Tits' systems in Chevalley groups over Laurent polynomial rings

Chevalley Groups over Commutative Rings

Projecttve Modules over Laurent Polynomial Rings

Quillen's solution of Serre's problem is extended to Laurent polynomial rings. An example is given of a A[T, r~']-module P which is not extended even though A is regular and Pm is extended for all maximal ideals m of A. The object of this note is to present several comments and examples related to some problems suggested by Quillen's recent solution of Serre's problem [7]. It is an immediate co...

On modules over Laurent polynomial rings

A finitely generated Λ = Z[t, t]-module without Z-torsion is determined by a pair of sub-lattices of Λ. Their indices are the absolute values of the leading and trailing coefficients of the order of the module. This description has applications in knot theory. MSC 2010: Primary 13E05, 57M25.

Chevalley Groups over Commutative Rings I. Elementary Calculations

This is the rst in a series of papers dedicated to the structure of Chevalley groups over commutative rings. The goal of this series is to systematically develop methods of calculations in Chevalley groups over rings, based on the use of their minimal modules. As an application we give new direct proofs for normality of the elementary subgroup, description of normal subgroups and similar result...

Tits Indices over Semilocal Rings

We present a simplified version of Tits’ proof of the classification of semisimple algebraic groups, which remains valid over semilocal rings. We also provide explicit conditions on anisotropic groups to appear as anisotropic kernels of semisimple groups of a given index.