17,238 research outputs found
Spacecraft technology. Volume VII - The Orbiting Astronomical Observatory
Design of command and data handling system for orbiting astronomical observatory, and scientific experiments for OAO spacecraf
On certain questions of the free group automorphisms theory
Certain subgroups of the groups of automorphisms of a free group
are considered. Comparing Alexander polynomials of two poly-free groups
and we prove that these groups are not isomorphic, despite the
fact that they have a lot of common properties. This answers the question of
Cohen-Pakianathan-Vershinin-Wu from \cite{CVW}. The questions of linearity of
subgroups of are considered. As an application of the properties of
poison groups in the sense of Formanek and Procesi, we show that the groups of
the type for certain groups and the subgroup of
-automorphisms are not linear for . This
generalizes the recent result of Pettet that are not linear for
.Comment: 11 page
Andrew Lenard: A Mystery Unraveled
The theory of bi-Hamiltonian systems has its roots in what is commonly
referred to as the "Lenard recursion formula". The story about the discovery of
the formula told by Andrew Lenard is the subject of this article.Comment: Published in SIGMA (Symmetry, Integrability and Geometry: Methods and
Applications) at http://www.emis.de/journals/SIGMA
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