The Kolchin Seminar in Differential Algebra
Saturday November 15th 2003
Lourdes Juan
Texas Tech University
A generic Approach to the Inverse Differential Galois Problem, Part I
2:00 - 3:00PM
******************************************
Alexander B. Levin
Catholic University of America
Finitely Generated Difference Field Extensions
3:30 - 4:30PM
Abstract: In 1956 R. Cohn introduced a new invariant of a finitely generated extension of an ordinary difference field. He called it the limit degree of the extension. This invariant, that does not have analogs in differential algebra, appears to be a helpful tool in the study of difference field extensions. In particular, using the properties of limit degree, R. Cohn has proved that a subextension of a finitely generated difference field extension is finitely generated. In 1984 P. Evanovich proved a similar result for partial difference fields using a generalization of the concept of limit degree. In this talk we shall discuss properties of the limit degree and present a few new results in this area. In conclusion we are going to give a short proof of the Evanovich's result.
******************************************
Lourdes Juan
Texas Tech University
A generic Approach to the Inverse Differential Galois Problem, Part II
5:00 - 6:00PM
******************************************
Coffee and tea will be served beginning at 1:30 PM
Room HW706
Click here for directions to Hunter College and location of room