Math Colloquium February 28, 2019

<picture class="lw_image"> <source type="image/webp" srcset="/live/image/gid/75/width/1000/77406_yung-pin.rev.1550854736.webp 1x"/> <source type="image/jpeg" srcset="/live/image/gid/75/width/1000/77406_yung-pin.rev.1550854736.jpg 1x"/> <img src="/live/image/gid/75/width/1000/77406_yung-pin.rev.1550854736.jpg" width="180" height="217" alt="Yung-Pin Chen" data-max-w="180" data-max-h="217"/></picture>