Castelnuovo-Mumford regularity and Ratliff-Rush closure

Time: 09:30 to  10:30 Ngày 01/02/2018

Venue/Location: B4-705, VIASM

Speaker: Dinh Thanh Trung

Content:

In this talk I will present an example of an m-primary ideal I in k[x,y], generated by monomials of the same degree, such that reg R(I) > reg F(I), where R(I) and F(I) are the Rees algebra and the fiber ring of I. This gives a negative answer to a conjecture of Eisenbud and Ulrich. This example is generated from algorithms based on earlier work on connection between Castelnuovo-Mumford regularity and Ratliff-Rush filtration.