Galois modules over local and global fields form the main subject of this monograph, which can serve both as a textbook for students, and as a reference book for the working mathematician, on cohomological topics in number theory. The first part provides necessary algebraic background: profinite groups and their cohomology, duality groups, free products, modules over complete group rings and their homotopy theory. The arithmetic part deals with Galois groups of local and global fields: local Tate duality, the structure of the absolute Galois group of a local field, extensions of global fields with restricted ramification, cohomology of the idèle and the idèle class groups, Poitou-Tate duality for finitely generated Galois modules, the Hasse principle, the theorem of Grunwald-Wang, Leopoldt's conjecture, Riemann's existence theorem for number fields, embedding problems, the theorems of Iwasawa and of Safarevic on solvable groups as Galois groups over global fields, Iwasawa theory of local and global number fields, and the characterization of number fields by their absolute Galois groups.
Galois modules over local and global fields form the main subject of this monograph, which can serve both as a textbook for students, and as a reference book for the working mathematician, on cohomological topics in number theory. The first part provides necessary algebraic background: profinite groups and their cohomology, duality groups, free products, modules over complete group rings and their homotopy theory. The arithmetic part deals with Galois groups of local and global fields: local Tate duality, the structure of the absolute Galois group of a local field, extensions of global fields with restricted ramification, cohomology of the idèle and the idèle class groups, Poitou-Tate duality for finitely generated Galois modules, the Hasse principle, the theorem of Grunwald-Wang, Leopoldt's conjecture, Riemann's existence theorem for number fields, embedding problems, the theorems of Iwasawa and of Safarevic on solvable groups as Galois groups over global fields, Iwasawa theory of local and global number fields, and the characterization of number fields by their absolute Galois groups.
In the words of a reviewer: “This monograph gives a very complete treatment of a vast array of cental topics in algebraic number theory
There is so much material written down systematically which was known to the experts, but whose detailed proof did not actually exist in the literature (most notable amongst these is the celebrated duality theorem of Poitou and Tate)”
Jürgen Neukirch
Algebraic number fields Cohomology theory Galois groups
From the reviews of the second edition:
"The publication of a second edition gives me a chance to … emphasize what an important book it is. … the book a necessary part of the number theorist’s library. That it’s also well written, clear, and systematic is a very welcome bonus. … There are many goodies here … . it is an indispensable book for anyone working in number theory. … Neukirch, Schmidt, and Wingberg have, in fact, produced … authoritative, complete, careful, and sure to be a reliable reference for many years." (Fernando Q. Gouvêa, MathDL, May, 2008)
"The second edition will continue to serve as a very helpful and up-to-date reference in cohomology of profinite groups and algebraic number theory, and all the additions are interesting and useful. … the book is fine as it is: systematic, very comprehensive, and well-organised. This second edition will be a standard reference from the outset, continuing the success of the first one." (Cornelius Greither, Zentralblatt MATH, Vol. 1136 (14), 2008)