共查询到20条相似文献,搜索用时 46 毫秒
1.
Jin-yen Tai 《Southeast Asian Bulletin of Mathematics》2000,24(2):305-312
A result of Neisendorfer says that, for every connected p-complete finite complex Y with 2Y torsion, the p-completion of PK(/p, 1) (Ym) and Y are of the same homotopy type for any positive integer m. Here, PK(/p, 1)(Ym) is the periodization functor of Bousfield and Ym) is the m-connective cover of the space Y. The proof of this result depends on Millers Theorem of Sullivans conjecture. The aim in this paper is to study the phenomenon without the use of Millers Theorem.AMS Subject Classification (2000): 55P60 相似文献
2.
F. A. Sukochev 《Integral Equations and Operator Theory》1996,26(1):102-124
If is a surjective isometry of the separable symmetric operator spaceE(M, ) associated with the approximately finite-dimensional semifinite factorM and if ·
E(M,)
is not proportional to ·
L
2, then there exist a unitary operatorUM and a Jordan automorphismJ ofM such that(x)=UJ(x) for allxME(M, ). We characterize also surjective isometries of vector-valued symmetric spacesF((0, 1), E(M, )).Research supported by the Australian Research Council 相似文献
3.
We consider a selfadjoint and smooth enough operator-valued functionL() on the segment [a, b]. LetL(a)0,L(b)0, and there exist two positive numbers and such that the inequality |(L()f, f)|< ([a, b] f=1) implies the inequality (L'()f, f)>. Then the functionL() admits a factorizationL()=M()(I-Z) whereM() is a continuous and invertible on [a, b] operator-valued function, and operatorZ is similar to a selfadjoint one. This result was obtained in the first part of the present paper [10] under a stronge conditionL()0 ( [a,b]). For analytic functionL() the result of this paper was obtained in [13]. 相似文献
4.
If (, M)is a factorization system on a category C, we define new classes of maps as follows: a map f:AB is in if each of its pullbacks lies in (that is, if it is stably in ), and is in M
* if some pullback of it along an effective descent map lies in M(that is, if it is locally in M). We find necessary and sufficient conditions for (, M
*) to be another factorization system, and show that a number of interesting factorization systems arise in this way. We further make the connexion with Galois theory, where M
*is the class of coverings; and include self-contained modern accounts of factorization systems, descent theory, and Galois theory. 相似文献
5.
Anna Maria Pastore 《Geometriae Dedicata》1989,30(2):235-246
We study homogeneous Riemannian structures belonging to the class 13 of the classification given by Tricerri and Vanhecke. The main result is the following: a connected, simply connected Riemannian manifoldM admits a homogeneous structureT of type 13,T3, if and only ifM is isometric to a hyperbolic space
n
.This work was partially supported by M.P.I. 相似文献
6.
ONBAHADURASYMPTOTICEFFICIENCYINASEMIPARAMETRICREGRESSIONMODELLIANGHUA(梁华);CHENGPING(成平)(InstituteofSystemsScience,theChineseA... 相似文献
7.
Tassilo Küpper 《Numerische Mathematik》1976,25(2):201-214
Summary For differential operatorsM of second order (as defined in (1.1)) we describe a method to prove Range-Domain implications—Mu–u and an algorithm to construct these functions , , , . This method has been especially developed for application to non-inverse-positive differential operators. For example, for non-negativea
2 and for given functions = we require =C
0[0, 1] C
2([0, 1]–T) whereT is some finite set), (M) (t)(t), (t[0, 1]–T) and certain additional conditions for eachtT. Such Range-Domain implications can be used to obtain a numerical error estimation for the solution of a boundary value problemMu=r; further, we use them to guarantee the existence of a solution of nonlinear boundary value problems between the bounds- and . 相似文献
8.
M. Akkouchi 《Periodica Mathematica Hungarica》1994,29(2):127-136
Let be a Guelfand measure (cf. [A, B]) on a locally compact groupG DenoteL
1
(G)=*L
1(G)* the commutative Banach algebra associated to . We show thatL
1
(G) is semi-simple and give a characterization of the closed ideals ofL
1
(G). Using the -spherical Fourier transform, we characterize all linear bounded operators inL
1
(G) which are invariants by -translations (i.e. such that
1((
x
f)
)=(
x
((f))
for eachxG andfL
1
(G); where
x
f(y)=f(xy); x,y G). WhenG is compact, we study the algebraL
1
(G) and obtain results analogous to ones obtained for the commutative case: we show thatL
1
(G) is regular, all closed sets of its Guelfand spectrum are sets of synthesis and establish theorems of harmonic synthesis for functions inL
p
(G) (p=1,2 or +). 相似文献
9.
U. M. Swamy G. C. Rao R. V. G. Ravi Kumar Ch. Pragati 《Southeast Asian Bulletin of Mathematics》2003,26(3):509-516
In this paper, it is proved that the Boolean centre of a semigroup S with sufficiently many commuting idempotents is isomorphic to the inverse limit of the directed family of Birkhoff centres (or Boolean centres) of a class of bounded semigroups. The Birkhoff centre is defined for any poset and proved that it is a relatively complemented distributive lattice whenever it is nonempty. It is observed that for a semilattice S, the Birkhoff centres as a semigroup and as a poset coincide. Also it is observed that for a Lattice (L, , ), the Birkhoff centres of the semilattices (L, ) and (L, ) coincide with the Birkhoff centre of L. Finally it is proved that for a lattice (L, , ), the Boolean centres of the semilattices (L, ) and (L, ) coincide with the Boolean centre of L.AMS Subject classification (1991): 06A12, 20M15 相似文献
10.
V. F. Ignatenko 《Journal of Mathematical Sciences》1994,72(4):3178-3181
Let G be an infinite group generated by oblique reflections with respect to hyperplanes in the real space E
m
; let II
, II
, II
be the linear spans of dimensions , , of three G-orbits of directions of symmetry, where II
II
II
=0 and dim(II
+ II
+ II
) < + +. Some singularities of the equation of an algebraic hypersurface invariant with respect to G are established.
Translated from Ukrainskii Geometricheskii Sbornik, No. 35, pp. 34–38, 1992. 相似文献
11.
Jan -Cees van der Meer Richard Cushman 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1986,37(3):402-424
Summary Consider a Hamiltonian system (H, 2n
,). LetM be a symplectic submanifold of (2n
,). The system (H, 2n
,) constrained toM is (HM, M, M). In this paper we give an algorithm which normalizes the system on 2n
in such a way that restricted toM we have normalized the constrained system. This procedure is then applied to perturbed Kepler systems such as the lunar problem and the main problem of artificial satellite theory.
Zusammenfassung Wir betrachten ein Hamiltonisches System (H, 2n ,). SeiMein symplectisches Submanifold von (2n ,). Das System (H, 2n ,), aufM beschränkt, ist (HM,M,M). In der vorliegenden Arbeit wird ein Algorithmus vorgeschlagen, der dieses System so auf 2n normalisiert, daß das aufM beschränkte System auch normalisiert ist. Dieser Algorithmus wird dann auf gestörte Keplersysteme, wie z. B. das Hill-sche Mondproblem und das Hauptproblem der Theorie der künstlichen Satelliten, angewendet.相似文献
12.
Let a selfadjoint operator-valued functionL() be given on the interval [a,b] such thatL(a)0,L(b)0,L()0 (ab), andL() has a certain smoothness (for instance, it satisfies Hölder's condition). It turns out that the spectral theory of the operator-valued functionL() can be reduced to the spectral theory of one operatorZ, the spectrum of which lies on (a, b) and which is similar to a selfadjoint operator. In particular, the factorization takes place:L()=M()(I–Z), where the operator-valued functionM() is invertible on [a, b]. Earlier similar results were known only for analytic operator-valued functions. The authors had to use new methods for the proof of the described theorem. The key moment is the decomposition ofL
–1() into the sume of its principal and regular parts. 相似文献
13.
Stefan Veldsman 《Monatshefte für Mathematik》1996,122(3):227-238
The relationship between the radical of a ringR and a structural matrix ring overR has been determined for some radicals. We continue these investigations, amongst others, determining exactly which radicals have the property (M(,R))=M(
s
,(R))+M(
a
,+(R))for any structural matrix ringM(,R) and finding (M(,R)) for any hereditary subidempotent radical . 相似文献
14.
Hans-Joachim Baues 《Compositio Mathematica》1998,110(1):50-64
For manifolds M,M of the form S2 e4 e6 we compute the homomorphisms H*M H*M between homology groups which are realizable by a map F: M M. 相似文献
15.
J. Rätz 《Aequationes Mathematicae》1976,14(1-2):67-71
LetK be a ring with an identity 1 0 andM, L two unitaryK-modules. Then, for any additive mappingf:M L, the setH
f
:={ K f(x)=f(x) for allx M} forms a subring ofK, the homogeneity ring off. It is shown that, forM {0},L {0} and any subringS ofK for whichM is a freeS-module, there exists an additive mappingf:ML such thatH
f
=S. This result is applied to the four Cauchy functional equations, and it leads also to an answer to the question as to whether it is possible to introduce onM a multiplication ·:M × M M makingM into a ring but not into aK-algebra. 相似文献
16.
We fix a rich probability space (,F,P). Let (H,) be a separable Hilbert space and let be the canonical cylindrical Gaussian measure on H. Given any abstract Wiener space (H,B,) over H, and for every Hilbert–Schmidt operator T: HBH which is (|{}|,)-continuous, where |{}| stands for the (Gross-measurable) norm on B, we construct an Ornstein–Uhlenbeck process : (,F,P)×[0,1](B,|{}|) as a pathwise solution of the following infinite-dimensional Langevin equation d
t
=db
t
+T(
t
)dt with the initial data 0=0, where b is a B-valued Brownian motion based on the abstract Wiener space (H,B,). The richness of the probability space (,F,P) then implies the following consequences: the probability space is independent of the abstract Wiener space (H,B,) (in the sense that (,F,P) does not depend on the choice of the Gross-measurable norm |{}|) and the space C
B
consisting of all continuous B-valued functions on [0,1] is identical with the set of all paths of . Finally, we present a way to obtain pathwise continuous solutions :d
t
=
db
t
+
t
dt
with initial data 0=0, where ,R,0 and 0<. 相似文献
17.
Naum Krupnik 《Integral Equations and Operator Theory》1991,14(5):760-763
It is proved that the operator of singular integration along a bounded rectifiable curve is self-adjoint in the weighted spaceL
2(, ) if and only if is a circle and (t)=const. 相似文献
18.
Rodney Nillsen 《Monatshefte für Mathematik》1992,114(1):77-82
A special case of the main result proved in this paper is the following. IfG is a locally compact, -compact, non-compact connected abelian group, thenL
2
(G)={f–*f:fL
2
(G), L
1
(G), 0 and
G
=1}. In this case, any topologically invariant linear form onL
2
(G) is 0. 相似文献
19.
Summary Let (
N
) be a sequence of random variables with values in a topological space which satisfy the large deviation principle. For eachM and eachN, let
M, N
denote the empirical measure associated withM independent copies of
N
. As a main result, we show that (
M, N
) also satisfies the large deviation principle asM,N. We derive several representations of the associated rate function. These results are then applied to empirical measure processes
M, N
(t) =M
–1
i=1
N
i
N
(t) 0tT, where (
1
N
,...,
M
N
(t)) is a system of weakly interacting diffusions with noise intensity 1/N. This is a continuation of our previous work on the McKean-Vlasov limit and related hierarchical models ([4], [5]).Research partially supported by a Natural Science and Engineering Research Council of Canada operating grant 相似文献
20.
N. K. Smolentsev 《Siberian Mathematical Journal》2001,42(6):1165-1169
Let A
M
be the space of all almost Kahlerian smooth metrics on a symplectic manifold M
2n
, such that the fundamental form of each metric coincides with . It is well known that A
M
is a retractor of the space M of all smooth metrics on M. We show that M is a smooth trivial bundle over A
M
. A similar fact holds also in the case of a contact manifold. 相似文献