Instanton 2-torsion and fibered knots

Deeparaj Bhat, Zhenkun Li, Fan Ye

We prove that the unreduced singular instanton homology $I^{♯}(Y,K;\mathbb{Z})$ has $2$-torsion for any null-homologous fibered knot $K$ of genus $g>0$ in a closed $3$-manifold…