2013

Tradeoffs for number-squeezing in collisions of Bose-Einstein condensates

P. Deuar 1, T. Wasak 2, P. Zin 3, 4, J. Chwedenczuk 2, M. Trippenbach 2, 3 Physical Review A 88 (2013) 013617 We investigate the factors that influence the usefulness of supersonic collisions of Bose-Einstein condensates as a potential source of entangled atomic pairs by analyzing the reduction of the number difference fluctuations between regions of opposite momenta. We show that non-monochromaticity of the mother clouds

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Thick Filament Length and Isoform Composition Determine Self-Organized Contractile Units in Actomyosin Bundles

Todd Thoresen 1 Martin Lenz 2, 1, 3 Margaret Gardel 1, 3 Biophysical Journal, Biophysical Society, 2013, 104, pp.655-665. <10.1016/j.bpj.2012.12.042> Diverse myosin II isoforms regulate contractility of actomyosin bundles in disparate physiological processes by variations in both motor mechanochemistry and the extent to which motors are clustered into thick filaments. Although the role of mechanochemistry

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The Lyapunov exponent of products of random $2\times2$ matrices close to the identity

A. Comtet 1, 2, J. M. Luck 3, C. Texier 1, 4, Y. Tourigny 5 Journal of Statistical Physics 150 (2013) 13-65 We study products of arbitrary random real $2 \times 2$ matrices that are close to the identity matrix. Using the Iwasawa decomposition of $\text{SL}(2,{\mathbb R})$, we identify a continuum regime where the mean values and the covariances of the three Iwasawa parameters are

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Statistics of quantum transport in weakly non-ideal chaotic cavities

Sergio Rodriguez-Perez 1, Ricardo Marino 2, Marcel Novaes 1, Pierpaolo Vivo 2 Physical Review E 88 (2013) 052912 We consider statistics of electronic transport in chaotic cavities where time-reversal symmetry is broken and one of the leads is weakly non-ideal, i.e. it contains tunnel barriers characterized by tunneling probabilities $\Gamma_i$. Using symmetric function expansions and a generalized Selberg integral, we develop a systematic

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Statistical analysis of networks and biophysical systems of complex architecture

Olga Valba 1 Université Paris Sud – Paris XI (15/10/2013), Sergeï Nechaev (Dir.) Complex organization is found in many biological systems. For example, biopolymers could possess very hierarchic structure, which provides their functional peculiarity. Understating such, complex organization allows describing biological phenomena and predicting molecule functions. Besides, we can try to characterize the specific phenomenon by some

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Static replica approach to critical correlations in glassy systems

Silvio Franz 1, Hugo Jacquin 2, Giorgio Parisi 3, Pierfrancesco Urbani 1, Francesco Zamponi 4 Journal of Chemical Physics 138 (2013) 12A540 We discuss the slow relaxation phenomenon in glassy systems by means of replicas by constructing a static field theory approach to the problem. At the mean field level we study how criticality in the four point correlation functions arises because of the presence

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Spatial extent of an outbreak in animal epidemics

Eric Dumonteil 1, Satya N. Majumdar 2, Alberto Rosso 2, Andrea Zoia 1 Proceedings of the National Academy of Sciences 110 (2013) 4239-4244 Characterizing the spatial extent of epidemics at the outbreak stage is key to controlling the evolution of the disease. At the outbreak, the number of infected individuals is typically small, so that fluctuations around their average are important: then, it

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Sampling fractional Brownian motion in presence of absorption: a Markov chain method

Alexander K. Hartmann 1, Satya N. Majumdar 2, Alberto Rosso 2 Physical Review E 88 (2013) 022119 We study fractional Brownian motion (fBm) characterized by the Hurst exponent H. Using a Monte Carlo sampling technique, we are able to numerically generate fBm processes with an absorbing boundary at the origin at discrete times for a large number of 10^7 time steps

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