Elliptic diffeomorphisms of symplectic 4-manifolds (Q2216149)

In the paper under review the authors introduce and study a new type of symplectomorphisms for 4-manifolds. An example of a 4-manifold \(X\) and a $(-1)$-torus \(C\) in it, where the elliptic twist TC turns out to be always symplectically trivial is presented. The authors also show that it is possible for an ellliptic twist to contribute nontrivially to a symplectic mapping class group.