• Numerical semigroups, minimal presentations, and posets (Chris O’Neill, SDSU)

    Roberts North 102, CMC

    A numerical semigroup is a subset S of the natural numbers that is closed under addition.  One of the primary attributes of interest in commutative algebra are the relations (or trades) between the generators of S; any particular choice of minimal trades is called a minimal presentation of S (this is equivalent to choosing a […]

  • Biquandle power brackets (Sam Nelson, CMC)

    Roberts North 102, CMC

    Biquandle brackets are skein invariants of biquandle-colored knots, with skein coefficients that are functions of the colors at a crossing. Biquandle power brackets take this idea a step further with state component values that also depend on biquandle colors. This is joint work with Neslihan Gügümcü (IYTE).

  • Chromatic numbers of abelian Cayley graphs (Michael Krebs, Cal State LA)

    Roberts North 102, CMC

    A classic problem in graph theory is to find the chromatic number of a given graph: that is, to find the smallest number of colors needed to assign every vertex a color such that whenever two vertices are adjacent, they receive different colors.  This problem has been studied for many families of graphs, including cube-like […]

  • On the spectra of syntactic structures (Isabella Senturia, Yale University)

    On Zoom

    We explore the application of spectral graph theory to the problem of characterizing linguistically-significant classes of tree structures. We focus on various classes of syntactically-defined tree graphs, and show that the spectral properties of different matrix representations of these classes of trees provide insight into the linguistic properties that characterize these classes. More generally, our […]

  • Frobenius coin-exchange generating functions (Matthias Beck, San Francisco State University)

    Roberts North 102, CMC

    We study variants of the Frobenius coin-exchange problem: Given n positive relatively prime parameters, what is the largest integer that cannot be represented as a nonnegative integral linear combination of the given integers? This problem and its siblings can be understood through generating functions with 0/1 coefficients according to whether or not an integer is representable. […]

  • Skein algebra of a punctured surface (Helen Wong, CMC)

    Roberts North 102, CMC

    The Kauffman bracket skein algebra of a surface is at once related to quantum topology and to hyperbolic geometry. In this talk, we consider a generalization of the skein algebra due to Roger and Yang for surfaces with punctures. In joint work with Han-Bom Moon, we show that the generalized skein algebra is a quantization […]