15:00 – Ryan Barnett ( University of Maryland)
Multi-Component Ultracold Quantum Gases: Themes from Condensed Matter Physics and Beyond
Abstract: Ultracold atomic gases have recently proven to be enormously rich systems from the perspective of a condensed matter theorist. With the advent of optical lattices, such systems can now realize idealized model Hamiltonians used to study complex materials. Conversely, ultracold atomic gases can exhibit quantum phases and dynamics with no counterpart in the solid state due to their extra degrees of freedom and unique environments virtually free of dissipation. In this talk, I will discuss examples of such behavior arising from spinor degrees of freedom on which my recent research has focused. Examples will include bosons with artificially induced pin-orbit coupling and the non-equilibrium dynamics of spinor condensates.
16:00 – Ginestra Bianconi (Northeastern University, Boston)
Entropy of network ensembles
Abstract: The quantification of the complexity of networks is, today, a fundamental problem in the theory of complex systems. A possible roadmap to solve the problem is via extending key concepts of statistical mechanics and information theory to networks. In this talk we discuss recent works defining the Shannon entropy of a network ensemble and evaluating how it relates to the Gibbs and von Neumann entropies of network ensembles. The quantities we introduce here play a crucial role for the formulation of null models of networks through maximum-entropy arguments and contribute to inference problems emerging in the field of complex networks.