共查询到20条相似文献,搜索用时 234 毫秒
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Let be an algebraically closed field of characteristic 0, and a Cohen–Macaulay graded domain with . If A is semi-standard graded (i.e., A is finitely generated as a -module), it has the h-vector, which encodes the Hilbert function of A. From now on, assume that . It is known that if A is standard graded (i.e., ), then A is level. We will show that, in the semi-standard case, if A is not level, then divides . Conversely, for any positive integers h and n, there is a non-level A with the h-vector . Moreover, such examples can be constructed as Ehrhart rings (equivalently, normal toric rings). 相似文献
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Akaki Tikaradze 《Journal of Pure and Applied Algebra》2017,221(1):229-236
Let k be a perfect field of characteristic . Let be an Azumaya algebra over a smooth symplectic affine variety over k. Let be a deformation quantization of over . We prove that all -flat two-sided ideals of are generated by central elements. 相似文献
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Yong-Gao Chen 《Comptes Rendus Mathematique》2018,356(2):121-124
Recently, motivated by Stanley's sequences, Kiss, Sándor, and Yang introduced a new type sequence: a sequence A of nonnegative integers is called an -covering sequence if there exists an integer such that, if , then there exist , such that form a k-term arithmetic progression. They prove that there exists an -covering sequence A such that . In this note, we prove that there exists an -covering sequence A such that . 相似文献
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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
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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
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《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
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《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
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《Discrete Mathematics》2007,307(17-18):2209-2216