A NEW TYPE OF CLUSTER SETS AND ITS APPLICATIONS

Authors

  • M. N. MUKHERJEE Department of Pure Mathematics, University of Calcutta, 35-Ballygunge Circular Road, Calcutta-700 019, India.
  • S. RAYCHAUDHURI Department of Pure Mathematics, University of Calcutta, 35-Ballygunge Circular Road, Calcutta-700 019, India.

DOI:

https://doi.org/10.5556/j.tkjm.26.1995.4413

Keywords:

delta-cluster set, multifunction, nearly compact space, nearly Lindelof space, almost regularity

Abstract

In this paper we introduce the concept of a new type of cluster sets, termed $\delta$-cluster sets, of functions and multifunctions between topological spaces. Expressions of such sets are found and multifunctions with $\delta$-closed graphs are characterized. Also the behaviour of $\delta$-cluster sets toward a-continuity of a func- tion is observed. Finally as applications, we find new characterizations of almost regularity, near compactness and near Lindelofness of a topological space in terms of $\delta$-cluster sets of suitable multifunctions.

References

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Published

1995-12-01

How to Cite

MUKHERJEE, M. N., & RAYCHAUDHURI, S. (1995). A NEW TYPE OF CLUSTER SETS AND ITS APPLICATIONS. Tamkang Journal of Mathematics, 26(4), 327–336. https://doi.org/10.5556/j.tkjm.26.1995.4413

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Section

Papers