共查询到20条相似文献,搜索用时 422 毫秒
1.
D. I. Panyushev 《Functional Analysis and Its Applications》2004,38(1):38-44
Let
be a reductive Lie algebra over an algebraically closed field of characteristic zero and
an arbitrary
-grading. We consider the variety
, which is called the commuting variety associated with the
-grading. Earlier it was proved by the author that
is irreducible, if the
-grading is of maximal rank. Now we show that
is irreducible for
and (E6,F4). In the case of symmetric pairs of rank one, we show that the number of irreducible components of
is equal to that of nonzero non--regular nilpotent G
0-orbits in
. We also discuss a general problem of the irreducibility of commuting varieties. 相似文献
2.
3.
The paper deals with the problem of recovering the parameters (functions)
and
of the Maxwell dynamical system
(tan is the tangent component;
is a solution) by the response operator
(
is the normal). The parameters determine the velocity
, the c-metric
, and the time
. It is shown that for any fixed
, the operator
determines
and
in
uniquely. Bibliography: 15 titles. 相似文献
4.
We prove the absolute continuity of the spectrum of the Schrödinger operator in
,
, with periodic (with a common period lattice
) scalar
and vector
potentials for which either
,
, or the Fourier series of the vector potential
converges absolutely,
, where
is an elementary cell of the lattice
,
for
, and
for
, and the value of
is sufficiently small, where
and
otherwise,
, and
. 相似文献
5.
Satoshi Tanaka 《Czechoslovak Mathematical Journal》2001,51(3):573-583
The higher order neutral functional differential equation
is considered under the following conditions:
is strictly increasing in
is nonnegative on
and nondecreasing in
. A necessary and sufficient condition is derived for the existence of certain positive solutions of (1). 相似文献
6.
This article improves results of Hamada, Helleseth and Maekawa on minihypers in projective spaces and linear codes meeting the Griesmer bound.In [10,12],it was shown that any
-minihyper, with
, where
, is the disjoint union of
points,
lines,...,
-dimensional subspaces. For q large, we improve on this result by increasing the upper bound on
non-square, to
non-square,
square,
, and (4) for
square, p prime, p<3, to
. In the case q non-square, the conclusion is the same as written above; the minihyper is the disjoint union of subspaces. When q is square however, the minihyper is either the disjoint union of subspaces, or the disjoint union of subspaces and one subgeometry
. For the coding-theoretical problem, our results classify the corresponding
codes meeting the Griesmer bound. 相似文献
8.
Let
be a continuous semimartingale and let
be a continuous function of bounded variation. Setting
and
suppose that a continuous function
is given such that F is C1,2 on
and F is
on
. Then the following change-of-variable formula holds:
where
is the local time of X at the curve b given by
and
refers to the integration with respect to
. A version of the same formula derived for an Itô diffusion X under weaker conditions on F has found applications in free-boundary problems of optimal stopping. 相似文献
9.
Yu. V. Nagrebetskaya 《Algebra and Logic》2000,39(6):396-406
We study into the question of whether some rings and their associated matrix rings have equal decidability boundaries in the scheme and scheme-alternative hierarchies. Let
be a decidability boundary for an algebraic system A; w.r.t. the hierarchy H. For a ring R, denote by
an algebra with universe
. On this algebra, define the operations + and in such a way as to extend, if necessary, the initial matrices by suitably many zero rows and columns added to the underside and to the right of each matrix, followed by ordinary addition and multiplication of the matrices obtained. The main results are collected in Theorems 1-3. Theorem 1 holds that if R is a division or an integral ring, and R has zero or odd characteristic, then the equalities
hold for any n1. And if R is an arbitrary associative ring with identity then
for any n 1 and i,j { 1,..., n}, where e
ij
is a matrix identity. Theorem 2 maintains that if R is an associative ring with identity then
. Theorem 3 proves that
for any n 1. 相似文献
10.
The paper deals with the system
where
and
are
-matrix functions;
is a boundary control;
is the solution. The singularities of the fundamental solution corresponding to the controls
(
is the Dirac
-function) are under investigation. In the case of
, the singularities of the fundamental solution are described in terms of the standard scale
. In the presence of points
an interesting effect occurs: singularities of intermediate (fractional) orders appear. Bibliography: 1 title. 相似文献
11.
It is proved that the even-order equationy
(2n)
+p(t)y=0 is (n,n) oscillatory at if
相似文献
12.
C. S. Lin 《Czechoslovak Mathematical Journal》2002,52(3):665-672
In this paper we prove two results. The first is an extension of the result of G. D. Jones [4[:Every nontrivial solution for
13.
A. Salvatore 《Annali di Matematica Pura ed Applicata》1989,155(1):271-284
In questo lavoro si considera il problema
|
设为首页 | 免责声明 | 关于勤云 | 加入收藏 |
Copyright©北京勤云科技发展有限公司 京ICP备09084417号 |