Discriminants: calculation, properties, and connection to the root distribution of polynomials with rational generating functions

This document was uploaded by one of our users. The uploader already confirmed that they had the permission to publish it. If you are author/publisher or own the copyright of this documents, please report to us by using this DMCA report form.

Simply click on the Download Book button.

Yes, Book downloads on Ebookily are 100% Free.

Sometimes the book is free on Amazon As well, so go ahead and hit "Search on Amazon"

Author(s): Khang D. Tran
Series: PhD thesis at University of Illinois at Urbana-Champaign
Year: 2012

Language: English

Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Chapter 2 New discriminant calculations: Triangular numbers and a di-
agonal sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1 Triangular numbers and Chebyshev polynomials . . . . . . . . . . . . . . . . 4
2.2 A linear polynomial transformation and its root distribution . . . . . . . . . 7
2.3 The diagonal sequence of a resultant . . . . . . . . . . . . . . . . . . . . . . 9
Chapter 3 A property of q-discriminants of certain cubics . . . . . . . . . 18
3.1 Factorization of the q-Discriminant . . . . . . . . . . . . . . . . . . . . . . . 21
3.2 Sensitive Asymptotics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Chapter 4 Factorization of discriminants of transformed Chebyshev poly-
nomials: The Mutt and Jeff syndrome . . . . . . . . . . . . . . . . . . . 32
4.1 Discriminant, resultant and Chebyshev polynomials . . . . . . . . . . . . . . 34
4.2 The Mutt and Jeff polynomial pair . . . . . . . . . . . . . . . . . . . . . . . 36
4.3 The discriminant of J(x) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.4 The discriminant of M(x) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.5 The roots of M(x) and J(x) . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Chapter 5 Roots of polynomials and their generating functions: A specific
example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5.1 A general form of the discriminant . . . . . . . . . . . . . . . . . . . . . . . 52
5.2 Generating function for H (1)
m (q)
. . . . . . . . . . . . . . . . . . . . . . . . . 55
5.3 Generating function for H (2)
m (x) . . . . . . . . . . . . . . . . . . . . . . . . .
57
5.4 A hypergeometric identity from Euler’s contiguous relation and the Wilf-
Zeilberger algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.5 Generating function for H (n)
m (x) . . . . . . . . . . . . . . . . . . . . . . . . .
63
Chapter 6 Roots of polynomials and their generating functions: A general
approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93