“Perverse sheaf”的意思、由来-开放百科全书

词条

Perverse sheaf

释义

Preliminary remarks
Definition and examples
Properties
Applications
See also
Notes
References

The mathematical term perverse sheaves refers to a certain abelian category associated to a topological space X, which may be a real or complex manifold, or a more general topologically stratified space, usually singular. This concept was introduced in the thesis of Zoghman Mebkhout, gaining more popularity after the (independent) work of Joseph Bernstein, Alexander Beilinson, and Pierre Deligne (1982) as a formalisation of the Riemann-Hilbert correspondence, which related the topology of singular spaces (intersection homology of Mark Goresky and Robert MacPherson) and the algebraic theory of differential equations (microlocal calculus and holonomic D-modules of Joseph Bernstein, Masaki Kashiwara and Takahira Kawai). It was clear from the outset that perverse sheaves are fundamental mathematical objects at the crossroads of algebraic geometry, topology, analysis and differential equations. They also play an important role in number theory, algebra, and representation theory. Note that the properties characterizing perverse sheaves already appeared in the 75's paper of Kashiwara on the constructibility of solutions of holonomic D-modules.

Preliminary remarks

The name perverse sheaf comes through rough translation of the French "faisceaux pervers"^[1]. The justification is that perverse sheaves are complexes of sheaves which have several features in common with sheaves: they form an abelian category, they have cohomology, and to construct one, it suffices to construct it locally everywhere. The adjective "pervers" originates in the intersection homology theory,^[2] and its origin was explained by {{harvtxt|Goresky|2010}}.

The Beilinson–Bernstein–Deligne definition of a perverse sheaf proceeds through the machinery of triangulated categories in homological algebra and has very strong algebraic flavour, although the main examples arising from Goresky–MacPherson theory are topological in nature because the simple objects in the category of perverse sheaves are the intersection cohomology complexes. This motivated MacPherson to recast the whole theory in geometric terms on a basis of Morse theory. For many applications in representation theory, perverse sheaves can be treated as a 'black box', a category with certain formal properties.

Definition and examples

A perverse sheaf is an object C of the bounded derived category of sheaves with constructible cohomology on a space X such that the set of points x with

or

has dimension at most 2i, for all i. Here j_x is the inclusion map of the point x.

If X is smooth and everywhere of dimension d, then

is a perverse sheaf for any local system .^[3] If X is a flat, locally complete intersection (for example, regular) scheme over a henselian discrete valuation ring, then the constant sheaf shifted by is an étale perverse sheaf.^[4]

Properties

The category of perverse sheaves is an abelian subcategory of the (non-abelian) derived category of sheaves, equal to the core of a suitable t-structure, and is preserved by Verdier duality.

The bounded derived category of perverse l-adic sheaves on a scheme X is equivalent to the derived category of constructible sheaves and similarly for sheaves on the complex analytic space associated to a scheme X/C.^[5]

Applications

Perverse sheaves are a fundamental tool for the geometry of singular spaces. Therefore, they are applied in a variety of mathematical areas. In the Riemann-Hilbert correspondence, perverse sheaves correspond to regular holonomic D-modules. This application establishes the notion of perverse sheaf as occurring 'in nature'. The decomposition theorem, a far-reaching extension of the hard Lefschetz theorem decomposition, requires the usage of perverse sheaves. Hodge modules are, roughly speaking, a Hodge-theoretic refinement of perverse sheaves. The geometric Satake equivalence identifies equivariant perverse sheaves on the affine Grassmannian with representations of the Langlands dual group of a reductive group G - see {{harvtxt|Mirković|Vilonen|2007}}. A proof of the Weil conjectures using perverse sheaves is given in {{harvtxt|Kiehl|Weissauer|2001}}.

Notes

1. ^Les faisceaux pervers n'etant ni des faisceaux, ni pervers, la terminologie requiert une explication. BBD, p. 10
2. ^What is the etymology of the term "perverse sheaf"? – MathOverflow
3. ^{{harvtxt|Beilinson|Bernstein|Deligne|1982|loc=Proposition 2.2.2, §4.0}}
4. ^{{harvtxt|Illusie|2003|loc=Corollaire 2.7}}
5. ^{{harvtxt|Beilinson|1987|loc=Theorem 1.3}}

References

{{cite journal

| url = http://www.ams.org/notices/201005/rtx100500632p.pdf
| last1 = Andrea de Cataldo
| first1 = Mark
| first2 = Luca |last2=Migliorini
| title=What is a perverse sheaf?
| journal = Notices of the AMS
| date=May 2010
| volume = 57
| issue = 5
| ref = harv
}}

{{citation|mr=2668828|author1=Arinkin|first1=Dmitry|author2=Bezrukavnikov|first2=Roman|title=Perverse coherent sheaves|journal=Mosc. Math. J.|

volume=10|year=2010|issue=1|pages=3–29|arxiv=0902.0349|bibcode=2009arXiv0902.0349A}}

{{citation|mr=923133|author=Beilinson|first=A. A.|chapter=On the derived category of perverse sheaves|title=K-theory, arithmetic and geometry (Moscow, 1984–1986)|series=Lecture Notes in Math.|volume=1289|pages=27–41|publisher=Springer, Berlin|year=1987|doi=10.1007/BFb0078365|isbn=978-3-540-18571-0}}

{{cite journal

| last1 = Beilinson
| first1 = Alexander A.
| authorlink = Alexander Beilinson
| authorlink2 = Joseph Bernstein
| first2=Joseph |last2=Bernstein
| authorlink3=Pierre Deligne
| first3=Pierre |last3=Deligne
| year = 1982
| title = Faisceaux pervers
| journal = Astérisque
| volume = 100
| publisher = Société Mathématique de France, Paris
| language = French
| ref = harv
}}

{{citation|author=Brasselet|first=Jean-Paul|title=Introduction to intersection homology and perverse sheaves|

publisher=Instituto Nacional de Matemática Pura e Aplicada (IMPA)|year=2009|mr=2533465}}

{{citation|mr=3085024|author1=Bremer|first1=Christopher L.|author2=Sage|first2=Daniel S.|

title=Generalized Serre conditions and perverse coherent sheaves|journal=J. Algebra|volume=392|year=2013|pages=85–96

|doi=10.1016/j.jalgebra.2013.06.018|arxiv=1106.2616}}

{{Cite web | last1=Goresky | first1=Mark | authorlink1=Mark Goresky | title=What is the etymology of the term "perverse sheaf"? | url=http://mathoverflow.net/questions/44149 | year=2010 | ref=harv | postscript={{inconsistent citations}}}}
{{citation|author=Illusie|first=Luc|title=Perversité et variation|journal=Manuscripta Math.|year=2003|volume=112|issue=3|pages=271–295| mr=2067039|doi=10.1007/s00229-003-0407-z}}
{{Citation | last1=Kiehl | first1=Reinhardt | last2=Weissauer | first2=Rainer | title=Weil conjectures, perverse sheaves and l'adic Fourier transform | publisher=Springer-Verlag | location=Berlin, New York | series=Ergebnisse der Mathematik und ihrer Grenzgebiete. 3. Folge. A Series of Modern Surveys in Mathematics [Results in Mathematics and Related Areas. 3rd Series. A Series of Modern Surveys in Mathematics] | isbn=978-3-540-41457-5 | mr=1855066 | year=2001 | volume=42}}
{{cite journal

| author = MacPherson
| first = Robert
| title = Intersection Homology and Perverse Sheaves
| date = December 15, 1990
| type = unpublished manuscript
| url = http://faculty.tcu.edu/gfriedman/notes/ih.pdf
| ref = harv
| authorlink = Robert MacPherson (mathematician)
}}

{{Citation | last1=Mirković | first1=I. | last2=Vilonen | first2=K. | title=Geometric Langlands duality and representations of algebraic groups over commutative rings | doi=10.4007/annals.2007.166.95 | mr=2342692 | year=2007 | journal=Annals of Mathematics |series=Second Series | issn=0003-486X | volume=166 | issue=1 | pages=95–143 |arxiv=math/0401222}}

{{cite arXiv

| eprint=math.RT/0307349
| title=An introduction to perverse sheaves
| author=Rietsch
| first=Konstanze
| year=2003
}}

Alexander Beilinson, Joseph Bernstein, Pierre Deligne and Ofer Gabber « Faisceaux Pervers » - Astérisque 100 - second edition (2018)

2 : Homological algebra|Morse theory

随便看