Abstract
The Bernstein polynomial of an isolated hypersurface singularity has subtle relations with the spectral numbers and the Tjurina number. To study these relations we use the Gauβ–Manin connection, Malgrange's description of the Bernstein polynomial and ideas of M. Saito. A general discussion of μ-constant families leads to manageable methods for explicit calculations, which we use on a number of examples. We introduce a matrix which determines simultaneously the Bernstein polynomial and the Tjurina number.
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Arnold, V. I., Gusein-Zade, S. M. and Varchenko, A. N.: Singularities of Differentiable Maps, Vol. II, Birkhäuser, Boston, 1988.
Bernstein, I. N.: The analytic continuation of generalized functions with respect to a parameter, Funct. Anal. Appl. 6 (1972), 273–285.
Björk, J. E.: Rings of Differential Operators, North-Holland, Amsterdam, 1979.
Briançon, J., Geandier, F., and Maisonobe, Ph.: Déformation d'une singularité isoleé d'hypersurface et polynômes de Bernstein, Bull. Soc. Math. France 120 (1992), 15–49.
Briançon, J., Granger, M., Maisonobe, Ph. and Miniconi, M.: Algorithme de calcul du polynôme de Bernstein: cas non dégénéré, Ann. Inst. Fourier Grenoble 39(3) (1989), 553–618.
Brieskorn, E.: Die Monodromie der isolierten Singularitäten von Hyperflächen, Manuscripta Math. 2 (1970), 103–161.
Cassou-Noguès, P.: Racines des Polynômes de Bernstein, Ann. Inst. Fourier Grenoble 36(4) (1986), 1–30.
Cassou-Noguès, P.: Etude du comportement du polynôme de Bernstein lors d'une déformation à μ constant de x a + y b avec (a, b) = 1, Compositio Math. 63 (1987), 291–313.
Geandier, F.: Polynômes de Bernstein et déformations à μ-constant, Thèse de doctorat, Université de Nice, 1989.
Geandier, F.: Polynômes de Bernstein et déformations à nombre de Milnor constant, C.R. Acad. Sci. Paris Sér Math. 309 (1989), 831–834.
Geandier, F.: Déformations à nombre de Milnor constant: quelques résultats sur les polynômes de Bernstein, Compositio Math. 77 (1991), 131–163.
Greuel, G.-M., Hertling, C. and Pfister, G.: Moduli Spaces of semiquasihomogeneous singularities with fixed principal part, J. Algebra Geom. 6 (1997), 169–199.
Hartshorne, R.: Residues and Duality, Lecture Notes in Math. 20, Springer-Verlag, Heidelberg, 1966.
Hertling, C.: Analytische Invarianten bei den unimodularen und bimodularen Hyperflächensingularitäten, Dissertation, Bonner Math. Schriften 250, Bonn, 1993.
Hertling, C.: Ein Torellisatz für die unimodalen und bimodularen Hyperflächensingularitäten, Math. Ann. 302 (1995), 359–394.
Hertling. C.: Classifying spaces for polarized mixed Hodge structures and for Brieskorn lattices, Compositio Math. 116 (1999), 1–37.
Kashiwara, M.: b-functions and holonomic systems, Invent. Math. 38 (1976), 33–53.
Kato, M.: The b-function of μ-constant deformation of x 7 + y 5, Bull. Coll. Sci. Univ. Ryukyu 32 (1981), 5–10.
Kato, M.: The b-function of μ-constant deformation of x 9 + y 4, Bull. Coll. Sci. Univ. Ryukyu 33 (1982), 5–8.
Laudal, O. A. and Pfister, G.: Local Moduli and Singularities, Lecture Notes in Math. 1310, Springer-Verlag, Heidelberg, 1988.
Malgrange, B.: Intégrales asymptotiques et monodromie, Ann. Sci. École Norm. Sup. 7 (1974), 405–430.
Malgrange, B.: Le polynôme de Bernstein d'une singularité isolée, In: Fourier Integral Operators and Partial Differential Equations, Lecture Notes in Math. 459, Springer, New York, 1975, pp. 98–119.
Milnor, J.: Singular Points of Complex Hypersurfaces, Ann. Math. Stud. 61, Princeton University Press, 1968.
Pham, F.: Singularités des systèmes différentielles de Gauss-Manin, Prog. Math. 2, Birkhäuser, Boston, 1979.
Saito, K.: Primitive forms for a universal unfolding of a function with an isolated critical point, J. Fac. Sci. Univ. Tokyo, Sect. IA Math. 28 (1981), 775–792.
Saito, K.: Period mapping associated to a primitive form, Publ. RIMS Kyoto Univ. 19 (1983), 1231–1264.
Saito, M.: On the structure of Brieskorn lattices, Ann. Inst. Fourier Grenoble 39 (1989), 27–72.
Saito, M.: Period Mapping via Brieskorn Modules, Bull. Soc. Math. France 119 (1991), 141–171.
Scherk, J. and Steenbrink, J. H. M.: On the mixed Hodge structure on the cohomology of the Milnor fibre, Math. Ann. 271 (1985), 641–665.
Stahlke, C.: Das Sprungverhalten der Nullstellen des Bernstein-Polynoms bei μ-konstant-Deformationen der Singularitäten x σ + y τ, Diplomarbeit, Bonn, 1992.
Stahlke, C.: Bernstein-Polynom und Tjurinazahl von μ-konstant-Deformationen der Singularitäten x a + y b, Dissertation, Bonn, 1997.
Steenbrink, J. H. M.: Mixed Hodge structure on the vanishing cohomology. In: P. Holm (ed.), Real and Complex Singularities (Oslo 1976), Sijthoff and Noordhoff, Alphen aan den Rijn, 1977, pp. 525–562.
Varchenko, A.N.: The asymptotics of holomorphic forms determine a mixed Hodge structure, Soviet Math. Dokl. 22 (1980), 772–775.
Varchenko, A.N.: The Gauss-Manin connection of isolated singular point and Bernstein polynomial, in: Bull. Sci. Math. 2 série e 104, Gauthier-Villars, Paris, 1980, pp. 205–223.
Varchenko, A.N.: The complex of a singularity does not change along the stratum μ = constant, Funct. Anal. Appl. 16 (1982), 1–9.
Varchenko, A.N.: A lower bound for the codimension of the stratum μ = constant in terms of the mixed Hodge structure, Moscow Univ. Math. Bull. 37 (1982), 30–33.
Varchenko, A.N.: On the local residue and the intersection form on the vanishing cohomology, Math. USSR Izvest. 26 (1986), 31–52.
Yano, T.: On the theory of b-functions, Publ. RIMS Kyoto Univ. 14 (1978), 111–202.
Yano, T.: b-Functions and exponents of hypersurface isolated singularities, In: Singularities, Proc. Sympos. Pure Math. 40, Amer. Math. Soc., Providence, 1983, Part 2, pp. 641–652.
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Hertling, C., Stahlke, C. Bernstein Polynomial and Tjurina Number. Geometriae Dedicata 75, 137–176 (1999). https://doi.org/10.1023/A:1005012325661
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DOI: https://doi.org/10.1023/A:1005012325661