Memory effect in uniformly heated granular gases

We evidence a Kovacs-like memory effect in a uniformly driven granular gas. A system of inelastic hard particles, in the low density limit, can reach a non-equilibrium steady state when properly forced. By following a certain protocol for the drive time dependence, we prepare the gas in a state where the granular temperature coincides with its long time value. The temperature subsequently does not remain constant, but exhibits a non-monotonic evolution with either a maximum or a minimum, depending on the dissipation, and on the protocol. We present a theoretical analysis of this memory effect, at Boltzmann-Fokker-Planck equation level, and show that when dissipation exceeds a threshold, the response can be coined anomalous. We find an excellent agreement between the analytical predictions and direct Monte Carlo simulations

Kovacs-like memory effect in driven granular gases

While memory effects have been reported for dense enough disordered systems such as glasses, we show here by a combination of analytical and simulation techniques that they are also intrinsic to the dynamics of dilute granular gases. By means of a certain driving protocol, we prepare the gas in a state where the granular temperature $T$ coincides with its long time limit. However, $T$ does not subsequently remain constant, but exhibits a non-monotonic evolution before reaching its non-equilibrium steady value. The corresponding so-called Kovacs hump displays a normal behavior for weak dissipation (as observed in molecular systems), but is reversed under strong dissipation, where it thus becomes anomalous.Comment: 5 pages, to appear in Physical Review Letter

Comment on "Critique and correction of the currently accepted solution of the infinite spherical well in quantum mechanics" by Huang Young-Sea and Thomann Hans-Rudolph

We comment on the paper "Critique and correction of the currently accepted solution of the infinite spherical well in quantum mechanics" by Huang Young-Sea and Thomann Hans-Rudolph, EPL 115, 60001 (2016) .Comment: 2 pages; Submitted to the Comments Section of EP

Glass-like dynamical behavior in hierarchical models submitted to continuous cooling and heating processes

The dynamical behavior of a kind of models with hierarchically constrained dynamics is investigated. The models exhibit many properties resembling real structural glasses. In particular, we focus on the study of time-dependent temperature processes. In cooling processes, a phenomenon analogous to the laboratory glass transition appears. The residual properties are analytically evaluated, and the concept of fictive temperature is discussed on a physical base. The evolution of the system in heating processes is governed by the existence of a normal solution of the evolution equations, which is approached by all the other solutions. This trend of the system is directly related to the glassy hysteresis effects shown by these systems. The existence of the normal solution is not restricted to the linear regime around equilibrium, but it is defined for any arbitrary, far from equilibrium, situation.Comment: 20 pages, 7 figures; minor changes, accepted in Phys. Rev.

European patterns of development in historical perspective

Europe provides a suitable scenario for testing empirical regularities of growth since, to a large extent, its countries share institutions, policies, and resource endowments. Patterns of development, which associate structural change with variations in GDP per head and population, are constructed for modern Europe (1850-1990) along the lines of Chenery and Syrquin's pathbreaking work. Thus, it is possible to discern whether a common set of development processes is observable for the whole continent and whether countries that had a late start exhibited, as suggested by Gerschenkron, a differential behaviour in terms of accumulation, resource allocation, and demographic transition. The results tend to confirm the different nature of latecomers' development.Publicad

Growth, inequality, and poverty in Spain, 1850-2000: evidence and speculation.

Was the Civil War (1936-39) originated by staggering inequality and extreme poverty? How did Franco's dictatorship (1939-75) affect inequality and poverty? As a first step to provide an answer, growth and inequality over the long-run are assessed and their impact on absolute poverty calibrated. The paper concludes that during the last one and a half centuries economic growth, but also the decline in inequality during the Interwar years and since the late 1950s, led to a substantial reduction in absolute poverty. Raising inequality and poverty do not seem to have triggered the Civil War

Kovacs-like memory effect in athermal systems: linear response analysis

We analyse the emergence of Kovacs-like memory effects in athermal systems within the linear response regime. This is done by starting from both the master equation for the probability distribution and the equations for the physically relevant moments. The general results are applied to a general class of models with conserved momentum and non-conserved energy. Our theoretical predictions, obtained within the first Sonine approximation, show an excellent agreement with the numerical results.Comment: 18 pages, 6 figures; submitted to the special issue of the journal Entropy on "Thermodynamics and Statistical Mechanics of Small Systems

The Kovacs effect in the one-dimensional Ising model: a linear response analysis

We analyze the so-called Kovacs effect in the one-dimensional Ising model with Glauber dynamics. We consider small enough temperature jumps, for which a linear response theory has been recently derived. Within this theory, the Kovacs hump is directly related to the monotonic relaxation function of the energy. The analytical results are compared with extensive Monte Carlo simulations, and an excellent agreement is found. Remarkably, the position of the maximum in the Kovacs hump depends on the fact that the true asymptotic behavior of the relaxation function is different from the stretched exponential describing the relevant part of the relaxation at low temperatures.Comment: accepted for publication in Phys. Rev.