Karen Butt



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I am an L. E. Dickson Instructor and NSF postdoc in the Department of Mathematics at the University of Chicago. I completed my PhD at the University of Michigan in April 2023, advised by Ralf Spatzier.

My research is on rigidity phenomena in smooth dynamics and differential geometry.

I am on the job market during the 2025-2026 academic year.

Papers

6. Monotonicity of topological entropy along the Ricci flow near a hyperbolic metric. Joint with Alena Erchenko and Tristan Humbert. (arXiv)

5. Marked Poincaré rigidity near hyperbolic metrics and injectivity of the Lichnerowicz Laplacian in dimension 3. Joint with Alena Erchenko, Tristan Humbert, Thibault Lefeuvre, Amie Wilkinson. (arxiv)

4. Quantitative marked length spectrum rigidity for surfaces (arXiv)

3. Monotonicity of the Liouville entropy along the Ricci flow on surfaces. Joint with Alena Erchenko, Tristan Humbert, Daniel Mitsutani. (arXiv)

2. Approximate control of the marked length spectrum by short geodesics. Ergodic Theory and Dynamical Systems (2025) (journal) (arXiv)

1. Quantitative marked length spectrum rigidity. Geometry & Topology 29:8 (2025) pp. 3995--4054. (journal) (arXiv)