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Simplicial Complexes, Configuration Spaces, and “Chromatic” Invariants (Andrew Cooper, NC State)

Roberts North 104, CMC 320 E. 9th St., Claremont, CA, United States

Given a space $X$, the configuration space $F(X,n)$ is the space of possible ways to place $n$ points on $X$, so that no two occupy the same position. But what if we allow some of the points to coincide? The natural way to encode the allowed coincidences is as a simplicial complex $S$. I will […]

The Roger-Yang Arc Algebra (Helen Wong, CMC)

Roberts North 104, CMC 320 E. 9th St., Claremont, CA, United States

  Based on geometric considerations, J. Roger and T. Yang in 2014 defined a version of the Kauffman bracket skein algebra for punctured surfaces that includes arcs going from puncture to puncture. We'll provide a brief survey of known results about this arc algebra. In particular, I'd like to mention a recent algebraic result whose […]

A nonorientable version of the Milnor Conjecture (Cornelia A. Van Cott, USF)

Roberts North 104, CMC 320 E. 9th St., Claremont, CA, United States

In 1968, Milnor famously conjectured that the smooth 4-genus of the torus knot T(p,q) is given by (p-1)(q-1)/2. This conjecture was first verified by Kronheimer and Mrowka in 1993 and has received several other proofs since then. In this talk, we discuss a nonorientable analogue of this conjecture, first formulated by Josh Batson. We prove […]

Applying Quantum Representations of Mapping Class Groups (Wade Bloomquist, UCSB)

Roberts North 104, CMC 320 E. 9th St., Claremont, CA, United States

One foundational pillar of low dimensional topology is the connection between link invariants and 3-manifold invariants.  One generalization of this has been given by Reshetikhin and Turaev to a surgery theory for colored ribbon graphs.  Then to complete the analogy rather than 3-manifold invariants we now have a 2+1 dimensional topology quantum field theory (TQFT).  […]

Geometry of quotient varieties and the algebra of conformal blocks (Han-Bom Moon Fordham University)

Roberts North 104, CMC 320 E. 9th St., Claremont, CA, United States

An important question in classical representation theory is when the tensor product of two irreducible representations has another representation as a factor. In this talk, I will introduce a quantum generalization of this question and explain how we may relate this question to geometry of quotients of certain complex manifolds. This is joint work with […]

Enhancements of the quandle coloring invariant for knots (Karina Cho, Harvey Mudd College)

Roberts North 104, CMC 320 E. 9th St., Claremont, CA, United States

Quandles are algebraic structures that play nicely with knots. The multiplicative structure of finite quandles gives us a way to "color" knot diagrams, and the number of such colorings for a given knot and quandle is called the quandle coloring invariant. We strengthen this invariant by examining the relationships between the colorings, which are given […]

A (Z⊕Z)-family of knot quandles (Jim Hoste, Pitzer College)

Suppose K is an oriented knot in a 3-manifold M with regular neighborhood N (K). For each element γ ∈ π 1 (∂N (K)) we define a quandle Q γ (K; M) which generalizes the concept of the fundamental quandle of a knot. In particular, when γ is the meridian of K, we obtain the […]

Topology Seminar: Sam Nelson (CMC)

Millikan 2099, Pomona College 610 N. College Ave., Claremont, CA, United States

Title: Biquandle Brackets and Knotoids Abstract: Biquandle brackets are a type of quantum enhancement of the  biquandle counting invariant for oriented knots and links, defined by a set of skein relations with coefficients which are functions of biquandle colors at a crossing. In this talk we use biquandle brackets to enhance the biquandle counting matrix […]

Topology Seminar: Jesse Levitt (USC)

Millikan 2099, Pomona College 610 N. College Ave., Claremont, CA, United States

Title: Understanding Structure in the Single Variable Knot Polynomials Abstract: We examine the dimensionality and internal structure of the aggregated data produced by the Alexander, Jones, and Z0 polynomials using topological data analysis and dimensional reduction techniques. By examining several families of knots, including over 10 million distinct examples, we find that the Jones data is well described as a three […]