Silver’s fundamental dichotomy in the classical theory of Borel reducibility states that any Borel (or even co-analytic) equivalence relation with uncountably many classes has a perfect set of classes. The natural generalisation of this to the generalised Baire space for a regular uncountable κ fails in Gödel’s L, even for κ-Borel equivalence relations. We show here that Silver’s dichotomy for κ-Borel equivalence relations in for uncountable regular κ is however consistent (with GCH), assuming the existence of .
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-fm227-2-4, author = {Sy-David Friedman}, title = {Consistency of the Silver dichotomy in generalised Baire space}, journal = {Fundamenta Mathematicae}, volume = {227}, year = {2014}, pages = {179-186}, zbl = {06339424}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm227-2-4} }
Sy-David Friedman. Consistency of the Silver dichotomy in generalised Baire space. Fundamenta Mathematicae, Tome 227 (2014) pp. 179-186. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-fm227-2-4/