## Events - Weekly

Sunday,
May 1 |
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Monday,
May 2 |

Condensed Matter Seminar, Chetan Nayak, Microsoft, "Floquet Time Crystals: Spontaneously Broken Discrete Time-Translational Symmetry in Periodically-D I will define what it means for time translation symmetry to be spontaneously broken in a quantum system, and show with analytical arguments and numerical simulations that this occurs in a large class of driven systems with discrete time-translation symmetry. PCTS Seminar Room · 1:15 p.m.– 2:30 p.m.High Energy Theory Seminar - Ethan Dyer, Stanford University - "small black holes in near extremal gravity" The extremal gravity proposal is a conjectured duality between pure gravity in three dimensions and a speculative set of 2d CFTS. I will discuss a computation of the number of black hole micro-states in these theories. This micro-state counting inspires a mild modification of the extremal gravity proposal which passes many non-trivial checks, and evades a no-go theorem of the original conjecture. I will further comment on the implications for more general sparse theories of gravity. PCTS Seminar Room · 2:30 p.m.– 3:30 p.m. |

Tuesday,
May 3 |

High Energy Theory Seminar - Masahito Yamazaki, Kavli Institute - "Determinant Formulas for General CFTs" I will discuss determinant formulas for higher-dimensional CFTs, which was known in the 70's but extended to SCFTs only recently. I will discuss the implications of the formula for the discussion of unitarity bounds and for the analytic structures of conformal blocks. PCTS Seminar Room · 2:00 p.m.– 3:00 p.m.Pheno & Vino Seminar, Jesse Thaler, MIT, "Probing the Core of QCD with Jet Substructure" Jet substructure techniques have emerged as an essential tool for new physics searches at the LHC. In this talk, I highlight the ways that theoretical studies of jet substructure have revealed fascinating new phenomena in QCD. Using the Run 1 ATLAS diboson excess as motivation, I present jet substructure observables that blur the boundary between perturbative and nonperturbative aspects of QCD, yielding new insights into the universality of the collinear limit. Jadwin 303 · 4:00 p.m.– 5:30 p.m. |

Wednesday,
May 4 |

Physics Group Meeting - IAS - Discussion Group led by Edward Witten, IAS - "On Kevin Costello's Approach to Integrable Spin Systems” Bloomberg Hall of Physics Library - Institute for Advanced Study · 1:30 p.m.– 2:30 p.m. |

Thursday,
May 5 |

High Energy Theory Seminar - Adam Brown, Stanford University - "Hot Bubbles of Nothing" “Bubbles of nothing” are a dramatic instability of spacetimes with compact extra dimensions. A hole appears in spacetime, inside of which there is neither space nor time: there is literally “nothing”. Witten showed that they may nucleate by quantum tunneling. I will discuss bubbles of nothing that nucleate instead by thermal fluctuation (or by a part-quantum part-thermal hybrid process), and exhibit a high-temperature/low-temperature duality with the nucleation of caged black holes. Reference: http://arxiv.org/abs/1408.5903 PCTS Seminar Room · 1:45 p.m.– 3:00 p.m. |

Friday,
May 6 |

Saturday,
May 7 |