## The Specht property for varieties of Zn-graded Lie algebras, talk by Daniela Martinez Correa

A seminar talk by Daniela Martinez Correa, Faculty of Mathematics and Informatics, Sofia University “St. Kliment Ohridski”

## Ellipsoid superpotentials: obstructing symplectic embeddings by singular algebraic curves, a talk by Grigory Mikhalkin

How singular can be a local branch of a plane algebraic curve of a given degree d? A remarkable series of real algebraic curves was constructed by Stepan Orevkov. It is based on even-indexed numbers in the Fibonacci series: a degree 5 curve with a 13/2 cusp, a degree 13 curve with a 34/5-cusp, and so on. We discuss this and other series of algebraic curves in the context of the problem of symplectic packing of an ellipsoid into a ball...

## Dynamical zeta function for billiard flow, colloquium talk by Vesselin Petkov

Vesselin Petkov is a professor emeritus ат the University of Bordeaux who has made important contributions to hyperbolic partial differential equations, spectral and scattering theory and dynamical systems.

## The Cox ring perspective in birational geometry, talk by Morgan Brown

A seminar talk by Morgan Brown, University of Miami.

## Quantum circuit complexity for light polarisation or complexity with no complex number, talk by Jean-Pierre Gazeau

I will present a form of quantum circuit complexity that extends to open systems. To illustrate the methodology, I focus on a basic model where the Hilbert space of states is represented by the Euclidean plane. Specifically, the investigation is about the dynamics of mixed quantum states as they undergo interactions with a sequence of gates.

## A categorical view of singularity theory I and II, talks by Paul Horja

The mirror symmetry phenomenon was discovered by string theorists more than thirty years ago as an equivalence of two physical theories associated with very different geometries. The categorical point of view on this remarkable conjecture was famously introduced by M. Kontsevich in his 1994 ICM talk. As it became clear over time, homological mirror symmetry provides new approaches to many topics in symplectic and algebraic geometry. In these two talks, I will present a brief overview of the conjecture as well as some results inspired by mirror symmetry and obtained in joint work with L. Katzarkov about classical problems on discriminants and singularity theory.