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Neighbourhood passivity is not preserved by Glauber annealing

Abstract

A Petersen-graph Glauber annealing run violates neighbourhood passivity.

The finite state space is Fin N. Energies, inverse temperatures and populations are real-valued, and populations are columns. The relation A describes a regular neighbourhood, while beta is the inverse-temperature schedule. All sums over Fin N include every state; a sum indexed by membership in a filtered Finset ranges over exactly the displayed neighbours. The bracketed DecidableRel A is an anonymous instance argument.

Definition 1.1 (Neighbourhood passivity at the next temperature).

Formalization. D5/S3/StatisticalMechanics/GlauberNeighbourhoodPassivityRefutation.neighbourhoodPassivity (✓ std3).

Citation. Yutong Luo; Yi-Zheng Zhen; Xiangjing Liu; Daniel Ebler; Oscar Dahlsten (2023). Bound on annealing performance from stochastic thermodynamics, with application to simulated annealing. DOI: 10.1103/PhysRevE.108.054119. URL: https://arxiv.org/abs/2311.10424v1.

Commentary.

For state i at step k, the Gibbs weights are evaluated at beta(k + 1), while the population differences use p(k). The sum runs over the states adjacent to i and is the ratio-weighted passivity expression in Eq. (41). The five reused annealing definitions are displayed below.

Definition 1.2 (The neighbourhood-passivity expectation).

Formalization. D5/S3/StatisticalMechanics/GlauberNeighbourhoodPassivityRefutation.claim (✓ std3).

Citation. Yutong Luo; Yi-Zheng Zhen; Xiangjing Liu; Daniel Ebler; Oscar Dahlsten (2023). Bound on annealing performance from stochastic thermodynamics, with application to simulated annealing. DOI: 10.1103/PhysRevE.108.054119. URL: https://arxiv.org/abs/2311.10424v1.

Commentary.

The source expects every connected regular neighbourhood with distinct energies to preserve nonnegative neighbourhood passivity throughout a Glauber annealing run started in the Gibbs state. The schedule is strictly increasing and starts at a positive inverse temperature. The conclusion quantifies over every step and every state.

Theorem 1.3 (A Petersen graph gives negative neighbourhood passivity).

Proof. Machine-checked in Lean as D5/S3/StatisticalMechanics/GlauberNeighbourhoodPassivityRefutation.result (✓ std3). ∎

Resolves. Problems/luo-zhen-liu-ebler-dahlsten-2023-neighbourhood-passivity-refutation (refuted) by D5/S3/StatisticalMechanics/GlauberNeighbourhoodPassivityRefutation.result.

Source. Repository-derived.

Acknowledgement. Yutong Luo; Yi-Zheng Zhen; Xiangjing Liu; Daniel Ebler; Oscar Dahlsten (2023). Bound on annealing performance from stochastic thermodynamics, with application to simulated annealing. DOI: 10.1103/PhysRevE.108.054119. URL: https://arxiv.org/abs/2311.10424v1.

Commentary.

Use the Petersen graph on ten states. Its neighbour sets, in order from 0 through 9, are {1,4,5}, {0,2,6}, {1,3,7}, {2,4,8}, {0,3,9}, {0,7,8}, {1,8,9}, {2,5,9}, {3,5,6}, and {4,6,7}. Every state has three neighbours, the relation is symmetric and irreflexive, and the graph is connected.

The energy vector on states 0 through 9 is (3,4,6,7,5,2,8,0,1,9). The inverse-temperature schedule is beta(0) = log(11/10) and beta(k) = log(4k) for every k at least 1; the first three values used here are log(11/10), log 4, and log 8. Start with the Gibbs population at log(11/10) and apply the Glauber matrix at the next scheduled temperature.

The exact first population is (6495040420/47812273803, 1579228369400/12287754367371, 531822026923/11522757986523, 160582769930/11522757986523, 442180927000/4095918122457, 4048016885/47812273803, 49100916611546/1388516243512923, 2707415959783376/11662677190645065, 268789869032696/1302071652477099, 782236372623151/87058739692823535). It is obtained by one exact matrix-vector multiplication.

At step 1 and state 0, the three neighbours have energies 4, 5 and 2. At beta(2) = log 8, the corresponding Gibbs-ratio weights are 7/9, 63/65 and −7/9. Substitution of the exact first population gives P_0(1) = −1454086156987/205381037283201, which is negative. Thus the universal nonnegativity assertion fails.

References