The Stacks project

9 Miscellany

  • Chapter 104: Examples
    • Section 104.1: Introduction
    • Section 104.2: An empty limit
    • Section 104.3: A zero limit
    • Section 104.4: Non-quasi-compact inverse limit of quasi-compact spaces
    • Section 104.5: A nonintegral connected scheme whose local rings are domains
    • Section 104.6: Noncomplete completion
    • Section 104.7: Noncomplete quotient
    • Section 104.8: Completion is not exact
    • Section 104.9: The category of complete modules is not abelian
    • Section 104.10: The category of derived complete modules
    • Section 104.11: Nonflat completions
    • Section 104.12: Nonabelian category of quasi-coherent modules
    • Section 104.13: Regular sequences and base change
    • Section 104.14: A Noetherian ring of infinite dimension
    • Section 104.15: Local rings with nonreduced completion
    • Section 104.16: A non catenary Noetherian local ring
    • Section 104.17: Existence of bad local Noetherian rings
    • Section 104.18: Dimension in Noetherian Jacobson rings
    • Section 104.19: Non-quasi-affine variety with quasi-affine normalization
    • Section 104.20: A locally closed subscheme which is not open in closed
    • Section 104.21: Nonexistence of suitable opens
    • Section 104.22: Nonexistence of quasi-compact dense open subscheme
    • Section 104.23: Affines over algebraic spaces
    • Section 104.24: Pushforward of quasi-coherent modules
    • Section 104.25: A nonfinite module with finite free rank 1 stalks
    • Section 104.26: A noninvertible ideal invertible in stalks
    • Section 104.27: A finite flat module which is not projective
    • Section 104.28: A projective module which is not locally free
    • Section 104.29: Zero dimensional local ring with nonzero flat ideal
    • Section 104.30: An epimorphism of zero-dimensional rings which is not surjective
    • Section 104.31: Finite type, not finitely presented, flat at prime
    • Section 104.32: Finite type, flat and not of finite presentation
    • Section 104.33: Topology of a finite type ring map
    • Section 104.34: Pure not universally pure
    • Section 104.35: A formally smooth non-flat ring map
    • Section 104.36: A formally étale non-flat ring map
    • Section 104.37: A formally étale ring map with nontrivial cotangent complex
    • Section 104.38: Ideals generated by sets of idempotents and localization
    • Section 104.39: A ring map which identifies local rings which is not ind-étale
    • Section 104.40: Non flasque quasi-coherent sheaf associated to injective module
    • Section 104.41: A non-separated flat group scheme
    • Section 104.42: A non-flat group scheme with flat identity component
    • Section 104.43: A non-separated group algebraic space over a field
    • Section 104.44: Specializations between points in fibre étale morphism
    • Section 104.45: A torsor which is not an fppf torsor
    • Section 104.46: Stack with quasi-compact flat covering which is not algebraic
    • Section 104.47: Limit preserving on objects, not limit preserving
    • Section 104.48: A non-algebraic classifying stack
    • Section 104.49: Sheaf with quasi-compact flat covering which is not algebraic
    • Section 104.50: Sheaves and specializations
    • Section 104.51: Sheaves and constructible functions
    • Section 104.52: The lisse-étale site is not functorial
    • Section 104.53: Derived pushforward of quasi-coherent modules
    • Section 104.54: A big abelian category
    • Section 104.55: Weakly associated points and scheme theoretic density
    • Section 104.56: Example of non-additivity of traces
    • Section 104.57: Being projective is not local on the base
    • Section 104.58: Descent data for schemes need not be effective, even for a projective morphism
    • Section 104.59: A family of curves whose total space is not a scheme
    • Section 104.60: Derived base change
    • Section 104.61: An interesting compact object
    • Section 104.62: Two differential graded categories
    • Section 104.63: The stack of proper algebraic spaces is not algebraic
    • Section 104.64: An example of a non-algebraic Hom-stack
    • Section 104.65: An algebraic stack not satisfying strong formal effectiveness
    • Section 104.66: A counter example to Grothendieck's existence theorem
    • Section 104.67: Affine formal algebraic spaces
    • Section 104.68: Flat maps are not directed limits of finitely presented flat maps
    • Section 104.69: The category of modules modulo torsion modules
    • Section 104.70: Different colimit topologies
    • Section 104.71: Universally submersive but not V covering
    • Section 104.72: The spectrum of the integers is not quasi-compact
  • Chapter 105: Exercises
    • Section 105.1: Algebra
    • Section 105.2: Colimits
    • Section 105.3: Additive and abelian categories
    • Section 105.4: Tensor product
    • Section 105.5: Flat ring maps
    • Section 105.6: The Spectrum of a ring
    • Section 105.7: Localization
    • Section 105.8: Nakayama's Lemma
    • Section 105.9: Length
    • Section 105.10: Associated primes
    • Section 105.11: Ext groups
    • Section 105.12: Depth
    • Section 105.13: Cohen-Macaulay modules and rings
    • Section 105.14: Singularities
    • Section 105.15: Hilbert Nullstellensatz
    • Section 105.16: Dimension
    • Section 105.17: Catenary rings
    • Section 105.18: Fraction fields
    • Section 105.19: Transcendence degree
    • Section 105.20: Dimension of fibres
    • Section 105.21: Finite locally free modules
    • Section 105.22: Glueing
    • Section 105.23: Going up and going down
    • Section 105.24: Fitting ideals
    • Section 105.25: Hilbert functions
    • Section 105.26: Proj of a ring
    • Section 105.27: Cohen-Macaulay rings of dimension 1
    • Section 105.28: Infinitely many primes
    • Section 105.29: Filtered derived category
    • Section 105.30: Regular functions
    • Section 105.31: Sheaves
    • Section 105.32: Schemes
    • Section 105.33: Morphisms
    • Section 105.34: Tangent Spaces
    • Section 105.35: Quasi-coherent Sheaves
    • Section 105.36: Proj and projective schemes
    • Section 105.37: Morphisms from the projective line
    • Section 105.38: Morphisms from surfaces to curves
    • Section 105.39: Invertible sheaves
    • Section 105.40: Čech Cohomology
    • Section 105.41: Cohomology
    • Section 105.42: More cohomology
    • Section 105.43: Cohomology revisited
    • Section 105.44: Cohomology and Hilbert polynomials
    • Section 105.45: Curves
    • Section 105.46: Moduli
    • Section 105.47: Global Exts
    • Section 105.48: Divisors
    • Section 105.49: Differentials
    • Section 105.50: Schemes, Final Exam, Fall 2007
    • Section 105.51: Schemes, Final Exam, Spring 2009
    • Section 105.52: Schemes, Final Exam, Fall 2010
    • Section 105.53: Schemes, Final Exam, Spring 2011
    • Section 105.54: Schemes, Final Exam, Fall 2011
    • Section 105.55: Schemes, Final Exam, Fall 2013
    • Section 105.56: Schemes, Final Exam, Spring 2014
    • Section 105.57: Commutative Algebra, Final Exam, Fall 2016
    • Section 105.58: Schemes, Final Exam, Spring 2017
    • Section 105.59: Commutative Algebra, Final Exam, Fall 2017
    • Section 105.60: Schemes, Final Exam, Spring 2018
  • Chapter 106: A Guide to the Literature
    • Section 106.1: Short introductory articles
    • Section 106.2: Classic references
    • Section 106.3: Books and online notes
    • Section 106.4: Related references on foundations of stacks
    • Section 106.5: Papers in the literature
    • Section 106.6: Stacks in other fields
    • Section 106.7: Higher stacks
  • Chapter 107: Desirables
    • Section 107.1: Introduction
    • Section 107.2: Conventions
    • Section 107.3: Sites and Topoi
    • Section 107.4: Stacks
    • Section 107.5: Simplicial methods
    • Section 107.6: Cohomology of schemes
    • Section 107.7: Deformation theory à la Schlessinger
    • Section 107.8: Definition of algebraic stacks
    • Section 107.9: Examples of schemes, algebraic spaces, algebraic stacks
    • Section 107.10: Properties of algebraic stacks
    • Section 107.11: Lisse étale site of an algebraic stack
    • Section 107.12: Things you always wanted to know but were afraid to ask
    • Section 107.13: Quasi-coherent sheaves on stacks
    • Section 107.14: Flat and smooth
    • Section 107.15: Artin's representability theorem
    • Section 107.16: DM stacks are finitely covered by schemes
    • Section 107.17: Martin Olsson's paper on properness
    • Section 107.18: Proper pushforward of coherent sheaves
    • Section 107.19: Keel and Mori
    • Section 107.20: Add more here
  • Chapter 108: Coding Style
    • Section 108.1: List of style comments
  • Chapter 109: Obsolete
    • Section 109.1: Introduction
    • Section 109.2: Homological algebra
    • Section 109.3: Obsolete algebra lemmas
    • Section 109.4: Lemmas related to ZMT
    • Section 109.5: Formally smooth ring maps
    • Section 109.6: Sites and sheaves
    • Section 109.7: Cohomology
    • Section 109.8: Simplicial methods
    • Section 109.9: Obsolete lemmas on schemes
    • Section 109.10: Functor of quotients
    • Section 109.11: Spaces and fpqc coverings
    • Section 109.12: Very reasonable algebraic spaces
    • Section 109.13: Obsolete lemma on algebraic spaces
    • Section 109.14: Variants of cotangent complexes for schemes
    • Section 109.15: Deformations and obstructions of flat modules
    • Section 109.16: The stack of coherent sheaves in the non-flat case
    • Section 109.17: Modifications
    • Section 109.18: Intersection theory
    • Section 109.19: Dualizing modules on regular proper models
    • Section 109.20: Duplicate and split out references
  • Chapter 110: GNU Free Documentation License
    • Section 110.1: APPLICABILITY AND DEFINITIONS
    • Section 110.2: VERBATIM COPYING
    • Section 110.3: COPYING IN QUANTITY
    • Section 110.4: MODIFICATIONS
    • Section 110.5: COMBINING DOCUMENTS
    • Section 110.6: COLLECTIONS OF DOCUMENTS
    • Section 110.7: AGGREGATION WITH INDEPENDENT WORKS
    • Section 110.8: TRANSLATION
    • Section 110.9: TERMINATION
    • Section 110.10: FUTURE REVISIONS OF THIS LICENSE
    • Section 110.11: ADDENDUM: How to use this License for your documents