共查询到20条相似文献,搜索用时 31 毫秒
1.
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
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.
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
4.
Dr. Martin Funk 《Monatshefte für Mathematik》1982,93(1):1-14
Let
be a Minkowski-(incidence-)plane and let
be the group of free projectivities of
, i. e. the subgroup generated by pairs of proper perspectivities with identical centers. Our theorem then asserts that
is miquelian if
satisfies condition (P
5), i. e. every free projectivity with 5 fixed points is the identity. But first a lemma is shown, which holds in Möbius- and Laguerre-(incidence-)planes too: if
fulfills (P
5), then every affine derivation of
is pappian. 相似文献
5.
Luise Unger 《manuscripta mathematica》1986,57(1):1-31
Let
be the path algebra for some representation-infinite quiver
over some field k. There exists a bound
such that mI is faithful for all indecomposable injective
-modules I and all
, and such that there exists an indecomposable injective
-module J satisfying that
J is not faithful, denotes the Auslander-Reiten-translation. Let m() be the maximum of the
taken over all possible orientations of the underlying graph . In this article we determine the bounds m() for representation-infinite quivers
for which is a tree. 相似文献
6.
Let CP
(R) be the group of compactly supported homeomorphisms ofR=
which are piecewise
with a parabolic defect at each breakpoint. An acyclic extension
相似文献
7.
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
8.
Roman Drnovšek 《Integral Equations and Operator Theory》2001,39(3):253-266
Let
be a collection of bounded operators on a Banach spaceX of dimension at least two. We say that
is finitely quasinilpotent at a vectorx
0X whenever for any finite subset
of
the joint spectral radius of
atx
0 is equal 0. If such collection
contains a non-zero compact operator, then
and its commutant
have a common non-trivial invariant, subspace. If in addition,
is a collection of positive operators on a Banach lattice, then
has a common non-trivial closed ideal. This result and a recent remarkable theorem of Turovskii imply the following extension of the famous result of de Pagter to semigroups. Let
be a multiplicative semigroup of quasinilpotent compact positive operators on a Banach lattice of dimension at least two. Then
has a common non-trivial invariant closed ideal.This work was supported by the Research Ministry of Slovenia. 相似文献
9.
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
10.
Siegfried Bosch 《manuscripta mathematica》1977,20(1):1-27
Let X be a rigid analytic space and assume that X admits a formal covering inducing on X the structure of a formal scheme. Then, dependent on such a formal structure one associates to X the reduction
which is a scheme of locally finite type over the residue field corresponding to the ground field in question. In this paper the cohomology groups of X are compared with the cohomology groups of
and a dimension formula is proved. As a consequence it is shown that X is affinoid
is affine and that an analytic map :XY which is compatible with the formal structures on X and Y is finite if and only if
is finite. 相似文献
11.
El-B. Yallaoui 《Periodica Mathematica Hungarica》1991,23(2):109-120
Let X be an abstract set and L a lattice of subsets of X. To each lattice regular measure µ, we associate two induced measures
and
on suitable lattices of the Wallman space IR(L) and another measure µ on the spaceIR(L). We will investigate the reflection of smoothness properties of p onto
,
and µ; and try to set some new criterion for repleteness and measure repleteness. 相似文献
12.
Ignacio Bajo 《Monatshefte für Mathematik》1994,118(1-2):1-6
Let
be a complex Lie algebra,
its underlying real Lie algebra,
a real form of
and ·, · the euclidean product induced by the real part of an hermitian inner product on
. Let aut
be the Lie algebra of skew-symmetric derivations of
. We give necessary and sufficient conditions to ensure that aut
is composed of skew-hermitian derivations. As an application, we study holomorphy in large subgroups of isometries of Lie groups. 相似文献
13.
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
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.
S. N. Chernikov 《Mathematical Notes》1968,4(1):543-545
It is proved that if a periodic group
has an extremal normal divisor
, determining a complete abelian factor group
, then the center of the group
contains a complete abelian subgroup
, satisfying the relation
and intersecting
on a finite subgroup. It is also established with the aid of this proposition that every periodic group of automorphisms of an extremal group
is a finite extension of a contained in it subgroup of inner automorphisms of the group
.Translated from Matematicheskie Zametki, Vol. 4, No. 1, pp. 91–96, July, 1968. 相似文献
16.
Let
and
the foliations by the null geodesics of some lorentzian metricg on the torus
. We analyse how geodesic completeness properties ofg are related to the dynamics of
and
. 相似文献
17.
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
18.
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
19.
Dieter Kuhn 《Numerische Mathematik》1993,65(1):435-444
Summary Total Least Squares (TLS) is an estimation method for the solutiona of the linear system
when both data sets
and
are subject to error. The TLS-method minimizes the functional
with weighting parameter . In this paper the TLS-functional is analyzed by the technique of Lagrangian multipliers. The main part of the work deals with the case when the estimatea is restricted by an inequality of the formD
a–b0, D a diagonal matrix. It is shown that there exists a unique estimatea if the weighting parameter is chosen sufficiently large. 相似文献
20.
Spectral pictures of Aluthge transforms of operators 总被引:4,自引:0,他引:4
In this paper we continue our study, begun in [12], of the relationships between an arbitrary operatorT on Hilbert space and its Aluthge transform
. In particular, we show that in most cases the spectral picture ofT coincides with that of
, and we obtain some interesting connections betweenT and
as a consequence. 相似文献
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