Dense topological groups in Parovičenko spaces
Keywords:
$P$-space, Parovičenko space, $G_\delta$-topology, $\pi$-character, homogeneous, coset space, almost $P$-space, topological groupAbstract
We show that the statement 'the Cech-Stone remainder of the discrete space $\omega$ contains a dense subspace which is (homeomorphic to) a topological group' is not a statement of ZFC. We also discuss the question of whether this result can be extended to Parovičenko spaces.
References
A. V. Arhangel'skii and M. G. Tkachenko, Topological groups and related structures, Atlantis Studies in Mathematics, vol. 1, Atlantis Press, Paris, World Scientific, 2008.
A. V. Arhangel'skii and J. van Mill, Topological homogeneity, Recent Progress in General Topology. III, Atlantis Press, Paris, 2014, pp. 1-68.
J. Aubrey, Combinatorics for the dominating and unsplitting numbers, J. Symbolic Logic 69 (2004), 482-498.
M. G. Bell and K. Kunen, On the PI character of ultrafilters, C. R. Math. Rep. Acad. Sci. Canada 3 (1981), 351-356.
N. Bourbaki, Élements de Mathematique, Premiere Partie, Hermann, Paris, 1942, Livre 3, 3-m ed., Actualites Sci. et Ind. no. 916.
W. W. Comfort and S. Negrepontis, Homeomorphs of three subspaces of $\beta \mathbf{N} \setminus \mathbf{N}$, Math. Z. 107 (1968), 53-58.
W. W. Comfort and S. Negrepontis, The theory of ultrafilters, Grundlehren der mathematischen Wissenschaften, vol. 211, Springer-Verlag, Berlin, 1974.
E. K. van Douwen, Transfer of information about $\beta \mathbb{N}-\mathbb{N}$ via open remainder maps, Ill. J. Math. 34 (1990), 769-792.
E. K. van Douwen and J. van Mill, Parovičenko's characterization of $\beta \omega-\omega$ implies $C H$, Proc. Amer. Math. Soc. 72 (1978), 539 - 541.
A. Dow and J. van Mill, An extremally disconnected Dowker space, Proc. Amer. Math. Soc. 86 (1982), 669672.
B. A. Efimov, Extremally disconnected compact spaces and absolutes, Trans. Moscow Math. Soc. 23 (1970), 243285.
Z. Frolík, Homogeneity problems for extremally disconnected spaces, Comment. Math. Univ. Carolinae 8 (1967), 757-763.
Z. Frolík, Sums of ultrafilters, Bull. Amer. Math. Soc. 73 (1967), 8791.
L. Gillman and M. Henriksen, Rings of continuous functions in which every finitely generated ideal is principal, Trans. Amer. Math. Soc. 82 (1956), 366-391. K. P. Hart, Ultrafilters of character $\omega_1$, J. Symbolic Logic 54 (1989), no. 1, 1-15. N. Hindman and D. Strauss, Algebra in the Stone-Cech compactification, de Gruyter Textbook, vol. 1, Walter de Gruyter & Co., Berlin, 2012, Theory and applications, Second revised and extended edition [of MR1642231].
H. H. Hung and S. Negrepontis, Spaces homeomorphic to $\left(2^a\right)_a$. II, Trans. Amer. Math. Soc. 188 (1974), 1-30.
K. Kunen, Ultrafilters and independent sets, Trans. Amer. Math. Soc. 172 (1972), 299-306.
K. Kunen, Set theory. An introduction to independence proofs, Studies in Logic and the foundations of Mathematics, vol. 102, North-Holland Publishing Co., Amsterdam, 1980.
K. Kunen, Weak P-points in $\mathbb{N}^*$, Topology, Vol. II (Proc. Fourth Colloq., Budapest, 1978), North-Holland Publishing Co., Amsterdam, 1980, pp. 741-749.
J. van Mill, An introduction to $\beta \omega$, Handbook of Set-Theoretic Topology (K. Kunen and J.E. Vaughan, eds.), North-Holland Publishing Co., Amsterdam, 1984, pp. 503-567.
I. I. Parovičenko, A universal bicompact of weight $aleph$, Soviet Math. Doklady 4 (1963), 592-595.
W. Rudin, Homogeneity problems in the theory of Cech compactifications, Duke Math. J. 23 (1956), 409-419.
R. C. Walker, The Stone-Cech compactification, Springer-Verlag, Berlin, 1974.
E. Wimmers, The Shelah $P$-point independence theorem, Israel J. Math. 43 $(1982), 28-48$.