Bulletin of the
Korean Mathematical Society BKMS

In this paper, we classify all twisted torus knots which are doubly middle Seifert-fibered. Also we show that all of these knots possibly except a few admit Dehn surgery producing a non-Seifert-fibered graph manifold which consists of two Seifert-fibered spaces over the disk with two exceptional fibers, glued together along their boundaries. This provides another infinite family of knots in $S^3$ admitting Dehn surgery yielding such manifolds as done in \cite{K14}.

Keywords: knots, Dehn surgery, graph manifolds, Seifert curves, twisted torus knots, R-R diagrams

MSC numbers: Primary 57M25