Noriko Yui (Queen's University)

Date

Friday January 13, 2023
2:30 pm - 3:30 pm

Location

Jeffery Hall, Room 234

Math & Stats Department Colloquium

Friday, January 13th, 2023

Time: 2:30 p.m.  Place: Jeffery Hall, Room 234

Speaker: Noriko Yui (Queen's University)

Title: Modularity of certain Calabi-Yau threefolds of Hodge type (1,1,1,1)

Abstract: We will focus on (families of) Calabi-Yau threefolds of Hodge type (1, 1, 1, 1), and discuss their modularity/automorphy in the framework of the Langlands Philosophy. In the last thirty years or so, we have witnessed tremendous advances on the modularity questions for Calabi-Yau varieties. Most of these results rest on the modularity of the two-dimensional Galois representations associated to them. The next simplest cases are those Calabi{Yau threefolds of Hodge type (1, 1, 1, 1). I will present modularity results on some examples of such Calabi{Yau threefolds (and motives).

Noriko Yui is a professor of mathematics at Queen's University in Kingston, Ontario.
A native of Japan, Yui obtained her B.S. from Tsuda College, and her Ph.D. in Mathematics from Rutgers University in 1974 under the supervision of Richard Bumby.
Known internationally, Yui has been a visiting researcher at the Max-Planck-Institute in Bonn a number of times and a Bye-Fellow at Newnham College, University of Cambridge. Her research is based in arithmetic geometry with applications to mathematical physics and notably mirror symmetry. Currently, much of her work is focused upon the modularity of Calabi-Yau threefolds. Notably, she and Fernando Q. Gouvea have shown that for X, a projective rigid Calabi-Yau threefold defined over the rationals , the L-function of X is the L-function of a certain modular form.
Professor Yui has been the managing editor for the journal Communications in Number Theory and Physics since its inception in 2007. In 2022 she became a fellow of the Canadian Mathematical Society.

Nima Hoda (Cornell University)

Date

Monday January 9, 2023
4:30 pm - 5:30 pm

Location

TBA

Algebra & Geometry Seminar

Monday, January 9th, 2023

Time: 4:30 p.m.  Place: TBA

Speaker: Nima Hoda (Cornell University)

Title: Strong shortcut groups and asymptotic cones

Abstract:

Website details here: https://mast.queensu.ca/~georep/Fall%20'22.html

Monica Garcis (Paris-Saclay University)

Date

Monday December 12, 2022
4:30 pm - 5:30 pm

Location

TBA

Algebra & Geometry Seminar

Monday, December 12th, 2022

Time: 4:30 p.m.  Place: TBA

Speaker: Monica Garcis (Paris-Saclay University)

Title: Towards stability for projective presentation

Abstract:

Website details here: https://mast.queensu.ca/~georep/Fall%20'22.html

Moon Duchin (Tufts University)

Date

Wednesday December 7, 2022
4:00 pm - 5:00 pm

Location

Stirling Hall A, Online via Zoom

2022 Lorne Campbell Lecture Series

 

Moon Duchin (Tufts University)

Wednesday, December 7th, 2022

Time: 4:00 p.m.  Place: Stirling Hall A, or Online via Zoom (contact Abdol-Reza Mansouri for Zoom link)

Speaker: Moon Duchin (Tufts University)

Title: How Societies Choose

Abstract: How can we measure a healthy democracy? There are infinitely many election systems -- how voters fill out a ballot and then how we combine ballots to decide the outcome -- and they all have different properties and tendencies. I will give some philosophical and some mathematical perspectives on finding fairness in representative democracy.

Dr. Duchin is a mathematics professor at Tufts University and founder of the Metric Geometry and Gerrymandering group, a nonpartisan research group coordinating and publicizing research on geometry, computing, and their application to the redistricting process in the US. Her mathematical research concerns geometric topology, geometric group theory, Teichmuller theory, and the geometry of politics. Dr. Duchin is a fellow of the American Mathematical Society, gave a 2016 Mathematical Association of America distinguished lecture, was awarded a Guggenheim fellowship in 2018, and in 2018- 2019 was a fellow at the Radcliffe Institute for Advanced Study at Harvard.

Sonja Ruzic

Date

Wednesday November 30, 2022
1:00 pm - 2:00 pm

Location

Jeffery Hall, Room 222

Curves Seminar

Wednesday, November 30th, 2022

Time: 1:00 p.m.  Place: Jeffery Hall, Room 222

Speaker: Sonja Ruzic

Title: Localization Review, and Projective Toric Varieties

Abstract: We will give a brief review of localization. Afterwards, we will start the discussion of projective toric varieties.

Jean Pierre Mutanguha (IAS)

Date

Friday November 25, 2022
2:30 pm - 3:30 pm

Location

Jeffery Hall, Room 234

Math & Stats Department Colloquium

Friday, November 25th, 2022

Time: 2:30 p.m.  Place: Jeffery Hall, Room 234

Speaker: Jean Pierre Mutanguha (IAS)

Title: Finding relative immersions of free groups

Abstract: Given an injective endomorphism of a free group, what is the "best" way to represent it so as to read off its dynamical properties? For automorphisms, the prevailing answer since the 1990s has been train tracks and their variations. In this talk, I answer this question for nonsurjective endomorphisms. To some degree, it turns out nonsurjectivity greatly simplifies matters --- a result that I found rather surprising. I proved that all injective endomorphisms can be uniquely represented by certain kinds of expanding immersions on graphs; a bit paradoxically, this representation is trivial when the endomorphism is an automorphism.

Annette Karrer (McGill University)

Date

Friday December 2, 2022
2:30 pm - 3:30 pm

Location

Jeffery Hall, Room 234

Math & Stats Department Colloquium

Friday, December 2nd, 2022

Time: 2:30 p.m.  Place: Jeffery Hall, Room 234

Speaker: Annette Karrer (McGill University)

Title: From Stalling鈥檚 Theorem to Morse boundaries

Abstract: Every finitely generated group G has an associated topological space, called a Morse boundary. It was introduced by a combination of Cordes and Charney{Sultan and captures the hyperbolic-like behavior of G at in nity. In this talk, I will motivate the research on Morse boundaries in several steps. First, I will explain Stalling's theorem { a fundamental theorem in geometric group theory. Afterward, I will explain an analogous statement for so-called Gromov boundaries of Gromov-hyperbolic groups. As Morse boundaries generalize Gromov boundaries, this raises the question as to whether one can generalize this statement to Morse boundaries. Finally, we will see the relationship between a result on Morse boundaries of graphs of groups and this problem. Results presented are joint with Elia Fioravanti.

Dr. Karrer is a postdoc at McGill University, working in geometric group theory. After earning her PhD from Karlsruher Institute fur Tehcnoloqie under the advisement of Petra Schwer and Tobias Hartnick, and before her current position, Dr. Karrer worked as a postdoctoral fellow at the Technion in Israel.

Nic Fellini (黑料吃瓜资源)

Date

Tuesday November 29, 2022
2:00 pm - 3:00 pm

Location

Jeffery Hall, Room 422

Number Theory Seminar

Tuesday, November 29th, 2022

Time: 2:00 p.m.  Place: Jeffery Hall, Room 422

Speaker: Nic Fellini (黑料吃瓜资源)

Title: A graph theoretic inequality and it's applications

Abstract: In this talk I will provide a graph theoretic approach to developing a simple sieve. We will see as an application how one can derive a multidimensional generalization of the Tur谩n鈥揔ubilius inequality. Time permitting, various other application will be discussed.

Alexandre (Sasha) Zotine

Date

Wednesday November 23, 2022
1:00 pm - 2:00 pm

Location

Jeffery Hall, Room 222 or Zoom

Curves Seminar

Wednesday, November 23rd, 2022

Time: 1:00 p.m.  Place: Jeffery Hall, Room 222 or Zoom

Speaker: Alexandre (Sasha) Zotine

Title: Toric Morphisms and Projective Geometry

Abstract: We will finish off our discussion of affine toric varieties by discussing torus equivariant maps. Afterwards, we will establish the foundations for studying projective toric varieties.

Francesco Cellarosi (黑料吃瓜资源)

Date

Tuesday November 15, 2022
2:00 pm - 3:00 pm

Location

Jeffery Hall, Room 422

Number Theory Seminar

Tuesday, November 15th, 2022

Time: 2:00 p.m.  Place: Jeffery Hall, Room 422

Speaker: Francesco Cellarosi (黑料吃瓜资源)

Title: The dynamical generalization of the Prime Number Theorem by Bergelson and Richter (Part 2)

Abstract: In a series of two talks, I will illustrate some of the results from the recent papers 鈥淒ynamical generalizations of the Prime Number Theorem and disjointness of additive and multiplicative semigroup actions鈥 by V. Bergelson and F.K. Richter (Duke Math. J. 171(15): 3133-3200, October 2022) and 鈥淎 new elementary proof of the Prime Number Theorem鈥 by F.K. Richter (Bulletin of the London Math. Society. 53(5): 1365-1375, October 2021).

In the first talk, I will assume several results to give a proof of a generalization of the PNT. The key idea will be to replace the average of an arithmetic function by a double average. This will prove a uniform distribution for the sequence (T^\Omega(n)x)_{n\geq1}, where T is a uniquely ergodic transformation of a compact metric space X, x is a point in X, and \Omega(n) the number of prime factors of n (counted with multiplicity). A particular choice of X, T, and x will yield the classical PNT.

In the second talk, I will get into the proofs of the results used in the first talk. We will see that, in the proof of a key lemma, we could either use the PNT or a weaker form of the PNT. The latter choice yields a novel elementary proof of the PNT, along with several generalizations thereof (e.g. the PNT along arithmetic progressions).