На 17 май от 14.00 в зала 403 на ИМИ  нашият колега проф. Владимир  Тончев, Мичигански Технологичен университет, САЩ ще изнесе доклад на тема: Coding Theory, Combinatorial Designs, and Finite Geometry. Резюме. Error-correcting codes are used to protect data from random errors in satellite and wireless communication systems, audio and video recording devices, and data storage devices. A large class of codes with a wide range of applications are based on finite geometry. The most notable example of such codes are the Reed-Muller codes that are being used in deep space and mobile communications. The subject of this talk is a class of codes based on combinatorial designs. These combinatorial codes possess remarkable error-correction properties, admit efficient decoding, and present a viable alternative to a [...]

Семинар на Международния център по математически науки 14 септември 2021, 16:30-17:30, излъчван по Zoom Конгруентното свойство в двумерна рационална конформна теория на полето Докладчик: Веселин Димитров, Университет на Торонто Абстракт. In a joint work with Frank Calegari and Yunqing Tang, we use methods from transcendental number theory to prove a conjecture that goes back to Atkin and Swinnerton-Dyer, in a special case, and generalized by Mason to the following form: A vector-valued modular form on SL(2,Z) whose components have q-expansions with bounded denominators are exactly the ones for which the underlying representation of SL(2,Z) has a finite image with kernel containing the congruence subgroup of matrices reducing to the identity modulo some positive integer N. In this talk, I will outline the basic ideas [...]