Number Theory Web Seminar

This number theory seminar is purely online. Our talks come from various corners of the field and of the world. They are streamed live on Zoom.

Organizers:


There are no fees, but registration is necessary. To register please follow this link.

Registered users will receive an email a few hours before the talk with a link to the Zoom meeting. 

The seminar runs every Thursday. Please note the usual times of the seminar below and in the FAQ Section. 

Talks are usually 50 minutes and then time for some questions.

Contact: ntweb.seminar@gmail.com

Please consider the following:

Next talk:



Sarah Peluse, Divisibility of character values of the symmetric group
(Institute for Advanced Study and Princeton University)

Thursday, February 9, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 9:30pm Indian Standard Time)
Friday, February 10, 2023 (12am CST, 3am AEDT, 5am NZDT)

Abstract: In 2017, Miller computed the character tables of $S_n$ for all $n$ up to $38$ and looked at various statistical properties of the entries. Characters of symmetric groups take only integer values, and, based on his computations, Miller conjectured that almost all entries of the character table of $S_n$ are divisible by any fixed prime power as $n$ tends to infinity. In this talk, I will discuss joint work with K. Soundararajan that resolves this conjecture, and mention some related open problems.


Upcoming talks:

Wanlin Li, Ordinary and Basic Reductions of Abelian Varieties
(Université de Montréal)

Thursday, February 16, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 9:30pm Indian Standard Time)
Friday, February 17, 2023 (12am CST, 3am AEDT, 5am NZDT)

Abstract: Given an abelian variety A defined over a number field, a conjecture attributed to Serre states that the set of primes at which A admits ordinary reduction is of positive density. This conjecture had been proved for elliptic curves (Serre, 1977), abelian surfaces (Katz 1982, Sawin 2016) and certain higher dimensional abelian varieties (Pink 1983, Fite 2021, etc). 

In this talk, we will discuss ideas behind these results and recent progress for abelian varieties with non-trivial endomorphisms, including some cases of A with almost complex multiplication by an abelian CM field, based on joint work with Cantoral-Farfan, Mantovan, Pries, and Tang.

Apart from ordinary reduction, we will also discuss the set of primes at which an abelian variety admits basic reduction, generalizing a result of Elkies on the infinitude of supersingular primes for elliptic curves. This is joint work with Mantovan, Pries, and Tang.


Terence Tao, Infinite Partial Sumsets in the Primes
(UCLA)

Thursday, February 23, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 9:30pm Indian Standard Time)
Friday, February 24, 2023 (12am CST, 3am AEDT, 5am NZDT)

Abstract: It is an open question as to whether the prime numbers contain the sum A+B of two infinite sets of natural numbers A, B (although results of this type are known assuming the Hardy-Littlewood prime tuples conjecture).  Using the Maynard sieve and the Bergelson intersectivity lemma, we show the weaker result that there exist two infinite sequences a_1 < a_2 < ... and b_1 < b_2 < ... such that a_i + b_j is prime for all i<j.  Equivalently, the primes are not "translation-finite" in the sense of Ruppert.  As an application of these methods we show that the orbit closure of the primes is uncountable.


Alexandra Shlapentokh, TBA
(East Carolina University)

Thursday, March 2, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 9:30pm Indian Standard Time)
Friday, March 3, 2023 (12am CST, 3am AEDT, 5am NZDT)

Abstract: TBA


Alex Wilkie, TBA
(University of Oxford and University of Manchester)

Thursday, March 9, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 9:30pm Indian Standard Time)
Friday, March 10, 2023 (12am CST, 3am AEDT, 5am NZDT)

Abstract: TBA


Florian Luca, TBA
(University of the Witwatersrand)

Thursday, March 16, 2023 (9am PDT, 12pm EDT, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 9:30pm Indian Standard Time)
Friday, March 17, 2023 (12am CST, 3am AEDT, 5am NZDT)

Abstract: TBA


Ofir Gorodetsky, TBA
(University of Oxford)

Thursday, March 23, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 9:30pm Indian Standard Time)
Friday, March 24, 2023 (12am CST, 3am AEDT, 5am NZDT)

Abstract: TBA


Ziyang Gao, TBA
(Leibniz University Hannover)

Thursday, March 30, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 8:30pm Indian Standard Time, 11pm CST)
Friday, March 31, 2023 (2am AEDT, 4am NZDT)

Abstract: TBA


Kannan Soundararajan, TBA
(Stanford University)

Thursday, April 6, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 8:30pm Indian Standard Time, 11pm CST)
Friday, April 7, 2023 (1am AEST, 3am NZST)

Abstract: TBA


Hélène Esnault, TBA
(Freie Universität Berlin)

Thursday, April 13, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 8:30pm Indian Standard Time, 11pm CST)
Friday, April 14, 2023 (1am AEST, 3am NZST)

Abstract: TBA


Bjorn Poonen, TBA
(MIT)

Thursday, April 20, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 8:30pm Indian Standard Time, 11pm CST)
Friday, April 21, 2023 (1am AEST, 3am NZST)

Abstract: TBA


Pierre Le Boudec, TBA
(University of Basel)

Thursday, April 27, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 8:30pm Indian Standard Time, 11pm CST)
Friday, April 28, 2023 (1am AEST, 3am NZST)

Abstract: TBA


Peter Koymans, TBA
(University of Michigan)

Thursday, May 4, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 8:30pm Indian Standard Time, 11pm CST)
Friday, May 5, 2023 (1am AEST, 3am NZST)

Abstract: TBA


Ben Green, TBA
(University of Oxford)

Thursday, May 11, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 8:30pm Indian Standard Time, 11pm CST)
Friday, May 12, 2023 (1am AEST, 3am NZST)

Abstract: TBA


Mark Shusterman, TBA
(Harvard University)

Thursday, May 18, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 8:30pm Indian Standard Time, 11pm CST)
Friday, May 19, 2023 (1am AEST, 3am NZST)

Abstract: TBA


Barak Weiss, TBA
(Tel Aviv University)

Thursday, May 25, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 8:30pm Indian Standard Time, 11pm CST)
Friday, May 26, 2023 (1am AEST, 3am NZST)

Abstract: TBA


Lior Bary-Soroker, TBA
(Tel Aviv University)

Thursday, June 1, 2023 (8am PST, 11am EST, 4pm GMT, 5pm CET, 6pm Israel Standard Time, 8:30pm Indian Standard Time, 11pm CST)
Friday, June 2, 2023 (1am AEST, 3am NZST)

Abstract: TBA


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