# Queen's University - Department of Mathematics and Statistics

 Wednesday, October 25 Number Theory Seminar Time: 1:30 p.m. Place: Jeffery 319 Speaker: Richard Leyland Title: Galois Representations of CM Elliptic Curves Abstract Attached Wednesday, October 25 Curves Seminar Time: 3:30 p.m. Place: Jeffery 319 Speaker: Mike Roth Title: First applications of the connectedness theorem Abstract Attached Friday, October 27 Graduate Student Seminar Time: 11:30 a.m. Place: Jeffery 422 Speaker: Manjul Bhargava Title: Patterns in Numbers and Nature (Public Lecture Video, 2016) Abstract Attached Friday, October 27 Department Colloquium Time: 2:30 p.m. Place: Jeffery 234 Speaker: Daniel Wise, McGill University Title: The Cubical Route to Understanding Groups Abstract Attached Monday, October 30 Dynamics Seminar Time: 4:00 p.m. Place: Jeffery 422 Speaker: Tariq Osman, Queen’s University Title: Ergodicity of the geodesic flow via Hopf’s argument Abstract Attached Monday, October 30 Geometry and Representation Theory Seminar Time: 4:45 p.m. Place: Jeffery 319 Speaker: Ba Nguyen, Queen’s University Title: New formulas for cluster monomials of Type A quivers Abstract Attached

Items for the Info Sheet should reach Anne ( burnsa@queensu.ca) by noon on Monday. The Info Sheet is published every Tuesday.

Wednesday, October 25, 1:30 p.m. Jeffery 319 - Number Theory Seminar

Speaker: Richard Leyland

Title: Galois representations of CM Elliptic Curves

Abstract: We introduce the notion of the mod-N Galois representation $\rho_{E/F,N}$ attached to an elliptic curve $E/F$. Motivated by conjectures of Frey and Mazur, we aim to determine all elliptic curves $E’/F$ such that $\rho_{E’/F,N}\cong \rho_{E/F,N}$ in the case where both $E$ and $E’$ have complex multiplication. In this talk, we introduce the problems, terminology currently being worked on and present a small result in the case where $E$ and $E’$ have complex multiplication by different imaginary quadratic fields.

Wednesday, October 25, 3:30 p.m. Jeffery 319 - Curves Seminar

Speaker: Mike Roth

Title: First applications of the connectedness theorem

Abstract: We will deduce some consequence of the connectedness theorem, giving applications to fundamental questions about embeddings of varieties.

Friday, October 27, 11:30 a.m. Jeffery 422 - Graduate Student Seminar

Speaker: Manjul Bhargava

Title: Patterns in Numbers and Nature (Public Lecture Video, 2016)

Abstract: Each year, the Fields Institute holds the Fields Medal Symposium to showcase and celebrate the work of a Fields Medalist. Join us to watch the Public Opening of the 2016 Fields Medal Symposium, featuring a lecture for a general audience by Professor Manjul Bhargava (Fields Medal 2014).

Friday, October 27, 2:30 p.m. Jeffery 234 - Department Colloquium

Speaker: Daniel Wise

Title: The Cubical Route to Understanding Groups

Abstract: Cube complexes have come to play an increasingly central role within geometric group

theory, as their connection to right-angled Artin groups provides a powerful combinatorial bridge between geometry and algebra. This talk will introduce nonpositively curved cube complexes, and then describe the developments that recently culminated in the resolution of the virtual Haken conjecture for 3-manifolds, and simultaneously dramatically extended our understanding of many infinite groups.

Monday, October 30, 4:00 p.m. Jeffery 422 - Dynamics Seminar

Speaker: Tariq Osman

Title: Ergodicity of the geodesic flow via Hopf’s argument

Abstract: In this talk we will see the proof that the geodesic flow on a surface of constant negative curvature is ergodic. The proof uses the ergodic theorem and the so-called “Hopf’s argument”. Time permitting, we will also discuss how to prove mixing of the geodesic flow.

Monday, October 30, 4:45 p.m. Jeffery 319

Geometry and Representation Theory Seminar

Speaker: Ba Nguyen

Title: New formulas for cluster monomials of Type A quivers

Abstract: We introduce a new kind of combinatorial formula for the cluster monomials in terms of the so-called globally compatible collections. We give bijective proofs of these formulas by comparing with the well-known combinatorial models of the T-paths and of the perfect matchings in a snake diagram.

### Contact Info

 Department of Math & Stats Jeffery Hall, 48 University Ave. Kingston, ON Canada, K7L 3N6 Phone: (613) 533-2390 Fax: (613) 533-2964 mathstat@mast.queensu.ca Office Hours: 8:30am-12:00pm & 1:00pm-4:30pm