Kimberly Boddy (Johns Hopkins) : HET Seminar | Searching for Dark Matter Interactions in Cosmology | 1/10/20
There is a substantial effort in the physics ommunity to search for dark matter interactions with the Standard Model of particle physics. Collisions between dark matter particles and baryons exchange heat and momentum in the early Universe, enabling a search for dark matter interactions using cosmological observations in a parameter space that is complementary to that of direct detection. In this talk, I will describe the effects of scattering in cosmology and show constraints using Planck 2015 data and SDSS-identified satellite galaxies of the Milky Way. I will also discuss the implications of late-time scattering during the era of Cosmic Dawn.
Matthew Headrick (Brandeis) : Bit threads and holographic monogamy | 1/24/20
Entanglement entropies are well-studied in holographic field theories thanks to the Ryu-Takayanagi formula. Bit threads offer a conceptually and technically powerful new way to think about this formula. In this talk, after introducing bit threads, I will use them to give a new understanding of the so-called monogamy property of holographic entropies. The resulting picture will lead to an intriguing conjecture about the general entanglement structure of holographic states.
Kathryn Zurek (Caltech) : Spacetime fluctuations in AdS/CFT (and experiment) | 1/29/20 (please note special date)
LianTao Wang (UChicago) : Large Signals in the Cosmological Collider | 2/7/20
Cosmological inflation gives a unique opportunity of probing physics at high energies. In particular, non-Gaussianities contain information on new physics particles being produced through the interaction of the inflatons. In this talk, I will discuss the size of such signals and highlight the scenarios in which we expect it to be observable.
Mirjam Cvetic (UPenn) : Globally consistent three-family Standard Models in F-theory | 2/14/20
We present recent advances in constructions of globally consistent F-theory compactifications with the exact chiral spectrum of the minimal supersymmetric Standard Model. We highlight the first such example and then turn to a subsequent systematic exploration of the landscape of F-theory three-family Standard Models with a gauge coupling unification. Employing algebraic geometry techniques, all global consistency conditions of these models can be reduced to a single geometric criterion on the base of the underlying elliptically fibered Calabi-Yau four-folds. For toric bases, this criterion only depends on an associated polytope and is satisfied for at least quadrillion bases, each of which defines a distinct compactification. We
conclude by pointing out important outstanding issues.
Spiro Karigiannis (UWaterloo) : Conical singularities of G2-manifolds in mathematics and physics | 2/21/20
I will first give an introduction to and brief history of G2 geometry, to compare and contrast it to Calabi-Yau geometry. G2 manifolds are important in physics because they admit parallel spinors. It is of interest to construct compact examples with singularities. I will then give a survey of some of my work that is related to conical singularities of G2 manifolds, including: desingularization, deformation theory, and a possible strategy to construct such G2 conifolds. This will include some (separate) joint works with Dominic Joyce and Jason Lotay. No previous exposure to G2 geometry will be assumed, but the focus will be more mathematical than physical. I am hoping that some of you can teach me more physics during the day.
Seminars cancelled due to COVID19
3/13/20 Rachel Rosen
3/27/20 David E. Kaplan
4/3/20 Netta Engelhardt
4/10/20 Tien Tien Yu
4/17/20 Vijay Balasubramanian
