Research: Number Theory

Summer School 2019: Computational Aspects of Buildings

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From June 24 to 28, 2019, the University of North Carolina Greensboro will host the UNCG Summer School in Computational Number Theory and Algebra: Computational Aspects of Buildings.

Buildings provide a rich class of simplicial complexes with very nice local structure. They play key roles in several areas of mathematics, including number theory, geometry, algebra, and combinatorics. In this workshop, we will begin by studying the basic combinatorial and geometric structure of buildings. We will then explore applications and open questions related to their large scale geometry, structure of their automorphism groups, existence of buildings with cocompact lattices and prescribed vertex link, and their role in algebraic combinatorics and the study of symmetric functions.

On a typical day, external and local experts give talks in the morning, and in the afternoon students solve problems related to this material. The talks early in the week introduce the students to the subject. Talks later in the week cover related areas of current research and unsolved problems. The problems given to the students might be of a theoretical nature but could also involve programming problems and computer experiments. All problems are aimed at increasing the students’ understanding of the material by working with it.

Speakers

Thibaut Dumont (University of Jyväskylä, Finland)
Yusra Naqvi (University of Sydney, Australia)
Xiangdong Xie (Bowling Green State University)

Schedule

Talks are held in Petty Building 213.

Time	Monday 6/24	Tuesday 6/25	Wednesday 6/26	Thursday 6/27	Friday 6/28
9:00	Welcome	Coffee and Lightning Talks
9:30	Yusra Naqvi: Coxeter Groups, Chamber Systems, and Buildings I	Thibaut Dumont: Low dimensional Euclidean buildings [slides (pdf)]	Thibaut Dumont: Regularity and Parameter Systems	Yusra Naqvi: Hecke Algebra II	Yusra Naqvi: Folded Galleries [paper-a2 (pdf), paper-b2 (pdf), paper-g2 (pdf)]
10:45	Coffee
11:15	Yusra Naqvi: Coxeter Groups, Chamber Systems, and Buildings II	Xiangdong Xie: Retraction, curvature aspects of buildings [slides (pdf), paper (pdf)]	Yusra Naqvi: Hecke Algebras I	Xiangdong Xie: Some basics on Coxeter groups and cross ratio on the boundary [slides (pdf), paper (pdf)]/Thibaut Dumont: Low dimensional Euclidean buildings II [slides (pdf)]	Xiangdong Xie: Quasi-isometric rigidity of Fuchsian buildings [slides (pdf)]/Thibaut Dumont: Bruhat-Tits Buildings of \(\mathrm{SL}_{n + 1}(K)\)
12:30	Lunch
14:00	Xiangdong Xie: Geometric realizations of Coxeter groups and buildings [slides (pdf), paper (pdf)]	Thibaut Dumont: Intro C++ Computer lab [in.txt, main.cpp, CPP-lab_1.pdf]	Excursion: Greensboro Science Center and SKYWILD	Thibaut Dumont: Low dimensional Euclidean buildings III [slides (pdf)]
15:30	Paper and pen lab: [Yusra exercises (pdf), Xiandong exercises (pdf)]	Yusra Naqvi: BN-pairs		Thibaut Dumont: Computer Lab [Further projects (pdf)]

	Preliminaries
	Shared on open problems (or to conclude a minicourse)
	Lab
	Core of the minicourse	Lightning talks (9:05-9:20am): Jenny Beck, Kalani Thalagoda, Kristen Schekelhoff [slides (pdf)]	Lightning talks (9:05-9:20am): Amy Aswani, Fikreab Solomon [slides (pdf)]	Lightning talks (9:05-9:20am): Shivam Arora, Daniel Belin, Brian Grove [slides (pdf)]	Lightning talks (9:05-9:20am): Christopher Ratigan, Richard Mandel, Peter Huxford [slides (pdf)]