## Events - Weekly

Sunday,
November 29 |
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Monday,
November 30 |

Biophysics Seminar - Oskar Hallatschek, Berkeley "The role of chance in the survival of the fittest” Joseph Henry Room · 12:00 p.m.– 1:00 p.m.CM Seminar, Avraham Klein, Hebrew University of Jerusalem, "Vortex core deformation in weakly coupled superfluids" Quantum vortices in weakly coupled superfluids have a large healing length, so that many particles reside within the vortex core. They are characterized by topologically protected singular points, which in principal should keep their core structure rigid. I will describe how, in practice, the point singularity of a vortex deforms into a line singularity, in proportion with the Magnus force experienced by the vortex. The vortex structure is described by weak solutions of the Gross-Pitaevskii equation, similar to shock waves in hydrodynamics. I will discuss how the core deformation significantly affects many aspects of vortex dynamics. PCTS Seminar Room · 1:15 p.m.– 2:30 p.m.High Energy Theory IAS - Maurizio Pierini, CERN, “Signs of Hope: A Few LHC Run I Results to Watch for Run II” During the first LHC long shutdown, the CMS collaboration finalised the study of the 8TeV data collected in 2012. Within the impressive amount of results produced, a few searches for new physics show a tension with the prediction from the Standard Model. While the significance is still too small to allow any conclusion, some of these excesses could reveal the first footprint of new processes at the TeV scale. I will discuss a few of these excesses, and give a perspective of the expectation for Run II. Bloomberg Lecture Hall - Institute for Advanced Study · 2:30 p.m.– 3:30 p.m.Special Pheno & Vino, Clifford Cheung, Caltech, "The Periodic Table of Effective Field Theories" The modern S-matrix program has seen immense progress constructing scattering amplitudes in gauge and gravity theories without the aid of a Lagrangian, instead using only physical principles like Lorentz invariance and factorization. In this talk, I discuss how a similar approach is sufficient to construct effective field theories (EFTs), yielding a ``periodic table'' of scalar EFTs labelled by two numbers. We derive these EFTs--Lagrangians, symmetries, and all--from an ansatz of all possible S-matrices consistent with Lorentz invariance, factorization, and a certain infrared property, obtaining well-known examples like the chiral Lagrangian, Dirac-Born-Infeld theory, and the Galileon. We the show how tree amplitudes in these EFTs are constructible via on-shell recursion relations. With these methods one can prove stringent no-go theorems on the space of EFTs and, in principle, even discover new ones. Jadwin 303 · 4:00 p.m.– 5:30 p.m. |

Tuesday,
December 1 |

Wednesday,
December 2 |

Thursday,
December 3 |

Daniel Eisenstein to present The Raymond & Beverly Sackler Lecture in Astrophysics "Dark Energy and Cosmic Sound" Sound waves propagating through the plasma of the Universe only 400,000 years after the Big Bang now offer some of our most precise measures of the composition and history of the Universe. In the last decade, we have been able to detect the fossil imprint of these sound waves using maps of the distribution of galaxies from the Sloan Digital Sky Survey. I will give an overview of the cosmological role of the sound waves and our observational program then describe what the results tell us about the shape of the Universe and the evolution of dark energy. McDonnell A02 · 8:00 p.m.–10:30 p.m. |

Friday,
December 4 |

Gravity Group Seminar, Robert Brandenberger (McGill University) "Towards a construction of a bouncing cosmology making use of the AdS/CFT corresponden A key problem in constructing bouncing cosmologies is how to match the cosmological fluctuations in the high curvature bounce region. We study an approach to this problem in which we use the AdS/CFT correspondence to map the physics onto a boundary gauge theory which is weakly coupled at times when the bulk space-time has a high curvature. PCTS Seminar Room · 12:00 p.m.– 1:30 p.m.High Energy Theory IAS - Jennifer Lin, IAS - “Bulk Energy Conditions from Relative Entropy and Comments on Bulk Reconstruction” I will present results on how positivity properties of relative entropy in holographic CFT's give rise to energy conditions in asymptotically AdS spacetimes. This part will be a sequel to Nima Lashkari’s talk on 11/2. I will also comment on the status of reconstructing spacetime from entanglement in holography. Bloomberg Lecture Hall - Institute for Advanced Study · 1:45 p.m.– 3:00 p.m. |

Saturday,
December 5 |