共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Joel M Cohen 《Journal of Functional Analysis》1979,33(2):211-216
The simplest statement of the main results are these: Let π be a free group on 2 generators. Let Cπ be the complex ring and L1π the ring extension to L1 sums. Then L1π contains no idempotents. Furthermore, if α ? Cπ, β?L1π are nonzero, then αβ ≠ 0. The first result is in the direction of proving that a certain simple has no idempotents yielding a counter-example to the suggestion that simple are generated by their projections. 相似文献
3.
Let A be a -algebra, B be a -subalgebra of A, and φ be a factorial state of B. Sometimes, φ may be extended to a factorial state of A by a tensor product method of Sakai (“-algebras and -algebras, Springer-Verlag, Berlin/Heidelberg/ New York 1971”). Sometimes, there is a weak expectation of A into , and then factorial extensions may be found by a method of Sakai and Tsui (Yokohama Math. J.29 (1981), 157–160). These two methods are shown to have the same effect, and the factorial extensions produced by them are analysed. 相似文献
4.
The spaces in the title are associated to a fixed representing measure m for a fixed character on a uniform algebra. It is proved that the set of representing measures for that character which are absolutely continuous with respect to m is weakly relatively compact if and only if each m-negligible closed set in the maximal ideal space of L∞ is contained in an m-negligible peak set for H∞. J. Chaumat's characterization of weakly relatively compact subsets in therefore remains true, and is complete, under the first conditions. In this paper we also give a direct proof. From this we obtain that has the Dunford-Pettis property. 相似文献
5.
We consider nonlinear boundary value problems of the type for the existence of solutions. It is assumed that L is a 2nth-order linear differential operator in the real Hilbert space S = L2[a, b] which admits a decomposition of the form where T is an nth-order linear differential operator and N is a nonlinear operator defined on a subspace of S. The decomposition of L induces a natural decomposition of the generalized inverse of L. Using the method of “alternative problems,” we split the boundary value problem into an equivalent system of two equations. The theory of monotone operators and the theory of nonlinear Hammerstein equations are then utilized to consider the solvability of the equivalent system. 相似文献
6.
7.
Dario Cordero-Erausquin 《Comptes Rendus Mathematique》2002,334(9):767-772
A new approach to Santaló's inequality on is obtained by combining complex interpolation and Berndtsson's generalization of Prékopa's inequality. To cite this article: D. Cordero-Erausquin, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 767–772. 相似文献
8.
In this paper, we prove that admits a resolvable decomposition into TT3 or C3 if and only if n ≡ 0 (mod. 3), n ≠ 6. 相似文献
9.
In this paper, we show that the complete symmetric directed graph with n vertices admits an almost resolvable decomposition into TT3 (the transitive tournament on 3 vertices) or C3 (the directed cycle of length 3) if and only if n ≡ 1(mod 3). 相似文献
10.
The matrix equation is studied, under the assumption that (A, B1) is controllable, but allowing nonhermitian S. An inequality is given relating the dimensions of the eigenspaces of A and of the null space of S. In particular, if B has rank 1 and S is nonsingular, then S is hermitian, and the inertias of A and S are equal. Other inertial results are obtained, the role of the controllability of (A1, B1S1) is studied, and a class of D-stable matrices is determined. 相似文献
11.
Z.A Karian 《Journal of Number Theory》1976,8(2):233-244
Let k be a positive square free integer, the ring of algebraic integers in and S the unit sphere in Cn, complex n-space. If A1,…, An are n linearly independent points of Cn then L = {u1Au + … + unAn} with is called a k-lattice. The determinant of L is denoted by d(L). If L is a covering lattice for S, then is the covering density. L is called locally (absolutely) extreme if θ(S, L) is a local (absolute) minimum. In this paper we determine unique classes of extreme lattices for k = 1 and k = 3. 相似文献
12.
13.
Timothy W Tillson 《Journal of Combinatorial Theory, Series B》1980,29(1):68-74
It is shown that , 2m ≥ 8, can be decomposed into Hamiltonian circuits. A direct construction utilizing difference methods is given for 2m ≡ 0 (mod 4). The case 2m ≡ 2 (mod 4) is handled inductively by means of a construction which shows that admits such a decomposition if does. 相似文献
14.
David Handelman 《Advances in Mathematics》1983,48(1):1-15
The theory of inner-outer factorization in the Hardy spaces Hp in the unit disc is well known and has many applications. It does not carry over to the spaces Hp on the polydisc n or the ball n when n > 1. However, for Lumer's Hardy spaces (LH)p on any simply connected complex analytic manifold, we introduce the notions of internal and external functions and prove that every f? (LH)p has a factorization f = Iε × Eε, where Iε is internal and Eε is external, and Eε? (LH)p?ε, for any ε > 0. The factorization is not unique and an example of Rudin shows that the ε is needed, at least when , where m is an integer. 相似文献
15.
16.
H.B Kushner 《Journal of multivariate analysis》1985,17(1):84-98
The coefficients aτ?, sometimes called “generalized binomial coefficients” in the expansion , are computed explicitly when t = r + 1, where ? is a partition of r and τ a partition of t. A recursion formula permits the calculation of the general aτ?. Several properties of aτ? are proved. A connection between the aτ? and other coefficients is established. The main tools used are Bingham's identity, results from the theory of invariant differential operators, and a lemma concerning zonal polynomials. 相似文献
17.
18.
Abdellatif Agouzal 《Comptes Rendus Mathematique》2002,334(5):411-415
In this Note, we show that modification of Bank–Wieser estimator introduce an L∞-a posteriori error estimator for conforming and nonconforming methods. We prove, without saturation assumption nor comparison with residual estimators, the equivalence with the L∞ error. To cite this article: A. Agouzal, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 411–415. 相似文献
19.
20.
Philip L. Bowers 《Topology and its Applications》1984,17(2):173-187
It is shown that if G is an arbitrary upper semicontinuous decomposition of En for which π(NG embeds in Sm for some m?3, then the decomposition space embeds as a closed subset of En+m+1. The proof consists of constructing a cell-like upper semicontinuous decomposition G? of En+m+1 which intersects En to yield precisely G and using Edwards' Cell-Like Approximation Theorem to show that G? is shrinkable. As an immediate corollary, embeds in En+2k+2 whenever G is an arbitrary k-dimensional upper semicontinuous decomposition of En. This is an improvement of (n?1)-dimensions over the corresponding dimension theoretic result and examples due to Daverman show that this result is sharp in case n is odd and off by no more than one dimension in case n is even. 相似文献