Almost toric fibrations on symplectic blow ups

Abstract

Given a symplectic 4-manifold with an almost toric fibration and a symplectic ball embedding whose image under the moment map is contained in an affine convex set R, we produce a symplectomorphism between the almost toric blow-up and the symplectic blow-up which is the identity on the pre-image of the complement of R. Furthermore, under a compatibility condition of the ball embedding with the boundary divisor, we show that the symplectomorphism can be chosen to preserve the induced symplectic log canonical divisors.