796 research outputs found
Cohomology and projectivity of modules for finite group schemes
Let G be a finite group scheme over an algebraically closed field of positive
characteristic. Assume further that the connected component of G is unipotent.
It is shown that the projectivity of a rational G-module can be detected on a
family of closed subgroups. It is further shown that nilpotent cohomology or
extension classes can be detected on this family of subgroups.Comment: 21 page
Cohomology of algebraic groups, Lie algebras, and finite groups of Lie type
Let G be a reductive algebraic group over a field of prime characteristic.
One can associate to G (or subgroups thereof) its Lie algebra, its Frobenius
kernels, and the finite Chevalley group of points over a finite field. The
representation theories of these structures are highly interconnected. This
expository article will focus specifically on the cohomology theories of these
structures and the relationships between them with the aim of highlighting a
few key developments over the past 20 years and related open questions
The resistance of AISI 5160 (post-tensioned concrete tendons) to brittle fracture
The effect of thermal and mechanical treatments on the tensile and notched tensile properties of post-tensioned concrete tendon material (AISI Type 5160 steel) was studied. The process variables studied included normalizing, proof stressing and stress relieving sequence, stress relieving time and temperature, and tempering temperature of quenched materials. The effect of test temperature on the properties of two conditions was also studied. The fracture toughness parameters, KIc, were calculated where applicable
- …