*For this special year of the hyperbolic geometry seminar, please note the new location (Hunter College Room 921 Hunter East) and time (Wednesdays 3:30pm-5:30pm*
February 4th: Blanca Marmolejo (CUNY Graduate Center)
Title: Pants and infinite type surfaces
Abstract: A discussion of the pair of pants theorem and its relation to surfaces of infinite type. In particular, we will discuss flute surfaces and some of their geometric properties.
February 11th: Hugo Parlier (visiting faculty Hunter College, University of Fribourg)
Title: Combinatorial moduli spaces
February 18th: No meeting
February 25th: Hugo Parlier (visiting faculty Hunter College, University of Fribourg)
Title: Systolic inequalities and kissing number for surfaces
March 4th: Federica Fanoni (University of Fribourg)
Title: The maximum injectivity radius of surfaces and orbifolds
Abstract: Given a hyperbolic surface, its maximum injectivity radius is the radius of the biggest disc we can isometrically embed in the surface. There are known upper and lower bounds for this radius which depend only on the topology of the surface. In this talk I will present some of these results and I will discuss the same problem in the case of surfaces with a hyperbolic metric and some admitted singularities (hyperbolic 2-orbifolds).
March 11th: Hugo Parlier (visiting faculty Hunter College, University of Fribourg)
Title: Curve graphs, pants graphs, and flip graphs of surfaces
March 18th: Julien Paupert (Arizona State University)
Title: Real reflections, commutators, and cross-ratios in complex hyperbolic space
Abstract: A real reflection in complex hyperbolic space is an antiholomorphic involution (the prototype of such a map is complex conjugation in each coordinate). We provide a concrete criterion to determine whether or not a 2-generator subgroup of SU(2,1) is generated by real reflections. As an application we show that the Picard modular groups SU(2,1,Od) are generated by real reflections when d=1,2,3,7,11. This is joint work with Pierre Will.
March 25th: Bram Petri (University of Fribourg)
Title: The genus of curve, pants, and flip graphs
Abstract: Curve, pants, and flip graphs play an important role in the study of surfaces and their parameter spaces. In this talk, I will talk about a topological invariant of these graphs and their quotients by the mapping class group: their graph genus. This is joint work with Hugo Parlier.
April 1st: Hugo Parlier (visiting faculty Hunter College, University of Fribourg)
Title: Curve graphs for infinite type surfaces
April 8th: No meeting (Spring recess)
April 15th: No meeting (MSRI workshop)
April 12th: No meeting (Identities workshop)
April 29th: Hugo Parlier (visiting faculty Hunter College, University of Fribourg)
The following talk is intended for a general audience and will take place at 1:15pm in Room 619HW
Title: Puzzles, Triangulations, and Moduli Spaces
Diversity and Inclusion at the GC