Preface to the First Edition |
|
xvii | |
Preface to the Second Edition |
|
xxi | |
Notation |
|
xxiii | |
1 Basic Notation |
|
xxiii | |
2 Chapter-by-Chapter Notation |
|
xxv | |
|
|
|
|
3 | (22) |
|
|
4 | (6) |
|
|
8 | (2) |
|
1.2 Permutations of the Roots |
|
|
10 | (5) |
|
|
10 | (1) |
|
|
11 | (2) |
|
|
13 | (1) |
|
|
14 | (1) |
|
|
14 | (1) |
|
1.3 Cubic Equations over the Real Numbers |
|
|
15 | (10) |
|
A The Number of Real Roots |
|
|
15 | (3) |
|
B Trigonometric Solution of the Cubic |
|
|
18 | (1) |
|
|
19 | (4) |
|
|
23 | (2) |
|
|
25 | (30) |
|
2.1 Polynomials of Several Variables |
|
|
25 | (5) |
|
A The Polynomial Ring in n Variables |
|
|
25 | (2) |
|
B The Elementary Symmetric Polynomials |
|
|
27 | (2) |
|
|
29 | (1) |
|
2.2 Symmetric Polynomials |
|
|
30 | (12) |
|
A The Fundamental Theorem |
|
|
30 | (5) |
|
B The Roots of a Polynomial |
|
|
35 | (1) |
|
|
36 | (1) |
|
|
37 | (1) |
|
|
38 | (4) |
|
2.3 Computing with Symmetric Polynomials (Optional) |
|
|
42 | (4) |
|
|
42 | (2) |
|
|
44 | (2) |
|
|
46 | (9) |
|
|
48 | (2) |
|
|
50 | (3) |
|
|
53 | (2) |
|
|
55 | (18) |
|
3.1 The Existence of Roots |
|
|
55 | (7) |
|
|
59 | (2) |
|
|
61 | (1) |
|
3.2 The Fundamental Theorem of Algebra |
|
|
62 | (11) |
|
|
66 | (1) |
|
|
67 | (3) |
|
|
70 | (3) |
|
|
|
|
73 | (28) |
|
4.1 Elements of Extension Fields |
|
|
73 | (8) |
|
|
74 | (1) |
|
|
75 | (4) |
|
|
79 | (1) |
|
|
79 | (2) |
|
4.2 Irreducible Polynomials |
|
|
81 | (8) |
|
A Using Maple and Mathematica |
|
|
81 | (2) |
|
B Algorithms for Factoring |
|
|
83 | (1) |
|
C The Schonemann-Eisenstein Criterion |
|
|
84 | (1) |
|
|
85 | (2) |
|
|
87 | (2) |
|
4.3 The Degree of an Extension |
|
|
89 | (6) |
|
|
89 | (2) |
|
|
91 | (2) |
|
|
93 | (1) |
|
|
93 | (2) |
|
|
95 | (6) |
|
|
97 | (1) |
|
|
98 | (3) |
|
5 Normal and Separable Extensions |
|
|
101 | (24) |
|
|
101 | (6) |
|
A Definition and Examples |
|
|
101 | (2) |
|
|
103 | (4) |
|
|
107 | (2) |
|
|
108 | (1) |
|
|
109 | (10) |
|
A Fields of Characteristic 0 |
|
|
112 | (1) |
|
B Fields of Characteristic p |
|
|
113 | (1) |
|
|
114 | (2) |
|
|
116 | (3) |
|
5.4 Theorem of the Primitive Element |
|
|
119 | (6) |
|
|
122 | (1) |
|
|
122 | (1) |
|
|
123 | (2) |
|
|
125 | (22) |
|
6.1 Definition of the Galois Group |
|
|
125 | (5) |
|
|
128 | (2) |
|
6.2 Galois Groups of Splitting Fields |
|
|
130 | (2) |
|
6.3 Permutations of the Roots |
|
|
132 | (4) |
|
|
134 | (1) |
|
|
135 | (1) |
|
6.4 Examples of Galois Groups |
|
|
136 | (7) |
|
|
136 | (2) |
|
B The Universal Extension |
|
|
138 | (1) |
|
C A Polynomial of Degree 5 |
|
|
139 | (1) |
|
|
139 | (2) |
|
|
141 | (2) |
|
6.5 Abelian Equations (Optional) |
|
|
143 | (4) |
|
|
145 | (1) |
|
|
146 | (1) |
|
7 The Galois Correspondence |
|
|
147 | (44) |
|
|
147 | (7) |
|
A Splitting Fields of Separable Polynomials |
|
|
147 | (3) |
|
B Finite Separable Extensions |
|
|
150 | (1) |
|
|
151 | (1) |
|
|
152 | (2) |
|
7.2 Normal Subgroups and Normal Extensions |
|
|
154 | (7) |
|
|
154 | (1) |
|
|
155 | (4) |
|
|
159 | (1) |
|
|
160 | (1) |
|
7.3 The Fundamental Theorem of Galois Theory |
|
|
161 | (6) |
|
|
167 | (6) |
|
|
167 | (2) |
|
B The Universal Extension |
|
|
169 | (1) |
|
C The Inverse Galois Problem |
|
|
170 | (2) |
|
|
172 | (1) |
|
7.5 Automorphisms and Geometry (Optional) |
|
|
173 | (18) |
|
A Groups of Automorphisms |
|
|
173 | (2) |
|
B Function Fields in One Variable |
|
|
175 | (3) |
|
C Linear Fractional Transformations |
|
|
178 | (2) |
|
D Stereographic Projection |
|
|
180 | (3) |
|
|
183 | (5) |
|
|
188 | (3) |
|
|
|
8 Solvability by Radicals |
|
|
191 | (38) |
|
|
191 | (5) |
|
|
194 | (2) |
|
8.2 Radical and Solvable Extensions |
|
|
196 | (5) |
|
A Definitions and Examples |
|
|
196 | (2) |
|
B Compositums and Galois Closures |
|
|
198 | (1) |
|
C Properties of Radical and Solvable Extensions |
|
|
198 | (2) |
|
|
200 | (1) |
|
8.3 Solvable Extensions and Solvable Groups |
|
|
201 | (9) |
|
A Roots of Unity and Lagrange Resolvents |
|
|
201 | (3) |
|
|
204 | (3) |
|
|
207 | (1) |
|
|
208 | (2) |
|
|
210 | (5) |
|
|
213 | (1) |
|
|
214 | (1) |
|
8.5 Solving Polynomials by Radicals |
|
|
215 | (5) |
|
|
215 | (2) |
|
B The Universal Polynomial |
|
|
217 | (1) |
|
|
217 | (1) |
|
D The Fundamental Theorem of Algebra Revisited |
|
|
218 | (1) |
|
|
219 | (1) |
|
8.6 The Casus Irreducbilis (Optional) |
|
|
220 | (9) |
|
|
220 | (2) |
|
B Irreducible Polynomials with Real Radical Roots |
|
|
222 | (2) |
|
C The Failure of Solvability in Characteristic p |
|
|
224 | (2) |
|
|
226 | (1) |
|
|
227 | (2) |
|
|
229 | (26) |
|
9.1 Cyclotomic Polynomials |
|
|
229 | (9) |
|
|
230 | (1) |
|
B Definition of Cyclotomic Polynomials |
|
|
231 | (2) |
|
C The Galois Group of a Cyclotomic Extension |
|
|
233 | (2) |
|
|
235 | (3) |
|
9.2 Gauss and Roots of Unity (Optional) |
|
|
238 | (17) |
|
A The Galois Correspondence |
|
|
238 | (1) |
|
|
239 | (3) |
|
|
242 | (4) |
|
D Solvability by Radicals |
|
|
246 | (2) |
|
|
248 | (1) |
|
|
249 | (5) |
|
|
254 | (1) |
|
10 Geometric Constructions |
|
|
255 | (36) |
|
10.1 Constructible Numbers |
|
|
255 | (15) |
|
|
264 | (2) |
|
|
266 | (4) |
|
10.2 Regular Polygons and Roots of Unity |
|
|
270 | (4) |
|
|
271 | (3) |
|
|
274 | (17) |
|
|
274 | (2) |
|
|
276 | (3) |
|
C Marked Rulers and Intersections of Conics |
|
|
279 | (3) |
|
|
282 | (1) |
|
|
283 | (5) |
|
|
288 | (3) |
|
|
291 | (24) |
|
11.1 The Structure of Finite Fields |
|
|
291 | (10) |
|
A Existence and Uniqueness |
|
|
291 | (3) |
|
|
294 | (2) |
|
|
296 | (1) |
|
|
297 | (4) |
|
11.2 Irreducible Polynomials over Finite Fields (Optional) |
|
|
301 | (14) |
|
A Irreducible Polynomials of Fixed Degree |
|
|
301 | (3) |
|
B Cyclotomic Polynomials Modulo p |
|
|
304 | (1) |
|
|
305 | (2) |
|
|
307 | (3) |
|
|
310 | (5) |
|
|
|
12 Lagrange, Galois, and Kronecker |
|
|
315 | (42) |
|
|
315 | (19) |
|
|
317 | (3) |
|
|
320 | (3) |
|
|
323 | (3) |
|
|
326 | (2) |
|
|
328 | (1) |
|
|
329 | (5) |
|
|
334 | (13) |
|
|
335 | (1) |
|
|
335 | (2) |
|
|
337 | (2) |
|
D Natural and Accessory Irrationalities |
|
|
339 | (2) |
|
|
341 | (2) |
|
|
343 | (4) |
|
|
347 | (10) |
|
|
347 | (2) |
|
|
349 | (1) |
|
|
350 | (3) |
|
|
353 | (3) |
|
|
356 | (1) |
|
13 Computing Galois Groups |
|
|
357 | (56) |
|
|
357 | (11) |
|
|
363 | (3) |
|
|
366 | (2) |
|
|
368 | (18) |
|
A Transitive Subgroups of S5 |
|
|
368 | (3) |
|
B Galois Groups of Quintics |
|
|
371 | (5) |
|
|
376 | (1) |
|
|
377 | (1) |
|
|
378 | (2) |
|
|
380 | (6) |
|
|
386 | (14) |
|
|
386 | (3) |
|
|
389 | (1) |
|
C Quartics in All Characteristics |
|
|
390 | (3) |
|
|
393 | (3) |
|
|
396 | (4) |
|
|
400 | (13) |
|
|
400 | (4) |
|
|
404 | (2) |
|
|
406 | (4) |
|
|
410 | (3) |
|
14 Solvable Permutation Groups |
|
|
413 | (50) |
|
14.1 Polynomials of Prime Degree |
|
|
413 | (6) |
|
|
417 | (1) |
|
|
417 | (2) |
|
14.2 Imprimitive Polynomials of Prime-Squared Degree |
|
|
419 | (10) |
|
A Primitive and Imprimitive Groups |
|
|
419 | (2) |
|
|
421 | (3) |
|
|
424 | (1) |
|
|
425 | (1) |
|
|
426 | (3) |
|
14.3 Primitive Permutation Groups |
|
|
429 | (15) |
|
A Doubly Transitive Permutation Groups |
|
|
429 | (1) |
|
B Affine Linear and Semilinear Groups |
|
|
430 | (1) |
|
C Minimal Normal Subgroups |
|
|
431 | (2) |
|
|
433 | (4) |
|
|
437 | (2) |
|
|
439 | (5) |
|
14.4 Primitive Polynomials of Prime-Squared Degree |
|
|
444 | (19) |
|
A The First Two Subgroups |
|
|
444 | (2) |
|
|
446 | (4) |
|
|
450 | (7) |
|
|
457 | (1) |
|
|
458 | (4) |
|
|
462 | (1) |
|
|
463 | (52) |
|
15.1 Division Points and Arc Length |
|
|
464 | (6) |
|
A Division Points of the Lemniscate |
|
|
464 | (2) |
|
B Arc Length of the Lemniscate |
|
|
466 | (1) |
|
|
467 | (2) |
|
|
469 | (1) |
|
15.2 The Lemniscatic Function |
|
|
470 | (12) |
|
|
471 | (2) |
|
|
473 | (3) |
|
C Multiplication by Integers |
|
|
476 | (3) |
|
|
479 | (3) |
|
15.3 The Complex Lemniscatic Function |
|
|
482 | (7) |
|
A A Doubly Periodic Function |
|
|
482 | (2) |
|
|
484 | (3) |
|
|
487 | (1) |
|
|
488 | (1) |
|
15.4 Complex Multiplication |
|
|
489 | (15) |
|
|
490 | (1) |
|
B Multiplication by Gaussian Integers |
|
|
491 | (6) |
|
C Multiplication by Gaussian Primes |
|
|
497 | (4) |
|
|
501 | (1) |
|
|
502 | (2) |
|
|
504 | (11) |
|
A The Lemniscatic Galois Group |
|
|
504 | (2) |
|
B Straightedge-and-Compass Constructions |
|
|
506 | (2) |
|
|
508 | (2) |
|
|
510 | (3) |
|
|
513 | (2) |
|
|
515 | (22) |
|
|
515 | (9) |
|
|
515 | (4) |
|
|
519 | (1) |
|
|
520 | (2) |
|
|
522 | (2) |
|
|
524 | (4) |
|
A Addition, Multiplication, and Division |
|
|
524 | (1) |
|
B Roots of Complex Numbers |
|
|
525 | (3) |
|
A.3 Polynomials with Rational Coefficients |
|
|
528 | (2) |
|
|
530 | (2) |
|
|
532 | (5) |
|
|
532 | (1) |
|
B The Chinese Remainder Theorem |
|
|
533 | (1) |
|
C The Multiplicative Group of a Field |
|
|
533 | (1) |
|
D Unique Factorization Domains |
|
|
534 | (3) |
|
B Hints to Selected Exercises |
|
|
537 | (14) |
|
|
551 | (6) |
|
|
555 | (1) |
|
A Books and Monographs on Galois Theory |
|
|
555 | (1) |
|
B Books on Abstract Algebra |
|
|
556 | (1) |
|
|
556 | (1) |
Index |
|
557 | |