Physical Sciences and Mathematics Commons^™

Cohomology Of Absolute Galois Groups, Claudio Quadrelli

Electronic Thesis and Dissertation Repository

The main problem this thesis deals with is the characterization of profinite groups which are realizable as absolute Galois groups of fields: this is currently one of the major problems in Galois theory. Usually one reduces the problem to the pro-p case, i.e., one would like to know which pro-p groups occur as maximal pro-p Galois groups, i.e., maximal pro-p quotients of absolute Galois groups. Indeed, pro-p groups are easier to deal with than general profinite groups, yet they carry a lot of information on the whole absolute Galois group.

We define a new class of pro-p groups, called Bloch-Kato …

Polynomial Identities On Algebras With Actions, Chris Plyley

Electronic Thesis and Dissertation Repository

When an algebra is endowed with the additional structure of an action or a grading, one can often make striking conclusions about the algebra based on the properties of the structure-induced subspaces. For example, if A is an associative G-graded algebra such that the homogeneous component A₁ satisfies an identity of degree d, then Bergen and Cohen showed that A is itself a PI-algebra. Bahturin, Giambruno and Riley later used combinatorial methods to show that the degree of the identity satisfied by A is bounded above by a function of d and |G|. Utilizing a …

Ghost Number Of Group Algebras, Gaohong Wang

Electronic Thesis and Dissertation Repository

The generating hypothesis for the stable module category of a finite group is the statement that if a map in the thick subcategory generated by the trivial representation induces the zero map in Tate cohomology, then it is stably trivial. It is known that the generating hypothesis fails for most groups. Generalizing work done for p-groups, we define the ghost number of a group algebra, which is a natural number that measures the degree to which the generating hypothesis fails. We describe a close relationship between ghost numbers and Auslander-Reiten triangles, with many results stated for a general projective class …

Classification Of W-Groups Of Pythagorean Formally Real Fields, Fatemeh Bagherzadeh Golmakani

Electronic Thesis and Dissertation Repository

In this work we consider the Galois point of view in determining the structure of
a space of orderings of fields via considering small Galois quotients of absolute Galois
groups G _F of Pythagorean formally real fields. Galois theoretic, group theoretic and
combinatorial arguments are used to reduce the structure of W-groups.