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Irregularity of an analogue of the Gauss-Manin systems

C. Roucairol
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Abstract

In the D-modules theory, Gauss-Manin systems are defined by the direct image of the structure sheaf O by a morphism. A major theorem says that these systems have only regular singularities. This paper examines the irregularity of an analogue of the Gauss-Manin systems. It consists in the direct image complex of a D-module twisted by the exponential of a polynomial g by another polynomial f, where f and g are two polynomials in two variables. The analogue of the Gauss-Manin systems can have irregular singularities (at finite distance and at infinity). We express an invariant associated with the irregularity of these systems by the geometry of the map (f,g).

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C. Roucairol. 2005-05-04. Irregularity of an analogue of the Gauss-Manin systems. https://arxiv.org/abs/math/0505075

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