These notes are an introduction to the theory of algebraic varieties emphasizing the similarities to the theory of manifolds. In contrast to most such accounts they study abstract algebraic varieties, and not just subvarieties of affine and projective space. This approach leads more naturally into scheme theory.
Author(s): Milne, James S.
Edition: v6.02
Year: 2017
Language: English
Commentary: Available at www.jmilne.org/math/
Pages: 221
Tags: Algebraic Geometry;
Contents......Page 3
Introduction......Page 7
a Rings and ideals......Page 11
b Rings of fractions......Page 15
c Unique factorization......Page 21
d Integral dependence......Page 24
e Tensor Products......Page 30
Exercises......Page 33
a Definition of an algebraic set......Page 35
b The Hilbert basis theorem......Page 36
c The Zariski topology......Page 37
d The Hilbert Nullstellensatz......Page 38
e The correspondence between algebraic sets and radical ideals......Page 39
g Properties of the Zariski topology......Page 43
h Decomposition of an algebraic set into irreducible algebraic sets......Page 44
i Regular functions; the coordinate ring of an algebraic set......Page 47
k Hypersurfaces; finite and quasi-finite maps......Page 48
l Noether normalization theorem......Page 50
m Dimension......Page 52
Exercises......Page 56
a Sheaves......Page 57
b Ringed spaces......Page 58
c The ringed space structure on an algebraic set......Page 59
d Morphisms of ringed spaces......Page 62
e Affine algebraic varieties......Page 63
f The category of affine algebraic varieties......Page 64
g Explicit description of morphisms of affine varieties......Page 65
h Subvarieties......Page 68
i Properties of the regular map Spm(a)......Page 69
j Affine space without coordinates......Page 70
k Birational equivalence......Page 71
l Noether Normalization Theorem......Page 72
m Dimension......Page 73
Exercises......Page 77
a Tangent spaces to plane curves......Page 79
b Tangent cones to plane curves......Page 81
c The local ring at a point on a curve......Page 83
d Tangent spaces to algebraic subsets of Am......Page 84
e The differential of a regular map......Page 86
f Tangent spaces to affine algebraic varieties......Page 87
g Tangent cones......Page 91
h Nonsingular points; the singular locus......Page 92
i Nonsingularity and regularity......Page 94
j Examples of tangent spaces......Page 95
Exercises......Page 96
a Algebraic prevarieties......Page 97
b Regular maps......Page 98
c Algebraic varieties......Page 99
e Subvarieties......Page 101
f Prevarieties obtained by patching......Page 102
g Products of varieties......Page 103
h The separation axiom revisited......Page 108
i Fibred products......Page 110
j Dimension......Page 111
l Rational maps; birational equivalence......Page 113
m Local study......Page 114
n Étale maps......Page 115
o Étale neighbourhoods......Page 118
p Smooth maps......Page 120
q Algebraic varieties as a functors......Page 121
r Rational and unirational varieties......Page 124
Exercises......Page 125
a Algebraic subsets of Pn......Page 127
b The Zariski topology on Pn......Page 131
c Closed subsets of An and Pn......Page 132
e Pn is an algebraic variety......Page 133
f The homogeneous coordinate ring of a projective variety......Page 135
g Regular functions on a projective variety......Page 136
h Maps from projective varieties......Page 137
i Some classical maps of projective varieties......Page 138
k Projective space without coordinates......Page 143
m Grassmann varieties......Page 144
n Bezout's theorem......Page 148
o Hilbert polynomials (sketch)......Page 149
p Dimensions......Page 150
q Products......Page 152
Exercises......Page 153
a Definition and basic properties......Page 155
b Proper maps......Page 157
c Projective varieties are complete......Page 158
d Elimination theory......Page 159
e The rigidity theorem; abelian varieties......Page 163
f Chow's Lemma......Page 165
g Analytic spaces; Chow's theorem......Page 167
h Nagata's Embedding Theorem......Page 168
Exercises......Page 169
a Normal varieties......Page 171
b Regular functions on normal varieties......Page 174
c Finite and quasi-finite maps......Page 176
d The fibres of finite maps......Page 182
e Zariski's main theorem......Page 184
f Stein factorization......Page 189
h Resolution of singularities......Page 190
Exercises......Page 191
a The constructibility theorem......Page 193
b The fibres of morphisms......Page 196
c Flat maps and their fibres......Page 199
d Lines on surfaces......Page 206
f Birational classification......Page 211
Exercises......Page 212
Solutions to the exercises......Page 213
Index......Page 219