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1.
This article was processed by the author using the LaTEX style filepljourlm from Springer-Verlag.  相似文献   

2.
Let T X be the full transformation semigroup on a set X,
TE*(X)={a ? TX:"x,y ? X, (x,y) ? E? (xa,ya) ? E}T_{E^*}(X)=\{\alpha\in T_X:\forall x,y\in X, (x,y)\in E\Leftrightarrow (x\alpha,y\alpha)\in E\}  相似文献   

3.
On each compact Riemann surface Σ of genusp≥1, we have the Bergman metric obtained by pulling back the flat metric on its Jacobian via the Albanese map. Taking theL 2-product of holomorphic quadratic differentials w.r.t. this metric induces a Riemannian metric on the Teichmüller spaceT p that is invariant under the action of the modular group. We investigate geometric properties of this metric as an alternative to the usually employed Weil-Petersson metric. This article was processed by the author using the LATEX style filecljour1 from Springer-Verlag.  相似文献   

4.
The problem under consideration is the following: Let S: E′ → Lq, T: E′ → Lp, 0 < q ≦ 2, 0 < p ≦ 2, be operators, ‖Sa‖ ≦ ‖Ta‖, such that, T generates a stable measure on E, i.e., exp (-‖Tap), a ? E′, is the characteristic function of a RADON measure on E. Does this imply, that exp (-‖Saq), a ? E′, is the characteristic function of a RADON measure, too? In general this is not true provided q or p less than 2. A BANACH space is said to be of (q,p)-cotype if the answer to the above question is “yes”. We establish several properties of this classification and obtain as an application the well-known classes due to MOUCHTARI, TIEN, WERON and MANDREKAR, WERON, Finally we apply our results to so-called S-spaces.  相似文献   

5.
This article was processed by the author using the LATEX stule filepljourlm from Springer-Verlag.  相似文献   

6.
Let T X denote the full transformation semigroup on a set X. For an equivalence E on X, let $T_{E^*}(X)=\{\alpha\in T_X:\forall x,y\in X,(x,y)\in E\Leftrightarrow(x\alpha,y\alpha)\in E\}.$ Then $T_{E^{*}}(X)Let T X denote the full transformation semigroup on a set X. For an equivalence E on X, let
TE*(X)={a ? TX:"x,y ? X,(x,y) ? E?(xa,ya) ? E}.T_{E^*}(X)=\{\alpha\in T_X:\forall x,y\in X,(x,y)\in E\Leftrightarrow(x\alpha,y\alpha)\in E\}.  相似文献   

7.
Riassunto Si definisce e si studia una nozione di distanza nello spazio proiettivo q aternionaleT n Q , la quale si riduce nell'infinitesimo alla meirica riemanniana del modello metrico reale diT n Q assegnato daMartinelli, e subordina le nozioni di distanza diCayley-Klein e diFubini-Study negli spazi proiettivi reale e complessoT n R ,T n C subordinati aT n Q . A M. Enrico Bompiani nel suo giubileo scientifico Lavoro eseguito nell'ambito del Gruppo di ricerca n. 37 del C. N. R.  相似文献   

8.
In this paper we use generalized Fourier-Hermite functionals to obtain a complete orthonormal set in L 2(C a,b [0,T]) where C a,b [0,T] is a very general function space. We then proceed to give a necessary and sufficient condition that a functional F in L 2(C a,b [0,T]) has an integral transform ℱ γ,β F also belonging to L 2(C a,b [0,T]).  相似文献   

9.
We classify the homogeneous spacesX for which there is aT linearised ample line bundleL onX such thatX T ss(L)=XT s(L).  相似文献   

10.
Summary We study a generalized equivariantK-theory introduced by M. Karoubi. We prove, that it is anRO (G, U)-graded cohomology-theory and that the associated Tate spectrum is rational whenG is finite. This implies that for finite groups, the Atiyah-Segal Real equivariantK-theories have rational Tate theory. This article was processed by the author using the LATEX style filecljour1 from Springer-Verlag  相似文献   

11.
The purpose of this paper is to give an elementary proof of Griffiths' and Harris' normal form lemma [4, p.385]. The author thanks Gerd Fischer for his encouragement and support This article was processed by the author using the LATEX style filecljour1 from Springer-Verlag.  相似文献   

12.
We propose a definition of Gorenstein Differential Graded Algebra. In order to give examples, we introduce the technical notion of Gorenstein morphism. This enables us to prove the following: Theorem:Let A be a noetherian local commutative ring, let L be a bounded complex of finitely generated projective A-modules which is not homotopy equivalent to zero, and let ɛ=Hom A (L, L)be the endomorphism Differential Graded Algebra of L. Then ɛ is a Gorenstein Differential Graded Algebra if and only if A is a Gorenstein ring. Theorem:Let A be a noetherian local commutative ring with a sequence of elements a=(a 1,…,a n )in the maximal ideal, and let K(a)be the Koszul complex of a.Then K(a)is a Gorenstein Differential Graded Algebra if and only if A is a Gorenstein ring. Theorem:Let A be a noetherian local commutative ring containing a field k, and let X be a simply connected topological space with dim k H*(X;k)<∞,which has poincaré duality over k. Let C*(X;A)be the singular cochain Differential Graded Algebra of X with coefficients in A. Then C*(X; A)is a Gorenstein Differential Graded Algebra if and only if A is a Gorenstein ring. The second of these theorems is a generalization of a result by Avramov and Golod from [4].  相似文献   

13.
Summary We study the spectrum of the Laplacian acting on 1-forms for a surface of revolution diffeomorphic toS 2 and obtain, for theS 1 invariant spectrum, a trace formula for the eigenvalues of its Green’s operator. The trace formula is used to “hear” negative curvature for some metrics and to prove the existence of metrics onS 2 with rather unusual spectral characteristics. This article was processed by the author using the LATEX style file from Springer-Verlag.  相似文献   

14.
The Lorentz-Zygmund spaces, introduced by C. Bennett and K. Rudnick in [BR], are generalized by taking the exterior norm in arbitrary rearrangement invariant spaceE instead of onlyL r-spaces. On the spacesL p,α,E thus obtained, we study all operatorsT of two weak types (a, b) and (p, q) with 1≤a<p≤∞, 1≤b<q≤∞, and prove thatT:L p,α,EL q,α−1,E. Moreover, for any set of parametersp, q, α, E, we construct the smallest possible spaceB q,α,E such thatT:L p,α,EB q,α,E and the largest possible spaceA p,α,E such thatT:A p,α,EL q,α−1,E. For spaces of all three types, we find their fundamental functions and Boyd indices, state various embeddings, equivalences and other properties. The research was supported by the Center of Scientific Absorption of the Ministry of Absorption of the State of Israel.  相似文献   

15.
LetE be a real Banach space andL(E) the family of all nonempty compact starshaped subsets ofE. Under the Hausdorff distance,L(E) is a complete metric space. The elements of the complement of a first Baire category subset ofL(E) are called typical elements ofL(E). ForXL(E) we denote by the metrical projection ontoX, i.e. the mapping which associates to eachaE the set of all points inX closest toa. In this note we prove that, ifE is strictly convex and separable with dimE2, then for a typicalXL(E) the map is not single valued at a dense set of points. Moreover, we show that a typical element ofL(E) has kernel consisting of one point and set of directions dense in the unit sphere ofE.  相似文献   

16.
We give an estimate for the spectrum of the averaging operator T1(Γ, 1) over the radius 1 for the finite (q+1)-homogeneous quotient graph Γ/X, where X is an infinite (q+1)-homogeneous tree associated with the free group G over a finite set of generators S={x1 ..., xp} (2p=q+1), and Γ, a subgroup of finite index in G. T1(Γ, 1) is defined on the subspace L2(Γ/G, 1) ⊖ Eex, where Eex is the subspace of eigenfunctions of T1(Γ, 1) with eigenvalue λ such that |λ|=q+1. We present a construction of some finite homogeneous graphs such that the spectrum of their adjacency matrices can be calculated explicitly. Bibliography: 11 titles. Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 205, 1993, pp. 92–109. Translated by A. M. Nikitin.  相似文献   

17.
We show that for each positive integerk there is ak×k matrixB with ±1 entries such that puttingE to be the span of the rows of thek×2k matrix [√kI k,B], thenE,E is a Kashin splitting: TheL 1 2k and theL 2 2k are universally equivalent on bothE andE . Moreover, the probability that a random ±1 matrix satisfies the above is exponentially close to 1. Supported by the Israel Science Foundation.  相似文献   

18.
Basic facts for Gabor frame {Eu(m)bTu(n)ag}m,n∈p on local field are investigated. Accurately, that the canonical dual of frame {Eu(m)bTu(n)ag}m,n∈p also has the Gabor structure is showed; that the product ab decides whether it is possible for {Eu(m)bTu(n)ag}m,n∈p to be a frame for L2(K) is discussed; some necessary conditions and two sufficient conditions of Gabor frame for L2(K) are established. An example is finally given.  相似文献   

19.
In this paper we establish a relation between an appropriate version of the Casson-Gordon invariant of a satellite knot and those of its orbit and companion. We note that in some cases the contribution from, the companion falls. This gives a way to construct algebraically but not smoothly slice knots. This article was processed by the author using theLaTEX style filecljouri from Springer-Verlag.  相似文献   

20.
Summary.  We prove that the derivative of a differentiable family X t (a) of continuous martingales in a manifold M is a martingale in the tangent space for the complete lift of the connection in M, provided that the derivative is bicontinuous in t and a. We consider a filtered probability space (Ω,(ℱ t )0≤ t ≤1, ℙ) such that all the real martingales have a continuous version, and a manifold M endowed with an analytic connection and such that the complexification of M has strong convex geometry. We prove that, given an analytic family aL(a) of random variable with values in M and such that L(0)≡x 0M, there exists an analytic family aX(a) of continuous martingales such that X 1(a)=L(a). For this, we investigate the convexity of the tangent spaces T ( n ) M, and we prove that any continuous martingale in any manifold can be uniformly approximated by a discrete martingale up to a stopping time T such that ℙ(T<1) is arbitrarily small. We use this construction of families of martingales in complex analytic manifolds to prove that every ℱ1-measurable random variable with values in a compact convex set V with convex geometry in a manifold with a C 1 connection is reachable by a V-valued martingale. Received: 14 March 1996/In revised form: 12 November 1996  相似文献   

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