I research differential geometry, more specifically Riemannian geometry. My early work began the program of studying ambient obstruction solitons, which applies the study of geometric flows to tensors with conformal properties. In the past year, my work has expanded to include both the representations of Lie algebras and quantitative geometry.
Differential geometry is a diverse field that is based on the idea of applying principles from calculus to a more general set of objects. Broadly stated, research in differential geometry aims to answer the question ``what is the best metric?'' with the hope that the answer to this question will provide valuable insights to the universe we inhabit. The word “best” takes on different meanings in different contexts and thus we use different approaches. Riemannian geometry focuses on answering this question for Riemannian manifolds (M, g). A Riemannian manifold is a smooth manifold, M, paired with a Riemannian metric, g. Riemannian metrics are inner products defined on the tangent space of M that vary smoothly across M. Like the dot product we learn in calculus, Riemannian metrics are positive definite inner products defined on the tangent space of M at every point. Returning to the question of finding the best metric, limiting our scope to Riemannian metrics allows us to use curvature as a tool to help define what ``best'' might mean. (There are many ways to measure a manifold's curvature, but I will use ``curvature'' to mean these measures in general.)
The study of geometric flows evolved as a way to use curvature to identify best metrics. A geometric flow is a differential equation in which the metric is considered as a function of time, g(t), and is changed over time in accordance with the curvature of the manifold. We are able to use tools from differential equations to analyze the relationship between metrics and curvature. One such tool is locating and classifying fixed points. In the study of geometric flows this manifests as the examination and classification of solitons. Solitons are solutions to the flow that, over time, change only by diffeomorphism and/or rescaling. Heuristically: if the flow is supposed to make metrics ``nicer'' over time, solitons isolate metrics that are not improving as they are pushed through the flow.
Summarizing my main results:
I classified steady and shrinking homogeneous gradient Bach solitons. I also show that the study of these solitons is distinct from that of Ricci solitons by showing the existence of an expanding homogeneous gradient Bach soliton.
I proved that compact homogeneous ambient obstruction solitons are ambient obstruction flat. My approach using general q-solitons establishes a more refined system of results for general q.
Established that, with additional regularity or curvature conditions, non-compact $q$-solitons are also $q$-flat. Applied these results to Cotton solitons, homogeneous ambient obstruction solitons, and Bach solitons with harmonic Weyl curvature. (Joint with A.W. Cunha)
Proved that any closed ambient obstruction soliton is ambient obstruction flat. We defined extended ambient obstruction solitons to extend result to nonhomogeneous manifolds. Notably, solutions to the geometric flow that stay within their conformal class are extended solitons. (Joint work with R. Poddar, R. Sharma, W. Wylie)
We are establishing the existence of Einstein metrics on homogeneous manifolds with contractible nerve complex and 3 or 4 irreducible isotropy summands. (Joint with I. Beach, H. Contreras Peruyero, M. Kerr, and C. Searle)
We establish natural geometric conditions that yield length estimates for the shortest possible orthogonal geodesic chords. (Joint with I. Beach, H. Contreras-Peruyero, R. Rottmann, and C. Searle)
Extended Solitons of the Ambient Obstruction Flow with R. Poddar, R. Sharma, and W. Wylie (May 2024)
On non-compact gradient solitons with A.W. Cunha (July 2021)
Dissertation: Gradient Ambient Obstruction Solitons on Homogeneous Manifolds (August 2020)
Lengths of the Orthogonal Geodesic Chords on Riemannian Manifolds (Anticipated Fall 2024)
Einstein Metrics on Homogeneous Manifolds (Anticipated Winter 2025)