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Normal forms for certain singularities of smooth map-germs. (English) Zbl 0564.58006

C\(^{\infty}\)-maps and their singularities, Proc. Symp., Kyoto 1984, RIMS Kokyuroku 550, 1-27 (1985).
[For the entire collection see Zbl 0552.00005.]
The paper deals with the \({\mathcal A}\)-classification of smooth map germs. First the author obtains some normal form theorems which give an efficient and simply way of doing this classification (sometimes).
These results are analogies of F. Takens’ normal form theorem for vector fields [Publ. Math., Inst. Hautes Étud. Sci. 43(1973), 47-100 (1974; Zbl 0279.58009)] and of the method of complete transversals introduced for the \({\mathcal K}\)-classification of map germs by the reviewer and C. G. Gibson [Q. J. Math., Oxf. II. Ser. 34, 281-295 (1983; Zbl 0537.58007) and Math. Scand. (to appear)]. Using these normal form theorems, some splitting lemmas for corank 1 map-germs are proved. As an application, the \({\mathcal A}\)-classification of finitely determined map germs \((R^ n,0)\to (R^ 2,0)\) with corank 1 and nontrivial 3-jets is given.
Reviewer: A.Dimca

MSC:

58C25 Differentiable maps on manifolds
58K99 Theory of singularities and catastrophe theory
37G99 Local and nonlocal bifurcation theory for dynamical systems