Course Identification

Introduction to the theory of algebraic D-modules
20254182

Lecturers and Teaching Assistants

Prof. Dmitry Gourevitch
Itay Pikaz

Course Schedule and Location

2025
Second Semester
Thursday, 10:15 - 13:00, Jacob Ziskind Building, Rm 155

Tutorials
Monday, 10:15 - 11:00, Goldsmith, Rm 108
27/03/2025
03/07/2025

Field of Study, Course Type and Credit Points

Mathematics and Computer Science: Lecture; Elective; Regular; 3.00 points

Comments

N/A

Prerequisites

Basic algebraic geometry.

Restrictions

20

Language of Instruction

English

Attendance and participation

Expected and Recommended

Grade Type

Pass / Fail

Grade Breakdown (in %)

100%

Evaluation Type

Other

Scheduled date 1

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-
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Estimated Weekly Independent Workload (in hours)

9

Syllabus

1. Algebraic properties of modules over the Weyl algebra D=Dn.
(i) Bernstein filtration of the Weyl algebra. Filtrations of D-modules. Good
filtrations.
(ii) Noetherian properties.
(iii) Associated varieties, Hilbert polynomials. Dimension and degree of a D-
module.
(iv) Basic inequality.
(v) Holonomic D-modules and their properties.
 
2. Relation with analysis.
(i) D-modules and systems of differential equations. Solutions of D-modules. Left
and right D-modules.
(ii) Digression on the theory of generalized functions and distributions.
(iii) Regularization of distributions xs and Qs using differerential equations.
 
3. Standard functors for D-modules.
(i) Inverse image functor
(ii) Relation between left and right D-modules
(iii) Direct image functor
(iv) Fourier transform
 
4. Properties of functors on categories of D-modules.
 
5. Stability of the holonomic property.
 
6. Further applications to analysis: regularization of di fferent type of integrals.
 
6. Homological techniques in study of D-modules.
 
7. Geometric picture of the the algebra D of differential operators.
(i) Geometric filtration on the algebra D.
(ii) Associated varieties for D-modules. Noetherian properties.
(iii) Comparison of two approaches.
(iv) Equivalence of two approaches to holonomic modules.
 
7. D-modules on smooth affine algebraic varieties.
(i) Short digression into affine algebraic varieties. The sheaf OX and the category M(OX)
of O-modules on X. Localization of OX-modules.
(ii) Recall of basic properties of smooth varieties.
(iii) Basic definition and the structure of the algebra D = DX of differential operators on a smooth affine algebraic variety X.
(iv) Category M(D) of D-modules on a smooth affine algebraic variety X. Localization of D-modules.
(v) Relation between left and right D-modules.
 
8. Basic functors between D-modules.
(i) Basic functors and their properties.
(ii) Kashiwara's lemma
(iii) Reduction to the case of affine space (Weyl algebra).
 
9. Study of D-modules using the geometric filtration.
(i) Associated module. Noetherian properties.
(ii) Singular support of a D-module. Relation with Kashiwara lemma.
(iii) Proof of the basic inequality.
 
If time permits:
 
10. Derived categories.
(i) General definition and properties.
(ii) Derived functors
(iii) The derived category of D-modules.
 
 
11. Construction of functors push, pull, and duality for D-modules on non-affine varieties.
 
12. Proof that all the functors we construct preserve holonomicity.
 
13. Classification of simple holonomic D-modules.

Learning Outcomes

Upon successful completion of this course students should:

  1. Demonstrate knowledge of the advanced language of algebraic D-modules and thus get access to the wide literature that uses it.
  2. Use the algebraic technique of D-modules to solve the complicated analytic problems concerning invariant distributions. 

Reading List

1. "A Primer on Algebraic D-modules" by S.C.Coutinho
2 . "Algebraic D-modules" by A.Borel et all
3. Lecture notes in algebraic D-modules, taught by J. Bernstein:
www.math.uchicago.edu/ mitya/langlands/Bernstein/Bernstein-dmod.ps
4. "D-Modules, Perverse Sheaves, and Representation Theory" by Hotta, Takeuchi, Tanisaki

Website

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