共查询到20条相似文献,搜索用时 26 毫秒
1.
Dr. John Walsh 《Probability Theory and Related Fields》1970,14(3):169-188
Summary In this paper we treat a time-symmetrical Martin boundary theory for continuous parameter Markov chains. This is done by reversing the time sense of a Markov chainX
t
in such a way as to obtain a dual Markov chain
, and considering the two chains together. Various relations between the Martin exit boundaries
and
of these processes are studied. The exit boundary
of
, is in a sense an entrance boundary forX
t
and vice versa. After a natural identification of certain points in
and
one can topologizeI
in such a way thatboth X
t and
have standard modifications in this space which are right continuous, have left limits, and are strongly Markov.Research supported in part at Stanford University, Stanford, California under AFOSR 0049. 相似文献
2.
D. N. Dudin 《Mathematical Notes》1968,3(1):42-44
For an algebra
of subsets of a set X there is constructed a set
and an algebra of its subsets so that the mapping
is a one-to-one correspondence between
and
and for each additive measure on
the measure
on
defined by the equation
is countably additive.Translated from Matematicheskie Zametki, Vol. 3, No. 1, pp. 71–76, January, 1968.The author wishes to express his deep appreciation to S. V. Fomin, under whose guidance this paper was written. 相似文献
3.
Oswald Riemenschneider 《manuscripta mathematica》1974,14(1):91-99
Let
be a 1-convex holomorphic mapping between complex spaces
resp.S, and let
be the blowingdown factorization of
over S. We prove in part 1 of the present note: The fiber –1(s0) over a point s0S is the Remmert quotient of
if and only if every holomorphic function on
(defined in a neighborhood of the exceptional subvariety of that fiber) can be extended holomorphically to
. This is true, for instance, in the case:
flat, S reduced at s0 and dim
, =const for all sS. In part 2, we use this result to obtain the following: For any Riemann surface R with genus g2 there exists a 2-dimensional normal complex analytic singularity X such that the minimal resolution
of X contains R as exceptional subvariety, and
has a deformation over the unit disc S={|s|<1} which can not be blown down to a deformation of X. 相似文献
4.
We consider the on-line computation of the lattice of maximal antichains of a finite poset
. This on-line computation satisfies what we call the linear extension hypothesis: the new incoming vertex is always maximal in the current subposet of
. In addition to its theoretical interest, this abstraction of the lattice of antichains of a poset has structural properties which give it interesting practical behavior. In particular, the lattice of maximal antichains may be useful for testing distributed computations, for which purpose the lattice of antichains is already widely used. Our on-line algorithm has a run time complexity of
, where |P| is the number of elements of the poset,
, |MA(P)| is the number of maximal antichains of
and (P) is the width of
. This is more efficient than the best off-line algorithms known so far. 相似文献
5.
Wolfgang Henke 《manuscripta mathematica》1976,19(2):165-188
Let M, resp.
, denote Riemannian manifolds of dimensions m>4, resp.
=m+2, and of constant sectional curvatures C, resp.
, with
0 and
is a standard space form, then the foliation L is a (globally) trivial fibre bundle with fibre Sm–1. 相似文献
6.
Edgar R. Lorch 《Integral Equations and Operator Theory》1981,4(3):422-434
The objects studied are the subalgebras of
which contain co. These are isometrically isomorphic to the algebras C(
) where
is a compactification of a discrete denumerable set N . It is shown: 1) If
is metric then there is a projection of norm 1, P: C(
) C(
) with kernel co defined by PF = f o where is a retraction of
onto
=
– N . 2) If
is metric, then the group of homeomorphisms of
is isomorphic to a complete group of permutations of the natural numbers . 3) The group of homeomorphisms of a compact metric space is the homomorphic image of a complete group of permutations of ("complete" means "no outer automorphisms, trivial center"). 相似文献
7.
Josip Globevnik 《Monatshefte für Mathematik》1988,105(1):47-58
We prove the followingTheorem. LetF be a closed subset of the unit circleT which has Lebesgue measure zero. Suppose thatp is a smooth positive function onT. GivenfC(F) which satisfies|f(s)|p(s) (sF) and a neighbourhoodU ofF there is an extension
off in the disc algebra such that
and
. 相似文献
8.
Günter Mayer 《Numerische Mathematik》1985,46(1):69-83
Summary Let
be a real irreduciblen×n interval matrix. Then a necessary and sufficient condition is given for the sequence
of the powers of an interval matrix
to converge to a matrix
which is not the null matrix. In addition a criterion for
is proved to decide whether the limit matrix
satisfies the condition of symmetry
. 相似文献
9.
We discuss purely singular finite-rank perturbations of a self-adjoint operator A in a Hilbert space . The perturbed operators
are defined by the Krein resolvent formula
, Im z 0, where B
z are finite-rank operators such that dom B
z dom A = |0}. For an arbitrary system of orthonormal vectors
satisfying the condition span |
i
} dom A = |0} and an arbitrary collection of real numbers
, we construct an operator
that solves the eigenvalue problem
. We prove the uniqueness of
under the condition that rank B
z = n. 相似文献
10.
Let
be an entire function of finite type with respect to finite order
and let
be a subset of an open cone in a certain n-dimensional subspace
(the smaller
, the sparser
). We assume that this cone contains a ray
0} \right\}$$
" align="middle" border="0">
. It is shown that the radial indicator
of
at any point
may be evaluated in terms of function values at points of the discrete subset
. Moreover, if
tends to zero fast enough as
over
, then this function vanishes identically. To prove these results, a special approximation technique is developed. In the last part of the paper, it is proved that, under certain conditions on
and
, which are close to exact conditions, the function
bounded on
is bounded on the ray. 相似文献
11.
LetT be a contraction acting in a separable Hilbert space
and leaving invariant a nest
of subspaces of
. We answer the question: when doesT have an isometric extension to
which leaves invariant the nest
= {N N :N
;}. 相似文献
12.
Andreas Blass 《Archive for Mathematical Logic》1990,30(1):1-11
We prove several theorems about the cardinal
associated with groupwise density. With respect to a natural ordering of families of nond-ecreasing maps from to, all families of size
are below all unbounded families. With respect to a natural ordering of filters on, all filters generated by
sets are below all non-feeble filters. If
then
and
. (The definitions of these cardinals are recalled in the introduction.) Finally, some consequences deduced from
by Laflamme are shown to be equivalent to
. 相似文献
13.
William M. McGovern 《Inventiones Mathematicae》1989,97(1):209-217
Summary LetG be a complex semisimple algebraic group with Lie algebra
. Let
be a nilpotentG-orbit,
its ring of regular functions. We derive a formula for
as aG-module and prove some partial results on
a cover of
. We then relate this formula to various existing multiplicity formulas forK-types in Harish-Chandra bimodules ofG.Supported by National Science Foundation Grant DMS-8505550 相似文献
14.
Summary A second order error bound is obtained for approximating h d
by h d
, where
is a convolution of measures andQ a compound Poisson measure on a measurable abelian group, and the functionh is not necessarily bounded. This error bound is more refined than the usual total variation bound in the sense that it contains the functionh. The method used is inspired by Stein's method and hinges on bounding Radon-Nikodym derivatives related to
. The approximation theorem is then applied to obtain a large deviation result on groups, which in turn is applied to multivariate Poisson approximation.Research of the second author was supported by Schweizerischer Nationalfonds 相似文献
15.
Al Dababseh Avni Faez 《Ukrainian Mathematical Journal》2001,53(1):129-133
We prove that if G is a nonsingle-element n-ary finite group that belongs to a -closed formation
, then
, where
is the intersection of all maximal -closed subformations of the -closed formation of n-ary groups
. 相似文献
16.
J. Hartmann 《Transformation Groups》2001,6(2):157-164
Let :GGl(n,
) be a representation of a finite groupG over a field
such that the ring of invariants
is a polynomial algebra
. It is known that in the nonmodular case (i.e., when the order of the group is not divisible by the characteristic of
), the invariants ofG acting on the tensor product
of a polynomial and an exterior algebra are given by
,d denoting the exterior derivative. We show that in the modular case, the ring of invariants in
is of this form if and only if
is a polynomial algebra and all pseudoreflections in (G) are diagonalizable. 相似文献
17.
Aluthge transforms of operators 总被引:7,自引:0,他引:7
Associated with every operatorT on Hilbert space is its Aluthge transform
(defined below). In this note we study various connections betweenT and
, including relations between various spectra, numerical ranges, and lattices of invariant subspaces. In particular, we show that if
has a nontrivial invariant subspace, then so doesT, and we give various applications of our results. 相似文献
18.
Paul H. Schuette 《Journal of Theoretical Probability》1994,7(1):3-45
Given a sequence of independent, but not necessarily identically distributed random variables,Y
i
, letS
k
denote thekth partial sum. Define a function
by taking
to be the piecewise linear interpolant of the points (k, S
k
), evaluated att, whereS
0=0, andk=0, 1, 2,... Fort[0, 1], let
. The
are called trajectories. With regularity and moment conditions on theY
i
, a large deviation principle is proved for the
. 相似文献
19.
P. Pych-Taberska 《分析论及其应用》1994,10(4):25-36
For measurable functions f of two real variables there are considered the Boolean sums
of parametric extensions of certain univariate Durmeyer-type operators
and
. The weighted mixed moduli of continuity of
are estimated and the degrees of approximation of f by
in some weighted norms are investigated. 相似文献
20.
The class
of orthomodular lattices which have only finitely many commutators is investigated. The following theorems are proved:
contains the block-finite orthomodular lattices. Every irreducible element of
is simple. Every element of
is a direct product of a Boolean algebra and finitely many simple orthomodular lattices. The irreducible elements of
which are modular, or are M-symmetric with at least one atom, have height two or less. 相似文献