共查询到20条相似文献,搜索用时 390 毫秒
1.
John G. Miller 《Proceedings of the American Mathematical Society》2007,135(12):4057-4061
Consider an orientable manifold with countably many complete components of bounded dimension. Suppose that its rational homology is infinitely generated in some degree. Then there is no choice of weight function for which the natural map from weighted cohomology to de Rham cohomology is surjective in that degree.
2.
We prove that certain spectral multipliers associated with the discrete Laplacian on graphs satisfying the doubling volume property and the Poincaré inequality are bounded on the Hardy space .
3.
Gregory C. Verchota 《Proceedings of the American Mathematical Society》2007,135(3):891-894
Harmonic maps from the closed disc onto bounded convex sets of the plane obey .
4.
Yifeng Yu 《Proceedings of the American Mathematical Society》2007,135(5):1449-1454
This note is motivated by Evans (2004) and Anantharaman (2004). We study the semiclassical measure arising from the operator when the potential has degenerate minimum points. We will use the technique of integration by parts and some identities of Evans to derive information on the support of the measure.
5.
Piotr Gajda Youming Li Leszek Plaskota Grzegorz W. Wasilkowski. 《Mathematics of Computation》2004,73(246):813-825
We present and analyze a new randomized algorithm for numerical computation of weighted integrals over the unbounded domain . The algorithm and its desirable theoretical properties are derived based on certain stochastic assumptions about the integrands. It is easy to implement, enjoys convergence rate, and uses only standard random number generators. Numerical results are also included.
6.
Martin Mathieu 《Proceedings of the American Mathematical Society》2004,132(2):443-446
A linear mapping from a subspace of a Banach algebra into another Banach algebra is called spectrally bounded if there is a constant such that for all , where denotes the spectral radius. We prove that every spectrally bounded unital operator from a unital purely infinite simple -algebra onto a unital semisimple Banach algebra is a Jordan epimorphism.
7.
Zhongwei Shen 《Transactions of the American Mathematical Society》2005,357(7):2843-2870
Let , , be a bounded Lipschitz domain. For Laplace's equation in , we study the Dirichlet and Neumann problems with boundary data in the weighted space , where , is a fixed point on , and denotes the surface measure on . We prove that there exists such that the Dirichlet problem is uniquely solvable if , and the Neumann problem is uniquely solvable if . If is a domain, one may take . The regularity for the Dirichlet problem with data in the weighted Sobolev space is also considered. Finally we establish the weighted estimates with general weights for the Dirichlet and regularity problems.
8.
José Bonet Mikael Lindströ m Elke Wolf 《Proceedings of the American Mathematical Society》2008,136(12):4267-4273
We characterize those weighted composition operators on weighted Banach spaces of holomorphic functions of type which are an isometry.
9.
L. Godinho 《Transactions of the American Mathematical Society》2006,358(11):4919-4933
A theorem of Tolman and Weitsman states that all symplectic semifree circle actions with isolated fixed points on compact symplectic manifolds must be Hamiltonian and have the same equivariant cohomology and Chern classes of equipped with the standard diagonal circle action. In this paper, we show that the situation is much different when we consider compact symplectic orbifolds. Focusing on -orbifolds with isolated cone singularities, we show that such actions, besides being Hamiltonian, can now be obtained from either or a weighted projective space, or a quotient of one of these spaces by a finite cyclic group, by a sequence of special weighted blow-ups at fixed points. In particular, they can have any number of fixed points.
10.
G. Barbatis S. Filippas A. Tertikas 《Transactions of the American Mathematical Society》2004,356(6):2169-2196
We present a unified approach to improved Hardy inequalities in . We consider Hardy potentials that involve either the distance from a point, or the distance from the boundary, or even the intermediate case where the distance is taken from a surface of codimension . In our main result, we add to the right hand side of the classical Hardy inequality a weighted norm with optimal weight and best constant. We also prove nonhomogeneous improved Hardy inequalities, where the right hand side involves weighted norms, .
11.
Marcos P. A. Cavalcante 《Proceedings of the American Mathematical Society》2008,136(1):287-294
In this paper we give sufficient conditions for a bounded domain in an -minimal hypersurface of the Euclidean space to be -stable. The Gauss-Kronecker curvature of this hypersurface may be zero on a set of capacity zero.
12.
P. N. Dowling C. J. Lennard B. Turett 《Proceedings of the American Mathematical Society》2004,132(6):1659-1666
A nonempty, closed, bounded, convex subset of has the fixed point property if and only if it is weakly compact.
13.
Frances Hammock Peter Luthy Alexander M. Meadows Phillip Whitman 《Proceedings of the American Mathematical Society》2007,135(5):1419-1430
We show partial regularity of bounded positive solutions of some semilinear elliptic equations in domains of . As a consequence, there exists a large variety of nonnegative singular solutions to these equations. These equations have previously been studied from the point of view of free boundary problems, where solutions additionally are stable for a variational problem, which we do not assume.
14.
Raú l Curto Sang Soo Park 《Proceedings of the American Mathematical Society》2003,131(9):2761-2769
We characterize -hyponormality and quadratic hyponormality of powers of weighted shifts using Schur product techniques.
15.
Gang Yu 《Transactions of the American Mathematical Society》2006,358(4):1563-1584
In this paper, we study a class of elliptic curves over with -torsion group , and prove that the average order of the -Selmer groups is bounded.
16.
Lisa Orloff Clark Astrid an Huef 《Proceedings of the American Mathematical Society》2008,136(2):623-634
Suppose is a second countable, locally compact, Hausdorff, principal groupoid with a fixed left Haar system. We define a notion of integrability for groupoids and show is integrable if and only if the groupoid -algebra has bounded trace.
17.
W. Allegretto 《Proceedings of the American Mathematical Society》2007,135(7):2177-2185
We consider the problem of establishing conditions on that ensure that the form associated with the -Laplacean is positive bounded below. It was shown recently by Fan, Zhang and Zhao that - unlike the constant case - this is not possible if has a strict extrema in the domain. They also considered the closely related problem of eigenvalue existence and estimates. Our main tool is the adaptation of a technique, employed by Protter for involving arbitrary vector fields. We also examine related results obtained by a variant of Picone Identity arguments. We directly consider problems in with and while we focus on Dirichlet boundary conditions we also indicate how our approach can be used in cases of mixed boundary conditions, of unbounded domains and of discontinuous Our basic criteria involve restrictions on and its gradient.
18.
Mohsen Pourahmadi Akihiko Inoue Yukio Kasahara 《Proceedings of the American Mathematical Society》2007,135(4):1233-1239
For a nonnegative integrable weight function on the unit circle , we provide an expression for , in terms of the series coefficients of the outer function of , for the weighted distance , where is the normalized Lebesgue measure and ranges over trigonometric polynomials with frequencies in , , . The problem is open for .
19.
In this paper, the inequalities for the weighted mean of -convex functions are established. As applications, inequalities between the two-parameter mean of an -convex function and extended mean values are given.
20.
Christopher B. Croke 《Proceedings of the American Mathematical Society》2008,136(2):715-717
We consider Riemannian metrics on the -sphere for such that the distance between any pair of antipodal points is bounded below by 1. We show that the volume can be arbitrarily small. This is in contrast to the -dimensional case where Berger has shown that .