共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
Florence Merlevède Magda Peligrad Sergey Utev 《Journal of Theoretical Probability》1997,10(3):681-693
In this paper we study the behavior of sums of a linear process
associated to a strictly stationary sequence
with values in a real separable Hilbert space and
are linear operators from H to H. One of the results is that
satisfies the CLT provided
are i.i.d. centered having finite second moments and
. We shall provide an example which shows that the condition on the operators is essentially sharp. Extensions of this result are given for sequences of weak dependent random variables
under minimal conditions. 相似文献
3.
Let
be a C*-algebra and X a Hilbert C*
-module. If
is a projection, let
be the p-sphere of X. For φ a state of
with support p in
and
consider the modular vector state φx of
given by
The spheres
provide fibrations
and
These fibrations enable us to examine the homotopy type of the sets of modular vector states, and relate it to the homotopy type of unitary groups and spaces of projections. We regard modular vector states as generalizations of pure states to the context of Hilbert C*-modules, and the above fibrations as generalizations of the projective fibration of a Hilbert space. 相似文献
4.
Let C be a set of objects in a triangulated compactly generated category
We denote by
the smallest suspended subcategory closed under coproducts which contains C (the smallest cosuspended subcategory closed under products which contains
C). We prove that if C is a set of compacts objects then
is a t-structure in
where TC
I is the dual of C with respect to an injective cogenerator
I in the category Mod
C. Moreover, we show that:
C is a tilting set if and only if
And, this is equivalent to TCI is a cotilting object in
Received: 28 March 2003 相似文献
5.
The C*-algebra
generated by the Bergman and anti-Bergman projections and by the operators of multiplication by piecewise continuous functions on the Lebesgue space L2(Π) over the upper half-plane is studied. Making use of a local principle, limit operators techniques, and the Plamenevsky results on two-dimensional singular integral operators with coefficients admitting homogeneous discontinuities we reduce the study to simpler C*-algebras associated with points
and pairs
We construct a symbol calculus for unital C*-algebras generated by n orthogonal projections sum of which equals the unit and by m one-dimensional orthogonal projections. Such algebras are models of local algebras at points z ∈∂Π being the discontinuity points of coefficients. A symbol calculus for the C*- algebra
and a Fredholm criterion for the operators
are obtained. Finally, a C*-algebra isomorphism between the quotient algebra
where
is the ideal of compact operators, and its analogue
for the unit disk is constructed. 相似文献
6.
7.
Let X be a rearrangement-invariant Banach function space
over a complete probability space
, and denote by
the Hardy space consisting of all martingales
such that
. We prove that
implies
for any filtration
if and only if Doobs inequality holds in
X, where
denotes the martingale defined by
, n = 0, 1, 2, ..., and
a.s.Received: 1 August 2000 相似文献
8.
Summary.
Let
be a field of real or complex numbers and
denote the set of nonzero elements of
.
Let
be an abelian group. In this paper, we solve the functional equation
f
1
(x +
y) +
f
2
(x -
y) =
f
3
(x) +
f
4
(y) +
g(xy)
by modifying the domain of the unknown functions
f
3,
f
4, and
g from
to
and using a method different from [3]. Using this result,
we determine all functions
f
defined on
and taking values on
such that the difference
f(x + y) + f
(x -
y) - 2
f(x) - 2
f(y)
depends only on the product
xy for all
x and
y in
相似文献
9.
We consider the three-dimensional Schrödinger operators
and
where
, A is a magnetic potential generating a constant magnetic
field of strength
, and
where
decays fast enough at infinity. Then, A. Pushnitskis representation of the spectral shift function (SSF)
for the pair of operators
is well defined for energies
We study the behaviour of the associated representative of the equivalence class
determined by the SSF, in a neighbourhood of the Landau levels
Reducing our analysis to the study of the eigenvalue asymptotics for a family of
compact operators of Toeplitz type, we establish a relation between the type of the
singularities of the SSF at the Landau levels and the decay rate of V at infinity.
Communicated by Bernard HelfferSubmitted 23/09/03, accepted 15/01/04 相似文献
10.
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
must be unbounded, provided
, in
and for every bounded subset I, f(t, z) is bounded in E × I.(B) Every bounded solution for
, in
, must be constant, provided
in
and for every bounded subset I,
is bounded in
. 相似文献
11.
We compare the two recently introduced semidirect product operations
*r and
*rr within the lattice of e-varieties of locally inverse
semigroups. For each e-variety
which
contains all rectangular bands and is properly contained in the e-variety of all completely
simple semigroups, the inclusions
are proved where
is the e-variety of all semilattices and
the variety of all abelian
groups of exponent dividing q where q is any
integer greater than one. Some consequences for the class of finite locally inverse semigroups are also obtained. 相似文献
12.
Sergio Albeverio Saidakhmat N. Lakaev Zahriddin I. Muminov 《Annales Henri Poincare》2004,5(4):743-772
The Hamiltonian of a system of three quantum mechanical particles moving
on the three-dimensional lattice
and interacting via zero-range attractive
potentials is considered. For the two-particle energy operator h(k), with
the two-particle quasi-momentum, the existence of a unique positive eigenvalue
below the bottom of the continuous spectrum of h(k) for k 0 is proven,
provided that h(0) has a zero energy resonance. The location of the essential and
discrete spectra of the three-particle discrete Schrödinger operator H(K),
being the three-particle quasi-momentum, is studied. The existence of infinitely
many eigenvalues of H(0) is proven. It is found that for the number N(0, z) of
eigenvalues of H(0) lying below
the following limit exists
with
Moreover, for all sufficiently small nonzero values of the three-particle
quasi-momentum K the finiteness of the number
of eigenvalues of H(K)
below the essential spectrum is established and the asymptotics for the number
N(K, 0) of eigenvalues lying below zero is given.
Communicated by Gian Michele GrafSubmitted 19/11/03, accepted 08/03/04 相似文献
13.
14.
A class of bounded operators on Sobolev spaces 总被引:2,自引:0,他引:2
We describe a class of nonlinear operators which are bounded on the
Sobolev spaces
, for
and 1 < p <
. As a corollary, we prove that the Hardy-Littlewood maximal operator is bounded on
, for
and 1 < p <
; this extends the result of J. Kinnunen [7], valid for s = 1.
Received: 5 December 2000 相似文献
15.
For suitable positive integers n and k let m(n, k) denote the maximum number of edges in a graph of order n which has a unique k-factor. In 1964, Hetyei and in 1984, Hendry proved
for even n and
, respectively. Recently, Johann confirmed the following conjectures of Hendry:
for
and kn even and
for n = 2kq, where q is a positive integer. In this paper we prove
for
and kn even, and we determine m(n, 3). 相似文献
17.
Summary.
In this paper we determine all iseomorphic pairs (isomorphic
pairs with monotonic, thus continuous isomorphisms) of
continuous, strictly increasing, linearly homogeneous functions defined on
cartesian squares
I
2 and
J
2 of
intervals of positive numbers or on their restrictions
or
and
or
We prove that, if the iseomorphy is nontrivial, then each
homogeneous function is a (weighted) geometric or power mean or a
joint pair of such means.
In functional equations terminology this means that all nontrivial
continuous strictly increasing linearly homogeneous solutions
G, H
(with the continuous strictly monotonic
F also unknown) of the
equation
on D
< or
D
>
are weighted geometric or power means, while on
I
2
they are joint pairs of weighted geometric means or of weighted
power means. 相似文献
18.
Estimates of Marcinkiewicz Integrals with Bounded Homogeneous Kernels of Degree Zero 总被引:2,自引:0,他引:2
Under the cancellation property and a certain Dini-type condition
on kernels, we prove that Marcinkiewicz integrals with kernels which are homogeneous
functions of degree zero, are bounded from
to
,
from
to
, and from
to
for
. 相似文献
19.
We prove a Lie-Trotter product formula for the Ornstein--Uhlenbeck
semigroup associated with the stochastic linear Cauchy problem
Here A is the generator of a
C0-semigroup
on a separable real Banach space E and
is an E-valued Brownian motion. 相似文献
20.
Stefan Gille 《Archiv der Mathematik》2007,88(4):333-343
Let
be a closed subscheme of the noetherian scheme X. We show that if X has a dualizing complex
then there exists a dualizing complex
of Z such that there is an isomorphism of coherent Witt groups
for all
.
Received: 3 March 2006 相似文献