Topologies making a given ideal nowhere dense or meager
نویسندگان
چکیده
منابع مشابه
Meager-nowhere Dense Games (iii): Remainder Strategies
Player ONE chooses a meager set and player TWO, a nowhere dense set per inning. They play ω many innings. ONE's consecutive choices must form a (weakly) increasing sequence. TWO wins if the union of the chosen nowhere dense sets covers the union of the chosen meager sets. A strategy of TWO which depends on knowing only the uncovered part of the most recently chosen meager set is said to be a re...
متن کاملAvoiding Families and Tukey Functions on the Nowhere Dense Ideal
We investigate Tukey functions from the ideal of all closed nowhere dense subsets of 2N. In particular, we answer an old question of Isbell and Fremlin by showing that this ideal is not Tukey reducible to the ideal of density zero subsets of N. We also prove non-existence of various special types of Tukey reductions from the nowhere dense ideal to analytic P-ideals. In connection with these res...
متن کاملA Gδ Ideal of Compact Sets Strictly above the Nowhere Dense Ideal in the Tukey Order
We prove that there is a Gδ σ-ideal of compact sets which is strictly above NWD in the Tukey order. Here NWD is the collection of all compact nowhere dense subsets of the Cantor set. This answers a question of Louveau and Veličković asked in [4].
متن کاملA Gdelta ideal of compact sets strictly above the nowhere dense ideal in the Tukey order
We prove that there is a Gδ σ-ideal of compact sets which is strictly above NWD in the Tukey order. Here NWD is the collection of all compact nowhere dense subsets of the Cantor set. This answers a question of Louveau and Veličković asked in [4].
متن کاملSaturated null and meager ideal
We prove that the meager ideal and the null ideal could both be somewhere א1saturated.
متن کاملذخیره 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: Topology and its Applications
سال: 1995
ISSN: 0166-8641
DOI: 10.1016/0166-8641(95)00074-q