Taubes nonvanishing theorem
= Taubes nonvanishing theorem
{c}
A closed <symplectic manifold> of real dimension four with $b_2^+>1$ has a nonzero <Seiberg–Witten invariant of a four-manifold> in its canonical structure, with value $\pm1$. The <positive index of the intersection form> hypothesis avoids chamber dependence. This provides the <symplectic connected-sum obstruction>.
https://intlpress.com/site/pub/files/_fulltext/journals/mrl/1994/0001/0006/MRL-1994-0001-0006-a015.pdf