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Mathematics Seminar 14 September 2016 Mahidol University International College. The Ham-Sandwich and the Brouwer Fixed Point Theorem. Wayne Lawton Adjunct Professor School of Mathematics and Statistics University of Western Australia, Perth, Australia. wlawton50@gmail.com.
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Mathematics Seminar 14 September 2016 Mahidol University International College The Ham-Sandwich and the Brouwer Fixed Point Theorem Wayne Lawton Adjunct Professor School of Mathematics and Statistics University of Western Australia, Perth, Australia wlawton50@gmail.com https://sites.google.com/site/wlawton2011
Intermediate Value Theorem Bolzano, B., 1817. Rein analytischer Beweis des Lehrsatzes, daß zwischen je zwey Werthen, die ein entgegengesetztes Resultat gewähren, wenigstens eine reelle Wurzel der Gleichung liegt. Gottlieb Haase, Prague.
Uniform Continuity Lebesgue, H. (1909). "Sur les intégrales singulières". Ann. Fac. Sci. Univ. Toulouse. 3. pp. 25–117.
Heine-Cantor Theorem https://en.wikipedia.org/wiki/Heine%E2%80%93Cantor_theorem E. Heine, "Die Elemente der Funktionenlehre" J. Reine Angew. Math. , 74 (1872) pp. 172–188 G. Cantor, E. Zermelo (ed.) , Gesammelte Abhandlungen , Springer (1932)
Algorithmic Solution Theorem q Exists Proof Let Let We may assume that Since is odd hence nonzero.
Algorithmic Solution Theorem q Exists Proof Let Let We may assume that Since is odd hence nonzero.
Algorithmic Solution Pour-El and Richards showed that the intermediate value theorem is not computable because there is no algorithm that given a program for continuous computes a zero for The problem is the inverse m.o.c.
The Pancake Problem Cut two pancakes, each lying in a common plane, into equal amounts by a line L in the plane.
The Pancake Solution For each angle choose an of angle oriented line with and continuous function of Pancake 1 Pancake 2
The Pancake Solution by Define continuous Pancake 2 Pancake 1 so the result follows Clearly from the intermediate value theorem.
The Ham-Sandwich Theorem Three objects, consisting of a chunk of ham and two chunks of bread, can simultaneously be bisected with a single planar cut. It was proposed by Hugo Steinhaus and proved by Stefan Banach (explicitly in dimension 3, without bothering to automatically state the theorem in the n-dimensional case), and also years later called the Stone–Tukey theorem after Arthur H. Stone and John Tukey.
The Ham-Sandwich Reduction Fix a closed hemisphere H of radius 1 centered at an origin and for point choose an oriented plane that bisects the ham and is a continuous function of Construct continuous by to reduce problem to the following version of Borsuk-Ulam Theorem continuous,