The Open Seminar provides a platform for students and researchers to present their work, discuss new ideas, and explore a broad range of mathematical topics in a collaborative and friendly environment.

The seminar is hosted by the School of Mathematical Sciences at Hebei Normal University (HebNU). Organized by Salvatore Tringali (contact details) and Liping Yuan, it features a mix of guests and members of the local academic community as speakers. Unless otherwise stated in the individual announcements, all talks will be

Thursday 4:00–5:00 PM (Beijing time) · HebNU School of Mathematical Sciences, Room D203 or D204.

To enable participants from around the world, we stream the seminar on Zoom via the link:

https://us06web.zoom.us/j/86763384947?pwd=qXhOzOcHvaaiw2jqADI8iqNavdgm14.1

To receive announcements about upcoming talks, please send an email to one of the organizers. Prospective speakers are required to submit both the TeX file and a PDF version of their abstract, including a short academic bio, using the template available here.

Spring–Summer 2026

Thursday, March 5, 2026 · 4:30–5:30 PM (Beijing time) · in person
Mikko KORHONEN · Mathematics Research Centre, Tampere University (Tampere, Finland)
Maximal solvable subgroups (abstract · slides)
Thursday, March 12, 2026 · 4:30–5:30 PM (Beijing time) · online
Dein WONG(*) · School of Mathematics, China Univ. of Mining and Technology (Xuzhou, China)
On automorphism groups of power semigroups over numerical semigroups (abstract · slides)
(*) Due to a last-minute change of programme, the talk was given by Songnian XU, a 3rd-year PhD student of Prof. Wong at the China Univ. of Mining and Technology.
Thursday, March 19, 2026 · 5:00–6:00 PM (Beijing time) · in person
Weihao YAN · School of Mathematical Sciences, Hebei Normal Univ. (Shijiazhuang, China)
Torsion groups and the Bienvenu–Geroldinger conjecture (abstract · slides)
Monday, March 23, 2026 · 10:30–11:30 AM (Beijing time) · in person
Alexey GALT · Sobolev Institute of Mathematics (Novosibirsk, Russia)
The structure of the normalizers of maximal tori in groups of Lie type (abstract · slides)
Friday, April 3, 2026 · 4:30–5:30 PM (Beijing time) · in person
Kerou WEN · School of Mathematical Sciences, Hebei Normal Univ. (Shijiazhuang, China)
On the automorphisms of numerical power semigroups (abstract · slides)
April 9, 2026 · 4:30–5:30 PM (Beijing time) · online
Balint RAGO · Dept. of Mathematics and Scientific Computing, Univ. of Graz (Graz, Austria)
On an isomorphism problem for reduced finitary power monoids (abstract · slides)
April 14, 2026 · 4:40–5:40 PM (Beijing time) · in person
Vladislav KABANOV · School of Mathematical Sciences, Hebei Normal Univ. (Shijiazhuang, China) Vladislav KABANOV · Krasovskii Inst. of Mathematics and Mechanics (Yekaterinburg, Russia)
Divisible design graphs derived from collections of affine designs (abstract · slides)
April 14, 2026 · 5:40–6:40 PM (Beijing time) · in person
Ilia PONOMARENKO · St. Petersburg Dept. of Steklov Inst. of Mathematics (St. Petersburg, Russia)
The Weisfeiler–Leman dimension of graphs, old and new results (abstract · slides)
April 16, 2026 · 4:30–5:30 PM (Beijing time) · in person
Yi Lin XIE · School of Mathematical Sciences, Hebei Normal Univ. (Shijiazhuang, China)
On the minimal degree of finite permutation groups (abstract · slides)
April 22, 2026 · 10:30‑11:30 AM (Beijing time) · online
Zachary MESYAN · Dept. of Mathematics, University of Colorado (Colorado Spring, USA)
Factorization in Finitely-Presented Monoids (abstract · slides)
April 30, 2026 · 3:00–4:00 PM (Beijing time) · online
Andreas REINHART · Dept. of Mathematics and Scientific Computing, Univ. of Graz (Graz, Austria)
Power monoids and their arithmetic (abstract · slides)
May 7, 2026 · 3:00–4:00 PM (Beijing time) · online
Paolo LEONETTI · Dept. of Economics, University of Insubria (Varese, Italy)
On the largeness of sumsets (abstract · slides)
May 14, 2026 · 4:30–5:30 PM (Beijing time) · in person
Gurinder SINGH · School of Mathematical Sciences, Hebei Normal Univ. (Shijiazhuang, China)
A proof of the \(J\)-generalization of the Göllnitz–Gordon–Andrews identities via commutative algebra (abstract · slides)
May 19, 2026 · 4:00–5:00 PM (Beijing time) · in person
Grigory RYABOV · Sobolev Institute of Mathematics (Novosibirsk, Russia)
Classification of abelian Schur groups and beyond (abstract · slides)
May 28, 2026 · 3:00–4:00 PM (Beijing time) · online
Hanbin ZHANG · School of Mathematics, Sun Yat-sen University, Zhuhai Campus (Zhuhai, China)
Combinatorial problems on zero-sum sequences (abstract · slides)
June 4, 2026 · 3:00–4:00 PM (Beijing time) · online
Dongchun HAN · School of Mathematics, Southwest Jiaotong University (Chengdu, China)
An Overview of the MDS Conjecture (abstract · slides)
June 11, 2026 · 7:00–8:00 PM (Beijing time) · in person
Salvatore TRINGALI · School of Mathematical Sciences, Hebei Normal Univ. (Shijiazhuang, China)
Some rigidity theorems for groups and numerical monoids (abstract · slides)
June 18, 2026 · 7:30–8:30 PM (Beijing time) · online
Stefano BONZIO · Dept. of Mathematics, University of Cagliari (Cagliari, Italy)
To be announced (abstract · slides)

Fall–Winter 2025

John Doe · University of Joy, Serendipity
Recent trends in the theory of summer holidays (slides)

Mario Rossi · Paramount Institute of Gattology, Venus
Cats and the maximum meowing principle (slides)