Pretty pictures and diagrams

von Stengel, Bernhard (2014) Pretty pictures and diagrams. LSE Research Festival 2014, The London School of Economics and Political Science. (Unpublished)

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Abstract

This is a new film which presents a slideshow on ‘Pretty Pictures and Diagrams’, or PPAD, which is actually a technical acronym for ‘Polynomial Parity Argument with Direction’. This ‘parity argument’ says that a path that starts somewhere and does not branch must end somewhere, so it has a pair of endpoints. The path represents a computation path that finds an equilibrium in an economic model. The film shows, in pictures, how such a path-following method works: A knight can find his princess in a castle if each room has only one door. An abstract scenario of ‘triangle partitions’ that are connected by following a path of ‘triangle flipping’ via ‘butterflies’ is then considered. However, these paths can be exponentially long. Hence, path-following is sometimes impractical, and we need research into other methods for finding an economic equilibrium.

Item Type:	Video
Official URL:	http://www.lse.ac.uk/lseresearchfestival
Additional Information:	© 2014 The Author
Library of Congress subject classification:	Q Science > QA Mathematics
Sets:	Departments > Mathematics Collections > LSE Research Festival 2014
Projects:	LSE Research Festival 2014
Date Deposited:	15 Jul 2014 15:10
URL:	http://eprints.lse.ac.uk/57855/

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