## 8th European Congress of Mathematics closes with great success

### 1766 registered participants, more than 1000 contributions, numerous distinguished speakers

Inspite of the insecure circumstances, Slovenian coastal town Portorož hosted the 8th ECM from June 20 to June 26, 2021. The largest scientific meeting of mathematicians in Europe takes place every four years under the auspices of European Mathematical Society (EMS).

During the congress, only about 200 of altogether 1766 registered participants were able to attend the congress venue in person. The others were unable to travel to Slovenia due to COVID crisis, so the official congress programme was completely available online. However, a number of speakers present in Portorož did broadcast their lectures live from the congress halls, where they spoke in front of the small audience.

I have arrived to the Congress Centre on Sunday, June 20, in the afternoon. I was really impressed by a nicely decorated reception hall, where several congress booklets and other materials were given out by kind volunteers along with several promotion materials on Slovenia. Also, two interesting exihibitions were greeting the newly arrived: mathematical stamps (by Robin Wilson) and historical Slovenian mathematicians Vega, Plemelj, Močnik, Vidav and Lah (by Marko and Nada Razpet and Izidor Hafner).

After the welcome reception with speeches and music at a lovely plateou with a seaside view, attendants walked along the coast to a nearby gallery Monfort, where several interesting graphic artworks with mathematical background were exhibited: collection *Mathematics in Colors* by Bogdan Soban, *Random Art* by Andrej Bauer and *selected mathematical posters* by staff and students of the Mathematics department at the University of Ljubljana..

In the following days, the guests were also offered a piano evening by Teja Jeličić, a visit of artwork exhibition "X" of Teja Krašek in the nearby town Izola, poster exhibition "European Women of Mathematics" at the University of Primorska in Koper, as well as a visit to a marine biology station or several math sculpture workshops for the children.

The 8ECM really started on Monday, June 21st, in the morning, with an online Opening Ceremony. The opening speeches were held by Slovenian president Borut Pahor, the president of EMS Volker Mehrmann, the chair of the Organizing Committee Tomaž Pisanski, and rector of the host institution Klavdija Kutnar.

The opening adresses were followed by EMS prize committe chair Martin Bridson, Otto Neugebauer prize committee chair Eberhardt Knobloch and Felixa Kleina prize committee Ralf Korn, who presented the awards. Each of the 12 award recepients was represented by a 3 minute video portrait. On behalf of the prize recepients, Karine Chemla, the Otto Neugebauer prize recepient, thanked the committee and the organizers for their commitment to make the congress as memorable as possible.

The scientific programme of the congress opened by an incredibly interesting plenary lecture by Alfio Quateroni on mathematical models of heart and blood circulation. The lecture on minimal surfaces from the complex analisys point of view by Franc Forstnerič was the first ever plenary lecture by a Slovene mathematician in the history of ECM. Other plenary lectures were also excellent, with two lectures on deep/statistical learning by Gitta Kutinyok and Peter Buhlmann standing a bit out of the more traditional topics from algebraic geometry, combinatorics, analysis and probability.

Unfortunately, the 10 EMS prize talks were presented in 5 parallel sections, so I could only attend two. The first one was by Kaisa Matomaki on primes and almost primes in short intervals, and the second one by Alexander Logunov on zero sets of Laplacian eigenfunctions.

The 30 invited lectures were also very interesting, and I was really impressed by Daniela Kuhn's latest results on the famous Erdos-Faber-Lovasz conjecture on the edge-chromatic number of hypergraphs. 3 of the invited lectures were also contributed by Slovenian mathematicians. Špela Špenko presented the concept of HMS categorical symmetries and hypergeometric systems as an extension of Plemelj's solution of the 21st Hibert problem on existence of DE system with a prescribed monodromy group. Aleksey Kostenko presented the two complementing types of Laplacian operators in the context of infinite graphs, while Andrej Bauer convinced me that the recent formalization of mathematics by using type theory instead of set theory is changing foundaments of mathematics.

Among the lectures mentioned so far, some others also stood out. This year's Abel prize winner (together with Avi Widgerson) Laszlo Lovasz dedicated his Abel lecture to hot topic of connecting continuous and discrete mathematics by using graph limits - graphons. Among the 6 public lectures, we were able to hear a lectures by Robin Wilson on the history of math in Europe (through stamps), Bojan Mohar on the crossing numbers, Kathrynn Hess on topological applications in neuroscience, Martin Hairer on mathematical journey through scales, Fields medalist Stanislav Smirnov on mathematics and art and Fields medalist Alexeia Okounkova on Lie Theory without groups.

A majority of the remaining more tha 1000 contributed talks were shorter and distributed within 62 minisymposiums that were proposed by their organizers and confirmed by the local scientific committee, chaired by Dragan Marušič. We shall only list the ones organized or coorganized by our Slovenian colleagues:: Energy methods and their application in material science (org. Martin Jesenko), Mathematics in biology and medicine (org. Barbara Boldin), Mathematical challenges in insurance (org. Mihael Perman), Mathematics in the Digital age of Science (org. Katja Berčič), Algorithmic Graph Theory (coorg. Martin Milanič and Sandi Klavžar), Spectral Theory and Integrable Systems (coorg. Aleksey Kostenko), Harmonic analysis and partial differential equations (org. Oliver Dragičević), Mathematics in education (org. Amalija Žakelj), Noncommutative structures within order structures, semigroups and universal algebra (org. Karin Cvetko-Vah, coorg. Joao Pita Costa), Symmetry of Graphs, Maps and Polytopes (org. Primož Potočnik, coorg. Primož Šparl), Low dimensional topology (org. Sašo Strle), Computational aspects of commutative and noncommutative positive polynomials (coorg. Igor Klep), Topics in complex and quaternionic geometry (org. Jasna Prezelj), Analysis on graphs (org. Aleksey Kostenko), Complex analysis and geometry (org. Franc Forstnerič), Recent developments on preservers (org. Lajos Molnar, soorg. Bojan Kuzma).

Apart from the main congress programme, several other special events also took place during the 8ECM: a panel discussion on ERC, a panel discussion on gender ballance in mathematics, a panel discussion on open access in mathematics, the annual meeting of LMS and the annual meeting of EWM. For the younger generation, a carrier day with presentations of study and employment at several European institutions, a reception of the IMO and EGMO medalists, and the prize ceremony of the student competition for projects in financial math. Aside of the congress, the editorial board of (Slovenian) international scientific journals Ars Mathematica Contemporanea and Art of Discrete and Applied Mathematics presented the Petra Šparl annual award for their best recent paper by a female mathematician, which was shared by Simona Bonvicini and Klavdija Kutnar.

The programme of the last day of the congress has finished by a longer live interview with current ERC president and EMS ex-president Jean Pierre Bourguignon, who shared with the audience his vivid thoughts on the role of mathematics, universities, science and research in the current society. He also stressed the importance of math teacher education, which is necessary to develop new mathematical talents on our own, European ground.

After that, the congress was closed with a nice ceremony. EMS president Volker Mehrmann thanked the main organizers Tomaž Pisanski and Klavdija Kutnar for their incredible efforts and reliance, while representatives of Spanich and Russian organizers invited the audience to attend ICM2022 in Skt. Petersburg and ECM2024 in Sevilla.

In my opinion, the 8ECM successfully presented the current image of European mathematics with its most propulsing young names as well as the distinguished senior researchers. We should be proud of our colleagues at the University of Primorska and their main supporters University of Ljubljana, University of Maribor, IMFM, DMFA, SDAMS, Abelium, and IJS, to have managed to succesfully organize such a huge event in this incredibly difficult times. I believe this opinion is shared by most other participants and I congratulate the organizers sincerely for their amazing effort.

**Dr. Boštjan Kuzman, Committee for Mathematics, DMFA Slovenije**