### Research Problems

**1.** Is the 3-string braid group the only braid group isomorphic to a
knot group?

*Answer:* no and yes. No for a trivial reason: the 2-string
braid group is *Z*, the group of the unknot. If we take this trivial
counter-example into account, then the answer is "yes", because the
commutator subgroup of the braid group with more than 3 strings is finitely
generated, but not free, while by Neuwirth-Stallings theorem the commutator
subgroup of a classical knot group either is free and finitely generated or
is not finitely generated.

**2.** Develop theory of fibered ribbon braids. Ask me what is a
fibered ribbon braid.