52,961 research outputs found
Pro-Lie Groups: A survey with Open Problems
A topological group is called a pro-Lie group if it is isomorphic to a closed
subgroup of a product of finite-dimensional real Lie groups. This class of
groups is closed under the formation of arbitrary products and closed subgroups
and forms a complete category. It includes each finite-dimensional Lie group,
each locally compact group which has a compact quotient group modulo its
identity component and thus, in particular, each compact and each connected
locally compact group; it also includes all locally compact abelian groups.
This paper provides an overview of the structure theory and Lie theory of
pro-Lie groups including results more recent than those in the authors'
reference book on pro-Lie groups. Significantly, it also includes a review of
the recent insight that weakly complete unital algebras provide a natural
habitat for both pro-Lie algebras and pro-Lie groups, indeed for the
exponential function which links the two. (A topological vector space is weakly
complete if it is isomorphic to a power of an arbitrary set of copies of
. This class of real vector spaces is at the basis of the Lie theory of
pro-Lie groups.) The article also lists 12 open questions connected with
pro-Lie groups.Comment: 19 page
The effect of extreme temperatures on the elastic properties and fracture behavior of graphite/polyimide composites
The influence of elevated and cryogenic temperatures on the elastic moduli and fracture strengths of several C6000/PMR-15 and C6000/NR-15082 laminates was measured. Tests were conducted at -157 C, 24 C, and 316 C (-250 F, 75 F, and 600 F). Both notched and unnotched laminates were tested. The average stress failure criterion was used to predict the fracture strength of quasi-isotropic notched laminates
The weights of closed subgroups of a locally compact group
Let be an infinite locally compact group and a cardinal
satisfying for the weight of . It is
shown that there is a closed subgroup of with . Sample
consequences are:
(1) Every infinite compact group contains an infinite closed metric subgroup.
(2) For a locally compact group and a cardinal satisfying
\aleph_0\le\aleph\le \lw(G), where \lw(G) is the local weight of , there
are either no infinite compact subgroups at all or there is a compact subgroup
of with .
(3) For an infinite abelian group there exists a properly ascending
family of locally quasiconvex group topologies on , say,
(\tau_\aleph)_{\aleph_0\le \aleph\le \card(G)}, such that
.
Items (2) and (3) are shown in Section 5
Nonmeasurable subgroups of compact groups
In 1985 S.~Saeki and K.~Stromberg published the following question: {\it Does
every infinite compact group have a subgroup which is not Haar measurable?} An
affirmative answer is given for all compact groups with the exception of some
metric profinite groups known as strongly complete. In this spirit it is also
shown that every compact group contains a non-Borel subgroup
Creep and creep rupture of laminated graphite/epoxy composites
An incremental numerical procedure based on lamination theory is developed to predict creep and creep rupture of general laminates. Existing unidirectional creep compliance and delayed failure data is used to develop analytical models for lamina response. The compliance model is based on a procedure proposed by Findley which incorporates the power law for creep into a nonlinear constitutive relationship. The matrix octahedral shear stress is assumed to control the stress interaction effect. A modified superposition principle is used to account for the varying stress level effect on the creep strain. The lamina failure model is based on a modification of the Tsai-Hill theory which includes the time dependent creep rupture strength. A linear cumulative damage law is used to monitor the remaining lifetime in each ply
Invasive Diseases and Fruit Tree Production: Economic Tradeoffs of Citrus Greening Control on Florida's Citrus Industry
An investment model of Florida oranges was used to evaluate various management strategies for controlling Huanglongbing, or citrus greening, a highly destructive disease. This analysis will enable the Florida citrus industry to make more informed decisions about the economic tradeoffs among current citrus greening management alternatives.Crop Production/Industries,
Impacts of International Wheat Breeding Research in the Developing World, 1988-2002
Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,
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