Knot surgered elliptic surfaces for a $(2,2h+1)$-torus knot
Naoyuki Monden, Reo Yabuguchi
TL;DR
This work proves that knot surgered elliptic surfaces $E(n)_{T(2,2h+1)}$ admit handle decompositions free of $1$- and $3$-handles for all $h\ge1$ and $n\ge1$, advancing the Kirby problem on eliminating such handles in simply connected 4-manifolds. The authors leverage Kirby diagrams derived from Lefschetz fibrations on $E(n)_K$, together with a detailed analysis of the monodromy and fiber-sum constructions, to translate the problem into explicit handle cancellations on a surface diagram. A key tool is the explicit global monodromy ${}_{\Phi_K}(W)^2 \cdot W^2$ for knot-surgered elliptic surfaces and its behavior under cyclic permutations and diffeomorphisms $\Phi_K$, especially for torus knots $T_{2,2h+1}$. The result generalizes prior work on genus-$1$ and higher-genus Lefschetz fibrations and contributes to a broader understanding of when 4-manifolds admit 1- and 3-handle-free decompositions, with potential implications for exotic smooth structures and Kirby's problem list.
Abstract
We show that for any positive integer $h$, a knot surgered elliptic surface $E(n)_{T(2,2h+1)}$ for a $(2,2h+1)$-torus knot $T(2,2h+1)$ and the elliptic surface $E(1)_{2,2h+1}$ admit handle decompositions without 1- and 3-handles using the Kirby diagrams derived from Lefschetz fibrations on them.
