內容簡介
The last decade has seen a number of exciting developments at the intersection of commutative algebra with combinatorics. New methods have evolved out of an influx of ideas from such diverse areas as polyhedral geometry, theoretical physics, representation theory, homological algebra, symplectic geometry, graph theory, integer programming, symbolic computation, and statistics. The purpose of this volume is to provide a selfcontained introduction to some of the resulting combinatorial techniques for dealing with polynomial rings, semigroup rings, and determinantal rings.Our exposition mainly concerns combinatorially defined ideals and their quotients, with a focus on numerical invariants and resolutions, especially under gradings more refined than the standard integer grading.
目錄
Preface
I Monomial Ideals
1 Squarefree monomial ideals
1.1 Equivalent descriptions
1.2 Hilbert series
1.3 Simplicial complexes and homology
1.4 Monomial matrices
1.5 Betti numbers
Exercises
Notes
2 Borel-fixed monomial ideals
2.1 Group actions
2.2 Generic initial ideals
2.3 The Eliahou-Kervaire resolution
2.4 Lex-segment ideals
Exercises
Notes
3 Three-dimensional staircases
3.1 Monomial ideals in two variables
3.2 An example with six monomials.
3.3 The Buchberger graph
3.4 Genericity and deformations...
3.5 The planar resolution algorithm.
Exercises
Notes
4 Cellular resolutions
4.1 Construction and exactness
4.2 Betti numbers and K-polynomials
4.3 Examples of cellular resolutions
4.4 The hull resolution
4.5 Subdividing the simplex
Exercises
Notes
5 Alexander duality
5.1 Simplicial Alexander duality
5.2 Generators versus irreducible components.
5.3 Duality for resolutions
5.4 Cohull resolutions and other applications
5.5 Projective dimension and regular!ty
Exercises
Notes
6 Generic monomial ideals
6.1 Taylor complexes and genericity
6.2 The Scarf complex
6.3 Genericity by deformation
6.4 Bounds on Betti numbers
6.5 Cogeneric monomial ideals
Exercises
Notes
II Toric Algebra
7 Semigroup rings
7.1 Semigroups and lattice ideals
7.2 Affine semigroups and polyhedral cones
7.3 Hilbert bases
7.4 Initial ideals of lattice ideals
Exercises
Notes
8 Multigraded polynomial rings
8.1 Multigradings
8.2 Hilbert series and K-polynomials
8.3 Multigraded Betti numbers
8.4 K-polynomials in nonpositive gradings
8.5 Multidegrees
Exercises
Notes
9 Syzygies of lattice ideals
9.1 Betti numbers
9.2 Laurent monomial modules
9.3 Free resolutions of lattice ideals
9.4 Genericity and the Scarf complex
Exercises
Notes
……
III Determinants
References
Glossary of notation
Index
前言/序言
組閤交換代數 epub pdf mobi txt 電子書 下載 2024
組閤交換代數 下載 epub mobi pdf txt 電子書