Past Events

  • High Energy Theory seminar

    David Rittenhouse Laboratory, 2N36

    Lara Anderson, Virgina Tech

  • High Energy Theory seminar: "Holographic Entropy Cone with Time Dependence"

    David Rittenhouse Laboratory, 2N36

    Bartek Czech, Tsinghua University

    In the AdS/CFT correspondence, if a CFT state is dual to a semiclassical spacetime, its entanglement entropies (minimal surface areas) must obey certain inequalities. The best-known examples are the strong subadditivity of entanglement entropy (SSA) and the monogamy of mutual information (MMI). Together, such inequalities define the so-called holographic entropy cone.

  • High Energy Theory seminar: "Shift Symmetries in (A)dS"

    David Rittenhouse Laboratory, 2N36

    Kurt Hinterbichler, Case Western Reserve University

    I will discuss the generalizations of shift symmetries, galileon symmetries, and extended galileon symmetries to (A)dS space and to higher spin.   Unlike flat space, these symmetries are present only for particles with particular masses, and are related to partially massless symmetries.  For the case of scalars, I will discuss non-linear extensions of the symmetries and invariant interactions. This leads to a unique ghost-free theory in (A)dS space that is an (A)dS extension of the special Galileon.

  • High Energy Theory seminar: "Axion couplings and implications for cosmology and astrophysics"

    David Rittenhouse Laboratory, 2N36

    JiJi Fan, Brown University

    Many cosmological models rely on large couplings of axions (pseudo-scalar fields) to gauge fields. Examples include theories of magnetogenesis, inflation on a steep potential, chiral gravitational waves, and chromonatural inflation.

  • High Energy Theory Seminar: "SYK, harmonic analysis, and multipoint conformal blocks"

    David Rittenhouse Laboratory, 2N36

    Vladimir Rosenhaus, IAS, Princeton University

  • 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.

  • 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.

  • High Energy Theory Seminar: "Pulling the Holographic Boundary into the Bulk"

    David Rittenhouse Laboratory, 2N36

    Yasunori Nomura, University of California Berkeley

  • Special High Energy Theory Seminar: "Primordial black holes as dark matter"

    David Rittenhouse Laboratory, 4N12

    Alex Kusenko, UCLA

    I will discuss new and rather generic scenarios for production of black holes in the early universe.  In some mass range, such black holes can account for all dark matter.  Primordial black holes can also contribute to synthesis of heavy elements by disrupting neutron stars.