Báo cáo viên: Shigeru Kuroda (Hokkaido University, Japan)
Thời gian: 9h00, Thứ 4, Ngày 2/5/2018 Địa điểm: Phòng 611-612, tầng 6 nhà A6, Viện Toán học Tóm tắt: Hilbert's fourteenth problem asks whether certain kind of subalgebras of a polynomial ring are finitely generated. The first counterexample to this problem was given by Nagata in 1958. In this talk, we present a technique for "converting" a given subalgebra (with some mild conditions) into a non-finitely generated subalgebra using a polynomial automorphism. As a consequence, we obtain a number of counterexamples to Hilbert's fourteenth problem and its generalization by Zariski. |