Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-23T06:54:47.306Z Has data issue: false hasContentIssue false

Open, Connected Functions

Published online by Cambridge University Press:  20 November 2018

Louis Friedler*
Affiliation:
University of Alberta, Edmonton Alberta
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Recall that a function f:X→ Yis called connected if f(C) is connected for each connected subset C of X. These functions have been extensively studied. (See Sanderson [6].) A function f:X → Y is monotone if for each y ∊ Y, f-1(y) is connected. We shall use the techniques of multivalued functions to prove that if f: X→ Y is open and monotone onto Y, then f-1(C) is connected for each connected subset C of Y. This result is used to prove that the product of semilocally connected spaces is semilocally connected and that the image of a maximally connected space under an open, connected, monotone function is maximally connected.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1973

References

1. Borges, C., A study of multivalued functions, Pacific J. Math. 23 (1967), 451461.Google Scholar
2. Guthrie, J.A. and Stone, H.E., Subspaces of maximally connected spaces, Notices Amer. Math. Soc, Abstract 71T-G94, June 1971.Google Scholar
3. Hagan, M.R., A note on connected and peripherally continuous functions, Proc. Amer. Math. Soc. 26 (1970), 219223.Google Scholar
4. Long, P.E., Concerning semiconnected maps, Proc. Amer. Math. Soc. 21 (1969), 117118.Google Scholar
5. Long, P.E., Connected mappings, Duke Math. J. 35 (1968), 677682.Google Scholar
6. Sanderson, D.E., Relations among some basic properties of noncontinuous functions, Duke Math. J. 35 (1968), 407414.Google Scholar
7. Thomas, J.P., Maximal connected topologies, J. Austral. Math. Soc. 8 (1968), 700705.Google Scholar
8. Whyburn, G.T., Continuity of mult if unctions, Proc. Nat. Acad. Sci. U.S.A. (6) 54 (1965), 14951501.Google Scholar
9. Whyburn, G.T., Semilocally connected sets, Amer. J. Math. 61 (1939), 733741.Google Scholar
10. Lee, Yu-Lee, Some characterizations of semilocally connected spaces, Proc. Amer. Math. Soc. 16 (1965), 13181320.Google Scholar