentially with $\omega$, the linear-response bound of Eq. (29) is falsified.
Extended reading notes
Core claim
The central claim is that a $D$-dimensional spin system with power-law interactions $1/r^{\alpha}$, driven periodically by a local drive, has a heating time exponentially large in the drive frequency $\omega$ whenever $\alpha$ exceeds a critical value. Under linear response theory (a weak harmonic drive and an initial thermal state), the paper proves this for all $\alpha>D$, bounding the heating rate by $C N \exp[-(1-D/\alpha)\kappa\omega]$ (Eq. (29)). For generic drives, the paper constructs an effective time-independent Hamiltonian $H_*$ through a Magnus-like expansion; the residual time-dependent part has local norm bounded by $C\lambda e^{-\kappa'\omega_*}$, and combining this with Lieb-Robinson bounds gives exponentially long heating times for $\alpha>2D$ (Eqs. (48), (49)). The paper further generalizes recent Lieb-Robinson bounds from two-body to $k$-body interactions, and shows that if a conjectured tight Lieb-Robinson bound of the form $\|[A(t),B]\|\le C\|A\|\|B\|(t^{\beta}/r)^{\alpha}$ (Eq. (50)) existed, the $\alpha>D$ result would extend to generic drives, closing the gap.
Load-bearing premise
The $\alpha>D$ result assumes linear response theory—a weak harmonic drive and an initial thermal state—and for strong drives the proof covers only $\alpha>2D$ unless the conjectured tight bound on the spread of quantum signals (Eq. (50)) is true.
Editorial extensions
If this is right
- Rapidly driven platforms with power-law interactions—trapped ions, Rydberg atoms, polar molecules—can host prethermal Floquet phases for exponentially long times when α>2D (for strong drives) or α>D (for weak drives).
- The generalized k-body Lieb-Robinson bounds are tools in their own right, applicable to error bounds for digital quantum simulation and to limits on information propagation in long-range systems.
- The effective Hamiltonian H* inherits the power-law structure of the original Hamiltonian, so the prethermal regime preserves long-range physics rather than becoming effectively short-range.
- For D<α<2D, the paper predicts exponential heating time but leaves the strong-drive case contingent on a tight Lieb-Robinson bound; the gap is expected to vanish once such a bound is proven.
Reading between the lines
- If the conjectured tight Lieb-Robinson bound is true, the same Magnus construction would likely yield prethermalization for all α>D, making exponential heating time a universal feature of power-law interactions.
- The exponential suppression of heating under weak drives should be directly measurable in current trapped-ion simulators with tunable α: measuring absorbed power per cycle versus ω for α just above D would test Eq. (29).
- The emphasis on light-cone shape suggests a general principle: any interaction ensemble whose Lieb-Robinson light cone grows at most algebraically should exhibit exponentially long heating times under local periodic drives, so the result may extend to other long-range models.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper studies heating times in periodically driven quantum spin systems on a D-dimensional lattice with power-law interactions decaying as 1/r^alpha. The main results are: (i) under linear response theory, for a weak harmonic drive and an initial thermal state, the heating rate is bounded by C N exp[-(1-D/alpha) kappa omega] for alpha>D, giving an exponentially long heating time in the drive frequency; (ii) for generic (possibly strong) drives, a Magnus-like expansion combined with Lieb-Robinson bounds yields a quasi-conserved effective Hamiltonian and an exponentially long heating time for alpha>2D; (iii) several Lieb-Robinson bounds are generalized from two-body to k-body interactions, including the Tran et al. bound; and (iv) the paper conjectures that a tight Lieb-Robinson bound for alpha>D would close the gap between the alpha>D linear-response result and the alpha>2D generic-drive result, and it presents a derivation of this gap-closing statement assuming such a bound. The appendices contain the detailed proofs of the Lieb-Robinson generalizations, the linear-response estimate, and the Magnus expansion estimates.
Significance. If the results hold, they extend the finite-range prethermalization and heating-suppression results to power-law interacting systems with a sharp alpha-dependent threshold, matching numerical evidence and clarifying the role of locality in Floquet heating. The k-body generalization of state-of-the-art Lieb-Robinson bounds is a useful technical contribution in its own right, as such bounds are likely to find applications beyond this paper. The authors are appropriately careful to label the tight-bound statement as a conjecture and to distinguish the proven alpha>2D result from the conjectured alpha>D extension. The main theorems are supported by detailed appendices, and the paper is honest about the assumptions entering the linear-response analysis. However, as discussed below, the conjectured tight bound in Section V is not valid in the form written, which affects the gap-closing demonstration as stated, though it does not invalidate the two main theorems.
major comments (1)
- [Section V, Eq. (50) and the derivation of Eq. (55)] The conjectured tight Lieb-Robinson bound in Eq. (50), ||[A(t),B]|| <= C ||A|| ||B|| (t^beta/r)^alpha, cannot hold for all t for a power-law Hamiltonian that contains the direct two-body interaction. For two operators supported a distance r apart, the first-order short-time expansion gives ||[A(t),B]|| >= c t / r^alpha for sufficiently small t. Since the paper's choices beta=1/(alpha-D) for D<alpha<D+1 and beta=1 for alpha>D+1 both satisfy alpha beta > 1, the conjectured bound is smaller than the direct lower bound for all sufficiently small t. Therefore Eq. (50) is too strong as a Lieb-Robinson bound. Because the derivation of the gap-closing estimate Eq. (55) integrates the conjectured bound from s=0, the demonstration that the gap vanishes does not follow as written. The problem is repairable by replacing t^beta with max(t,t^beta) or by treating the s<1 contribution separately with the direct-interaction lower bound; the exponential-in-omega conclusion should survive. This issue does not affect the linear-response result of Section IV or the alpha>2D result in Section V that uses the published Lieb-Robinson bounds.
minor comments (3)
- [Appendix B, Eq. (B10)] In the far-distance sum, the exponential term should carry a factor of r_*^{D-1} from the D-dimensional density of sites, so the second term is C N r_*^{D-1} e^{-mu r_*} rather than C N e^{-mu r_*}. As written, Eq. (B10) is not a valid upper bound. Because the exponential is subdominant relative to the algebraic term in the regime of interest, the final bound Eq. (B12) remains valid once the prefactor is restored, but the displayed inequality should be corrected.
- [Appendix A] The generalization of the Gong et al. bound to k-body interactions is carried out explicitly only for D=1, with the statement 'The proof for D>1 follows a very similar analysis.' Since this generalization is subsequently used in the main text for general D, please provide the D>1 convolution bound and the corresponding summation factor in at least as much detail as the one-dimensional case.
- [Section V, discussion after Eq. (55)] The sentence 'Recall that the best values we can hope for beta are beta=1/(alpha-D) when D+1>alpha>D and beta=1 when alpha>D+1' is used to infer an exponential heating time for all alpha>D. Once Eq. (50) is corrected as suggested in the major comment, it would be helpful to state explicitly that the corrected bound still yields the same beta and the same exponential dependence up to a constant in the time exponent.
Circularity Check
No significant circularity: the heating-time bounds are derived from separately proven Lieb-Robinson bounds and self-contained estimates; the tight-bound conjecture is explicitly conditional.
full rationale
We find no step in which a prediction reduces by construction to an input. In Sec. IV, Eq. (29) combines (i) the exponential smallness of individual response-matrix entries, Eq. (26), proved for power-law H0 in App. B1 from a commutator norm bound, and (ii) a distance suppression from the Gong et al. Lieb-Robinson bound, Eq. (B9). The optimization r_* = exp(kappa omega/alpha) is not a fit of the final decay exponent; it is a saddle-point choice between two independently bounded contributions. In Sec. V, the smallness of the residual drive V' in Eq. (45) follows from Lemmas 1 and 2 proven in App. C; it does not assume an exponentially long heating time. The commutator bound on delta, Eq. (46), is then estimated with published Lieb-Robinson bounds (Refs. 19 and 20), including the two-body bound of Tran et al. [20] generalized to k-body interactions in Sec. III by an explicit truncation proof. Ref. [20] is a self-citation, but it is a published, parameter-free theorem proved independently, and the present generalization is also proved here, so the citation is real evidence rather than a circular premise. The conjectured tight bound Eq. (50) and the resulting gap-closing estimate Eq. (55) are explicitly labeled a conjecture and are used only conditionally; even if Eq. (50) cannot hold at very short times, that is a soundness concern, not a circularity, and the paper does not count the conjectured statement as a theorem. No fitted input is renamed as a prediction.
Assumptions & free parameters
assumptions (5)
- domain assumption Power-law Hamiltonians with alpha > D have finite local norm lambda = 1 + sum_{j != i} 1/r_ij^alpha (Definition 1 and Eq. (A3)).
- domain assumption Linear response theory gives the energy absorption rate; the drive is weak and the state is initially thermal (Section IV).
- domain assumption Repeated commutators of power-law Hamiltonians grow at most as k! lambda^k (Lemma 3, Appendix E).
- domain assumption Existing Lieb-Robinson bounds with algebraic light cones hold for the effective Hamiltonians (Refs [19,20] and their k-body generalizations).
- ad hoc to paper The conjectured tight Lieb-Robinson bound (Eq. (50)) of the form ||[A(t),B]|| <= C ||A|| ||B|| (t^beta/r)^alpha for all alpha > D.
Cite this review
Pith. "Pith review of Locality and Heating in Periodically Driven, Power-law Interacting Systems." pith.science (2026). https://pith.science/paper/HMQ4MDLV
@misc{pith2026190802773,
author = {Pith},
title = {Pith review of: Locality and Heating in Periodically Driven, Power-law Interacting Systems},
year = {2026},
howpublished = {\url{https://pith.science/paper/HMQ4MDLV}},
note = {Machine review of arXiv:1908.02773}
}
abstract
We study the heating time in periodically driven $D$-dimensional systems with interactions that decay with the distance $r$ as a power-law $1/r^\alpha$. Using linear response theory, we show that the heating time is exponentially long as a function of the drive frequency for $\alpha>D$. For systems that may not obey linear response theory, we use a more general Magnus-like expansion to show the existence of quasi-conserved observables, which imply exponentially long heating time, for $\alpha>2D$. We also generalize a number of recent state-of-the-art Lieb-Robinson bounds for power-law systems from two-body interactions to $k$-body interactions and thereby obtain a longer heating time than previously established in the literature. Additionally, we conjecture that the gap between the results from the linear response theory and the Magnus-like expansion does not have physical implications, but is, rather, due to the lack of tight Lieb-Robinson bounds for power-law interactions. We show that the gap vanishes in the presence of a hypothetical, tight bound.
Forward citations
Cited by 2 Pith papers
-
Prethermalization without temperature
An emergent approximate conservation of magnetization creates a long-lived prethermal time-crystal regime at infinite temperature, and tuning the drive field can exponentially extend the NMR time-crystal signal.
-
Long-Range Prethermal Phases of Nonequilibrium Matter
The paper proves, with one explicit assumption in the intermediate regime, that prethermal Floquet phases exist for power-law interacting systems with exponent alpha > d, and predicts a disorder-free one-dimensional p...
Reference graph
Works this paper leans on
-
[20]
M. C. Tran, A. Y. Guo, Y. Su, J. R. Garrison, Z. El- dredge, M. Foss-Feig, A. M. Childs, and A. V. Gorshkov, Physical Review X 9, 031006 (2019)
work page 2019
-
[1]
We denote by Uti,tj the evolution unitary of the system from time ti to tj
First, divide [0,t ] into M equal time intervals and define t0,t 1,...,t M such that t0 = 0 and tj+1 − tj = τ = t/M. We denote by Uti,tj the evolution unitary of the system from time ti to tj
-
[2]
Setting Uj =UtM −j ,tM −j+1 for brevity, we can de- compose the evolution of A intoM timesteps: A(t) = U † MU † M−1...U † 1AU1...U M−1UM. (5)
-
[3]
We then use a truncation technique (explicitly de- scribed below) to approximate U † 1AU1 by some op- eratorA1 such that ‖ ‖ ‖U † 1AU1 −A1 ‖ ‖ ‖ =ε1, (6) and A1 is supported on a ball of size at most ℓ larger than the size of the support of A
-
[4]
find A2,...,A M such that ‖ ‖ ‖U † 2A1U2 −A2 ‖ ‖ ‖ =ε2, (7) ‖ ‖ ‖U † 3A2U3 −A3 ‖ ‖ ‖ =ε3, (8)
Repeat the above approximation for the other time slices, i.e. find A2,...,A M such that ‖ ‖ ‖U † 2A1U2 −A2 ‖ ‖ ‖ =ε2, (7) ‖ ‖ ‖U † 3A2U3 −A3 ‖ ‖ ‖ =ε3, (8) ... ‖ ‖ ‖U † MAM−1UM −AM ‖ ‖ ‖ =εM. (9) By the end of this process, we have approximated A(t) by an operator AM whose support is at most Mℓ larger than the support of A
-
[5]
Therefore, [AM,B ] = 0, and C(t,r ) is at most the total error of the approximation, i.e
By choosing Mℓ just smaller than r, the support of AM does not overlap with the support of B. Therefore, [AM,B ] = 0, and C(t,r ) is at most the total error of the approximation, i.e. ε =ε1 + · · · +εM. (10) The total error ε, and hence the bound, depends on the truncation technique used in Step 3. In Ref. [ 20], the authors used a technique inspired by d...
-
[6]
D. A. Abanin, W. De Roeck, W. W. Ho, and F. Huveneers, Physical Review B 95, 014112 (2017) , arXiv:1510.03405 [cond-mat.stat-mech]
arXiv 2017
- [7]
Show all 56 references
-
[8]
Kuwahara, T
T. Kuwahara, T. Mori, and K. Saito, Annals of Physics 367, 96 (2016)
2016
-
[9]
The drive is local if it can be written as a sum of local terms
-
[10]
J. W. Britton, B. C. Sawyer, A. C. Keith, C. C. J. Wang, J. K. Freericks, H. Uys, M. J. Biercuk, and J. J. Bollinger, Nature 484, 489 (2012)
2012
-
[11]
Cayssol, B
J. Cayssol, B. D´ ora, F. Simon, and R. Moessner, Physica Status Solidi Rapid Research Letters 7, 101 (2013) , arXiv:1211.5623 [cond-mat.mes-hall] . 9
2013 arXiv
-
[12]
Moessner and S
R. Moessner and S. L. Sondhi, Nature Physics 13, 424 (2017) , arXiv:1701.08056 [cond-mat.dis-nn]
2017 arXiv
-
[13]
Therefore, the error of the approximation in the j-th time slice is at most εj ≤ ‖A‖φ(Xj−1)f (τ,ℓ ), (16) where Xj is the support of Aj
that ‖A1‖ ≤ ‖A‖. Therefore, the error of the approximation in the j-th time slice is at most εj ≤ ‖A‖φ(Xj−1)f (τ,ℓ ), (16) where Xj is the support of Aj. Thus, the new bound is C(t,r ) ≤ 2 ‖B‖ε ≤ 2M ‖A‖ ‖B‖φmaxf (τ,ℓ ) (17) = 2 ‖A‖ ‖B‖ t τφmaxf (τ,ℓ ), (18) where φmax = max jφ...
-
[14]
D. V. Else, C. Monroe, C. Nayak, and N. Y. Yao, arXiv e-prints , arXiv:1905.13232 (2019), arXiv:1905.13232 [cond-mat.str-el]
2019 arXiv
-
[15]
Harper, R
F. Harper, R. Roy, M. S. Rudner, and S. L. Sondhi, arXiv e-prints , arXiv:1905.01317 (2019), arXiv:1905.01317 [cond-mat.str-el]
2019 arXiv
-
[16]
D. A. Abanin, W. De Roeck, and F. Huveneers, PRL 115, 256803 (2015) , arXiv:1507.01474 [cond-mat.stat-mech]
2015 arXiv
-
[17]
W. W. Ho, I. Protopopov, and D. A. Abanin, Phys. Rev. Lett. 120, 200601 (2018)
2018
-
[18]
Machado, G
F. Machado, G. D. Meyer, D. V. Else, C. Nayak, and N. Y. Yao, arXiv e-prints , arXiv:1708.01620 (2017), arXiv:1708.01620 [quant-ph]
2017 arXiv
-
[19]
Because f (τ,ℓ ) is a decreasing function of ℓ, the bound Eq
is equivalent to ℓ < rτ/t. Because f (τ,ℓ ) is a decreasing function of ℓ, the bound Eq. ( 18) would be the tightest if we chose ℓ = ξrτ/t for some ξ less than, but very close to, 1. The bound Eq. ( 18) becomes C(t,r ) ≤ 2 ‖A‖ ‖B‖φmaxf ( τ, ξrτ t ) t τ. (22) Note that the only...
-
[21]
K. Kim, S. Korenblit, R. Islam, E. E. Edwards, M.- S. Chang, C. Noh, H. Carmichael, G.-D. Lin, L.-M. Duan, C. C. J. Wang, J. K. Freericks, and C. Monroe, New Journal of Physics 13, 105003 (2011)
2011
-
[22]
Saffman, T
M. Saffman, T. G. Walker, and K. Mølmer, Rev. Mod. Phys. 82, 2313 (2010)
2010
-
[23]
J. S. Douglas, H. Habibian, C.-L. Hung, A. V. Gorshkov, H. J. Kimble, and D. E. Chang, Nature Photonics 9, 326 (2015) , article
2015
-
[24]
B. Yan, S. A. Moses, B. Gadway, J. P. Covey, K. R. A. Hazzard, A. M. Rey, D. S. Jin, and J. Ye, Nature 501, 521 (2013)
2013
-
[25]
J. R. Maze, A. Gali, E. Togan, Y. Chu, A. Trifonov, E. Kaxiras, and M. D. Lukin, New Journal of Physics 13, 025025 (2011)
2011
-
[26]
Such superextensivity is non-physical, as it would imply that a local drive instigates a diver- gent absorption per site in the thermodynamic limit
by sum- ming over the indices i,j yields a superextensive heating rate ∼ N 2e−κω. Such superextensivity is non-physical, as it would imply that a local drive instigates a diver- gent absorption per site in the thermodynamic limit. To address this, Ref. [ 5] introduced a bound ...
-
[27]
Otten, S
D. Otten, S. Rubbert, J. Ulrich, and F. Hassler, Phys. Rev. B 94, 115403 (2016)
2016
-
[28]
E. H. Lieb and D. W. Robinson, Comm. Math. Phys. 28, 251 (1972)
1972
-
[29]
D. V. Else, F. Machado, C. Nayak, and N. Y. Yao, arXiv e-prints , arXiv:1809.06369 (2018), arXiv:1809.06369 [quant-ph]
2018 arXiv
-
[30]
as: H ′(t) = e−adΩ [H0 +V (t)] −i 1 −e−adΩ adΩ ∂tΩ, (31) with ad ΩA = [Ω,A ]. From Eq. ( 31), we can define H ′ q(t) forq = 0, 1,... such that H ′ =∑ ∞ q=0H ′ q(t) is expanded 6 in powers of T : H ′ q(t) = Gq(t) −i∂tΩ q+1(t), (32) where we define Gq via Ω 1,..., Ω q as follows: ...
-
[31]
While our results are derived considering a simple square lattice, we believe that it is not difficult to extend them to other regular lattices
-
[32]
M. B. Hastings and T. Koma, Communications in Mathematical Physics 265, 781 (2006) , arXiv:math-ph/0507008 [math-ph]
2006 arXiv
-
[33]
Z.-X. Gong, M. Foss-Feig, S. Michalakis, and A. V. Gorshkov, PRL 113, 030602 (2014) , arXiv:1401.6174 [quant-ph]
2014 arXiv
-
[34]
Foss-Feig, Z.-X
M. Foss-Feig, Z.-X. Gong, C. W. Clark, and A. V. Gorshkov, PRL 114, 157201 (2015) , arXiv:1410.3466 [quant-ph]
2015 arXiv
-
[35]
Matsuta, T
T. Matsuta, T. Koma, and S. Naka- mura, Ann. Henri Poincare 18, 519 (2017) , arXiv:1604.05809 [math-ph]
2017 arXiv
-
[36]
We note that the approach in Ref. [ 20] also gives the effective Hamiltonian that generates the evolution from A to AM , which is more useful than the technique pre- sented here when knowing such a Hamiltonian is impor- tant, e.g. in digital quantum simulation
-
[37]
Bravyi, M
S. Bravyi, M. B. Hastings, and F. Verstraete, Phys. Rev. Lett. 97, 050401 (2006)
2006
-
[39]
Blanes, F
S. Blanes, F. Casas, J. Oteo, and J. Ros, Physics Reports 470, 151 (2009)
2009
-
[40]
Bukov, L
M. Bukov, L. D’Alessio, and A. Polkovnikov, Advances in Physics 64, 139 (2015) , https://doi.org/10.1080/00018732.2015.1055918
2015
-
[41]
Eckardt and E
A. Eckardt and E. Anisimovas, New Journal of Physics 17, 093039 (2015)
2015
-
[42]
Eldredge, Z.-X
Z. Eldredge, Z.-X. Gong, J. T. Young, A. H. Moosavian, M. Foss-Feig, and A. V. Gorshkov, Phys. Rev. Lett. 119, 170503 (2017)
2017
-
[43]
Machado, D
F. Machado, D. V. Else, G. D. Kahanamoku- Meyer, C. Nayak, and N. Y. Yao, arXiv e-prints , arXiv:1908.07530 (2019), arXiv:1908.07530
2019 arXiv
-
[44]
Chen and A
C.-F. Chen and A. Lucas, arXiv e-prints , arXiv:1907.07637 (2019), arXiv:1907.07637. Appendix A: Generalization of Gong et al. [23] to many-body interactions In this section, we prove Eq. ( 3) and thereby gener- alize the bound in Gong et al. [23] from two-body to k-body inter...
2019 arXiv
-
[45]
( 29) [Appendix B 2]
[Appendix B 1] and Eq. ( 29) [Appendix B 2]
-
[46]
light cone
using Lieb- Robinson bounds for power-law interactions. First, we provide an intuitive explanation why the norm of δ is small for small time. Recall that the op- erator O is initially localized on a single site. At small time, it is still quasilocal and therefore significantly ...
-
[47]
( 26) In this section, we prove the statement of Eq
Proof of Eq. ( 26) In this section, we prove the statement of Eq. ( 26) [also Eq. (B2) below]. We recall that the system Hamiltonian H0 is a power-law Hamiltonian, while the harmonic drive V (t) = g cos(ωt)O is a sum of local terms, g cos(ωt)Oi, each of which is supported on t...
-
[48]
( 29) We now provide a rigorous proof of Eq
Proof of Eq. ( 29) We now provide a rigorous proof of Eq. ( 29) in the main text. Equation ( B2) says that the ( i,j ) entry of σ([ω,ω +δω]) is exponentially suppressed. In principle, summing over all i,j implies that σ([ω,ω +δω]) is also exponentially small as a function of ω...
-
[49]
Structure of Gq for q < q max First, we prove the statement of Lemma 1 that the operatorsGq are also power-law Hamiltonians for all q < qmax. Proof. We proceed by induction and assume that Lemma 1 holds for all q up to q =q0 − 1 for some q0 ≥ 1. We now prove that it also holds...
-
[50]
( 44), which is a similar result to Lemma 1, but for q ≥qmax =ω∗
Structure of Gq for q ≥ qmax We now prove Eq. ( 44), which is a similar result to Lemma 1, but for q ≥qmax =ω∗. Lemma 2. For all q ≥ qmax = ω∗, Gq ∈ Ce −κ′qHα, whereC and κ′ are constants. 14 Proof. Let us first look at the first term in Eq. ( 33): Gq,1 = q∑ k=1 (−1)k k! ∑ 1≤i1,...
-
[51]
[ 23]’s bound First, we consider a generalization of the bound in Gong et al
Using Gong et al. [ 23]’s bound First, we consider a generalization of the bound in Gong et al. [23] [See also Eq. ( A12)]. The bound holds for α>D , has a logarithmic light cone t /greaterorsimilarlogr, and is extended to many-body interactions. To bound the com- mutator norm...
-
[52]
[ 19]’s bound Instead of using Gong et al
Using Else et al. [ 19]’s bound Instead of using Gong et al. ’s bound, we now use the bound in Else et al. [19], which already holds for many- body interactions. The bound states that when |X| = 1, ‖[A(t),B]‖≤C‖A‖‖B‖ { exp ( vt−r1−σ) +(vt)1+D/(1−σ) rσ(α−D) } , (D9) where 1 >σ ...
-
[53]
[20]’s bound In addition to Else et al
Using Tran et al. [20]’s bound In addition to Else et al. [19]’s bound, we can also use the bound in Tran et al. [20] [see also Eq. ( 24) for a generalization to k-body interactions], which also works for α > 2D. Compared to the bound in Else et al. , the bound in Tran et al. ...
-
[54]
In Appendix E 2, we present some bounds on discrete sums
-
[55]
We recall from the main text that Hα is the set of power-law Hamiltonians with the exponent α
Properties of the set Hα of power-law Hamiltonians In this section, we explore some properties of Hα that are useful for proving that the effective Hamiltonian is also power-law [See Appendix C]. We recall from the main text that Hα is the set of power-law Hamiltonians with the...
-
[56]
i, j ∈ X and i, j / ∈ Y , hold and ξ1 = 0 otherwise
For example, ξ1 = 1 if all of the conditions in the first row, i.e. i, j ∈ X and i, j / ∈ Y , hold and ξ1 = 0 otherwise. as a sum over the nine cases: ∑ Z∋i,j ‖hZ‖ = ∑ X∪Y ∋i,j ‖[aX,b Y ]‖ ≤ 2 ∑ X ∑ Y ‖aX ‖ ‖bY ‖ξ(X ∩Y ⁄= ∅)ξ(X ∪Y ∋i,j ) = 2 9∑ n=1 ∑ X ∑ Y ‖aX ‖ ‖bY ‖ξ(X ∩Y ⁄= ...
-
[57]
Bounds on discrete sums In this section, we provide bounds on some discrete sums used in the main text. Lemma 4. For all 1 ≤ k ≤ q, we have the following inequalities: ∑ 1≤i1,...,ik≤q i1+···+ik=q k∏ j=1 ij! ≤ q! (k − 1)!, (E10) ∑ 0≤i1,...,ik≤q i1+···+ik=q k∏ j=1 ij! ≤ 2kq!. (E...
Reviewed August 14, 2026 · model on record in the stance chip above.
Discussion (0). Continue with ORCID to comment.