共查询到20条相似文献,搜索用时 15 毫秒
1.
Jeong Hee Hong 《Proceedings of the American Mathematical Society》2005,133(1):115-126
We give conditions on an arbitrary directed graph for the associated Cuntz-Krieger algebra to be decomposable as a direct sum. We describe the direct summands as certain graph algebras.
2.
Stefano Meda Peter Sjö gren Maria Vallarino 《Proceedings of the American Mathematical Society》2008,136(8):2921-2931
We prove that if is in , is a Banach space, and is a linear operator defined on the space of finite linear combinations of -atoms in with the property that then admits a (unique) continuous extension to a bounded linear operator from to . We show that the same is true if we replace -atoms by continuous -atoms. This is known to be false for -atoms.
3.
Istvá n Juhá sz Zoltá n Szentmikló ssy 《Proceedings of the American Mathematical Society》2008,136(8):2979-2984
All spaces below are Tychonov. We define the projective - character of a space as the supremum of the values where ranges over all (Tychonov) continuous images of . Our main result says that every space has a -base whose order is ; that is, every point in is contained in at most -many members of the -base. Since for compact , this is a significant generalization of a celebrated result of Shapirovskii.
4.
For all previous constructions of lattice space-time codes with a positive diversity product, the rank was at most . In this paper, we give an example of a lattice space-time code of rank with a positive diversity product.
5.
Russ Woodroofe 《Proceedings of the American Mathematical Society》2008,136(11):3795-3801
In a 2001 paper, Shareshian conjectured that the subgroup lattice of a finite, solvable group has an -labeling. We construct such a labeling and verify that our labeling has the expected properties.
6.
Rosa Maria Miró -Roig Helena Soares 《Proceedings of the American Mathematical Society》2008,136(11):3751-3757
A very long-standing problem in Algebraic Geometry is to determine the stability of exceptional vector bundles on smooth projective varieties. In this paper we address this problem and we prove that any exceptional vector bundle on a smooth complete intersection -fold of type with and is stable.
7.
Rui Miguel Saramago 《Proceedings of the American Mathematical Society》2008,136(8):2699-2709
We use Dieudonné theory for periodically graded Hopf rings to determine the Dieudonné ring structure of the -graded Morava -theory , with an odd prime, when applied to the -spectrum (and to ). We also expand these results in order to accomodate the case of the full Morava -theory .
8.
Michael J. Fisher 《Proceedings of the American Mathematical Society》2003,131(11):3617-3621
Let be a fixed odd prime. In this paper we prove an exponent conjecture of Bousfield, namely that the -exponent of the spectrum is for . It follows from this result that the -exponent of is at least for and , where denotes the -connected cover of .
9.
Madjid Mirzavaziri Mohammad Sal Moslehian 《Proceedings of the American Mathematical Society》2006,134(11):3319-3327
Let be a -algebra acting on a Hilbert space , let be a linear mapping and let be a -derivation. Generalizing the celebrated theorem of Sakai, we prove that if is a continuous -mapping, then is automatically continuous. In addition, we show the converse is true in the sense that if is a continuous --derivation, then there exists a continuous linear mapping such that is a --derivation. The continuity of the so-called - -derivations is also discussed.
10.
Xia Zhou Tianxin Cai David M. Bradley 《Proceedings of the American Mathematical Society》2008,136(8):2689-2698
We introduce signed -analogs of Tornheim's double series and evaluate them in terms of double -Euler sums. As a consequence, we provide explicit evaluations of signed and unsigned Tornheim double series and correct some mistakes in the literature.
11.
Serguei V. Astashkin Guillermo P. Curbera 《Proceedings of the American Mathematical Society》2008,136(10):3493-3501
Let be a rearrangement invariant function space on [0,1]. We consider the Rademacher multiplicator space of measurable functions such that for every a.e. converging series , where are the Rademacher functions. We characterize the situation when . We also discuss the behaviour of partial sums and tails of Rademacher series in function spaces.
12.
Theodore A. Slaman 《Proceedings of the American Mathematical Society》2004,132(8):2449-2456
Working in the base theory of , we show that for all , the bounding principle for -formulas ( ) is equivalent to the induction principle for -formulas ( ). This partially answers a question of J. Paris.
13.
We prove that there is a compact separable continuum that (consistently) is not a remainder of the real line.
14.
Srdjan Petrovic 《Proceedings of the American Mathematical Society》2008,136(12):4283-4288
We consider the spectral radius algebras associated to contractions. If is such an operator we show that the spectral radius algebra always properly contains the commutant of .
15.
Edward M. Fan 《Proceedings of the American Mathematical Society》2008,136(9):3255-3261
Consider an -dimensional smooth Riemannian manifold with a given smooth measure on it. We call such a triple a Riemannian measure space. Perelman introduced a variant of scalar curvature in his recent work on solving Poincaré's conjecture , where and is the scalar curvature of . In this note, we study the topological obstruction for the -stable minimal submanifold with positive -scalar curvature in dimension three under the setting of manifolds with density.
16.
Florian Enescu 《Proceedings of the American Mathematical Society》2003,131(11):3379-3386
The notion of stability of the highest local cohomology module with respect to the Frobenius functor originates in the work of R. Hartshorne and R. Speiser. R. Fedder and K.-i. Watanabe examined this concept for isolated singularities by relating it to -rationality. The purpose of this note is to study what happens in the case of non-isolated singularities and to show how this stability concept encapsulates a few of the subtleties of tight closure theory. Our study can be seen as a generalization of the work by Fedder and Watanabe. We introduce two new ring invariants, the -stability number and the set of -stable primes. We associate to every ideal generated by a system of parameters and an ideal of multipliers denoted and obtain a family of ideals . The set is independent of and consists of finitely many prime ideals. It also equals prime ideal such that is -stable. The maximal height of such primes defines the -stability number.
17.
Winston Ou 《Proceedings of the American Mathematical Society》2008,136(9):3239-3245
We use variants of the Hardy-Littlewood maximal and the Cruz-Uribe-Neugebauer minimal operators to give direct characterizations of and that clarify their near symmetry and yield elementary proofs of various known results, including Cruz-Uribe and Neugebauer's refinement of the Jones factorization theorem.
18.
Hui Li 《Proceedings of the American Mathematical Society》2003,131(11):3579-3582
Let be a connected, compact symplectic manifold equipped with a Hamiltonian action. We prove that, as fundamental groups of topological spaces, , where is the symplectic quotient at any value in the image of the moment map .
19.
Mamoru Furuya Hiroshi Niitsuma 《Proceedings of the American Mathematical Society》2004,132(11):3189-3193
We introduce the concept of -adic -basis as an extension of the concept of -basis. Let be a regular local ring of prime characteristic and a ring such that . Then we prove that is a regular local ring if and only if there exists an -adic -basis of and is Noetherian.
20.
Yu. I. Lyubich 《Proceedings of the American Mathematical Society》2008,136(11):3953-3956
The isometric embeddings (, ) over a field are considered, and an upper bound for the minimal is proved. In the commutative case ( ) the bound was obtained by Delbaen, Jarchow and Pełczyński (1998) in a different way.