Generalized collective modes of a Lennard-Jones fluid. High mode approximation

Nonequilibrium statistical operator in the generalized hydrodynamics of fluids

“…The central peak of the dynamic structure factor is not present due to the absence of the heat mode in such a two variable formalism. All the numerical data are taken from [6]. Time correlation functions are calculated at reduced density n * = 0.845 and temperature T * = 1.706 for four values of wave-vector k, namely kσ LJ = 0.936 = k min σ LJ , 1.404, 1.872, and 4.678. τ σ = (σ 2 LJ m/ LJ ) 1/2 is constructed of parameters of the problem for argon.…”

“…On the other hand, an important achievement of the nonequilibrium theory of fluids are the results in the theory of molecular hydrodynamics, based on which the collective modes, timecorrelation functions, and generalized transport coefficients for the Lennard-Jones model of simple fluids were investigated [5][6][7]. Since a definite nonequilibrium statistical operator corresponds to the state of molecular hydrodynamics, the issue of a nonequilibrium state of a system of interacting particles relaxing to the state of molecular hydrodynamics presents definite interest.…”

Propagating Collective Excitations in Molten Salts

“…Molecular dynamics simulations were performed in the standard microcanonical ensemble on a system of 1000 particles in a cubic box in order to obtain the time evolution of hydrodynamic and short-time extended dynamical variables: (12) where the total number density n t (k, t), charge density n q (k, t), total mass-current density J t (k, t) and energy density ε(k, t) belong to the most slow hydrodynamic variables. Time correlation functions and static averages were used to estimate the matrix elements of the generalized hydrodynamic matrix T(k), constructed on the variables A = {A i (k, t)}.…”

“…Within the generalized collective mode (GCM) approach, proposed originally in reference [6] and developed then in references [12][13][14][15], the collective excitations in the fluids are directly connected with eigenvalues of the so-called generalized hydrodynamic matrix, which determines the time evolution of the system. Such a definition of collective modes is in agreement with the generally accepted principle of statistical physics, when the collective modes are identified with the poles of the relevant Green function or generalized susceptibility.…”

Zubarev's Method of a Nonequilibrium Statistical Operator and Some Challenges in the Theory of Irreversible Processes

“…For dense and strongly correlated systems, however, the interplay between the kinetic and long-lived collective modes is of the utmost significance. Linear irreversible processes in classical fluids [21][22][23] and plasmas [24] are the examples.…”