9 Miscellany

Chapter 110: Examples

Section 110.1: Introduction

Section 110.2: An empty limit

Section 110.3: A zero limit

Section 110.4: Nonquasicompact inverse limit of quasicompact spaces

Section 110.5: The structure sheaf on the fibre product

Section 110.6: A nonintegral connected scheme whose local rings are domains

Section 110.7: Noncomplete completion

Section 110.8: Noncomplete quotient

Section 110.9: Completion is not exact

Section 110.10: The category of complete modules is not abelian

Section 110.11: The category of derived complete modules

Section 110.12: Nonflat completions

Section 110.13: Nonabelian category of quasicoherent modules

Section 110.14: Nonsplit locally split sequence

Section 110.15: Regular sequences and base change

Section 110.16: A Noetherian ring of infinite dimension

Section 110.17: Local rings with nonreduced completion

Section 110.18: Another local ring with nonreduced completion

Section 110.19: A non catenary Noetherian local ring

Section 110.20: Existence of bad local Noetherian rings

Section 110.21: Dimension in Noetherian Jacobson rings

Section 110.22: Underlying space Noetherian not Noetherian

Section 110.23: Nonquasiaffine variety with quasiaffine normalization

Section 110.24: Taking scheme theoretic images

Section 110.25: Images of locally closed subsets

Section 110.26: A locally closed subscheme which is not open in closed

Section 110.27: Nonexistence of suitable opens

Section 110.28: Nonexistence of quasicompact dense open subscheme

Section 110.29: Affines over algebraic spaces

Section 110.30: Pushforward of quasicoherent modules

Section 110.31: A nonfinite module with finite free rank 1 stalks

Section 110.32: A noninvertible ideal invertible in stalks

Section 110.33: A finite flat module which is not projective

Section 110.34: A projective module which is not locally free

Section 110.35: Zero dimensional local ring with nonzero flat ideal

Section 110.36: An epimorphism of zerodimensional rings which is not surjective

Section 110.37: Finite type, not finitely presented, flat at prime

Section 110.38: Finite type, flat and not of finite presentation

Section 110.39: Topology of a finite type ring map

Section 110.40: Pure not universally pure

Section 110.41: A formally smooth nonflat ring map

Section 110.42: A formally étale nonflat ring map

Section 110.43: A formally étale ring map with nontrivial cotangent complex

Section 110.44: Flat and formally unramified is not formally étale

Section 110.45: Ideals generated by sets of idempotents and localization

Section 110.46: A ring map which identifies local rings which is not indétale

Section 110.47: Non flasque quasicoherent sheaf associated to injective module

Section 110.48: A nonseparated flat group scheme

Section 110.49: A nonflat group scheme with flat identity component

Section 110.50: A nonseparated group algebraic space over a field

Section 110.51: Specializations between points in fibre étale morphism

Section 110.52: A torsor which is not an fppf torsor

Section 110.53: Stack with quasicompact flat covering which is not algebraic

Section 110.54: Limit preserving on objects, not limit preserving

Section 110.55: A nonalgebraic classifying stack

Section 110.56: Sheaf with quasicompact flat covering which is not algebraic

Section 110.57: Sheaves and specializations

Section 110.58: Sheaves and constructible functions

Section 110.59: The lisseétale site is not functorial

Section 110.60: Sheaves on the category of Noetherian schemes

Section 110.61: Derived pushforward of quasicoherent modules

Section 110.62: A big abelian category

Section 110.63: Weakly associated points and scheme theoretic density

Section 110.64: Example of nonadditivity of traces

Section 110.65: Being projective is not local on the base

Section 110.66: Noneffective descent data for projective schemes

Section 110.67: A family of curves whose total space is not a scheme

Section 110.68: Derived base change

Section 110.69: An interesting compact object

Section 110.70: Two differential graded categories

Section 110.71: The stack of proper algebraic spaces is not algebraic

Section 110.72: An example of a nonalgebraic Homstack

Section 110.73: An algebraic stack not satisfying strong formal effectiveness

Section 110.74: A counter example to Grothendieck's existence theorem

Section 110.75: Affine formal algebraic spaces

Section 110.76: Flat maps are not directed limits of finitely presented flat maps

Section 110.77: The category of modules modulo torsion modules

Section 110.78: Different colimit topologies

Section 110.79: Universally submersive but not V covering

Section 110.80: The spectrum of the integers is not quasicompact

Chapter 111: Exercises

Section 111.1: Algebra

Section 111.2: Colimits

Section 111.3: Additive and abelian categories

Section 111.4: Tensor product

Section 111.5: Flat ring maps

Section 111.6: The Spectrum of a ring

Section 111.7: Localization

Section 111.8: Nakayama's Lemma

Section 111.9: Length

Section 111.10: Associated primes

Section 111.11: Ext groups

Section 111.12: Depth

Section 111.13: CohenMacaulay modules and rings

Section 111.14: Singularities

Section 111.15: Constructible sets

Section 111.16: Hilbert Nullstellensatz

Section 111.17: Dimension

Section 111.18: Catenary rings

Section 111.19: Fraction fields

Section 111.20: Transcendence degree

Section 111.21: Dimension of fibres

Section 111.22: Finite locally free modules

Section 111.23: Glueing

Section 111.24: Going up and going down

Section 111.25: Fitting ideals

Section 111.26: Hilbert functions

Section 111.27: Proj of a ring

Section 111.28: CohenMacaulay rings of dimension 1

Section 111.29: Infinitely many primes

Section 111.30: Filtered derived category

Section 111.31: Regular functions

Section 111.32: Sheaves

Section 111.33: Schemes

Section 111.34: Morphisms

Section 111.35: Tangent Spaces

Section 111.36: Quasicoherent Sheaves

Section 111.37: Proj and projective schemes

Section 111.38: Morphisms from the projective line

Section 111.39: Morphisms from surfaces to curves

Section 111.40: Invertible sheaves

Section 111.41: Čech Cohomology

Section 111.42: Cohomology

Section 111.43: More cohomology

Section 111.44: Cohomology revisited

Section 111.45: Cohomology and Hilbert polynomials

Section 111.46: Curves

Section 111.47: Moduli

Section 111.48: Global Exts

Section 111.49: Divisors

Section 111.50: Differentials

Section 111.51: Schemes, Final Exam, Fall 2007

Section 111.52: Schemes, Final Exam, Spring 2009

Section 111.53: Schemes, Final Exam, Fall 2010

Section 111.54: Schemes, Final Exam, Spring 2011

Section 111.55: Schemes, Final Exam, Fall 2011

Section 111.56: Schemes, Final Exam, Fall 2013

Section 111.57: Schemes, Final Exam, Spring 2014

Section 111.58: Commutative Algebra, Final Exam, Fall 2016

Section 111.59: Schemes, Final Exam, Spring 2017

Section 111.60: Commutative Algebra, Final Exam, Fall 2017

Section 111.61: Schemes, Final Exam, Spring 2018

Section 111.62: Commutative Algebra, Final Exam, Fall 2019

Section 111.63: Algebraic Geometry, Final Exam, Spring 2020

Section 111.64: Commutative Algebra, Final Exam, Fall 2021

Section 111.65: Algebraic Geometry, Final Exam, Spring 2022

Chapter 112: A Guide to the Literature

Section 112.1: Short introductory articles

Section 112.2: Classic references

Section 112.3: Books and online notes

Section 112.4: Related references on foundations of stacks

Section 112.5: Papers in the literature

Section 112.6: Stacks in other fields

Section 112.7: Higher stacks

Chapter 113: Desirables

Section 113.1: Introduction

Section 113.2: Conventions

Section 113.3: Sites and Topoi

Section 113.4: Stacks

Section 113.5: Simplicial methods

Section 113.6: Cohomology of schemes

Section 113.7: Deformation theory à la Schlessinger

Section 113.8: Definition of algebraic stacks

Section 113.9: Examples of schemes, algebraic spaces, algebraic stacks

Section 113.10: Properties of algebraic stacks

Section 113.11: Lisse étale site of an algebraic stack

Section 113.12: Things you always wanted to know but were afraid to ask

Section 113.13: Quasicoherent sheaves on stacks

Section 113.14: Flat and smooth

Section 113.15: Artin's representability theorem

Section 113.16: DM stacks are finitely covered by schemes

Section 113.17: Martin Olsson's paper on properness

Section 113.18: Proper pushforward of coherent sheaves

Section 113.19: Keel and Mori

Section 113.20: Add more here

Chapter 114: Coding Style

Section 114.1: List of style comments

Chapter 115: Obsolete

Section 115.1: Introduction

Section 115.2: Preliminaries

Section 115.3: Homological algebra

Section 115.4: Obsolete algebra lemmas

Section 115.5: Lemmas related to ZMT

Section 115.6: Formally smooth ring maps

Section 115.7: Sites and sheaves

Section 115.8: Cohomology

Section 115.9: Differential graded algebra

Section 115.10: Simplicial methods

Section 115.11: Results on schemes

Section 115.12: Derived categories of varieties

Section 115.13: Representability in the regular proper case

Section 115.14: Functor of quotients

Section 115.15: Spaces and fpqc coverings

Section 115.16: Very reasonable algebraic spaces

Section 115.17: Obsolete lemmas on algebraic spaces

Section 115.18: Obsolete lemmas on algebraic stacks

Section 115.19: Variants of cotangent complexes for schemes

Section 115.20: Deformations and obstructions of flat modules

Section 115.21: The stack of coherent sheaves in the nonflat case

Section 115.22: Modifications

Section 115.23: Intersection theory

Section 115.24: Commutativity of intersecting divisors

Section 115.25: Dualizing modules on regular proper models

Section 115.26: Duplicate and split out references

Chapter 116: GNU Free Documentation License

Section 116.1: APPLICABILITY AND DEFINITIONS

Section 116.2: VERBATIM COPYING

Section 116.3: COPYING IN QUANTITY

Section 116.4: MODIFICATIONS

Section 116.5: COMBINING DOCUMENTS

Section 116.6: COLLECTIONS OF DOCUMENTS

Section 116.7: AGGREGATION WITH INDEPENDENT WORKS

Section 116.8: TRANSLATION

Section 116.9: TERMINATION

Section 116.10: FUTURE REVISIONS OF THIS LICENSE

Section 116.11: ADDENDUM: How to use this License for your documents