Invited Speakers Titles & Abstracts

• Douglas Abraham, University of Oxford
  Title: Ising Strips, Confinement and all that
  Abstract:This presentation will describe new, exact calculations of the local magnetisation in Ising strips with, and without, surface magnetic fields. The results will show the interplay of various length scales in the system; these include the bulk phase correlation length, the capillary length and the wetting film thickness. This work also leads into a resolution of the thorny problem of intrinsic structure: can a capillary wave-type of distribution be attached to an intrinsic structure by convolution? As calculations show, this is fundamentally incorrect. But we can define a basis, the elements of which are termed domain wall states, which is compatible with the notion of capillary waves in which the local magnetisation is described by an off diagonal matrix. Were the intrinsic structure hypothesis to be correct, this matrix would be purely diagonal, which is not the case. It is important to note that these results do not invalidate the concept of an interface Hamiltonian; rather, they give a precise interpretation and justification of this notion which is vital to a great many applications. A new example will be given of the geodesic-zigzag transition which has been reported over the past few years for systems with grain boundaries. Finally, the status of "entropic" fluctuation effects, which induce thermal Casimir forces, will be reviewed and some new results presented.
  
  
• Natan Andrei, Rutgers University
  Title: Quantum Impurities out of Equilibrium
  Abstract: TBA
  
  
• J. Beck, Rutgers University
  Title: Randomness in mathematics
  Abstract: I will discuss the following vague complexity law: (1) discrete systems are either "simple" or they exhibit "advanced pseudorandomness" with or without constraints (even when there is no apparent independence); and roughly speaking (2) a priory probabilities often exist, even when there is no intrinsic symmetry. Part of the difficulty os how to clarify these vague statements (that I like to call the "Solid-Liquid-Gas Conjecture"). Here "advanced" means roughly around the central limit theorem. An indirect evidence for the underlying "hidden randomness" is a mysterious phenomenon that I call Threshold Clustering. I give several illustrations (taken from my new book with the same title).
  
  
• Thierry Bodineau, Ecole Normale Superieure
  Title: Current large deviations for dissipative dynamics
  Abstract: TBA
  
  
• Gunduz Caginalp, University of Pittsburgh
  Title: Phase Field Equations: The Next Generation
  Abstract: Phase field models for the dynamics of interfaces arising from phase change have been used to understand solidification and other phenomena for over a quarter century. One application involves approximation of a (sharp) interface with the smooth parabolic phase field equations that facilitate numerical computation. Until recently these models were all first order in the (phase field) interface thickness.
  Recently, a new model developed in collaboration with Xinfu Chen and Christof Eck has been proven to approximate the limiting sharp interface to second order in the interface thickness. Numerical computations confirm that, with typical material parameters, the interface location of this phase field system will differ by at most this magnitude.
  These new models can be used in resolving more subtle interface problems involving complex geometries, for example.
  
  References: "A rapidly converging phase field model," Discrete and Continuous Dynamical Systems, 15, 1017-1034 (2006) www.pitt.edu/~caginalp/pub98.pdf
  "Numerical tests of a phase filed model with second order accuracy," SIAM J. Appl. Math. 68, 1518-1534 (2008) www.pitt.edu/~caginalp/pub101.pdf
  Both papers can be downloaded from www.pitt.edu/~caginalp.
  
  
• Predrag Cvitanovic, Georgia Tech.
  Title: Geometry of Turbulence: A Stroll Through 61,506 Dimensions
  Coauthors: F. Gibson, J. Halcrow and D. Viswanath
  Abstract: In the world of moderate Reynolds number, everyday turbulence of fluids flowing across planes and down pipes a velvet revolution is taking place. Experiments are almost as detailed as the numerical simulations, DNS is yielding exact numerical solutions that one dared not dream about a decade ago, and dynamical systems visualization of turbulent fluid's state space geometry is unexpectedly elegant.
  We shall take you on a tour of this newly breached, hitherto inaccessible territory. Mastery of fluid mechanics is no prerequisite, and perhaps a hindrance: the talk is aimed at anyone who had ever wondered why - if no cloud is ever seen twice - we know a cloud when we see one? And how do we turn that into mathematics?
  
  
• Gregory Falkovich, Weizmann Institute
  Title: Symmetries of turbulent state
  Abstract: TBA
  
  
• Jack Harris, Yale University
  Title: New measurements of persistent currents in normal metal rings
  Coauthors: A. C. Bleszynski-Jayich, W. E. Shanks, B. Peaudecerf, E. Ginnosar, F. von Oppen, and L. Glazman
  Abstract: We have developed a new technique for measuring persistent currents in normal metal rings which offers greater sensitivity, lower back action, and operation over a wider range of experimental parameters. Using this approach we have measured persistent currents in several samples as a function of ring size, array size, sample temperature, and magnetic field, and found quantitative agreement with the predictions for noninteracting diffusive electrons.
  
  
• Dan Hone, Kavli Institute for Theoretical Physics, UCSB
  Title: Statistical Mechanics of Floquet Systems
  Abstract: Although the statistical mechanics of periodically driven ("Floquet") systems in contact with a heat bath has some formal analogy with the traditional statistical mechanics of undriven systems, closer examination reveals radical differences. We give an explicit prescription for the reduced density matrix, even as the states and quasienergies become pathological as the dimension of the state space increases without limit.
  
  
• David Huse, Princeton University
  Title: Strongly-correlated cold atomic Fermi gas
  Abstract: TBA
  
  
• Sabre Kais, Purdue University
  Title: Finite Size Scaling in Quantum Mechanics
  Abstract: TBA
  
  
• Aharon Kapitulnik, Stanford University
  Title: Recent results on the Superconductor-Insulator transition
  Abstract: TBA
  
  
• Gady Kozma, Weizmann Institute
  Title: Geometric scale-free graphs
  Abstract: TBA
  
  
• James Langer, University of California, Santa Barbara
  Title: Effective Disorder Temperature and Nonequilibrium Thermodynamics of Amorphous Materials
  Abstract: TBA
  
  
• Ron Levy, Rutgers University
  Title: Exploring landscapes for protein folding, binding, and fitness
  Abstract: We present an approach to the study of protein folding and binding that makes use of the combined power of replica exchange simulations and a network model for the kinetics. We carry out replica exchange simulations to generate a very large (~10⁶) set of states using an all-atom effective potential function and construct a kinetic model for the folding, using an ansatz that allows kinetic transitions between states based on structural similarity. Despite the power of the technique, a better understanding of the relationship between the physical kinetics of the systems being studied and their "kinetics" in the replica exchange ensemble is needed in order to use this new technology to maximum advantage. Towards this end, I will discuss our use of network models to "simulate" replica exchange simulations of protein folding and binding.
  References:
  [1] A.K. Felts, Y. Harano, E. Gallicchio, and R.M. Levy, Proteins, 56, 310-321 (2004).
  [2] M. Andrec, A.K. Felts, E. Gallicchio, and R.M. Levy, Proceedings Natl. Acad. Sci. USA, 102, 6801-6806 (2005).
  [3] K.P. Ravindranathan, E. Gallicchio, R.A. Friesner, A.E. McDermott, and R.M. Levy, Conformational equilibrium of cytochrome P450 complexed with substrate: a replicaa exchange MD study.
  
  
  
• Roberto Livi, Instituto Nazionale di Fisica Nucleare (INFN)
  Title: Multiple timescales in a model for DNA denaturation dynamics
  Abstract: The denaturation dynamics of a long double-stranded DNA is studied by a model of the Poland-Scheraga type, where helicity constraints are taken into account. The update rule modifies locally the linking of the two strands, allowing twist dissipation at the two ends of the double strand. The result is a slow denaturation, characterized by two time scales that depend on the chain length $L$. In a regime up to a first characteristic time $\tau_1\sim L^{2.15}$ the chain embodies an increasing number of small bubbles. Then, in a second regime, bubbles coalesce and form entropic barriers that effectively trap residual double-stranded segments within the chain, slowing down the relaxation to fully molten configurations, which takes place at $\tau_2\sim L3$. This scenario is different from the picture in which the helical constraints are neglected.
  
  
• Bruno Nachtergaele, University of California, Davis
  Title: Applications of Lieb-Robinson bounds
  Abstract: TBA
  
  
• Marcelo Magnasco, Rockefeller University
  Title: Self-tuned critical network
  Abstract: TBA
  
  
• Alan Middleton, Syracuse University
  Title: Simulating Dynamics in Glassy Models Using Exact Sampling
  Abstract: The simulation of materials with random competing interactions, such as spin glasses, is simultaneously of great interest and very difficult due to the glassy dynamics which makes equilibration times extremely long. The challenge is to both find the ground state or lowest free energy state which the system finds at long times and to study the approach of the system to that long-time state. Heuristic speed-up of the dynamics can be carried out by finding ground states or sampling equilibrium states on randomly selected patches of a given scale which is putatively the coarsening scale at some long time. This approach implements a realization of exact sampling that exactly samples the configurations of a 2D spin glass in a sample with fixed boundaries and selected size. This patchwork dynamics is also a useful heuristic for finding ground states in systems that are otherwise difficult to optimize.
  
  
• Kathryn Moler, Stanford University
  Title: Persistent Currents in Gold Rings
  Abstract: TBA
  
  
• Gilles Montambaux, Universite Paris-Sud, CNRS
  Title: Quantum transport and Aharonov-Bohm effect in diffusive networks
  Abstract: We have considered the physics of quantum oscillations (persistent current, conductance oscillations,) for arrays of mesoscopic disordered rings, in the presence of an external magnetic field. If the case of the isolated ring is well known, we show that for connected rings, the winding of the Brownian trajectories around each ring is modified, leading to a new harmonics content of the quantum oscillations. This analysis is based on the calculation of the spectral determinant of the diffusion equation for which we find a simple expression on any network. We study especially the three cases: a single ring connected to an arbitrary network, a linear array of rings connected with long or short wires, and the square network.
  
  
• Stefano Olla, Universite de PARIS - DAUPHINE
  Title:From microscopic Hamiltonian dynamics to heat equation: a weak coupling approach
  Abstract: TBA
  
  
• David Ruelle, IHES, France
  Title(s): Linear response for general smooth dynamical systems
  Randomness in nature
  Abstract: A natural model for nonequilibrium statistical mechanics is given by a general smooth dynamical system on a compact manifold. Nonequilibrium steady states correspond to SRB measures, entropy creation to volume contraction, etc. Of course, this misses some important physical features related to the thermodynamic limit. Nevertheless, it is instructive to study linear response in this setting. For uniformly hyperbolic dynamical systems, the SRB measure depends differentiably on parameters, and linear response can be interpreted in terms of a susceptibility function with the expected analyticity properties. For systems that are not uniformly hyperbolic, however, nondifferentiable response arises, and also 'acausal' singularities of the susceptibility, for which we shall give a physical interpretation in terms of 'energy nonconservation'.
  
  
• Doug Scalapino, University of California, Santa Barbara
  Title: A twisted ladder: relating the Fe superconductors to the the high Tc cuprates
  Abstract: During the past year, the Fe-superconductors have been the object of intense study. Here we discuss a simple model that relates these new superconductors to the high Tc cuprates.
  
  
• Moshe Schechter, University of British Columbia
  Title: Low temperature universality in disordered solids
  Abstract: Amorphous solids, polymers, and disordered solids show striking universal characteristics at low temperatures, despite enormous differences in their microscopic structure. The phenomenological model of tunneling two level systems (TLS) (Anderson, Halperin, and Varma, and Phillips) accounts well for much of the observed phenomena. However, the model can not account for the smallness and universality of the phonon attenuation nor for the energy scale (3K) below which universality is observed, and the nature of the TLS is not known. I will argue here that a model containing two kinds of TLS, differing by their symmetry under inversion, can explain the above questions. The symmetric TLS interact weakly with the phonon field, but gap the strongly interacting asymmetric TLS below 3K, and therefore dictate weak and universal phonon attenuation at low temperatures.
  
  
• Beate Schmittmann, Virginia Tech.
  Title: Consensus formation in social networks
  Abstract: TBA
  
  
• Gerd Schoen, Universitat Karlsruhe
  Title: Single-electron tunneling and fluctuation theorem
  Coauthor: Y. Utsimi
  Abstract: TBA
  
  
• Anirvan Sengupta, Rutgers University
  Title: Action at a Distance in Eukaryotic Gene Regulation
  Abstract: Higher organisms use collective phenomena to influence gene expression over large distances along the genome. I go over a model of epigenetic chromatin silencing in sir1 mutants in bakers yeast as an example non-local regulatory effects in chromosomes and show how modeling sheds some light on special features of genetic switches with modification of extended regions of chromatin. Time permitting, I will get into the issues of long range action of enhancers and plausible mechanisms of insulators blocking such action.
  
  
• Israel Michael Sigal, University of Toronto
  Title: On Quantum Decoherence
  Abstract: In this talk I consider a small quantum system interacting with the environment described by a massless Bose or Fermi quantum field. I review recent results (jointly with Marco Merkli and Gennady Berman) on decoherence and thermolization times for such systems. In particular, I will describe a connection of the decoherence and thermolization with quantum resonances originating in stationary states of the decoupled total system.
  
  
• Sara Solla, Northwestern University
  Title: Statistical physics, Bayesian inference, and neural information processing
  Abstract:TBA
  
  
• Tom Spencer, Institute for Advanced Study
  Title: Diffusion in a 3D SUSY hyperbolic sigma model
  Abstract: A simplified model for Anderson localization and delocalization in 3D is shown to have a "diffusive" phase in 3D. Correlations may be expressed as a random walk in a highly correlated random environment.
  
  
• Frank Stillinger, Princeton University
  Title:Modeling Prebiotic Appearance of Biological Chirality
  Abstract: Living organisms incorporate molecules whose geometric structures display virtually invariant chirality. A major scientific puzzle is how this geometric symmetry-breaking occurred on the early earth. A simple statistical model has been devised and explored to illustrate one possible scenario.
  
  
• Cedric Villani, UMPA, Ecole Normale Superieure de Lyon
  Title: Landau Damping
  Abstract: TBA
  
  
• John Weeks, University of Maryland
  Title: Competition between local hydrogen-bonding and long-ranged dipolar forces in water
  Abstract: TBA
  
  
• Michael Widom, Carnegie Mellon
  Title: Folding of riboswitches during RNA transcription
  Abstract: Riboswitches are primitive mechanisms for gene regulation found in bacteria, in which messenger RNA molecules directly regulate their own activities. To function properly, riboswitches must fold correctly, and do so quickly enough that specific conformations occur during their own transcription. We show that genetic sequences have been naturally selected for efficiency of folding, and that essential metastable structures are sufficiently long-lived to perform their necessary biological functions.
  
  
• Peter Woelfle, Universitat Karlsruhe
  Title: Transport through a barrier embedded in a Luttinger liquid: nonuniversal scaling at strong coupling
  Abstract: The linear response conductance of a quantum wire with a single potential barrier is calculated within a fermionic description, by summing up infinite classes of terms in perturbation theory in the interaction [1,2]. We find it convenient to employ the Luttinger liquid model, and a current algebra representation. The fermionic description avoids difficulties present in earlier bosonization treatments of the problem. We find that the conductance obeys scaling with either the length of the wire (at zero temperature) or with the temperature. The leading scaling exponents are found to be universal and agree with those determined earlier [3]. The respective scaling functions differ, however, in the regime of intermediate conductance values. The role of scale independent terms in perturbation theory is high-lighted.
  [1] D.N. Aristov and P. Woelfle, EPL 82, 27001 (2008)
  [2] D. N. Aristov and P. Woelfle, arXiv:0902.4170 [cond-mat.str-el]
  [3] C.L. Kane and M.P.A. Fisher, PRL 68. 1212; PR B46, 15233 (1992)
  
  
  
• Fred Wu, Northeastern University
  Title: Lattice statistics on kagome-type lattices
  Abstract: Kagome-type lattices are lattices having an underlying kagome structure. Examples are the 3-12 lattice and kagome-triangular lattices considered recently in the literature. We discuss both recent and new results of lattice models on kagome-type lattices. These include exact results on close-packed dimers and a conjectured result on the q-state Potts model. Specifically, a closed-form expression is conjectured for the Potts critical point for a general kagome-type lattice. It is shown that for q = 1 the conjecture yields results agreeing extremely well with the highly accurate bond percolation thresholds obtained recently by Ziff and co-workers.
  
  
• Amir Yacoby, Harvard University
  Title: Coherent Control of Two-Electron Logical Spin Qubits
  Abstract: TBA