Products of ultrafilters and irresolvable spaces
Sbornik. Mathematics, Tome 19 (1973) no. 1, pp. 105-115 Cet article a éte moissonné depuis la source Math-Net.Ru

Voir la notice de l'article

A space dense in itself is said to be $k$-resolvable if there exists a system of cardinality $k$ of disjoint dense subsets. The main results of the paper can be formulated as follows: 1. If there exists a countably-centered free ultrafilter, then there are dense in themselves $T_1$-spaces whose product is irresolvable. 2. Any sets $X$ and $Y$ support irresolvable $T_1$-topologies whose product is maximally resolvable. 3. Assuming the continuum hypothesis, an ultrafilter whose cartesian square is dominated by only three ultrafilters is constructed on a countable set. 4. If a set of uncountable cardinality supports an ultrafilter whose square is dominated by exactly three ultrafilters, then its cardinality is measurable. A number of problems are posed. Bibliography: 9 titles.
@article{SM_1973_19_1_a6,
     author = {V. I. Malykhin},
     title = {Products of ultrafilters and irresolvable spaces},
     journal = {Sbornik. Mathematics},
     pages = {105--115},
     year = {1973},
     volume = {19},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1973_19_1_a6/}
}
TY  - JOUR
AU  - V. I. Malykhin
TI  - Products of ultrafilters and irresolvable spaces
JO  - Sbornik. Mathematics
PY  - 1973
SP  - 105
EP  - 115
VL  - 19
IS  - 1
UR  - http://geodesic.mathdoc.fr/item/SM_1973_19_1_a6/
LA  - en
ID  - SM_1973_19_1_a6
ER  - 
%0 Journal Article
%A V. I. Malykhin
%T Products of ultrafilters and irresolvable spaces
%J Sbornik. Mathematics
%D 1973
%P 105-115
%V 19
%N 1
%U http://geodesic.mathdoc.fr/item/SM_1973_19_1_a6/
%G en
%F SM_1973_19_1_a6
V. I. Malykhin. Products of ultrafilters and irresolvable spaces. Sbornik. Mathematics, Tome 19 (1973) no. 1, pp. 105-115. http://geodesic.mathdoc.fr/item/SM_1973_19_1_a6/

[1] E. Hewitt, “A problem of set-theoretic topology”, Duke Math. J., 10 (1943), 309–333 | DOI | MR | Zbl

[2] A. G. Elkin, “Ultrafiltry i nerazlozhimye prostranstva”, Vestnik MGU, seriya matem. mekh., 1969, no. 5, 51–56 | MR

[3] J. Ceder, J. Pearson, “On product of maximally resolvable spaces”, Pacific J. Math., 32 (1967), 31–45 | MR

[4] P. Vopenka, “Postroenie modelei teorii mnozhestv metodom ultraproizvedenii”, Z. Math. Logik. Grund. Math., 8 (1962), 293–304 | DOI | MR | Zbl

[5] Z. Frolik, “Sums of ultrafilters”, Bull. Amer. Math. Soc., 73 (1967), 87–91 | DOI | MR | Zbl

[6] S. Ulam, “Zur Masstheorie in der allgemeinen Mengenlehre”, Fundam. math., 16 (1930), 140–150 | Zbl

[7] F. P. Ramsey, “On a problem of formal logic”, Proc. London Math. Soc., 30 (1930), 262–286 | DOI

[8] W. Rudin, “Homogenity problems in theory of Čech compactifications”, Duke Math. J., 23:3 (1956), 409–423 | DOI | MR

[9] J. Juhasz, A. Verbeek, N. S. Kroonenberg, Cardinal functions in topology, Math. Centre Tracts., 34, Amsterdam, 1971 | MR | Zbl