Hoạt động trong tuần

Thời gian: 9h00 Thứ 5, ngày 4 tháng 10 năm 2018

Địa điểm: Phòng 302, Nhà A5, Viện Toán học

Tóm tắt: Plus-one generated arrangements are introduced recently by Takuro Abe through the inspiration of Dimca-Sticlaru's notion of nearly free line and plane arrangements. Terao's deletion theorem concerns the freeness of an arrangement obtained by deleting a hyperplane from a free arrangement. We are going to discuss two results in the recent works of Abe. Firstly, the deleted arrangement is either free or strictly plus-one generated. Secondly, the Terao's deletion theorem is combinatorial i.e. whether the deleted arrangement is free depends only on the intersection lattice.