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Non-Markovian out-of-equilibrium dynamics: A general numerical procedure to construct time-dependent memory kernels for coarse-grained observables Meyer, Hugues ; ; in Europhysics Letters (2020), 128(4), 40001 We present a numerical method to compute non-equilibrium memory kernels based on experimental data or molecular dynamics simulations. The procedure uses a recasting of the non-stationary generalized ... [more ▼] We present a numerical method to compute non-equilibrium memory kernels based on experimental data or molecular dynamics simulations. The procedure uses a recasting of the non-stationary generalized Langevin equation, in which we expand the memory kernel in a series that can be reconstructed iteratively. Each term in the series can be computed based solely on knowledge of the two-time auto-correlation function of the observable of interest. We discuss how to optimize this method in order to be the most numerically convenient. As a proof of principle, we test the method on the problem of crystallization from a super-cooled Lennard-Jones melt. We analyze the nucleation and growth dynamics of crystallites and observe that the memory kernel has a time extent that is about one order of magnitude larger than the typical timescale needed for a particle to be attached to the crystallite in the growth regime. [less ▲] Detailed reference viewed: 53 (0 UL)Cation distribution of Mn-Zn ferrite nanoparticles using pair distribution function analysis and resonant X-ray scattering ; ; et al in Europhysics Letters (2018) Detailed reference viewed: 84 (0 UL)Carnot efficiency at divergent power output Polettini, Matteo ; Esposito, Massimiliano in Europhysics Letters (2017), 118(40003), The widely debated feasibility of thermodynamic machines achieving Carnot efficiency at finite power has been convincingly dismissed. Yet, the common wisdom that efficiency can only be optimal in the ... [more ▼] The widely debated feasibility of thermodynamic machines achieving Carnot efficiency at finite power has been convincingly dismissed. Yet, the common wisdom that efficiency can only be optimal in the limit of infinitely slow processes overlooks the dual scenario of infinitely fast processes. We corroborate that efficient engines at divergent power output are not theoretically impossible, framing our claims within the theory of Stochastic Thermodynamics. We inspect the case of an electronic quantum dot coupled to three particle reservoirs to illustrate the physical rationale. [less ▲] Detailed reference viewed: 213 (8 UL)Sequencing chess ; Schilling, Tanja ; in Europhysics Letters (2016), 116(10009), We analyze the structure of the state space of chess by means of transition path sampling Monte Carlo simulations. Based on the typical number of moves required to transpose a given configuration of chess ... [more ▼] We analyze the structure of the state space of chess by means of transition path sampling Monte Carlo simulations. Based on the typical number of moves required to transpose a given configuration of chess pieces into another, we conclude that the state space consists of several pockets between which transitions are rare. Skilled players explore an even smaller subset of positions that populate some of these pockets only very sparsely. These results suggest that the usual measures to estimate both the size of the state space and the size of the tree of legal moves are not unique indicators of the complexity of the game, but that considerations regarding the connectedness of states are equally important. [less ▲] Detailed reference viewed: 93 (4 UL)Dissipation by a crystallization process Dorosz, Sven ; ; Schilling, Tanja in Europhysics Letters (2016), 113(10004), We discuss crystallization as a non-equilibrium process. In a system of hard spheres under compression at a constant rate, we quantify the amount of heat that is dissipated during the crystallization ... [more ▼] We discuss crystallization as a non-equilibrium process. In a system of hard spheres under compression at a constant rate, we quantify the amount of heat that is dissipated during the crystallization process. We interpret the dissipation as arising from the resistance of the system against phase transformation. An intrinsic compression rate is identified that separates a quasistatic regime from one of rapidly driven crystallization. In the latter regime the system crystallizes more easily, because new relaxation channels are opened, at the cost of forming a higher fraction of non-equilibrium crystal structures. We rationalize the change in the crystallization mechanism by analogy with shear thinning, in terms of a kinetic competition between near-equilibrium relaxation and external driving. [less ▲] Detailed reference viewed: 112 (3 UL)Socio-economic utility and chemical potential Lemoy, Rémi ; ; in Europhysics Letters (2011), 93(3), 38002-6 In statistical physics, the conservation of particle number results in the equalization of the chemical potential throughout a system at equilibrium. In contrast, the homogeneity of utility in socio ... [more ▼] In statistical physics, the conservation of particle number results in the equalization of the chemical potential throughout a system at equilibrium. In contrast, the homogeneity of utility in socio-economic models is usually thought to rely on the competition between individuals, leading to Nash equilibrium. We show that both views can be reconciled by introducing a notion of chemical potential in a wide class of socio-economic models, and by relating it in a direct way to the equilibrium value of the utility. This approach also allows the dependence of utility across the system to be determined when agents take decisions in a probabilistic way. Numerical simulations of a urban economic model also suggest that our result is valid beyond the initially considered class of solvable models. Copyright (C) EPLA, 2011 [less ▲] Detailed reference viewed: 76 (1 UL)Dissipative quantum dynamics in terms of a reduced density matrix distributed over the environment energy Esposito, Massimiliano ; in Europhysics Letters (2004), 65(6), Detailed reference viewed: 44 (0 UL) |
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