Discrete Laplace-Darboux sequences, Menelaus' theorem and the pentagram map

46 mins 39 secs,  194.04 MB,  Flash Video  480x360,  25.0 fps,  44100 Hz,  567.89 kbits/sec
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Description: Wolfgang K. Schief (TU Berlin)
Friday 03 April 2009, 09:30-10:15
Geometric Aspects of Discrete and Ultra-discrete Integrable Systems
 
Created: 2011-03-10 13:15
Collection: Discrete Integrable Systems
Publisher: Isaac Newton Institute
Copyright: Wolfgang K. Schief
Language: eng (English)
Distribution: World     (downloadable)
Credits:
Author:  Wolfgang K. Schief
Producer:  Jonathan Nimmo
Director:  Ehsan Ashraf
Editor:  Steve Greenham
Explicit content: No
Aspect Ratio: 4:3
Screencast: No
Bumper: UCS Default
Trailer: UCS Default
 
Abstract: A seminar from the Geometric Aspects of Discrete and Ultra-discrete Integrable Systems conference in association with the Newton Institute programme: Discrete Integrable Systems

http://www.gla.ac.uk/departments/mathematics/research/isamp/events/gadudis/programme/

The discrete analogue of the classical notion of Laplace-Darboux sequences of conjugate nets was introduced by Doliwa. In view of the associated classification problem, we take a fresh look at this topic and re-formulate the theory in terms of the multi-ratio condition associated with Menelaus' theorem. As an application, we demonstrate that the pentagram map analysed in detail by Ovsienko, Schwartz and Tabachnikov may be regarded as a particular Laplace-Darboux sequence leading to a (non-standard) discrete version of the Schwarzian Boussinesq equation.
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