Research Seminars @ Illinois

Tailored for undergraduate researchers, this calendar is a curated list of research seminars at the University of Illinois. Explore the diverse world of research and expand your knowledge through engaging sessions designed to inspire and enlighten.

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GGT seminar: Growth of Essential Surfaces via Measured Laminations

Dec 11, 2025   11:00 am - 12:00 pm  
347 Altgeld Hall
Sponsor
Groups, Geometry, and Topology Seminar
Speaker
Brevan Ellefsen
Views
35
Originating Calendar
Mathematics Seminar Series: Groups, Geometry, and Topology

Due to the work of Thurston, Rivin, and Mirzakhani, it is known that the count of essential curves in a compact surface S of geodesic length at most n grows like n^d, where d is the dimension of the space of measured laminations on S (equivalently, the Teichmuller space of S).

Recent work of Dunfield, Garoufalidis, and Rubenstein showed the count of essential multi-surfaces of Euler characteristic  –2n in a sufficiently nice 3-manifold grows like n^d, where d is described in terms of normal surfaces associated to specific triangulation of M. In analogy with the 2-dimensional picture, the authors conjectured that d should be the dimension of an associated space of measured laminations.

The measured lamination space of a 3-manifold M was first defined by Hatcher in the 1980s, but unlike its 2-dimensional counterpart has remained rather obscure. In this talk we will recount foundational ideas about the measured lamination space, and will discuss how they lead to a resolution of the aforementioned conjecture.

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