## Proceedings of the Japan Academy, Series A, Mathematical Sciences

### A study of curvature using infinitesimals

#### Abstract

Motivated by a profound observation of A’Campo we investigate the behaviour of the curvature of $f(z,w)=c, f\in \mathbf{C}\{z,w\}, |c|$ small, along infinitesimals. We use the language of infinitesimals as introduced in [2]. Along the way we introduce the important notion of gradient canyon, and prove several theorems in which this notion plays the key role. In this paper we give three such theorems and mention several other facts, to be published elsewhere.

#### Article information

Source
Proc. Japan Acad. Ser. A Math. Sci., Volume 88, Number 5 (2012), 70-74.

Dates
First available in Project Euclid: 7 May 2012

https://projecteuclid.org/euclid.pja/1336394840

Digital Object Identifier
doi:10.3792/pjaa.88.70

Mathematical Reviews number (MathSciNet)
MR2925285

Zentralblatt MATH identifier
1250.30043

Subjects
Primary: 14HXX 32SXX 58K60: Deformation of singularities
Secondary: 58K40: Classification; finite determinacy of map germs

#### Citation

Koike, Satoshi; Kuo, Tzee-Char; Paunescu, Laurentiu. A study of curvature using infinitesimals. Proc. Japan Acad. Ser. A Math. Sci. 88 (2012), no. 5, 70--74. doi:10.3792/pjaa.88.70. https://projecteuclid.org/euclid.pja/1336394840

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