@article{d99ca951fc7f43f3981a54c109c71d19, title = "Determinacy of refinements to the difference hierarchy of co-analytic sets", abstract = "In this paper we develop a technique for proving determinacy of classes of the form ω2-Π1 1+Γ (a refinement of the difference hierarchy on Π1 1 lying between ω2-Π1 1 and (ω2+1)-Π1 1) from weak principles, establishing upper bounds for the determinacy-strength of the classes ω2-Π1 1+Σα 0 for all computable α and of ω2-Π1 1+Δ1 1. This bridges the gap between previously known hypotheses implying determinacy in this region.", keywords = "Descriptive set theory, Determinacy", author = "{Le Sueur}, Chris", year = "2018", month = "1", day = "1", doi = "10.1016/j.apal.2017.10.001", language = "English", volume = "169", pages = "83--115", journal = "Annals of Pure and Applied Logic", issn = "0168-0072", publisher = "Elsevier Masson SAS", number = "1", }