Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-30T20:17:07.621Z Has data issue: false hasContentIssue false

Specializations of complex quartic curves

Published online by Cambridge University Press:  24 October 2008

P. J. Giblin
Affiliation:
University of LiverpoolMoston College of Further Education, Manchester
C. M. Hui
Affiliation:
University of LiverpoolMoston College of Further Education, Manchester

Extract

Let F: n × r be a sufficiently small representative, defined near (0,0), of a versal unfolding of a germ F0: (n, 0) → (, 0) with isolated singularity at 0∈n. Then a result of Teissier ((4), p. 338) says that, for ur sufficiently close to 0, F acts as a versal unfolding of all the various singularities, close to 0, on the fibre Fu = 0 (where Fu(x) = F(x, u)). Let us fix a small neighbourhood W of 0 in n and restrict u to be so close to 0 that all singularities of Fu lie in W. Suppose that the fibre Fu = 0 has singularities of (contact) type χ1, …, χm, all isolated. Suppose that, for each i, the collection {χij}(1 ≤ jk(i)) of singularities specializes to χi, that is it occurs on a single fibre arbitrarily close to χi in a versal unfolding of χi. Then Teissier's result shows that there will exist fibres Fv = 0 of F, with v arbitrarily close to u, such that the fibre Fv = 0 carries singularities, all in W, of all the types χij for 1 ≤ im, 1 ≤ jk(i). In other words, if ‘despecializations’ {χij} of the separate singularities χi are possible, then they can all occur together on a single fibre of F, provided F is versal.

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1982

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

(1)Bruce, J. W. and Giblin, P. J.A stratification of the space of plane quartic curves. Proc. London Math. Soc. (3), 41 (1981), 270298.CrossRefGoogle Scholar
(2)Hui, C. M. Plane Quartic Curves (Ph.D. thesis, Liverpool, 1979).Google Scholar
(3)Lyashko, O. V.Decomposition of simple singularities of functions. Functional Analysis and its Applications 10 (1976), 122128.Google Scholar
(4)Teissier, B.Cycles évanescente, sections planes et conditions de Whitney. Astérisque 7–8 (1973), 285362.Google Scholar