Past Events

  • Condensed Matter Seminar: "Soft complexity in gels: network connectivity, viscoelasticity and failure"

    David Rittenhouse Laboratory, A6

    Emanuela Del Gado, Georgetown University

    Soft matter (colloids, polymers, proteins…) often self-assembles into gels with diverse structure and mechanics, ubiquitous in nature and extensively used to improve diverse industrial products, where they provide texture, softness, and stability. Through the interplay between their microstructure with an imposed deformation, they can be stretched, flow, squeezed or fractured, but controlling and being able to design such processes (think for example to soft inks for 3D printing technologies) requires a fundamental understanding that is still lacking.

  • Astronomy seminar: "Using the environment to infer supernova progenitor properties"

    David Rittenhouse Laboratory, A6

    Lluis Galbany, University of Pittsburgh

    Integral Field Spectroscopy (IFS) applied to supernova (SN) environmental studies have shown the potential of this technique to directly characterize the galactic environmental parameters at SN locations, compare them to those at different locations of the galaxy, and put constraints on progenitor stars for different SN types. In this talk, I will summarize current efforts from the PISCO compilation, Hi-KIDS, MaNGA, and the AMUSING surveys, that have put together more than 500 SN hosts observed with IFS, and give details about published results from these datasets. 

  • High Energy Theory Seminar: "Gauge-field inflation and the origin of the matter-antimatter asymmetry"

    David Rittenhouse Laboratory, 2N36

    Peter Adshead, University of Illinois, Urbana Champaign

    In this talk, I  describe a new class of inflationary scenarios which utilize gauge fields to generate inflationary dynamics in the early universe. Beyond simply providing yet another model for inflation, these scenarios furnish unique observational imprints which distinguish them from standard scalar-field scenarios.

  • Dissertation Defense: "Measuring Photometric Properties of SDSS and MaNGA Galaxies

    4N12 DRL

    Johanna-Laina Fischer

  • Experimental Partical Physics Seminar: "First results from the PROSPECT reactor neutrino experiment"

    David Rittenhouse Laboratory, 4N12

    Danielle Norcini, Yale University

    Experiments at nuclear reactors have played a key role in determining the properties of the weakly-interacting neutrinos. Results from recent reactor experiments suggest a disagreement between the observed antineutrino flux and energy spectrum when compared to predictions. Beyond the Standard Model sterile neutrinos and corrections to complex nuclear models have been posed to explain the discrepancy. To address this physics, the PROSPECT experiment precisely measures antineutrino energy spectra at multiple, very short baselines (< 10m) from the High Flux Isotope Reactor.

  • Rittenhouse Lecture: "The Planck Legacy: Inflation and the Origin of Structure in the Universe"

    David Rittenhouse Laboratory, A8

    George P. Efstathiou, University of Cambridge and Kavli Institute for Cosmology

    I will review the latest results on cosmic microwave background (CMB) anisotropies measured by the Planck satellite. These measurements agree extremely well with a spatially flat, cosmological constant dominated cosmology with nearly scale invariant Gaussian fluctuations,  as predicted by  inflationary models of the early Universe.

  • Dissertation Defense: "The Higgs from A_mu to Z_mu: Higgs boson cross section measurements using diphoton and four lepton decays at 13 TeV."

    David Rittenhouse Laboratory, 2N36

    Bijan Haney

  • High Energy Theory Seminar: "Newman-Penrose and BMS Charges Near Null Infinity"

    David Rittenhouse Laboratory, 4N12

    Chris Pope, Texas A&M University

    In 1965 Newman and Penrose (NP) showed that any asymptotically-flat spacetime admits 10 quantities, obtained as certain spherical-harmonic projections of a particular component of the Weyl tensor, which are exactly conserved on future null infinity.  In the same era, the BMS group of symmetries of asymptotically flat spacetimes was being extensively studied, primarily motivated by the goal of better understanding gravitational waves.

  • High Energy Theory Seminar: "Black Hole Microstate Cosmology"

    David Rittenhouse Laboratory, 2N36

    Brian Swingle, University of Maryland, College Park

    I will discuss the possibility that certain high-energy holographic CFT states correspond to black hole microstates with a geometrical behind-the-horizon region, modelled by a portion of a second asymptotic region terminating at an end-of-the-world (ETW) brane. The ETW boundary geometry takes the form of a closed FRW spacetime, and, in many cases, this behind-the-horizon physics can be probed directly by looking at the time dependence of entanglement entropy for sufficiently large spatial CFT subsystems.

  • Special Seminar: "This Is Not A Diversity Talk" - POSTPONED MAKE UP DATE TBD

    David Rittenhouse Laboratory, A8

    John A. Johnson, The Harvard-Smithsonian Center for Astrophysics

    The American discourse on the various disparities present in society generally, and academia specifically, focuses primarily on observations of the state of a given situation---e.g. a lack of diversity---rather than on the actions that lead to such a state. This approach is just as dissatisfying and ultimately ineffectual as observing that certain stars are "bright," rather than describing any of the physical principles that lead to the observed properties of a star.