English

Two-numbers and their applications - A survey

Differential Geometry 2018-05-15 v1 Algebraic Topology Group Theory

Abstract

The notion of two-numbers of connected Riemannian manifolds was introduced about 35 years ago in [Un invariant geometrique riemannien, C. R. Acad. Sci. Paris Math. 295 (1982), 389--391] by B.-Y. Chen and T. Nagano. Later, two-numbers have been studied by a number of mathematicians and it was then proved that two-numbers related closely with several important areas in mathematics. The main purpose of this article is to survey on two-numbers and their applications. At the end of this survey, we present several open problems and conjectures on two-numbers.

Keywords

Cite

@article{arxiv.1805.04796,
  title  = {Two-numbers and their applications - A survey},
  author = {Bang-Yen Chen},
  journal= {arXiv preprint arXiv:1805.04796},
  year   = {2018}
}

Comments

33 pages, to be published in Bull. Belg. Math. Soc. Simon Stevin

R2 v1 2026-06-23T01:53:04.315Z