Category: Kourovka forum

Kourovka Forum: talk by Dan Segal

On Thursday the 17-th of February, 2022, Dan Segal (All Souls College, Oxford) will give an online talk “Groups, rings, logic” at 20:00 Novosibirsk time (13:00 London time).

Abstract: In group theory, interesting statements about a group usually can’t be expressed in the language of first-order logic. It turns out, however, that some groups can actually be determined by their first-order properties, or, even more strongly, by a single first-order sentence. In the latter case the group is said to be finitely axiomatizable. I will describe some examples of this phenomenon (joint work with A. Nies and K. Tent). One family of results concerns axiomatizability of p-adic analytic pro-p groups, within the class of all profinite groups. Another main result is that for an adjoint simple Chevalley group of rank at least 2 and an integral domain R; the group G(R) is bi-interpretable with the ring R. This means in particular that first-order properties of the group G(R) correspond to first-order properties of the ring R. As many rings are known to be finitely axiomatizable we obtain the corresponding result for many groups; this holds in particular for every finitely generated group of the form G(R).

Chair of the session: Evgeny Khukhro

The link to the Zoom meeting: https://us02web.zoom.us/j/3167567840?pwd=aExXZmUxVmE5blYxYTVRMHhrakxuQT09

(ID 316 756 7840, Password gD11t2).

See the program updates at http://mca.nsu.ru/kourovkaforum/.

If you wish to be added to the seminar mailing list and receive regular announcements, please contact the organizers at ilygor8@gmail.ru .

Kourovka Forum: talk by Alex Lubotzky

On Thursday the 3rd of February, 2022, Alex Lubotzky (Weizmann Institute and Hebrew University, Israel) will give an online talk “Stability and testability of permutations’ equations” at 16:00 Novosibirsk time (9:00 London time).

Abstract: Let A and B be two permutations in Sym(n) which “almost commute” — are they a small deformation of permutations that truly commute? More generally, if R is a system of word-equations in variables X=(x_1,….,x_d) and A=(A_1,…., A_d) permutations which are nearly solution; are they near true solutions? It turns out that the answer to this question depends only on the group presented by the generators X and relations R. This leads to the notions of “stable groups” and “testable groups”. We will present a few results and methods which were developed in recent years to check whether a group is stable\testable. We will also describe the connection of this subject with property testing in computer science, with the long-standing problem of whether every group is sofic and with IRS’s ( =invariant random subgroups).
A number of open questions will be presented.

Chair of the session: Mikhail Belolipetsky

The link to the Zoom meeting:  https://us02web.zoom.us/j/3167567840?pwd=aExXZmUxVmE5blYxYTVRMHhrakxuQT09 (ID 316 756 7840, Password gD11t2).

See the program updates at http://mca.nsu.ru/kourovkaforum/.

Re-launch of Kourovka Forum

A new series of online seminars “Kourovka Forum” will be launched in  February of 2022: http://mca.nsu.ru/kourovkaforum/ . 

The first seminar in the new series will be held on Thursday, February 3, at 16:00 Novosibirsk time (9:00 London time) via ZOOM. The first talk is by Alex Lubotzky, Stability and testability of permutations’ equations. The zoom link is https://us02web.zoom.us/j/5578968779 .

As an additional feature of the Kourovka Notebook, this series of seminars is intended to highlight the most promising research directions in group theory and, more generally, algebra, along with other relevant fields of mathematics. Clear formulations of the problems may help young researchers to focus their efforts and give them a higher chance of achieving outstanding mathematical results.

The seminars will be held once in two weeks on Thursdays. The starting time of the seminar will vary depending on the preferences of the speaker, taking into account the geography of the audience.

Kourovka Forum further talks

The online seminars “Kourovka Forum” continue their work; see http://mca.nsu.ru/kourovkaforum/ . 

The next seminar will be held on Thursday, 10 December, at 20:00 Novosibirsk time (=13:00 London time) via ZOOM. Efim Zelmanov (University of California, San Diego) will speak on Growth and complexity functions for basic algebraic structures. The zoom link is https://us02web.zoom.us/j/5578968779

Previous talks, with slides and recorded lectures, can be found at http://mca.nsu.ru/kourovkaforum/scheduleandabstracts/

Recall that this series of seminars is intended to highlight the most promising research directions in group theory and, more generally, algebra, along with other relevant fields of mathematics. Clear formulations of the problems may help young researchers to focus their efforts and give them a higher chance of achieving outstanding mathematical results.

The seminars are held once in two weeks on Thursdays. The starting time of the seminar will vary depending on the preferences of the speaker, taking into account the geography of the audience.

 

Launch of Kourovka Forum

As an additional feature of the Kourovka Notebook, a new series of online seminars “Kourovka Forum” will be launched on 29th of October 2020: http://mca.nsu.ru/kourovkaforum/ . 

The first seminar will be held on Thursday, October 29, at 16:00 Novosibirsk time (=9:00 London time) via ZOOM. The first talk is by Evgeny Khukhro, Some problems about bounding length parameters of finite groups. The zoom link is https://us02web.zoom.us/j/5578968779

This series of seminars is intended to highlight the most promising research directions in group theory and, more generally, algebra, along with other relevant fields of mathematics. Clear formulations of the problems may help young researchers to focus their efforts and give them a higher chance of achieving outstanding mathematical results.

The seminars will be held once in two weeks on Thursdays. The starting time of the seminar will vary depending on the preferences of the speaker, taking into account the geography of the audience.