On the Legacy of Free Divisors Ii: Free* Divisors and Complete Intersections
نویسندگان
چکیده
We provide a criterion that for an equivalence group G on holomorphic germs, the discriminant of a G-versal unfolding is a free divisor. The criterion is in terms of the discriminant being Cohen– Macaulay and generically having Morse-type singularities. When either of these conditions fails, we provide a criterion that the discriminant have a weaker free* divisor structure. For nonlinear sections of a free* divisor V , we obtain a formula for the number of singular vanishing cycles by modifying an earlier formula obtained with David Mond and taking into account virtual singularities. 2000 Math. Subj. Class. Primary: 14B07, 14M12, 32S30; Secondary: 13C12, 14B10.
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