Commutative algebra and algebraic Geometry seminar
Speaker: R. V. Gurjar
Dates: Tuesday, 8 and 15 November 2022
Time: 3.30-5.00 pm
Venue: Ramanujan Hall

Title  : Positively Graded Domains

Abstract : We will discuss positively graded affine domains over complex
field from algebraic, geometric, and topological viewpoints.
Important results by M. Demazure, I. Dolgachev, H. Flenner, S. Goto, A.
Grothendieck, S. Mori, W. Neumann, P. Orlik- P. Wagreich,
H. Pinkham, Keiichi Watanabe will be mentioned. A very general result
"conjectured" by me in 1990 and proved by O. Mathieu
around 2003 will be discussed. It has important consequences for rings of
invariants of reductive algebraic groups.
Many naturally occurring examples of positively graded domains will be
discussed.

If time permits, I will mention closely related results proved recently by
A. Pramanik-S. Thandar-R.V. Gurjar
about affine surfaces with finite fundamental group at infinity.