Events on Thursday, April 30th, 2026
- R. G. Herb Condensed Matter Seminar
- A universal model of Floquet operator Krylov Space
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin
- Speaker: Aditi Mitra, NYU
- Abstract: It is shown that the stroboscopic time-evolution under a Floquet unitary, in any spatial dimension, and of any Hermitian operator, can be mapped to an operator Krylov space which is identical to that generated by the edge operator of the non-interacting Floquet transverse-field Ising model (TFIM) in one-spatial dimension, and with inhomogeneous Ising and transverse field couplings. The latter has four topological phases reflected by the absence (topologically trivial) or presence (topologically non-trivial) of edge modes. It is shown that the Floquet dynamics share certain universal features characterized by how the Krylov parameters vary in the topological phase diagram of the Floquet TFIM with homogeneous couplings. Connections of our results with methods based on orthogonal polynomials on the unit circle are discussed. Applications to slow dynamics of quasi-conserved quantities as well as Anderson localization and the localization-delocalization transition are presented.
- Host: Elio König
- Preliminary Exam
- Measurement of the Neutrino Flux from the Milky Way using the IceCube Multi-Flavor Astrophysical Neutrino Sample
- Time: 2:30 pm - 4:00 pm
- Place: 5280 CH
- Speaker: Matthias Thiesmeyer, Physics PhD Graduate Student
- Abstract: The IceCube Neutrino Observatory has provided new insights into the high-energy universe, unveiling neutrinos from the galactic plane to extragalactic supermassive black holes. In this talk, we present a 12.3-year, full-sky, all-flavor dataset, the IceCube Multi-Flavor Astrophysics Neutrino sample (ICEMAN). ICEMAN is the combination of three largely independent neutrino samples of different event morphologies. It builds upon the previous work of the DNN-based cascade sample, Enhanced Starting Track Event Selection, and the Northern Track sample. Recent improvements in ice modeling and detector calibration are also incorporated into the cascade simulation and reconstruction. This dataset was used in an unbinned maximum likelihood to carry out a template-based measurement of the diffuse galactic neutrino flux across four distinct model hypotheses. Preliminary measurement results will be presented, addressing the different model assumptions. Furthermore, prospects of a follow-up analysis targeting the galactic center using enhancements in background simulation will be discussed.
- Host: Lu Lu
- Astronomy Colloquium
- Whitford Lecture
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Prof. Bruce Draine, Princeton
- Abstract: TBD
- Host: TBD