L-space knots in twist families and satellite L-space knots
Twisting a knot $K$ in $S^3$ along a disjoint unknot $c$ produces a twist family of knots ${K_n}$ indexed by the integers. Comparing the behaviors of the Seifert genus $g(K_n)$ and the slice genus $g_4(K_n)$ under twistings, we prove that if $g(K_n) - g_4(K_n) < C$ for some constant $C$ for infinitely many integers $n > 0$ or $g(K_n) / g_4(K_n) \to 1$ as $n \to \infty$, then either the winding number of $K$ about $c$ is zero or the winding number equals the wrapping number. As an application, if ${K_n}$ contains infinitely many L-space knots, then the latter must occur. We further develop this to show that if $K_n$ is an L-space knot for infinitely many integers $n > 0$ and infinitely many integers $n < 0$, then $c$ is a braid axis. We then use this to show that satellite L-space knots are braided satellites. This is joint work with Ken Baker.