Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-26T07:36:40.307Z Has data issue: false hasContentIssue false

Countable products and sums of lines and circles: their closed subgroups, quotients and duality properties

Published online by Cambridge University Press:  24 October 2008

Ronald Brown
Affiliation:
University College of North Wales, Bangor, Gwynedd, Wales
Philip J. Higgins
Affiliation:
King's College, Strand, London, W.C.2, England
Sidney A. Morris
Affiliation:
University of New South Wales, Kensington, N.S.W., Australia

Extract

It is well-known ((2), Theorem 9·11) that any closed subgroup of Rn is isomorphic (topologically and algebraically) to Ra × Zb, where a, b are suitable non-negative integers. For an infinite product of copies of R, it is also known that any locally compact (hence closed) subgroup is a product of copies R and Z, and that any connected subgroup is a product of copies of R (see (7), (3), respectively). Some information is also given in (3) on closed subgroups of products of copies of R and T, where T = R/Z is the circle group.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1975

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

(1)Bourbaki, N.Elements of mathematics: general topology. Part 2, Addison-Wesley, Reading (Massachusetts, 1966).Google Scholar
(2)Hewitt, E. & Ross, K. A.Abstract harmonic analysis I. Springer-Verlag (Berlin, 1963).Google Scholar
(3)Hunt, D. C., Morris, S. A. & Van Der Poorten, A. J.Closed subgroups of products of reals. Bull. London Math. Soc. (to appear).Google Scholar
(4)Kaplan, S.Extensions of the Pontrjagin duality I: infinite products. Duke Math. J. 15 (1948), 649658.CrossRefGoogle Scholar
(5)Kaplan, S.Extensions of the Pontrjagin duality II: direct and inverse sequences. Duke Math.J. 17 (1950), 419435.CrossRefGoogle Scholar
(6)Kaplan, S.Cartesian products of reals. Amer. J. Math. 74 (1952), 936954.CrossRefGoogle Scholar
(7)Morris, S. A.Locally compact abelian groups and the variety of topological groups generated by the reals. Proc. Amer. Math. Soc. 34 (1972), 290292.CrossRefGoogle Scholar
(8)Negrepontis, J. W.Duality in analysis from the point of view of triples. J. Algebra, 19 (1971), 228253.CrossRefGoogle Scholar
(9)Saxon, S. A.Nuclear and product spaces, Baire-like spaces, and the strongest locally convex topology. Math. Ann. 197 (1972), 87106.CrossRefGoogle Scholar
(10)Taylor, A. E.Introduction to functional analysis. John Wiley and Sons (1963).Google Scholar
(11)Tychonoff, A.Ein Fixpunktsatz. Math. Ann. 111 (1935), 767776.CrossRefGoogle Scholar
(12)Varopoulos, N. Th.Studies in harmonic analysis. Proc. Cambridge Philos. Soc. 60 (1964), 465516.CrossRefGoogle Scholar
(13)Hooper, R. C.Topological groups and integer-valued norms. J. Functional Analysis 2 (1968), 243257.CrossRefGoogle Scholar
(14)Smith, M. F.The Pontrjagin duality theorem in linear spaces. Ann. of Math. (2) 56 (1952), 248253.CrossRefGoogle Scholar