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Partial Entropy production of active particles with hidden states in potentials

T0 review · 0 major / 2 minor · reviewed 2026-06-29 · grok-4.3

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Pith's one-line read A perturbative framework calculates the partial entropy production of active particles with hidden self-propulsion in generic confining potentials.

desk verdict The paper extends the 2026 PRL perturbative method to hidden self-propulsion and derives a new partial entropy production rate for run-and-tumble particles in harmonic traps while matching the known AOUP result. read the letter →

arxiv 2605.29201 v1 pith:T6MIUVT3 submitted 2026-05-28 cond-mat.stat-mech

Jacob Knight , Gunnar Pruessner This is my paper · ORCID
classification cond-mat.stat-mech
keywords partialentropyproductionactiveparticleshiddenstatesconfiningpotentialsOrnstein-Uhlenbeckprocessrun-and-tumblemotiontime-reversalasymmetryperturbationtheory
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper extends an existing perturbative method to compute the partial entropy production rate for active particles whose self-propulsion is hidden from direct observation. The rate quantifies the time-reversal asymmetry that remains visible in the observed particle trajectories even when the full dynamics operate far from equilibrium. The extension applies to any generic confining potential. In the harmonic potential the same method recovers the exact known result for the active Ornstein-Uhlenbeck particle and supplies an explicit expression for the run-and-tumble particle. A reader would care because many experimental tracks of active matter are only partially observed, and the framework offers a route to extract the hidden irreversibility without reconstructing the full state.

What carries the argument

The perturbative framework for partial entropy production, extended from the cited PRL paper and applied to the hidden self-propulsion dynamics inside a confining potential.

What would settle it

A direct numerical simulation or exact analytic calculation of the partial entropy production rate for a run-and-tumble particle in a harmonic potential that yields a numerical value different from the perturbative expression derived in the paper.

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Extended reading notes

Core claim

The perturbative framework can be extended to calculate the partial entropy production in a generic confining potential for a generic active particle with hidden self-propulsion, and in the harmonic case it reproduces the exact result for an active Ornstein-Uhlenbeck particle while deriving the rate for a run-and-tumble particle.

Load-bearing premise

The perturbative framework introduced in the 2026 PRL paper remains valid and accurate when applied to active particles with hidden self-propulsion in confining potentials, including the harmonic case.

Editorial extensions

If this is right

  • The partial entropy production rate becomes accessible for arbitrary confining potentials through the extended perturbative approach.
  • The framework recovers the exact partial entropy production rate for the active Ornstein-Uhlenbeck particle in the harmonic potential.
  • An explicit expression for the partial entropy production rate of the run-and-tumble particle is obtained in the harmonic potential.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The same perturbative construction could be tested against simulations of active particles in anharmonic or time-dependent potentials.
  • Experimental trajectories of colloidal or biological active particles could be analyzed with this method to bound the hidden propulsion strength without full state reconstruction.
  • If the framework generalizes, it may separate the entropy-production contribution of hidden variables from the observed motion in a wider class of partially observed stochastic systems.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit.

Referee Report

0 major / 2 minor

Summary. The manuscript extends the perturbative framework from Phys. Rev. Lett. 136, 198302 (2026) to compute the partial entropy production rate quantifying time-reversal asymmetry for a generic active particle with hidden self-propulsion in a generic confining potential. In the harmonic potential, the framework is shown to reproduce the known exact result for an active Ornstein-Uhlenbeck particle and to yield a new expression for the run-and-tumble particle.

Significance. If the central extension holds, the work supplies a practical perturbative route to partial entropy production in partially observed active systems, which is relevant for connecting theory to experiments where propulsion is hidden. The explicit reproduction of the exact AOUP result in the harmonic case provides a non-trivial validation that the perturbative construction captures the relevant asymmetry without additional corrections from the hidden-state dynamics or the potential.

minor comments (2)
  1. The abstract states that the framework 'reproduces an exact result' for AOUP but does not indicate the numerical or analytic tolerance of the match; adding a brief statement or reference to the relevant comparison (e.g., in the harmonic-case section) would strengthen the validation claim.
  2. Notation for the hidden self-propulsion process (Markov switching rates, observation map) is introduced without an explicit comparison table to the original PRL framework; a short table or paragraph clarifying which elements are carried over unchanged would improve readability.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for their positive summary and recommendation of minor revision. No specific major comments were provided in the report, so we have no points requiring point-by-point response. The validation against the exact AOUP result is already included in the manuscript as a non-trivial check.

Circularity Check

1 steps flagged · score 2.0 of 10

Minor self-citation of prior framework, not load-bearing due to exact reproduction benchmark

  1. self citation load bearing [Abstract]
    "The present work extends the perturbative framework introduced in [Phys. Rev. Lett. 136, 198302 (2026)] to calculate in a generic confining potential the partial entropy production, which quantifies the time-reversal asymmetry of a generic active particle with hidden self-propulsion. Focusing on the harmonic case, we apply our framework to reproduce an exact result for the partial entropy production rate of an active Ornstein-Uhlenbeck particle and to derive the partial entropy production rate of a run-and-tumble particle."

    The load-bearing method originates in a prior paper by the same research group, but the citation is not solely justificatory because the abstract explicitly states that the framework is tested by reproducing an independently known exact result for AOUP.

full rationale

The paper extends a perturbative framework from a 2026 PRL by overlapping authors but validates its application in the harmonic case by reproducing the known exact partial entropy production rate for the active Ornstein-Uhlenbeck particle. This reproduction against an external benchmark provides independent content, so the self-citation is not the sole justification for the central claim or the new RTP derivation. No reductions by construction, fitted inputs renamed as predictions, or ansatzes smuggled via citation are exhibited in the provided text.

Assumptions & free parameters 0 free parameters · 0 assumptions · 0 invented entities

Abstract supplies no information on free parameters, axioms, or invented entities; all such elements are unknown.

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Cite this review

Pith. "Pith review of Partial Entropy production of active particles with hidden states in potentials." pith.science (2026). https://pith.science/paper/T6MIUVT3

@misc{pith2026260529201,
  author       = {Pith},
  title        = {Pith review of: Partial Entropy production of active particles with hidden states in potentials},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/T6MIUVT3}},
  note         = {Machine review of arXiv:2605.29201}
}
read the original abstract

Partially observed stochastic systems can appear (almost) time-reversal symmetric while in fact operating far from equilibrium. The present work extends the perturbative framework introduced in [Phys. Rev. Lett. 136, 198302 (2026)] to calculate in a generic confining potential the partial entropy production, which quantifies the time-reversal asymmetry of a generic active particle with hidden self-propulsion. Focusing on the harmonic case, we apply our framework to reproduce an exact result for the partial entropy production rate of an active Ornstein-Uhlenbeck particle and to derive the partial entropy production rate of a run-and-tumble particle.

Figures

Figures reproduced from arXiv: 2605.29201 by the authors.

Figure 1
Figure 1. FIG. 1. Run-and-tumble (RnT) process with (i) fully resolved [PITH_FULL_IMAGE:figures/full_fig_p001_1.png] view at source ↗

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

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