Calendar

  • 03
    May 3, 2021

    Computational Biology Symposium

    10:00 AM-3:50 PM
    May 3, 2021

    On Monday, May 3rd the Harvard CMSA will be hosting a Computational Biology Symposium virtually on Zoom. Please visit the event webpage for the schedule and more information. The event poster is attached.

    Registration is free but required. Register here. Details on how to join the webinar will be sent to registered participants before the event.

    The speakers will be:
    Uri Alon, Weizmann Institute
    Elana Fertig, Johns Hopkins
    Martin Hemberg, Brigham and Women’s Hospital
    Peter Kharchenko, Harvard University
    Smita Krishnaswamy, Yale University
    John Marioni, EMBL-EBI
    Eran Segal, Weizmann Institute
    Meromit Singer, Harvard Medical School

  • 04
    May 4, 2021

    Lieb-Thirring bounds and other inequalities for orthonormal functions

    10:00 AM-11:00 AM
    May 4, 2021

    Lieb-Thirring inequalities are a mathematical expression of the uncertainty and exclusion principles in quantum mechanics. They were introduced by Lieb and Thirring in 1975 in their proof of stability of matter and have since played an important role in several areas of analysis and mathematical physics. We provide a gentle introduction to classical aspects of this subject and we also present some newer developments, concerning extensions of several inequalities in harmonic analysis to the setting of families of orthonormal functions.

    Zoom: https://harvard.zoom.us/j/779283357?pwd=MitXVm1pYUlJVzZqT3lwV2pCT1ZUQT09

  • 04
    May 4, 2021

    CMSA Computer Science for Mathematicians: Rank-Based Independence Testing in Near Linear Time

    11:30 AM-12:30 PM
    May 4, 2021

    In 1948 Hoeffding proposed a nonparametric test that detects dependence between two continuous random variables (X,Y), based on the ranking of n paired samples (Xi,Yi). The computation of this commonly-used test statistic requires O(n log n) time. Hoeffding’s test is consistent against any dependent probability density f(x,y), but can be fooled by other bivariate distributions with continuous margins. Variants of this test with stronger consistency have been considered in works by Blum, Kiefer, and Rosenblatt, Yanagimoto, and Bergsma and Dassios, and others. The so far best known algorithms to compute them have required quadratic time.

    We present an algorithm that computes these improved tests in time O(n log n). It is based on a new combinatorial approach for counting pattern occurrences in a given permutation, which we call corner tree formulas, and will be explained in the talk.

    Joint work with Calvin Leng.

    Zoom: https://harvard.zoom.us/j/98231541450

  • 04
    May 4, 2021

    Refined unramified cohomology

    3:00 PM-4:00 PM
    May 4, 2021

    We introduce refined unramified cohomology and prove some
    general comparison theorems to cycle groups. Our approach has several applications. For instance, it allows to construct the first example of a smooth complex projective variety whose Griffiths group has infinite torsion subgroup.

    Zoom: https://harvard.zoom.us/j/91794282895?pwd=VFZxRWdDQ0VNT0hsVTllR0JCQytoZz09

  • 04
    May 4, 2021

    An algebraic model for smoothing Calabi-Yau varieties

    9:00 PM-10:00 PM
    May 4, 2021

    We are interested in smoothing of a degenerate Calabi-Yau variety or a pair (degenerate CY, sheaf). I will explain an algebraic framework for solving such smoothability problems. The idea is to glue local dg Lie algebras (or dg Batalin-Vilkovisky algebras), coming from suitable local models, to get a global object. The key observation is that while this object is only an almost dg Lie algebra (or pre-dg Lie algebra), it is sufficient to prove unobstructedness of the associated Maurer-Cartan equation (a kind of Bogomolov-Tian-Todorov theorem) under suitable assumptions, so the former can be regarded as a singular version of the Kodaira-Spencer DGLA. Our framework applies to degenerate CY varieties previously studied by Kawamata-Namikawa and Gross-Siebert, as well as a more general class of varieties called toroidal crossing spaces (by the recent work of Felten-Filip-Ruddat). This talk is based on joint works with Conan Leung, Ziming Ma and Y.-H. Suen.

    Zoom: https://harvard.zoom.us/j/96709211410?pwd=SHJyUUc4NzU5Y1d0N2FKVzIwcmEzdz09