arXiv subjects

Kyota Tamano

Publications and source records attributed to Kyota Tamano.

2 recordsLinked to original sources

arXiv2026

Thermodynamic signatures of the period-doubling route to chemical chaos

Chemical reaction networks can evolve from stable oscillations to chaos through successive period doublings. We investigate general properties of entropy-production fluctuations near the onset of chaos and within the chaotic regime in reversible, well-mixed reaction networks. Near an isolated supercritical period-doubling bifurcation, we find a one-sided divergence of the diffusion constant with exponent one. For chaotic attractors satisfying the stated conditions, the entropy variance per unit volume grows exponentially when the macroscopic limit is taken first. Its exponential growth rate is $2λ_{\max}$, where $λ_{\max}$ is the largest Lyapunov exponent, implying a divergent diffusion constant. We also discuss the volume dependence of the fluctuations and the underlying physical mechanisms.

cond-mat.stat-mech↗

arXiv2026

Universal criticality of entropy production in chemical reaction networks

Stochastic thermodynamics gives universal relations for microscopic entropy production, yet its critical behavior at macroscopic nonequilibrium transitions remains unclassified. We study well-mixed reversible chemical reaction networks in the macroscopic-first limit, where transitions arise as local bifurcations of mass-action dynamics. Using linear-noise formulas, center-manifold normal forms, and Floquet theory, we obtain generic exponents for entropy-production fluctuations and responses at pitchfork, transcritical, saddle-node, and Hopf bifurcations. Beyond this low-order classification, a trajectory-space Cramér-Rao type bound yields the universal scaling inequality $α- 2β\geq 0$. Hence divergent responses require divergent fluctuations, but not conversely, making entropy-production fluctuations a sharper probe of nonequilibrium criticality.

cond-mat.stat-mech↗