Counterexamples related to rotations of shadows of convex bodies Maria AlfonsecaMichelle Cordier Indiana University Mathematics Journal 2017 text pdf 10.1512/iumj.2017.66.6001 10.1512/iumj.2017.66.6001 en Indiana Univ. Math. J. 66 (2017) 275 - 296 state-of-the-art mathematics http://iumj.org/access/