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1.
A SIMPLIFIED BRAUER'S THEOREM ON MATRIX EIGENVALUES 总被引:1,自引:0,他引:1
Luoluo Li 《高校应用数学学报(英文版)》1999,14(3):259-264
Let A=(a
ij)∈C
n×n
and
. Suppose that for each row of A there is at least one nonzero off-diagonal entry. It is proved that all eigenvalues of A are contained in
. The result reduces the number of ovals in original Brauer’s theorem in many cases. Eigenvalues (and associated eigenvectors)
that locate in the boundary of
are discussed.
The project is supported in part by Natural Science Foundation of Guangdong. 相似文献
2.
Solutions
of a semilinear elliptic boundary value problem,
(with
bounded below) can be put into a one-to-one correspondence with zeros
of a function
. Often d is small. The function
is called the bifurcation function. It can also be shown that the eigenvalues of the matrix
characterize the stability properties of the solutions of the elliptic problem as rest points of
. A finite element method that can be used for computing B and B
c has recently been proposed. An overview of these results and the finite element method is given.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
3.
Pierre Verlinden 《Numerical Algorithms》1999,22(2):183-192
Consider a weight
and a rational modification of it
is a polynomial. An algorithm is stabilized for the following problem: “Given the coefficients of the three-term recurrence
equation satisfied by the orthogonal polynomials relative to
, compute the coefficients of the recurrence equation satisfied by the orthogonal polynomials relative to
.”
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
4.
Let
and
. We are interested in the lower bounds of the integral:
where h > 0 and
. Using the lower bounds for these integrals we obtain in particular for the so-called Fejér operator
of
the following asymptotic expression
which essentially improves the results concerning the approximation behavior of this operator.
Received: 10 January 2006 相似文献
5.
Slowly convergent infinite products
are considered, where
is a sequence of numbers, or a sequence of linear operators. Using an asymptotic expansion for the “remainder” of the infinite
product a method for convergence acceleration is suggested. The method is in the spirit of the d-transformation for series. It is very simple and efficient for some classes of sequences
. For complicated sequences
it involves the solution of some linear systems, but it is still effective.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
6.
V. Yu. Popov 《Algebra and Logic》2001,40(1):55-66
It is proved that there exists an infinite sequence of finitely based semigroup varieties
such that, for all i, an equational theory for
and for the class
of all finite semigroups in
is undecidable while an equational theory for
and for the class
of all finite semigroups in
is decidable. An infinite sequence of finitely based semigroup varieties
is constructed so that, for all i, an equational theory for
and for the class
of all finite semigroups in
is decidable whicle an equational theory for
and for the class
of all finite semigroups in
is not. 相似文献
7.
We show that the zeros of the hypergeometric polynomials
,
, cluster on the loop of the lemniscate
as
. We also state the equations of the curves on which the zeros of
, lie asymptotically as
. Auxiliary results for the asymptotic zero distribution of other functions related to hypergeometric polynomials are proved,
including Jacobi polynomials with varying parameters and associated Legendre functions. Graphical evidence is provided using
Mathematica.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
8.
In this paper, we consider equations of the form
, where
is a function with values in the Hilbert space
, the operator B is symmetric, and the operator A is uniformly positive and self-adjoint in
. The linear operator
generating the C
0-semigroup in the energy space
is associated with this equation. We prove that this semigroup is exponentially stable if the operator B is uniformly positive and the operator A dominates B in the sense of quadratic forms. 相似文献
9.
S. Yu. Orevkov 《Mathematical Notes》2000,68(5-6):588-593
Dehornoy constructed a right invariant order on the braid group B
n uniquely defined by the condition
1{\text{ if }}\beta _0 ,\beta _1$$
" align="middle" border="0">
are words in
. A braid is called strongly positive if
1$$
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for any
. In the present paper it is proved that the braid
is strongly positive if the word
does not contain
. We also provide a geometric proof of the result by Burckel and Laver that the standard generators of a braid group are strongly positive. Finally, we discuss relations between the right invariant order and quasipositivity. 相似文献
10.
Jet Wimp 《Numerical Algorithms》2000,24(1-2):179-193
In this paper we investigate Hankel determinants of the form
, where c
n
(t) is one of a number of polynomials of combinatorial interest. We show how some results due to Radoux may be generalized,
and also show how “stepped up” Hankel determinants of the form
may be evaluated.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
11.
Given a single-input single-output system {A,b,c} with strictly proper transfer function g(s), we derive a Lanczos-based method to construct a tridiagonal state-space model
approximating the “pre-filtered” transfer function f(s)g(s), where f(s) is given in factored form
. We also show how to apply this idea to the Arnoldi process and mention a few other extensions.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
12.
Let Δ(1) be the uniform three direction mesh of the plane whose vertices are integer points of
.Let
(respectively
of degree d=3r (respectively d=3r+1 ) for r odd (respectively even) on the triangulation
, and of degree d=2r (respectively d=2r+1) for r odd (respectively even) on the triangulation
. Using linear combinations of translates of these splines we obtain Lagrange interpolants whose corresponding order of approximation
is optimal.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
13.
V. D. Lyakhovsky 《Theoretical and Mathematical Physics》2006,148(1):968-979
In accordance with the quantum duality principle, the twisted algebra
is equivalent to the quantum group
and has two preferred bases: one inherited from the universal enveloping algebra
and the other generated by coordinate functions of the dual Lie group
. We show howthe transformation
can be explicitly obtained for any simple Lie algebra and a factorable chain
of extended Jordanian twists. In the algebra
, we introduce a natural vector grading
, compatible with the adjoint representation of the algebra. Passing to the dual-group coordinates allows essentially simplifying
the costructure of the deformed Hopf algebra
, considered as a quantum group
. The transformation
can be used to construct new solutions of the twist equations. We construct a parameterized family of extended Jordanian
deformations
and study it in terms of
; we find new realizations of the parabolic twist.
Dedicated to the birthday of my teacher, Yurii Novozhilov
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 148, No. 1, pp. 112–125, July, 2006. 相似文献
14.
A complete parameterization for the m‐channel FIR orthogonal multifilter banks is provided based on the lattice structure of the paraunitary systems. Two forms
of complete factorization of the m‐channel FIR orthogonal multifilter banks for symmetric/antisymmetric scaling functions and multiwavelets with the same symmetric
center
(1 + γ + γ/(m - 1)) for some nonnegative integer γ are obtained. For the case of multiplicity 2 and dilation factor m = 2, the result of the factorization shows that if the scaling function Φ and multiwavelet Ψ are symmetric/antisymmetric
about the same symmetric center γ +
for some nonnegative integer γ, then one of the components of Φ (respectively Ψ) is symmetric and the other is antisymmetric.
Two examples of the construction of symmetric/antisymmetric orthogonal multiwavelets of multiplicity 3 with dilation factor
2 and multiplicity 2 with dilation factor 3 are presented to demonstrate the use of these parameterizations of orthogonal
multifilter banks.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
15.
Dong Zhe 《Czechoslovak Mathematical Journal》2006,56(2):287-298
In this paper we investigate finite rank operators in the Jacobson radical
of Alg(
), where
are nests. Based on the concrete characterizations of rank one operators in Alg(
) and
, we obtain that each finite rank operator in
can be written as a finite sum of rank one operators in
and the weak closure of
equals Alg(
) if and only if at least one of
is continuous. 相似文献
16.
Niels Jakob Laustsen 《K-Theory》2001,23(2):115-127
We prove that the K-groups of the Banach algebra
of bounded, linear operators on the pth James space
, where 1 < p < , are given by
and
. Moreover, for each Banach space
and each non-zero, closed ideal
contained in the ideal of inessential operators, we show that
and
. This enables us to calculate the K-groups of
for each Banach space
which is a direct sum of finitely many James spaces and
-spaces. 相似文献
17.
Let n be a positive integer, let
be complex numbers and let
be a nonsingular n × n complex Toeplitz matrix. We present a superfast algorithm for computing the determinant of T. Superfast means that the arithmetic complexity of our algorithm is
, where N denotes the smallest power of 2 that is larger than or equal to n. We show that det T can be computed from the determinant of a certain coupled Vandermonde matrix. The latter matrix is related to a linearized
rational interpolation problem at roots of unity and we show how its determinant can be calculated by multiplying the pivots
that appear in the superfast interpolation algorithm that we presented in a previous publication.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
18.
Given a unital C*-algebra
and a right C*-module
over
, we consider the problem of finding short smooth curves in the sphere
= {x ∈
: 〈x, x〉 = 1}. Curves in
are measured considering the Finsler metric which consists of the norm of
at each tangent space of
. The initial value problem is solved, for the case when
is a von Neumann algebra and
is selfdual: for any element x
0 ∈
and any tangent vector ν at x
0, there exists a curve γ(t) = e
tZ
(x
0), Z ∈
, Z* = −Z and ∥Z∥ ≤ π, such that γ(0) = x
0 and
(0) = ν, which is minimizing along its path for t ∈ [0, 1]. The existence of such Z is linked to the extension problem of selfadjoint operators. Such minimal curves need not be unique. Also we consider the
boundary value problem: given x
0, x
1 ∈
, find a curve of minimal length which joins them. We give several partial answers to this question. For instance, let us
denote by f
0 the selfadjoint projection I − x
0 ⊗ x
0, if the algebra f
0
f
0 is finite dimensional, then there exists a curve γ joining x
0 and x
1, which is minimizing along its path.
相似文献
19.
In this note, we show that if
is a π-partial character of the π-separable group
is a chain of normal subgroups of G, and H is a Hall π-subgroup of G, then
has a Fong character α
Irr(H) such that for every subgroup
, every irreducible constituent of α
H∩N
is Fong for N. We also show that if
is quasi-primitive, then for every normal subgroup M of G the irreducible constituents of
are Fong for M.
Received: 21 July 2006 Revised: 17 January 2007 相似文献
20.
Let A be a Banach algebra which does not contain any nonzero idempotent element, let γ > 0, and let
. We show that if
then
. We also show, assuming a suitable spectral condition on x, that if
, then
Received: 12 July 2006 Revised: 31 January 2007 相似文献