91PORNA

Analysis conference

Seminars and Conferences

Fall 2026 Colloquium Talks

  • Date: Thursday, November 5
    Time: 1:10鈥2:00 p.m.
    Location: MSB 114
    Speaker:  Ethan Ackelsberg

    Title: Structure and randomness in combinatorics and dynamics

    Abstract: Analytic and dynamical tools from ergodic theory are surprisingly adept at treating discrete, seemingly static problems in combinatorics and number theory. We will describe the deep connection between combinatorial patterns in subsets of the integers and recurrence phenomena in ergodic theory, as realized by Furstenberg in the 1970s. We will then explore how ideas from ergodic theory鈥攊n particular, the pervasive dichotomy between structure and randomness in dynamical systems鈥攑rovide deeper insight into combinatorial and number-theoretic problems and, conversely, how combinatorics and number theory enrich our understanding of the long-term statistical behavior of dynamical systems.
     

  • Date: Thursday, October 22
    Time: 1:10鈥2:00 p.m.
    Location: MSB 114
    Speaker:  Morley Davidson

    Title: "What is a Lean certification of a proof? And is it reliable?"

    Abstract: Abstract: In this talk we'll examine the ever-increasing use of proof assistant software nowadays, particularly the role of Lean 4 in OpenAI's Oct. 6 posting of 700+ preprints with purported major breakthroughs including the quasi-Riemann hypothesis. To illustrate the pros and cons of automated proof certification, we'll focus on very recent AI+Lean experiments on irrationality of "odd zeta values," including an application of the new idea behind Fauzan's Sept.17 posting that zeta(5) is irrational, the first such result since Apery's 1978 proof for zeta(3),  to showing (ostensibly!) that at least one of zeta(7), zeta(9), zeta(11), or zeta(13) is irrational. If its Lean certification holds water, this will update the 2001 breakthrough of Zudilin on four consecutive odd zeta values starting with zeta(5). But how can we be sure that a Lean certification is itself valid?

  • Date: Thursday, October 15
    Time: 1:10鈥2:00 p.m.
    Location: MSB 114
    Speaker: Fedor Nazarov

    Title: "What is a Lean certification of a proof? And is it reliable?"

    Abstract: The formal result we will discuss is the following: Let T be a finite tree with the set V of vertices and E of edges. Consider the space 鈩V of functions x: V 鈫 鈩 with the norm

     

    鈥x鈥 =鈭av|x(v)| +鈭ce触螖ex|
    v 鈭 Ve 鈭 E
    where av, ce > 0 are arbitrary and 螖ex = |x(v鈥) 鈭 x(v鈥)| for e = {v鈥, v鈥硙. Then this space is isomorphic to the usual 鈩1 with the underlying Banach鈥揗azur constant at most 14. Recall that the B-M constant for two Banach spaces X and Y is just
    inf { 鈥T鈥 鈥T鈭1鈥 : T 鈭 鈩(X, Y), T invertible }.
    Some meta-mathematical discussion will be present too, so bring your brains! This is joint work with Micha艂 Wojciechowski.
     

  • Date: Thursday, October 1
    Time: 1:10鈥2:00 p.m.
    Location: MSB 114
    Speaker: Fedor Nazarov

    Title: "Very simple questions that can get complicated quickly鈥.

    Abstract: We'll discuss an elementary discrete geometry question that I encountered first in my 8th grade but have never resolved to my complete satisfaction since then. The talk will be interactive, so, please, bring your brains (in full compliance with our great non-discrimination laws, free and unrestricted usage of prosthetics, a.k.a. AI, will also be allowed, regardless of the manufacturer, the model, and the monthly rent rate, and would not be discriminated against in any way during the discussion).

Seminars

Past Conferences

Spring 2026

Informal Analysis Seminar August 2023

November 9-10, 2019

April 20-21, 2019

Feb. 9-10, 2019, 91PORNA

October 11-13, 2018

February 24-25, 2018


April 7-9, 2017

October 28-30, 2016 

April 30- May 1, 2016

November 14-15, 2015

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