Past Events

  • Dissertation Defense: "Optical Spectroscopy of Defects in Two-Dimensional Materials and Applications for DNA Sequencing"

    LRSM, Reading Room

    William Parkin (U of Penn)

  • Dissertation Defense: "Two-point Statistics for Testing Models of Cosmic Structure"

    David Rittenhouse Laboratory, 4N9

    Yuedong Fang (U of Penn)

  • Condensed Matter Seminar: "Controlling Strong Light Matter Coupling with Photonic Crystals"

    David Rittenhouse Laboratory, A4

    Hui Deng (University of Michigan)

    Microcavity exciton-polaritons provide a unique photonic platform that manifests non-equilibrium quantum orders. It combines strong nonlinearity and rich many-body physics of matter with robust coherence and ready accessibility of light, allowing diverse quantum phenomena at high temperature, on a photonic chip. To go beyond 2D condensation physics, it becomes important to control the fundamental properties of polaritons without destroying the quantum orders.

  • Astro Seminar: "The Milky Way's Dust in Three Dimensions"

    David Rittenhouse Laboratory, A4

    Edward Schlafly (Lawrence Berkeley National Laboratory)

    Most observations of the Milky Way's gas and dust are limited to two dimensions; their angular distribution is precisely measured, but their distribution in distance is much more uncertain.  Large surveys of stars can be used to resolve this uncertainty.  Because light from stars is absorbed and scattered by intervening material before observation on earth, the Galaxy's stars can be used as a dense network of lighthouses to illuminate the structure and properties of the Milky Way's interstellar medium.

  • Elon Musk Public Lecture: "Will Evolution and Information Theory Provide the Fundamentals of Physics?"

    Meyerson Hall, B1 (210 S. 34th Street)

    Sylvester James Gates, Jr. (Brown)

    Join us for an evening with theoretical physicist Sylvester James Gates, Jr., as he talks about how the mathematical and theoretical aspects of his physics research have traversed concept spaces from equations to graphical imagery to coding theory error-correction, and how it points towards evidence that an evolution-like process may have acted on the mathematical laws that describe reality.

  • Math/Phys Joint Seminar: "Progress Toward A Mathematically Rigorous Space-time SUSY Representation Theory"

    David Rittenhouse Laboratory, 4C2

    Sylvester James Gates, Jr. (Brown University)

    While a fundamental representation theory for compact Lie algebras was settled by the work of Cartan (i.e. weights and roots), no analogous conceptual structure exists for space-time supersymmetry algebras.  Progress in this direction based on the graph theory concept of "adinkras" will be presented in this talk.

  • High Energy Theory Seminar: "Bit Threads in Space and Time"

    David Rittenhouse Laboratory, 2N36

    Matt Headrick (Brandeis University)

    Bit threads are a reformulation of the Ryu-Takayanagi holographic entanglement entropy formula that offer several conceptual advantages over the standard minimal-surface formulation.

  • Condensed Matter Seminar: "Soft matter physics in the gut"

    David Rittenhouse Laboratory, A4

    Sujit S. Datta (Princeton University)

    The gut governs digestion and nutrient absorption, is a promising target for drug delivery, and teems with micro-organisms that can have remarkably strong effects on host health. Despite its importance, however, little is known about how the structure and function of the gut are influenced by many of the soft materials that transit through it regularly.

  • **CANCELLED** Astro Seminar: (TBA)

    David Rittenhouse Laboratory, A4

    TBA

  • High Energy Theory Seminar: "Naturally Stabilizing the Weak Scale without Partners"

    David Rittenhouse Laboratory, 2N36

    Devin Walker (Dartmouth College)

    We generalize and adapt Veltman's condition to create a framework which naturally addresses the little hierarchy problem.  The resulting class of models is economical and ensures a minimum amount of fine-tuning for the bare Standard Model Higgs mass.  To demonstrate this framework, we provide a model with an extended Higgs sector and a top Yukawa coupling that is no longer unity.  The latter alleviates the largest radiative corrections to the Higgs mass.  The former features significant dimension-full coupl