English

Multiplicity of a space over another space

Category Theory 2015-03-17 v3 Commutative Algebra Group Theory Geometric Topology

Abstract

We define a concept which we call multiplicity. First, multiplicity of a morphism is defined. Then the multiplicity of an object over another object is defined to be the minimum of the multiplicities of all morphisms from one to another. Based on this multiplicity, we define a pseudo distance on the class of objects. We define and study several multiplicities in the category of topological spaces and continuous maps, the category of groups and homomorphisms, the category of finitely generated RR-modules and RR-linear maps over a principal ideal domain RR, and the neighbourhood category of oriented knots in the 3-sphere.

Keywords

Cite

@article{arxiv.1101.1700,
  title  = {Multiplicity of a space over another space},
  author = {Kouki Taniyama},
  journal= {arXiv preprint arXiv:1101.1700},
  year   = {2015}
}

Comments

22 pages, 3 figures, some references added, to appear in J. Math. Soc. Japan, Proof of Proposition 2.4 (3) corrected