Recognition of the general type-(4,3) fundamental group as a torus-bundle group
Determine whether the fundamental group presented for the genus-3 Lefschetz pencil $X_\phi$ associated with an arbitrary matrix $\begin{pmatrix}p&q\\r&s\end{pmatrix}\in\mathrm{SL}(2,\mathbb{Z})$ can be recognized as the fundamental group of a torus bundle over a torus.
References
It is not clear to the author how to recognize this as the fundamental group of a torus bundle.
— Genus-3 Lefschetz pencils on torus bundles
(2610.06440 - Huang, 5 Oct 2026) in Section 6, Remark following Proposition on the pencils $X_k$