 
Summary: OPERATIONS WITH REGULAR HOLONOMIC DMODULES
WITH SUPPORT A NORMAL CROSSING
JOSEP `ALVAREZ MONTANER
Abstract. The aim of this work is to describe some operations in the category
of regular holonomic Dmodules with support a normal crossing and variation
zero introduced in [2]. These operations will allow us to compute the Bass
numbers and the dual Bass numbers of these modules.
1. Introduction
Let X = Cn
, OX the sheaf of holomorphic functions in Cn
, and DX the sheaf
of differential operators in Cn
with holomorphic coefficients. Galligo, Granger and
Maisonobe [8], described in terms of linear algebra the category Mod(DX)T
hr of
regular holonomic DXmodules such that their solution complex RHomDX
(M, OX)
are perverse sheaves relatively to the stratification given by the union T of the
coordinate hyperplanes in Cn
.
