Date
Monday October 24, 2022Location
TBAMonday, October 24th, 2022
Time: 4:30 p.m. Place: TBA
Speaker: Debaditya Raychaudhary (Fields Institue)
Title: Continuous CM-regularity and generic vanishing
Abstract:
Website details here: https://mast.queensu.ca/~georep/Fall%20'22.html
Date
Friday October 21, 2022Location
Jeffery Hall, Room 422Friday, October 21st, 2022
Time: 10:00 a.m. Place: Jeffery Hall, Room 422
Speaker: Mirko Degli Esposti (Università di Bologna, Italy)
Title: Recurrence times, waiting times and universal entropy production estimators
Abstract: The universal typical-signal estimators of entropy and cross entropy based on the asymptotics of recurrence and waiting times play an important role in information theory. Building on their construction, we introduce and study universal typical-signal estimators of entropy production in the context of nonequilibrium statistical mechanics of one-sided shifts over finite alphabets. We will discuss some applications to DNA sequences.
Date
Friday October 7, 2022Location
Jeffery Hall, Room 422Friday, October 7th, 2022
Time: 10:00 a.m. Place: Jeffery Hall, Room 422
Speaker: Federico Salmoiraghi (Queen's University)
Title: Using contact geometry to study 3-dimensional Anosov flows
Abstract: Anosov flows are an important class of dynamical systems due to their ergodic properties and structural stability. Geometrically they are defined by two transverse invariant foliations with expanding and contracting behaviors. Much of our understanding of the structure of an Anosov flow relies on the study of the leaves space of the invariant foliations. In this talk we adopt a different approach: in the early 90s Mitsumatsu first noticed that an Anosov vector field also belongs to the intersection of two transverse contact structures rotating towards each other. After giving the necessary background, I will show how to use this point of view to address questions in the theory of surgery on Anosov flows.
Date
Wednesday October 5, 2022Location
Jeffery Hall, Room 222Wednesday, October 5th, 2022
Time: 1:00 p.m. Place: Jeffery Hall, Room 222
Speaker: Alexandre (Sasha) Zotine
Title: Polyhedral Cones
Abstract: This talk will cover section 1.2 in CLS. To quote: "We begin with a brief discussion of rational polyhedral cones, then explain how they relate to affine toric varieties."
Date
Tuesday October 4, 2022Location
Jeffery Hall, Room 422Tuesday, October 4th, 2022
Time: 2:00 p.m. Place: Jeffery Hall, Room 422
Speaker: Abhishek Bharadwaj (ºÚÁϳԹÏ×ÊÔ´)
Title: Sufficient conditions for classifying algebraic integers
Abstract: A result of Corvaja and Zannier states that given an algebraic number $\alpha$, if $\Tr_{Q(\alpha)/Q}\alpha^n$ is a non-zero integer for infinitely many natural numbers $n$, then $\alpha$ is an algebraic integer. We extend this result to generalized power sums and provide some applications. This is a joint work with Veekesh Kumar, Aparmeyo Pal and Ravindranathan Thangadurai.
Date
Friday September 30, 2022Location
Jeffery Hall, Room 422Friday, September 30th, 2022
Time: 10:00 a.m. Place: Jeffery Hall, Room 422
Speaker: Neil MacVicar (Queen's University)
Title: Multiplicative Invariance in the Complex Plane
Abstract: In the late 60s, Hillel Furstenberg proved results and made conjectures concerning the fractal nature of subsets of the unit interval that are invariant under the map that scales a real number by a positive integer r and then kills the integer part. Since then, these sets have been deeply studied. Considerably less has been said about analogous sets in the complex plane. I will review what is known for the case when r is a positive integer that scales real numbers and then introduce a notion of times b invariance in the plane where b is a Gaussian integer. The fractal dimension of these times b invariant sets will be discussed.
Date
Wednesday September 28, 2022Location
Jeffery Hall, Room 319Wednesday, September 28th, 2022
Time: 1:00 p.m. Place: Jeffery Hall, Room 319
Speaker: Sonja Ruzic
Title: Review of Affine Varieties
Abstract: We will backtrack to cover some prerequisite topics including affine varieties, the Zariski topology, the coordinate rings.
Date
Monday October 3, 2022Location
TBAMonday, October 3rd, 2022
Time: 4:30 p.m. Place: TBA
Speaker: Ruiran Sun (McGill University)
Title: On slope and valuative K-semistability for big and nef birational divisors
Abstract:
Website details here: https://mast.queensu.ca/~georep/Fall%20'22.html
Date
Tuesday September 27, 2022Location
Jeffery Hall, Room 422Tuesday, September 27th, 2022
Time: 2:00 p.m. Place: Jeffery Hall, Room 422
Speaker: Nic Fellini (ºÚÁϳԹÏ×ÊÔ´)
Title: Fermat quotients and the Ankeny-Artin-Chowla conjecture
Abstract: In 1952, Ankeny, Artin, and Chowla proved a congruence relation mod p relating the class number of the real quadratic field Q(√p), the fundamental unit of Q(√p), and some Bernoulli number. I will present joint work with Professor Murty where we generalize the results of Ankeny, Artin, and Chowla and will discuss some consequences of a conjecture related to their work.
Date
Friday September 23, 2022Location
Jeffery Hall, Room 422Friday, September 23rd, 2022
Time: 10:00 a.m. Place: Jeffery Hall, Room 422
Speaker: Henry Kavle (Queen's University)
Title: A Morse index-Maslov index correspondence for convex billiards
Abstract: In 1976, J.J. Duistermaat proved a general correspondence between the Morse index of a trajectory arising as a critical point of a variational problem and the Maslov index of a path of symplectic matrices describing the linearized flow along the trajectory in phase space. We will sketch an analogous correspondence for discrete time dynamics, emphasizing concrete computations for periodic orbits in smooth convex billiard tables. Time permitting, we will show that these indices allow us to determine the linear stability of periodic trajectories.
