Flags in zero dimensional complete intersection algebras and indices of real vector fields

Mathematische Zeitschrift - Tập 260 - Trang 77-91 - 2007
L. Giraldo1,2, X. Gómez-Mont3, P. Mardešić4
1Dep. Matemáticas, Universidad de Cádiz, Puerto Real, Spain
2Dep. Geometría y Topología, F. Matemáticas, Universidad Complutense de Madrid, Madrid, Spain
3CIMAT, Guanajuato, Mexico
4Institut de Mathématiques de Bourgogne, U.M.R. 5584 du C.N.R.S., Université de Bourgogne, Dijon Cedex, France

Tóm tắt

We introduce bilinear forms in a flag in a complete intersection local $$\mathbb {R}$$ -algebra of dimension 0, related to the Eisenbud–Levine, Khimshiashvili bilinear form. We give a variational interpretation of these forms in terms of Jantzen’s filtration and bilinear forms. We use the signatures of these forms to compute in the real case the constant relating the GSV-index with the signature function of vector fields tangent to an even dimensional hypersurface singularity, one being topologically defined and the other computable with finite dimensional commutative algebra methods.

Tài liệu tham khảo

Arnold V. (1978). Index of a singular point of a vector field, the Petrovskii–Oleinik inequality and mixed Hodge structures. Funct. Anal. Appl. 12(1): 1–14 Bonatti Ch. and Gómez-Mont X. (1994). The index of a holomorphic vector field on a singular variety, I. Astérisque 222: 9–35 Eisenbud D. and Levine H. (1977). An algebraic formula for the degree of a C ∞ map germ. Ann. Math. 106: 19–38 Eisenbud D. (1995). Commutative Algebra with a View Towards Algebraic Geometry. Springer, Heidelberg Giraldo L., Gómez-Mont X. and Mardešić P. (1999). Computation of topological numbers via linear algebra: Hypersurfaces, vector fields and vector fields on hypersurfaces. Contemp. Math. 240: 175–182 Gómez-Mont X. and Mardešić P. (1997). The index of a vector field tangent to a hypersurface and the signature of the relative Jacobian determinant. Ann. Inst. Fourier 47(5): 1523–1539 Gómez-Mont X. and Mardešić P. (1999). The index of a vector field tangent to an odd dimensional hypersurface and the signature of the relative Hessian. Funct. Anal. Appl. 33(1): 1–10 Gómez-Mont X., Seade J. and Verjovsky A. (1991). The index of a holomorphic flow with an isolated singularity. Math. Ann. 291: 737–751 Greuel, G.-M., Pfister, G., Schönemann, H.: Singular 3.0. A Computer Algebra System for Polynomial Computations. Center for Computer Algebra, University of Kaiserslautern (2005). http://www.singular.uni-kl.de Gunning, R.C.: Introduction to Holomorphic Functions of Several Complex Variables, vol. II. Local theory. Wadsworth & Brooks/Cole Mathematics series, Wadsworth & Brooks/Cole Pacific Grove, CA (1990) Jantzen J.C. (1979). Moduln mit einem Höchsten Gewicht. Lecture Notes in Mathematics, vol. 750. Springer, Berlin Khimshiashvili, G.N.: On the local degree of a smooth map. Trudi Tbilisi math. Inst, pp. 105–124 (1980) Montaldi J. and van Straten D. (1990). One-forms on singular curves and the topology of real curves singularities. Topology 294: 501–510 Vogan D. (1984). Unitarizability of certain series of representations. Ann. Math. (2) 120(1): 141–187