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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 .
Sy-David Friedman. "Consistency of the Silver dichotomy in generalised Baire space." Fundamenta Mathematicae 227.2 (2014): 179-186. <http://eudml.org/doc/282958>.
@article{Sy2014, abstract = {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 $κ^\{κ\}$ 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 $κ^\{κ\}$ for uncountable regular κ is however consistent (with GCH), assuming the existence of $0^\{#\}$.}, author = {Sy-David Friedman}, journal = {Fundamenta Mathematicae}, keywords = {Silver dichotomy; Silver indiscernibles; Borel reducibility; generalised Baire space}, language = {eng}, number = {2}, pages = {179-186}, title = {Consistency of the Silver dichotomy in generalised Baire space}, url = {http://eudml.org/doc/282958}, volume = {227}, year = {2014}, }
TY - JOUR AU - Sy-David Friedman TI - Consistency of the Silver dichotomy in generalised Baire space JO - Fundamenta Mathematicae PY - 2014 VL - 227 IS - 2 SP - 179 EP - 186 AB - 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 $κ^{κ}$ 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 $κ^{κ}$ for uncountable regular κ is however consistent (with GCH), assuming the existence of $0^{#}$. LA - eng KW - Silver dichotomy; Silver indiscernibles; Borel reducibility; generalised Baire space UR - http://eudml.org/doc/282958 ER -