• Central moments of autocorrelation demerit factors of binary sequences (Daniel Katz, CSUN)

    Estella 2099

    A low autocorrelation binary sequence of length $\ell$ is an $\ell$-tuple of $+1$s and $-1$s that does not strongly resemble any translate of itself.  Such sequences are used in communications and remote sensing for synchronization and ranging, where translation represents time delay.  A single number that indicates how good a sequence is for such purposes, […]

  • Tropical linear series and matroids (Dagan Karp, HMC)

    Estella 2099

    In this talk, I'll attempt to give a friendly introduction to tropical linear series and explore their relationship to matroid theory. Along the way, we'll stop to admire the beautiful view from enumerative geometry and combinatorics. This is joint work with Chih-Wei Chang, Matthew Dupraz, Hernan Iriarte, David Jensen, Sam Payne, and Jidong Wang, and also with […]

  • Coordinate ring of the universal centralizer via Demazure operators (Tom Gannon, UCR)

    Estella 2099

    One of the key objects used in Ngo's proof of the fundamental lemma is the group scheme of universal centralizers associated to a split reductive group G. In this talk, we'll discuss forthcoming work, joint with Victor Ginzburg, which describes the coordinate ring of the group scheme of universal centralizers in terms of the root datum of G using Demazure (or divided […]

  • Voting on relations using pairs information (Michael Orrison, HMC)

    Estella 2099

    Many aggregation problems ask us to turn individual judgments into a single collective outcome. In this talk, we model each voter’s input as a relation on a set of alternatives, allowing pairwise comparisons to include strict preferences, ties, or incomparability. This perspective gives a common framework for median procedures and scoring methods, including several familiar […]