کد مقاله کد نشریه سال انتشار مقاله انگلیسی ترجمه فارسی نسخه تمام متن
4661773 1344867 2016 21 صفحه PDF ندارد دانلود رایگان
عنوان انگلیسی مقاله
Borel structurability on the 2-shift of a countable group
ترجمه فارسی عنوان
ساختارگرایی بورل در 2 تغییر یک گروه قابل شمارش
کلمات کلیدی
تغییر برنولی؛ کاهش قابلیت بورل؛ ساختارگرایی بورل؛ ترکیبیات بورل؛ نقشه فاکتور؛ آنتروپی
03E15; 37A35; 37B10; 22F10Bernoulli shift; Borel reducibility; Borel structurability; Borel combinatorics; Factor map; Entropy
موضوعات مرتبط
مهندسی و علوم پایه ریاضیات منطق ریاضی
چکیده انگلیسی

We show that for any infinite countable group G   and for any free Borel action G↷XG↷X there exists an equivariant class-bijective Borel map from X   to the free part Free(2G)Free(2G) of the 2-shift G↷2GG↷2G. This implies that any Borel structurability which holds for the equivalence relation generated by G↷Free(2G)G↷Free(2G) must hold a fortiori for all equivalence relations coming from free Borel actions of G  . A related consequence is that the Borel chromatic number of Free(2G)Free(2G) is the maximum among Borel chromatic numbers of free actions of G. This answers a question of Marks. Our construction is flexible and, using an appropriate notion of genericity, we are able to show that in fact the generic G  -equivariant map to 2G2G lands in the free part. As a corollary we obtain that for every ϵ>0ϵ>0, every free p.m.p. action of G has a free factor which admits a 2-piece generating partition with Shannon entropy less than ϵ. This generalizes a result of Danilenko and Park.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Annals of Pure and Applied Logic - Volume 167, Issue 1, January 2016, Pages 1–21
نویسندگان
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