Please note: This master’s thesis presentation will be given online.
Seung
Gyu
Hyun, Master’s
candidate
David
R.
Cheriton
School
of
Computer
Science
Supervisor: Professor Éric Schost
Linear recurrent sequences are those whose elements are defined as linear combinations of preceding elements, and finding recurrence relations is a fundamental problem in computer algebra. In this paper, we focus on sequences whose elements are vectors over the ring A = K[x]/ of truncated polynomials. Finding the ideal of their recurrence relations has applications such as the computation of minimal polynomials and determinants of sparse matrices over A. We present three methods for finding this ideal: a Berlekamp-Massey-like approach due to Kurakin, one which computes the kernel of some block-Hankel matrix over A via a minimal approximant basis, and one based on bivariate Pade approximation. We propose complexity improvements for the first two methods, respectively by avoiding the computation of redundant relations and by exploiting the Hankel structure to compress the approximation problem. Then we confirm these improvements empirically through a C++ implementation, and we discuss the above-mentioned applications.
To join this master’s thesis presentation on Zoom, please go to https://uwaterloo.zoom.us/j/7321085721?pwd=djBlUlVoRndVR0dJVzZRckxrL1RiUT09.