arXiv subjects

Gokhan Baris Bagci

Publications and source records attributed to Gokhan Baris Bagci.

3 recordsLinked to original sources

arXiv2026

The Funessian process: Non-Markovian dynamics shaped by the first event

We construct a continuous-time, positively divisible non-Markovian process with memory of the initial state that satisfies the differential Chapman--Kolmogorov equation. In the stationary state, the correlation function exhibits exponential decay, a behavior typically regarded as characteristic of Markovian dynamics. Nevertheless, the memory is preserved throughout the evolution of the process, manifesting itself in observable statistical quantities. We further demonstrate that mutual information serves as a reliable measure of the non-Markovian character of the process. As an application, we study a random walk driven by the constructed process and show that the memory effect breaks ergodicity and modifies transport properties such as the diffusion coefficient.

math.PR↗

arXiv2016

Experimental evidence of the failure of Jarzynski equality in active baths

Most natural and engineered processes, such as biomolecular reactions, protein folding, and population dynamics, occur far from equilibrium and, therefore, cannot be treated within the framework of classical equilibrium thermodynamics. The Jarzynski equality holds the promise to calculate the free-energy difference between two states from the Boltzmann-weighted statistics of the irreversible work done along trajectories arbitrarily out of equilibrium. This equality is the subject of intense activity. However, the applicability of the Jarzynski equality to systems far from equilibrium such as living matter has not been investigated yet. We present an experimental test of the Jarzynski equality predictions on a paradigmatic physical model, i.e. a Brownian particle held in an optical potential, coupled either to a thermal bath or to an active bath. While in the thermal bath we find that the Jarzynski equality correctly retrieves the free-energy difference from nonequilibrium measurements, in the active bath the Jarzynski equality fails because of the presence of non-Boltzmann statistics. We corroborate our experimental findings with theoretical arguments and numerical simulations.

cond-mat.soft↗

arXiv2012

Canonical equilibrium distribution derived from Helmholtz potential

Plastino and Curado [Phys. Rev. E 72, 047103 (2005)] recently determined the equilibrium probability distribution for the canonical ensemble using only phenomenological thermodynamical laws as an alternative to the entropy maximization procedure of Jaynes. In the current paper we present another alternative derivation of the canonical equilibrium probability distribution, which is based on the definition of the Helmholtz free energy (and its being constant at the equilibrium) and the assumption of the uniqueness of the equilibrium probability distribution. Noting that this particular derivation is applicable for all trace-form entropies, we also apply it to the Tsallis entropy showing that the Tsallis entropy yields genuine inverse power laws.

cond-mat.stat-mech↗