## Events - Weekly

Sunday,
October 11 |
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Gandhi Jayanti by SAAG Employee Reasource Group Gandhi Jayanti celebration by SAAG Employee Reasource Group supported by Princeton University's Office of Human Resources. McDonnell A02 · 4:00 p.m.– 7:00 p.m. |

Monday,
October 12 |

Biophysics Seminar - Paul A. Wiggins, U.Washington “Visualization of replication conflicts and other stories of life at a molecular scale.” Cell proliferation requires timely and reliable DNA replication. Genetic and biochemical evidence reveals that the replication process is subject to a variety of conflict mechanisms, including DNA damage, concurrent DNA transcription, and DNA-bound protein complexes which can all act to stall the replication process. Without a mechanism for rapid and efficient resolution, these conflicts have the potential to cause genomic instability and even cell death. The frequency of these conflicts and their consequences to replisome structure remain unknown. We report the direct visualization of single replication conflicts with single-molecule sensitivity in two model organisms well suited for single-molecule microscopy (E. coli and Bacillus subtilis) and characterize the dynamics of these conflicts in vivo. These direct observations of the replication process reveal that conflicts are vastly more frequent than previously hypothesized and imply that the restart process in fact plays out multiple times in a typical cell cycle. Joseph Henry Room · 12:00 p.m.– 1:00 p.m.Condensed Matter Seminar, Roger Mong, U Pittsburgh, "Fibonacci anyons and charge density order in the 12/5 and 13/5 quantum Hall plateaus" The ν = 12/5 fractional quantum Hall plateau observed in GaAs wells is a suspect in the search for non-Abelian Fibonacci anyons. Fibonacci anyons are special i n that they are capable of performing universal topological quantum computation. Using the infinite density matrix renormalization group, we find clear evidence that—in the absence of Landau level mixing—fillings ν = 12/5 and ν = 13/5 are in the k = 3 Read-Rezayi phase, and thus supports Fibonacci anyons. We also find an extremely close energetic competition between the Read-Rezayi phase and a charge-density ordered phase, which may explain the experimentally observed asymmetry between ν = 12/5 and 13/5. Jadwin A09 · 1:15 p.m.– 2:30 p.m.High Energy Theory - Shamit Kachru, Stanford University - "Comments on chiral CFTs and gravity" The relationship between 3d gravity and 2d CFT provides a useful controlled playground in which to try and address issues of quantum gravity. In this talk I describe recent thoughts about two related problems: the construction of candidate duals to pure quantum gravity in AdS3, and the classification of chiral 2d CFTs. The talk is based on arXiv : 1507.00004, as well as work in progress with Alex Maloney and Greg Moore. Jadwin A08 · 2:30 p.m.– 3:30 p.m. |

Tuesday,
October 13 |

High Energy Theory - Davide Gaiotto, Perimeter Institute for Theoretical Physics - "Higher form symmetries and fermionic phases of matter" In this talk I will review some recent work on the characterization of gapped phases in gauge theories and in fermionic condensed matter systems. Jadwin A07 · 4:30 p.m.– 5:30 p.m. |

Wednesday,
October 14 |

Special Condensed Matter Seminar, Roman Orus, Mainz, “Entanglement, tensor networks, and topological quantum order” Topological order in a 2d quantum matter can be determined by the topological contribution to the entanglement Renyi entropies. However, when close to a quantum phase transition, its calculation becomes cumbersome. In this talk I will show how topological phase transitions in 2d systems can be much better assessed by multipartite entanglement, as measured by the topological geometric entanglement of blocks. Specifically, I will present an efficient tensor network algorithm based on Projected Entangled Pair States (PEPS) to compute this quantity for a torus partitioned into cylinders, and then use this method to find sharp evidence of topological phase transitions in 2d systems with a string-tension perturbation. When compared to tensor network methods for Renyi entropies, this approach produces almost perfect accuracies close to criticality and, on top, is orders of magnitude faster. Moreover, I will show how the method also allows the identification of Minimally Entangled States (MES), thus providing a very efficient and accurate way of extracting the full topological information of a 2d quantum lattice model from the multipartite entanglement structure of its ground states. If time allows I will also present briefly other ongoing projects at our group involving the use of tensor networks to study large-spin Kagome quantum antiferromagnets, 1d symmetry-protected topological order, continuous unitary transformations, and (1+1)d lattice gauge theories. Jadwin A07 · 1:15 p.m.– 2:15 p.m.Physics Group Meeting - IAS - Discussion group led by David Poland, IAS - “Mysteries in the Conformal Bootstrap” I will describe some situations where mysterious features have appeared in numerical studies of the conformal bootstrap. It is tempting to speculate that they may correspond to new CFTs, but we do not yet have good guesses for a microscopic description of these theories. This may be an interesting topic for discussion. 3D Fermion Bootstrap: http://arxiv.org/abs/1508.00012 4D N=1 and 3D N=2 Supersymmetric Bootstrap: http://arxiv.org/abs/1509.06368 http://arxiv.org/abs/1503.02081 http://arxiv.org/abs/1502.04124 http://arxiv.org/abs/1109.5176 Bloomberg Hall of Physics Library - Institute for Advanced Study · 1:30 p.m.– 2:30 p.m. |

Thursday,
October 15 |

Hamilton Colloquium Series - Laura Baudis, University of Zurich, "Direct detection of dark matter in the Milky Way" Cosmological observations and the dynamics of the Milky Way provide strong evidence for an invisible and dominant mass component that so far reveals its presence only by its gravitational interaction. If the dark matter is made of Weakly Interacting Massive Particles (WIMPs), it can be directly detected via elastic scattering from nuclei in ultra-low background, deep-underground detectors. WIMPs arise naturally in beyond standard model theories, a popular example being the neutralino, or the lightest supersymmetric particle. After an introduction to the direct dark matter detection method, I will review the current experimental techniques to search for these hypothetical particles. The focus will be on recent results and on the most promising techniques for the future. Jadwin A10 · 4:30 p.m.– 6:00 p.m. |

Friday,
October 16 |

Gravity Group Seminar, "Nitty Gritty Talks on CMB Experiments" Presented by, Christine Pappas, Patty Ho, Yaqiong Li, Stevie Bergman, and Anne Gambrel. Five short talks on different aspects of the instruments and analyses for Advanced ACTPol and SPIDER, putting each into context. Joseph Henry Room · 12:00 p.m.– 1:30 p.m.High Energy Theory - Davide Gaiotto, Perimeter Institute for Theoretical Physics - "Boundary conditions for three-dimensional N=4 gauge theories" In this talk I will describe the properties of half-BPS boundary conditions in three-dimensional N=4 gauge theories. I will discuss the relationship between this work and the mathematical theory of symplectic duality Jadwin A07 · 1:45 p.m.– 3:00 p.m. |

Saturday,
October 17 |