На 9 юни 2017 г. (петък) от 13:00 часа в зала 578 на ИМИ – БАН, новият сътрудник на секция "Алгебра и логика" доц. Йорг КОПИЦ ще изнесе своята встъпителна академична публична лекция на тема:

FROM TOURNAMENTS TO LJAPIN'S IDENTITIES

Поканват се всички желаещи.

Резюме. We would like to draw an arc from the Graph Theory over transformation semigroups and completely regular semigroups until Birkhoff Theory. In this presentation, we will uncover a relationship between endomorphisms on tournaments and semigroups of order-preserving transformations. One can extend the idea of order-preserving transformations from chains to fences (zig-zag posets). Recently, coregular semigroups of fence-preserving transformations were studied. The concept of coregularity was introduced byTodorov and Bijev in the 80’s. Coregular semigroups are particular completely regular semigroups. But we will show how completely regular semigroups can be described by classes "next" to Birkhoff`s varieties (introduced by Ljapin) due to an idea by J. P. Aroujo (2015).