456 research outputs found
Identities of finitely generated graded algebras with involution
We consider associative algebras with involution graded by a finite abelian
group G over a field of characteristic zero. Suppose that the involution is
compatible with the grading. We represent conditions permitting
PI-representability of such algebras. Particularly, it is proved that a
finitely generated (Z/qZ)-graded associative PI-algebra with involution
satisfies exactly the same graded identities with involution as some finite
dimensional (Z/qZ)-graded algebra with involution for any prime q or q = 4.
This is an analogue of the theorem of A.Kemer for ordinary identities, and an
extension of the result of the author for identities with involution. The
similar results were proved also recentely for graded identities
Finitely generated algebras with involution and their identities
Associative algebras with involution over a field of zero characteristic are
considered. It is proved that in this case for any finitely generated
associative algebra with involution there exists a finite dimensional algebra
with involution which satisfies exactly the same identities with involution
Finite basis problem for identities with involution
We consider associative algebras with involution over a field of
characteristic zero. We proved that any algebra with involution satisfies the
same identities with involution as the Grassmann envelope of some finite
dimensional -graded algebra with graded involution. As a consequence we
obtain the positive solution of the Specht problem for identities with
involution: any associative algebra with involution over a field of
characteristic zero has a finite basis of identities with involution. These
results are analogs of theorems of A.R.Kemer for ordinary identities
Influence of initial defects on defect formation process in ion doped silicon
We study the influence of initial defects in high-resistance epitaxial silicon
layers of high-resistance epitaxial silicon structures on defect formation processes at ion
boron doping. The method of reverse voltage-capacitance characteristics revealed two
maxima of dopant concentration in epitaxial silicon layers ion-doped by boron. Studing
the structure of the near-surface area in ion-doped epitaxial silicon by means of modern
methods has shown that in the field of the first concentration maximum (the nearest one
to a wafer surface), the fine-blocked silicon structure is localised. In the range of the
second doping concentration maximum, the grid of dislocations with the variable period
within one grid and consisting of 60° dislocations is found out. In the area of dislocation
grids, oxygen atoms have been found out. The variable period in the grid is related with a
change of mechanical stress and deformation distribution law in the plane of dopant
diffusion front as dependent on the presence of initial defects in silicon
- …