ABSTRACT: I will present a surprising relation between knot invariants
and quiver representation theory, motivated by various string theory
constructions involving BPS states. Consequences of this relation
include the proof of the famous Labastida-Marino-Ooguri-Vafa
conjecture (at least for symmetric representations), explicit (and
unknown before) formulas for colored HOMFLY polynomials for various
knots, new viewpoint on knot homologies, a novel type of
categorification, new dualities between quivers, and many others.