Skip to main content
Log in

A General Separation Theorem For Various Structures

  • Published:
Acta Mathematica Hungarica Aims and scope Submit manuscript

Abstract

There are several important separation theorems in various areas; for example, theorems of Gordan, Stone, Mazur, Hahn–Banach, etc. In this paper, we give a general treatment, in ZFC, of separation results with several examples in old and new settings. In order to achieve some uniformity of the treatment, we define the notion of a solid operator that leads to the notion of separation. We also characterize those topological spaces for which the closure of a set is a solid operator. Further, we prove a separation theorem for solid operators which we will use to characterize those graphic matroids whose span is a solid operator. We also use the separation theorem to prove a theorem of Páles.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. S. Banach, Théorie des opérations linéaires, Hafner Publishing Company (New York, 1932)

  2. J. B. Conway, A Course in Functional Analysis, 2nd ed., Springer-Verlag (New York, 2007)

  3. Gordan, P.: Über die Auflösung linearer Gleichungen mit reellen coefficienten. Math. Ann. 6, 23–28 (1873)

    Article  MathSciNet  Google Scholar 

  4. J. Oxley, Matroid Theory, Oxford University Press (New York, 1992)

  5. Zs. Páles, A Stone-type theorem for Abelian semigroups, Arch. Math. (Basel), 52 (1989), 265–268

  6. SIAM activity group on discrete mathematics, in: Proceedings of the Twelfth Annual ACM-SIAM Symposium on Discrete Algorithms, Society for Industrial and Applied Mathematics (Washington, 2001)

  7. M. Stone, Convexity, mimeographed notes prepared by Harley Flander, the Department of Mathematics, University of Chicago (Chicago, 1946)

  8. von Neumann, J.: Zur Theorie der Gesellschaftsspiele. Math. Ann. 100, 295–320 (1928)

    Article  MathSciNet  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to F. Jordan.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Jordan, F., Kalantari, I. & Pajoohesh, H. A General Separation Theorem For Various Structures. Acta Math. Hungar. 162, 345–363 (2020). https://doi.org/10.1007/s10474-020-01062-1

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10474-020-01062-1

Key words and phrases

Mathematics Subject Classification

Navigation