2009

Density ripples in expanding low-dimensional gases as a probe of correlations

A. Imambekov 1, 2, I. E. Mazets 3, 4, D. S. Petrov 5, 6, V. Gritsev 7, S. Manz 3, S. Hofferberth 8, T. Schumm 3, 9, E. Demler 8, J. Schmiedmayer 3 Physical Review A: Atomic, Molecular and Optical Physics 80 (2009) 033604 We investigate theoretically the evolution of the two-point density correlation function of a low-dimensional ultracold Bose gas after release from a tight transverse confinement. In the course of expansion thermal and quantum fluctuations

Density ripples in expanding low-dimensional gases as a probe of correlations Lire la suite »

Decimation flows in constraint satisfaction problems

Saburo Higuchi 1, Marc Mézard 2 Journal of statistical mechanics-theory and experiment (2009) P12009 We study hard constraint satisfaction problems with a decimation approach based on message passing algorithms. Decimation induces a renormalization flow in the space of problems, and we exploit the fact that this flow transforms some of the constraints into linear constraints over GF(2). In particular,

Decimation flows in constraint satisfaction problems Lire la suite »

Critical properties of 1D spin-gapped fermions at the onset of magnetization

T. Vekua 1, S. I. Matveenko 1, 2, G. V. Shlyapnikov 1, 3 JETP Letters / Sov Phys JETP Lett 90 (2009) 289-294 We develop an effective field theory for finding critical properties of 1D spin gapped fermions at the onset of magnetization. It is shown how the spin-charge interaction leads to a linear critical behavior and finite susceptibility for a wide range

Critical properties of 1D spin-gapped fermions at the onset of magnetization Lire la suite »

Creep dynamics of elastic manifolds via exact transition pathways

Alejandro B. Kolton 1, Alberto Rosso 2, Thierry Giamarchi 3, Werner Krauth 4 Physical Review B 79 (2009) 184207 We study the steady state of driven elastic strings in disordered media below the depinning threshold. In the low-temperature limit, for a fixed sample, the steady state is dominated by a single configuration, which we determine exactly from the transition pathways between metastable states.

Creep dynamics of elastic manifolds via exact transition pathways Lire la suite »

Convex Hull of N Planar Brownian Motions: Exact Results and an Application to Ecology

Julien Randon-Furling 1, Satya N. Majumdar 1, Alain Comtet 1, 2 Physical Review Letters 103 (2009) 140602 We compute exactly the mean perimeter and area of the convex hull of N independent planar Brownian paths each of duration T, both for open and closed paths. We show that the mean perimeter < L_N > = \alpha_N, \sqrt{T} and the mean area =

Convex Hull of N Planar Brownian Motions: Exact Results and an Application to Ecology Lire la suite »

Confinement Effects on the Kinetics and Thermodynamics of Protein Dimerization

Wei Wang 1, Wei-Xin Xu 1, Y. Levy 2, E. Trizac 3, P. G. Wolynes 4 Proceedings of the National Academy of Sciences of the United States of America 106 (2009) 5517-5522 In the cell, protein complexes form relying on specific interactions between their monomers. Excluded volume effects due to molecular crowding would lead to correlations between molecules even without specific interactions. What is the

Confinement Effects on the Kinetics and Thermodynamics of Protein Dimerization Lire la suite »

Casimir interactions of an object inside a spherical metal shell

Saad Zaheer 1, Sahand Jamal Rahi 1, Thorsten Emig 2, 3, Robert L. Jaffe 1, 4 Physical Review A: Atomic, Molecular and Optical Physics 81 (2009) 030502 We investigate the electromagnetic Casimir interactions of an object contained within an otherwise empty, perfectly conducting spherical shell. For a small object we present analytical calculations of the force, which is directed away from the center of the

Casimir interactions of an object inside a spherical metal shell Lire la suite »

Retour en haut