Distinguished Lecturer Series

Dr. Hendrik Lenstra

This November, from the 13th to the 17th, we will be hosting Dr. Hendrik Lenstra as part of the VIGRE Distinguished Lecturer Series. This series is designed to honor stellar ambassadors of mathematics, and to expand public interest in and understanding of mathematics. Our VIGRE Distinguished Lecturers are chosen for both their reputations as excellent speakers for a general audience, as well as for their contributions to the mathematical sciences. Our lecturers also give talks in their areas of interest aimed at the graduate student level to expose UW graduate students to excellent mathematicains and their research. Previous visitors in this series were Barry Mazur and Steven Strogatz.

Dr. Lenstra is one of the world's pre-eminent number theorists. He is first L in the LLL algorithm, one of "The Top Ten Algorithms of the Twentieth Century" as per the 2003 ACMS seminar. He is also known for his sense of humor; see "The Wisdom of Hendrik W. Lenstra, Jr." for examples. He will be giving three talks while he is here. The Math Colloquim on Tuesday, November 14th, at 4pm. This talk, "Searching for abc Triples ," is tenatively scheduled to be held in Smith 304. Please see the math department's seminars page for an abstract and final location.

Dr. Lenstra will also be giving a public lecture, titled "Escher and the Droste effect."

Escher and the Droste effect Dr. Hendrik Lenstra Wednesday, November 15th 4:00 pm Physics and Astronomy Building, A102 Abstract: In 1956, the Dutch graphic artist M.C. Escher made an unusual lithograph with the title `Print Gallery'. It shows a young man viewing a print in an exhibition gallery. Amongst the buildings depicted on the print, he sees paradoxically the very same gallery that he is standing in. A lot is known about the way in which Escher made his lithograph. It is not nearly as well known that it contains a hidden `Droste effect', or infinite repetition; but this is brought to light by a mathematical analysis of the studies used by Escher. On the basis of this discovery, a team of mathematicians at Leiden produced a series of hallucinating computer animations. These show, among others, what happens inside the mysterious spot in the middle of the lithograph that Escher left blank. Much of the math and graphics fun from this talk may be seen at http://escherdroste.math.leidenuniv.nl/. You can download the video of Lenstra's lecture here (WARNING: very large file!).