When Does Inversion Preserve Convexity?
David E. Blair
Department of Mathematics
Michigan State University
Given a smooth closed convex curve in the plane, what is the setof points in the plane as centers of inversion for which the image of thegiven curve will again be a convex curve? This question has an attractive answer. After reviewing the geometry of curve theory and of inversion theory (reflection in circles), we will give a proof of the answer. If time permits, we will discuss the corresponding question for convex bodies in 3-space.