Combinatorics

G2G2-Summer School is associated with G2G2-Minisymposia of 8ECM. It belongs to the G2-series that are about strong and beautiful mathematics, especially those involving group actions on combinatorial objects.

The main goal of G2G2-Summer School is to bring together experts and students to exchange ideas and to enrich their mathematical horizon.

We organize two short courses and four colloquium talks to let participants see order and simplicity from possibly new perspectives and share insights with experts.

Students will have a chance to present their results in a broad range of topics relevant to graph theory and group theory with connections to algebraic combinatorics, Finite geometries, designs, computational discrete algebra, vertex operator algebras, topological graph theory, network analysis, and their applications in physics, chemistry, biology. The scientific program of the G2G2-Summer School consists of the following two courses each of which is presented by eight lectures.

• Mini course 1 (Lecturer: Atsushi Matsuo, The University of Tokyo, Japan): Representations of vertex operator algebras

• Mini course 2 (Lecturer: Leonard H. Soicher, Queen Mary University of London, UK): Graphs, groups and geometries in GAP

There will be daily solving problems sessions on the mini courses to help students in understanding the courses. There will be at least 12 short contributed talks given by students.

29 June – 4 July 2020

**Rogla, Slovenia**

https://conferences.famnit.upr.si/event/13/

**Elena Konstantinova** (Sobolev Institute of Mathematics, Siberian Branch of Russian Academy of Science, Russia)

**Contact**: e_konsta@math.nsc.ru

**Ivanov Alexander A.** (Imperial College London, UK)

At the conference we will be celebrating the 65th birthday of Paul Terwilliger. As such, the general theme of this conference will be the mathematical topics that Paul has worked on over the years (which all have relationships to the q-Onsager algebra). These topics include the following:

• Topics in algebraic graph theory, such as distance-regular graphs, association schemes, the subconstituent algebra, and the Q-polynomial property;

• Topics in linear algebra, such as Leonard pairs, tridiagonal pairs, billiard arrays, lowering-raising triples, and a linear algebraic approach to the orthogonal polynomials of the Askey scheme;

• Topics in Lie theory, such as the tetrahedron algebra and the Onsager algebra;

• Topics in algebras and their representations, such as the equitable presentation of U_q(sl_2), the q-tetrahedron algebra, the mathematical physics of the q-Onsager algebra, and the universal Askey-Wilson algebra.

13 – 18 July 2020

**Kranjska gora, Slovenia**

**Štefko Miklavič** (University of Primorska, Andrej Marušič Institute, Slovenia)

**Contact**: stefko.miklavic@upr.si

**Mark Maclean** (Mathematics department, Seattle University, USA)

**Contact:** macleanm@seattleu.edu