No abstract available

[en] High and low temperature relaxation of crystal steps are described in a unified picture, using a continuum model based on a modified expression of the step-free energy. Results are in agreement with experiments and Monte Carlo simulations of step fluctuations and monolayer cluster diffusion and relaxation. In an extended model where mass exchange with neighboring terraces is allowed, step transparency and a low temperature regime for unstable step meandering are found

[en] Through a very simple treatment we have constructed a lower bound for the statistical fluctuations of total survival probability of particles moving diffusively in a medium with random traps. We show that the asymptotic behaviour of the total survival probability is a non self-averaging quantity in that the fluctuations dominate the mean value. (author). 29 refs

[en] We analyze the current-voltage characteristic of a quantum conduction channel coupled to an electromagnetic environment with arbitrary frequency-dependent impedance. In the weak blockade regime the correction to the Ohmic behavior is directly related to the channel current fluctuations, vanishing at perfect transmission in the same way as shot noise. This relation can be generalized to describe the environmental Coulomb blockade in a generic mesoscopic conductor coupled to an external impedance, as the response of the latter to the current fluctuations in the former

No abstract available

[en] In this paper, we study the two-dimensional magnetic topological insulators from the correlated Chern insulator and the correlated Z₂ topological insulator at finite temperature. For the 2D correlated Chern insulator, we find that the thermal-fluctuation-induced magnetic topological insulator (MTI) appears in the intermediate interaction region of the correlated Chern insulator. On the contrary, for the correlated Z₂ topological insulator, thermal-fluctuation-induced MTI does not exist. Finally, we offer an explanation on the difference between the two cases. (paper)

[en] We develop a theory of fluctuating hydrodynamics based on extended thermodynamics through studying the 13-variable theory for a monatomic rarefied gas as a representative case. After analyzing the relationship between the present theory and the Landau-Lifshitz theory, we discuss the hierarchy structure of the hydrodynamic fluctuations. -- Highlights: → We develop a theory of fluctuating hydrodynamics based on extended thermodynamics. → We make clear the relationship between the present theory and the Landau-Lifshitz theory. → We find the general hierarchy structure of the hydrodynamic fluctuations basing on extended thermodynamics.

[en] The density fluctuations associated with the formation of large scale cosmic pancake-like and filamentary structures can be evaluated (1) using the Zeldovich approximation (2) for the evolution of non-linear inhomogeneities in the expanding universe. At the scale introduced by these non-linear density fluctuations due to pancakes, the standard scale-invariant correlation function is modified

[en] It is commonly accepted that contour length fluctuations increase the viscosity exponent for chains that diffuse by reptation. We found that length fluctuations in the necklace model can play an unexpected role as they can also decrease this exponent. A detailed analysis of the interplay between the discrete character of the model and how the fluctuations take place is presented in this work. Basically, we found that when fluctuations are symmetric their influence is the expected one; when fluctuations are not symmetric new effects can appear

[en] Global oscillation of the Sun with a period of 160 min were first discovered in 1974 and since observed in Crimea during the last 6 years; they were confirmed, in 1976-1979, by Doppler measurements at Stanford (Scherrer et al., 1980) and quite recently by observations of Fossat and Grec at the south geographic pole. The average amplitude of the oscillation is about 0.5 m s^-1. The phase shows remarkable stability at the period 160.010 min and good agreement between different sites on the Earth; therefore, this oscillation should now be recognized as definitely of solar origin. It is probably accompanied by synchronous fluctuations in the IR brightness and radio-emission of the Sun, and exhibits a dependence of the amplitude on the phase of solar rotation (with a peak of power at 27.2 days). In agreement with results of the Birmingham group and the South Pole observation we also find evidence in favour of a discrete spectrum within the 5 min global oscillations of the Sun, with the average splitting of about 69,5 μHz in frequency. Strict gas-dynamical equations being solved in the adiabatic approximation for a polytropic sphere n = 3 display the pattern of radial oscillations with wave separated by 120 m time-intervals filled with high frequency (and split by 117 μHz) oscillations implying a similarity with the observed pattern. (orig.)