New methods for solving high degree polynomial equations that have multiple roots

43 mins 32 secs,  255.72 MB,  Flash Video  480x360,  25.0 fps,  44100 Hz,  801.99 kbits/sec
Share this media item:
Embed this media item:


About this item
Image inherited from collection
Description: Winkler, J (Sheffield)
Tuesday 22 January 2008, 15:30-16:00
Zeros of Graph Polynomials
 
Created: 2008-02-01 12:37
Collection: Combinatorics and Statistical Mechanics
Publisher: Isaac Newton Institute
Copyright: Winkler, J
Language: eng (English)
Distribution: World     (downloadable)
Credits:
Author:  Winkler, J
Explicit content: No
Aspect Ratio: 4:3
Screencast: No
Bumper: /sms-ingest/static/new-4x3-bumper.dv
Trailer: /sms-ingest/static/new-4x3-trailer.dv
 
Abstract: The determination of the roots of a polynomial is a classical problem in mathematics to which much effort has been devoted. There exist many methods for their computation, but they all fail on high degree polynomials, or polynomials that have multiple roots. In particular, roundoff errors due to finite precision arithmetic are sufficient to cause a multiple root to break up into a cluster of simple roots, and the problems are compounded when the coefficients of the polynomial are subject to error.

In this talk, I will describe a radically new, and significantly better, method of computing the roots of a polynomial. The method has two stages:

Stage 1: Perform a succession of greatest common divisor (GCD) computations to calculate the multiplicity of each distinct root.

Stage 2: Use the information from Stage 1 to calculate the roots, and then refine them using the method of non-linear least squares.

The GCD calculations in Stage 1 use structured matrix methods, algebraic geometry, the least squares equality problem and methods of information theory. The non-linear least squares in Stage 2 is performed by the Gauss-Newton iteration.

Examples will be given to illustrate the success of the method.
Available Formats
Format Quality Bitrate Size
MPEG-4 Video 480x360    1.84 Mbits/sec 601.01 MB View Download
WebM 480x360    484.94 kbits/sec 154.39 MB View Download
Flash Video * 480x360    801.99 kbits/sec 255.72 MB View Download
iPod Video 480x360    505.28 kbits/sec 161.11 MB View Download
QuickTime 384x288    848.38 kbits/sec 270.51 MB View Download
MP3 44100 Hz 125.04 kbits/sec 39.66 MB Listen Download
Windows Media Video 479.18 kbits/sec 152.79 MB View Download
Auto (Allows browser to choose a format it supports)