My research interests lie in low-dimensional geometric topology. I am especially interested in 3- and 4-manifolds and, in particular, concordance and homology cobordism. While the most familiar setting for studying concordance is the (topological or smooth) concordance group of knots in the 3-sphere, I enjoy thinking about concordance in extended settings, including concordance of links, concordance of surfaces and surface links, and concordance in non-simply-connected manifolds. I also like applying tools from concordance to other questions in geometric topology.
For detailed information on my research program, see my research statement.
I primarily study concordance, a notion of equivalence between knots, objects like the one pictured to the left. The knots I study live in spaces called manifolds. The surface of the earth is a 2-dimensional manifold; even though it may look flat from where we're standing, we know it has a more interesting global structure. The knots I study live in 3-dimensional manifolds, which again look "flat" locally but may not be globally. Knot concordance is a 4-dimensional relation, studying surfaces that knots bound in certain 4-dimensional manifolds.
We prove that every closed orientable 3-manifold may be obtained via 0-surgery on some link in the 3-sphere and examine the consequences of this fact.
We define concordance invariants of surfaces and surface links in closed orientable 4-manifolds and produce examples of pairwise homotopic but non-concordant positive genus surfaces.
We prove that if a rational homology sphere bounds a rational homology ball with no second homology, then the Freedman-Krushkal torsion triple linking form vanishes on the Lagrangian for the torsion linking pairing.
We study topological concordance modulo local knotting, or almost-concordance, of knots in non-simply-connected 3-manifolds M, partially resolving a conjecture of A. Levine, Celoria, and Friedl-Nagel-Orson-Powell.
We extend Milnor's link invariants to topological concordance invariants of knots and links in general closed orientable 3-manifolds. These invariants unify and generalize all previous versions of Milnor's invariants in dimension 3.
This project is a result of the 2024 University of Virginia Geometry & Topology REU. We give a general recursive formula for the Alexander polynomials of spiral knots, which are braid-theoretic generalizations of torus knots.
My undergraduate thesis. We give related recursive formulas for the determinants of several families of spiral knots.