Maximal almost disjoint families, determinacy, and forcing

نویسندگان

چکیده

We study the notion of $\mathcal J$-MAD families where J$ is a Borel ideal on $\omega$. show that if an arbitrary $F_\sigma$ ideal, or any finite countably iterated Fubini product ideals, then there are no analytic infinite families, and assuming Projective Determinacy projective families; under full Axiom + $V=\mathbf{L}(\mathbb{R})$ J$-mad families. These results apply in particular when sets $\mathrm{Fin}$, which corresponds to classical MAD The proofs combine ideas from invariant descriptive set theory forcing.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Mrówka Maximal Almost Disjoint Families for Uncountable Cardinals

We consider generalizations of a well-known class of spaces, called by S. Mrówka, N ∪R, where R is an infinite maximal almost disjoint family (MADF) of countable subsets of the natural numbersN . We denote these generalizations by ψ = ψ(κ,R) for κ ≥ ω. Mrówka proved the interesting theorem that there exists an R such that |βψ(ω,R) \ ψ(ω,R)| = 1. In other words there is a unique free z-ultrafilt...

متن کامل

Confinitary Groups, Almost Disjoint and Dominating Families

In this paper we show that it is consistent with ZFC that the cardinality of every maximal cofinitary group of Sym(ω) is strictly greater than the cardinal numbers d and a.

متن کامل

Martin's axiom and almost disjoint families

Assuming Martin’s Axiom and א1 < 2 א0 , we show that, for any κ, λ < 20 and any almost disjoint family {ai : i < λ} of countable subsets of κ, there is a partition {pn : n ∈ ω} of κ so that pn ∩ ai is finite for each 〈i, n〉 ∈ λ × ω.

متن کامل

Cofinitary Groups, almost Disjoint and Dominating Families

In this paper we show that it is consistent with ZFC that the cardinality of every maximal cofinitary group of Sym(co) is strictly greater than the cardinal numbers D and a. ?

متن کامل

Invariance properties of almost disjoint families

We answer a question of Gracia-Ferreira and Hrušák by constructing consistently a MAD family maximal in the Katětov order. We also answer several questions of Garcia-Ferreira.

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

ژورنال

عنوان ژورنال: Journal of Mathematical Logic

سال: 2021

ISSN: ['0219-0613', '1793-6691']

DOI: https://doi.org/10.1142/s0219061321500264