A note on PL-disks and rationally slice knots

Abstract

We give infinitely many examples of manifold-knot pairs ( Y , J ) (Y, J) such that Y Y bounds an integer homology ball, J J does not bound a non-locally-flat PL-disk in any integer homology ball, but J J does bound a smoothly embedded disk in a rational homology ball. The proof relies on formal properties of involutive Heegaard Floer homology.