TITLE: Must a locally compact group be Hausdorff in order to possess a Haar measure?
QUESTION [5 upvotes]: Does the existence of (left) Haar measure on a locally compact topological group require that the group be Hausdorff?

REPLY [6 votes]: No. Simon Rubinstein-Salzedo's "On the existence and uniqueness of invariant measures on locally-compact groups" presents a proof of existence (and uniqueness up to a multiplicative strictly positive constant) of a left Haar measure given a locally-compact, not necessarily Hausdorff, group.