The Quarterly Journal of Mathematics Advance Access published online on December 4, 2007
The Quarterly Journal of Mathematics, doi:10.1093/qmath/ham039
PLANE CURVE DIAGRAMS AND GEOMETRICAL APPLICATIONS

Universidade de São Paulo — ICMC, Av. do Trabalhador São Carlense, Centro, Caixa Postal 668, 13560-970 São Carlos, SP, Brazil
Departament de Geometria i Topologia, Universitat de València, Campus de Burjassot, 46100 Burjassot, Spain
Corresponding author. E-mail: scalco{at}icmc.usp.br
Received 28 November 2006;
revised 11 June 2007
| Abstract |
|---|
We look at plane curve diagrams (f,
), which are given by a plane curve multigerm
: (
, S)
2 and a function on it f:(
, S)
. We obtain a classification of all such diagrams, where
has
e-codimension
2 and f has finite order. Then we define an equivalence between plane curves which we call
h-equivalence and which is determined by the class of the diagram (h
,
). Here, h
denotes the height function of
with respect to its normal vector. This is an equivalence which not only takes into account the topology of the singularity of
, but also its flat geometry. Finally, we apply our results in order to obtain a classification of all the plane projections of a generic space curve
embedded in
3

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