Past Events

  • High Energy Theory Seminar: "Discrete Superconformal Matter"

    David Rittenhouse Laboratory, 2N36

    Paul Oehlmann (Virginia Tech)

    We construct a novel type of (2,0) discrete charged superconformal matter coupled to 6d supergravity using F-theory. For this, we consider smooth genus-one fibered and compact Calabi-Yau threefolds quotiented by a freely acting automorphism. The resulting geometries exhibit orbifold singularities in the base with so-called multiple fibers over them which is where the (2,0) discrete charged matter resides. We show this presence to be necessary for anomaly cancellation which we proof in generality.

  • HET & HEE Joint Seminar: "Unification from Scattering Amplitudes"

    David Rittenhouse Laboratory, 4N12

    Cliff Cheung (Caltech)

    Scattering amplitudes are fundamental observables that encode the dynamics of interacting particles. In this talk, I describe how to systematically construct these objects without reference to a Lagrangian or an underlying spacetime. The physics of real-world particles like gravitons, gluons, and pions are thus derived from the properties of amplitudes rather than vice versa. Remarkably, the expressions gleaned from this line of attack are marvelously simple, revealing new structures long hidden in plain sight.

  • High Energy Theory Seminar: "Coarse-Graining Holographic Entanglement"

    David Rittenhouse Laboratory, 2N36

    Netta Engelhardt (Princeton)

  • High Energy Theory Seminar: "Some New Mechanisms for Baryogenesis"

    David Rittenhouse Laboratory, 2N36

    Jeremy Sakstein (U of Penn)

    There is more matter than antimatter in the universe, and the origin of this asymmetry is still a mystery. The asymmetry can be generated dynamically in the early universe in a process referred to as baryogenesis but the standard model is not able to produce the amount observed. This is one hint that there is physics beyond the standard model. In this talk, I will present two new baryogenesis mechanisms, one using scalar-tensor theories and the other using Lorentz violating theories.

  • 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.

  • 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