Concave symplectic toric fillings
Aleksandra Marinković
TL;DR
The paper proves that every contact toric 3-manifold admits infinitely many concave symplectic toric fillings that are mutually not equivariantly symplectomorphic and not related by blow ups. It achieves this by constructing toric structures on linear and cyclic plumbings over spheres, using moment-map data and $SL(2,\mathbb Z)$-equivalence to distinguish fillings, and by separating the analysis into non-free and free toric actions. For non-free actions, distinct cases determined by the angle between moment-cone rays yield infinite families of linear plumbings (and sometimes cyclic ones) with distinct self-intersection data; for free actions, cyclic plumbings are built from elongated linear ones, producing fillings of $(T^3,\xi_N)$ with distinct toric data. The results unify toric and contact-topological methods to significantly broaden the known landscape of concave toric fillings, with concrete consequences for lens spaces and the 3-torus.
Abstract
As shown by Etnyre and Honda in [EH], every contact 3-manifold admits infinitely many concave symplectic fillings that are mutually not symplectomorphic and not related by blow ups. In this note we refine this result in the toric setting by showing that every contact toric 3-manifold admits infinitely many concave symplectic toric fillings that are mutually not equivariantly symplectomorphic and not related by blow ups. The concave symplectic toric structure is constructed on certain linear and cyclic plumbings over spheres.
