Emergent order in rheoscopic swirls (2009)
Wilkinson, Michael, Bezuglyy, Vlad, Mehlig, Bernhard
We discuss the reflection of light by a rheoscopic fluid (a suspension of microscopic rod-like crystals) in a steady two-dimensional flow. This is determined by an order parameter which is a...
Poincare Indices of Rheoscopic Visualisations (2009)
Bezuglyy, Vlad, Mehlig, Bernhard, Wilkinson, Michael
Suspensions of small anisotropic particles, termed 'rheoscopic fluids', are used for flow visualisation. By illuminating the fluid with light of three different colours, it is possible to determine...
Fingerprints of Random Flows? (2008)
Wilkinson, Michael, Bezuglyy, Vlad, Mehlig, Bernhard
We consider the patterns formed by small rod-like objects advected by a random flow in two dimensions. An exact solution indicates that their direction field is non-singular. However, we find from...
Planet Formation by Concurrent Collapse (2008)
Wilkinson, Michael, Mehlig, Bernhard
After reviewing the difficulties faced by the conventional theory of planet formation (based upon the aggregation of microscopic dust particles), we describe an alternative hypothesis. We propose...
Numerical Study of Eigenvector Statistics for Random Banded Matrices (2007)
Ville Uski, Bernhard Mehlig, Rudolf A. Römer, Michael Schreiber
The statistics of eigenvector amplitudes near the band center in random banded matrix ensembles is studied numerically. The nonlinear model provides a rigorous description of the statistics in these...
Semiclassical theory for absorption of radiation in particles with diffusive electron motion (2007)
Bernhard Mehlig, Michael Wilkinson
Abstract. We present a semiclassical analysis for the electric dipole absorption of electromagnetic radiation by small metallic particles, in the case where the electron motion is diffusive. We find...
Bernhard Mehlig, Nobuhiko Taniguchi
Fluctuations of expectation values of observables are calculated in complex quantum systems, such as disordered metallic grains or quantum systems with classically chaotic motion. We derive an exact...
Colliding Particles in Highly Turbulent Flows (2006)
Mehlig, Bernhard, Uski, Ville, Wilkinson, Michael
We discuss relative velocities and the collision rate of small particles suspended in a highly turbulent fluid. In the limit where the viscous damping is very weak, we estimate the relative...
Strength distribution of repeatedly broken chains (2006)
Wilkinson, Michael, Mehlig, Bernhard
We determine the probability distribution of the breaking strength for chains of N links, which have been produced by repeatedly breaking a very long chain.
Caustic activation of rain showers (2006)
Wilkinson, Michael, Mehlig, Bernhard, Bezuglyy, Vlad
We show quantitatively how the collision rate of droplets of visible moisture in turbulent air increases very abruptly as the intensity of the turbulence passes a threshold, due to the formation of...
Caustic activation of rain showers (2006)
Wilkinson, Michael, Mehlig, Bernhard, Bezuglyy, Vlad
We show quantitatively how the collision rate of droplets of visible moisture in turbulent air increases very abruptly as the intensity of the turbulence passes a threshold, due to the formation of...
Clustering by mixing flows (2005)
Duncan, Kevin, Mehlig, Bernhard, Ostlund, Stellan, Wilkinson, Michael
We calculate the Lyapunov exponents for particles suspended in a random three-dimensional flow, concentrating on the limit where the viscous damping rate is small compared to the inverse correlation...
Wilkinson, Michael, Mehlig, Bernhard, Cohen, Doron
We discuss the response of a quantum system to a time-dependent perturbation with spectrum \Phi(\omega). This is characterised by a rate constant D describing the diffusion of occupation probability...
Coagulation by random velocity fields as a Kramers Problem (2004)
Mehlig, Bernhard, Wilkinson, Michael
We analyze the motion of a system of particles suspended in a fluid which has a random velocity field. There are coagulating and noncoagulating phases. We show that the phase transition is related to...
Incipient localization in the Anderson model (1999)
Ville Uski, Bernhard Mehlig, Rudolf A. Römer, Michael Schreiber
We study statistical properties of the eigenfunctions in the three-dimensional Anderson model of localization. In the metallic regime, these are described by random matrix theory. As disorder is...
Smoothed universal correlations in the two-dimensional Anderson model (1998)
Uski, Ville, Mehlig, Bernhard, Roemer, Rudolf A., Schreiber, Michael
We report on calculations of smoothed spectral correlations in the two-dimensional Anderson model for weak disorder. As pointed out in (M. Wilkinson, J. Phys. A: Math. Gen. 21, 1173 (1988)), an...
Uski, Ville, Mehlig, Bernhard, Roemer, Rudolf A.
We have calculated wave functions and matrix elements of the dipole operator in the two- and three-dimensional Anderson model of localization and have studied their statistical properties in the...
Spectral Statistics in Chaotic Systems with Two Identical Connected Cells (1998)
Dittrich, Thomas, Koboldt, Gert, Mehlig, Bernhard, Schanz, Holger
Chaotic systems that decompose into two cells connected only by a narrow channel exhibit characteristic deviations of their quantum spectral statistics from the canonical random-matrix ensembles. The...
Semiclassical Linear Response: Far-Infrared Absorption for Ballistic Quantum Systems (1998)
Mehlig, Bernhard, Richter, Klaus
We derive a general semiclassical theory for linear response functions at finite temperatures and finite frequencies for quantum systems with internal ballistic dynamics. As a specific example, we...
Orbital Magnetism of Classically Chaotic Quantum Systems (1998)
Richter, Klaus, Mehlig, Bernhard
We employ orbital magnetic response functions as a tool to investigate flux-dependent spectral correlations of chaotic quantum dots in the ballistic regime. We compare for the first time results for...
Grundzustand und Anregungsspektrum des Hubbardmodells / (1993)
Stuttgart, Universiẗat, Diss., 1993.
An Accurate Model for Genetic Hitchhiking
Eriksson, Anders, Fernström, Pontus, Mehlig, Bernhard, Sagitov, Serik
We suggest a simple deterministic approximation for the growth of the favored-allele frequency during a selective sweep. Using this approximation we introduce an accurate model for genetic...