共查询到20条相似文献,搜索用时 31 毫秒
2.
3.
A finite Borel measure μ in is called a frame-spectral measure if it admits an exponential frame (or Fourier frame) for . It has been conjectured that a frame-spectral measure must be translationally absolutely continuous, which is a criterion describing the local uniformity of a measure on its support. In this paper, we show that if any measures ν and λ without atoms whose supports form a packing pair, then is translationally singular and it does not admit any Fourier frame. In particular, we show that the sum of one-fourth and one-sixteenth Cantor measure does not admit any Fourier frame. We also interpolate the mixed-type frame-spectral measures studied by Lev and the measure we studied. In doing so, we demonstrate a discontinuity behavior: For any anticlockwise rotation mapping with , the two-dimensional measure , supported on the union of x-axis and , always admit a Fourier frame. Furthermore, we can find such that it forms a Fourier frame for with frame bounds independent of θ. Nonetheless, does not admit any Fourier frame. 相似文献
4.
5.
Mohammad Daher 《Comptes Rendus Mathematique》2017,355(5):549-552
According to a previous result of the author, if is an interpolation couple, if is weakly LUR, then the complex interpolation spaces have the same property.Here we construct an interpolation couple where is LUR, but where the complex interpolation spaces are not strictly convex. 相似文献
6.
《Nonlinear Analysis: Real World Applications》2007,8(2):435-446
With the help of a continuation theorem based on Gaines and Mawhin's coincidence degree, easily verifiable criteria are established for the global existence of positive periodic solutions of the following nonlinear discrete state dependent delays predator–prey systemwhere are positive -periodic, is a fixed positive integer. are -periodic and . are -periodic with respect to their first arguments, respectively. are positive constants. 相似文献
7.
TextFor any given two positive integers and , and any set A of nonnegative integers, let denote the number of solutions of the equation with . In this paper, we determine all pairs of positive integers for which there exists a set such that for all . We also pose several problems for further research.VideoFor a video summary of this paper, please click here or visit http://www.youtube.com/watch?v=EnezEsJl0OY. 相似文献
8.
《Nonlinear Analysis: Real World Applications》2007,8(4):1040-1061
We consider the following model that describes the dynamics of epidemics in homogeneous/heterogeneous populations as well as the spreading of multiple inter-related infectious diseases:Our aim is to establish criteria such that the above system has one or multiple constant-sign periodic solutions , i.e., for each , is periodic and where is fixed. Examples are also included to illustrate the results obtained. 相似文献
9.
《Discrete Mathematics》2007,307(17-18):2209-2216
10.
11.
12.
13.
14.
Let V be an n-dimensional vector space over the finite field consisting of q elements and let be the Grassmann graph formed by k-dimensional subspaces of V, . Denote by the restriction of to the set of all non-degenerate linear codes. We show that for any two codes the distance in coincides with the distance in only in the case when , i.e. if n is sufficiently large then for some pairs of codes the distances in the graphs and are distinct. We describe one class of such pairs. 相似文献
15.
16.
17.
In this paper, we study operator-theoretic properties of the compressed shift operators and on complements of submodules of the Hardy space over the bidisk . Specifically, we study Beurling-type submodules – namely submodules of the form for θ inner – using properties of Agler decompositions of θ to deduce properties of and on model spaces . Results include characterizations (in terms of θ) of when a commutator has rank n and when subspaces associated to Agler decompositions are reducing for and . We include several open questions. 相似文献
18.
19.
Haïm Brezis Petru Mironescu 《Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire》2018,35(5):1355-1376
We investigate the validity of the Gagliardo–Nirenberg type inequality
(1)
with . Here, are non negative numbers (not necessarily integers), , and we assume the standard relationsBy the seminal contributions of E. Gagliardo and L. Nirenberg, (1) holds when are integers. It turns out that (1) holds for “most” of values of , but not for all of them. We present an explicit condition on which allows to decide whether (1) holds or fails. 相似文献
20.
Kazaros Kazarian 《Comptes Rendus Mathematique》2004,339(5):335-337
A complete orthonormal system of functions is constructed such that converges almost everywhere on if and diverges a.e. for any . We also show that for any complete ONS of functions defined on there exists a fixed non decreasing subsequence of natural numbers such that for any and some sequence of coefficients , To cite this article: K. Kazarian, C. R. Acad. Sci. Paris, Ser. I 339 (2004). 相似文献