Algebra seminar by David Stewart

On Wednesday the 30th of January 2019, David Stewart (Newcastle University) will be visiting the Charlotte Scott Centre for Algebra and giving a seminar on Gröbner bases, smooth centralisers and the Lefschetz principle. His talk will be at 3pm in INB 3305. All are welcome.

His talk abstract is as follows:

“(Joint with Ben Martin and Lewis Topley).  In a paper in the now defunct LMS Journal of Computation I used GAP to compute the Lie-theoretic centralisers in the exceptional groups of elements in their minimal modules in all characteristics, establishing when the centralisers in the groups were smooth. Non-smoothness was only found in very small characteristics, even where there are infinitely many orbits. This led to a question on when all centralisers of elements in a Z-defined representation would be smooth if the characteristic were large enough. With my co-authors we managed to prove this using the Lefschetz principle from model theory applied to Gröbner bases, which gave rise to what we call ‘d-bounded Hopf quadruples’. I’ll explain some of this.”