## Events - Weekly

**October 2013 >>**

Sunday,
October 13 |
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Monday,
October 14 |

Biophysics Seminar Series - Sarah Veatch (U. Mich) 'Lipid rafts reach a critical point' Jadwin 111 · 12:00 p.m.– 1:00 p.m.High Energy Theory Seminar - Mark Mezei, MIT - "Monopole Taxonomy in Three-Dimensional Conformal Field Theories" Monopole operators play an important role in the dynamics of three-dimensional conformal field theories. In this talk, I will explain how to use the 1/N_f expansion to study these operators at the infrared fixed points of non-Abelian gauge theories with N_f fermion flavors. At large N_f, the gauge field fluctuations are suppressed, and one can associate independent monopole operators to stable monopole backgrounds via the state-operator correspondence. I will discuss the stability of these backgrounds, calculate the scaling dimension of the corresponding monopole operators through next-to-leading order in 1/N_f, and describe their transformation properties under the flavor symmetry. These results give estimates for the number of flavors below which the theory confines and breaks "chiral symmetry". These estimates are consistent with bounds obtained using the F-theorem. This talk is based on 1309.1160 with E. Dyer and S. Pufu. PCTS Seminar Room · 2:30 p.m.– 3:30 p.m. |

Tuesday,
October 15 |

HEP/ Particle Astrophysics Special Seminar-Stefano Ragazzi- PCTS Seminar Room · 2:00 p.m.– 3:00 p.m.Math Physics Seminar, Yoshiko Ogata, "The Quantum Shannon-McMillan theorem and rank of spectral projections of macroscopic observables" The classical Shannon-McMillan theorem states that an ergodic system has typical sets satisfying the asymptotic equipartition property. This theorem demonstrates the significance of entropy which gives the size of the typical sets. There has recently been great progress in the quantum version of the Shannon-McMillan theorem .In particular, Bjelakovic et al. proved Shannon-McMillan theorem for ergodic quantum spin systems, by reducing the quantum setting to a classical one, and applying the classical Shannon-McMillan theorem. In this talk, I would like to introduce a direct proof of the quantum Shannon-McMillan theorem, without relying on the classical theory. Our proof is based on the variational principle, which is a well-known thermodynamic property of quantum spin systems. As an application, I would like to show that the quantum Shannon-McMillan theorem gives an estimate on rank of spectral projections of macroscopic observables. Using this estimate, we can show that a set of macroscopic observables can be approximated by commuting ones in the norm topology. Jadwin A06 · 4:30 p.m.– 5:30 p.m. |

Wednesday,
October 16 |

Thursday,
October 17 |

Hamilton Colloquium Series - Risa Wechsler, Kavli Institute, Stanford University: "Dark Matter Insights from Cosmological Structure Formation" There is now overwhelming evidence that more than eighty percent of the mass in the Universe is dark matter. This provides a clear indication for the existence of a particle or particles beyond the standard model, but we have yet to determine the nature of this particle. Models of dark matter make specific predictions for the formation of cosmological structure on a wide range of scales, from the shapes of and substructures within galaxies to the distribution of matter over cosmological distances. I will outline how theoretical predictions, simulations, and observations of cosmological structure formation shed light on the distribution and particle nature of dark matter. This includes both how they inform our understanding and interpretation of limits and signals from dark matter, direct and indirect detection experiments, and how astrophysical measurements can complement these studies. Jadwin A10 · 4:30 p.m.– 5:30 p.m. |

Friday,
October 18 |

Saturday,
October 19 |