Persi Diaconis
                          Mary V. Sunseri 
                            Professor of Statistics and Mathematics, Stanford 
                            University  
                          
                           
                          September 27, 2007 -- 4:00 p.m.
                          Mathematics and Magic Tricks
                          The way that a magic trick works can be even more 
                            amazing than the trick itself. I will illustrate by 
                            performing and explaining a trick whose mathematical 
                            underpinnings involve secret codes, robot vision, 
                            breaking and entering and the statistical design of 
                            taste testing experiments. The mathematical questions 
                            raised by the trick lead to the edge of what we know. 
                            This is a talk suitable for a general university audience. 
                          September 28, 2007 -- 4:00 p.m.
                          Gibbs sampling, orthogonal polynomials 
                            and Alternating projections
                          The Gibbs sampler (also known as the heat bath algorithm 
                          or Glauber dynamics) is a mainstay of scientific computing. 
                          I will explain the algorithm, give many examples where 
                          the operators can be explicitly diagonalized ( thus 
                          sharp rates of convergence are available) and explain 
                          a useful connection with von Neumann's alternating projection 
                          theorem. This meeting of operator theory and statistics 
                          has consequences for both subjects. All is joint work 
                          with Kshitij Khare and Laurent Saloff-Coste. 
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                          Persi W. Diaconis (born January 31, 1945) is an 
                          American statistician/mathematician and former professional 
                          magician. He is Mary V. Sunseri Professor of Statistics 
                          and Professor of Mathematics at Stanford University. 
                          He is particularly known for tackling mathematical problems 
                          involving randomness and randomization, but his expertise 
                          is much broader - taking in such topics as group theory, 
                          Fourier analysis, combinatorics, random matrices and 
                          zeros of the zeta function,... 
                          Professor Diaconis achieved national fame when he 
                            received a MacArthur Fellowship in 1979, and again 
                            in 1992 after the publication (with D. Bayer) of a 
                            paper entitled "Trailing the Dovetail Shuffle 
                            to its Lair" (a term coined by magician Charles 
                            Jordan in the early 1900's) which established rigorous 
                            results on how many times a deck of playing cards 
                            must be shuffled before it can be considered "random 
                            enough." They established that the deck gradually 
                            increases in randomness until seven  
                            shuffles, after which the thus-far experienced increase 
                            in randomness with each shuffle decreases sharply. 
                            Seven shuffles, for reasons made precise in the paper, 
                            is what casinos should use. 
                          Among his many honours, in addition to the MacArthur 
                            Fellowship, are a fellowshipo in the American Academy 
                            of Arts and Sciences (1989), membership in the National 
                            Academy of Sciences (1995), and honorary degrees from 
                            the University of Chicago (2003), Universite Paul 
                            Sabatier (Toulouse) (2003), Uppsala University (2005), 
                            and Queen Mary University of London (2006). 
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