共查询到20条相似文献,搜索用时 46 毫秒
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In this paper, we study the following coupled Choquard system in : where and , in which denotes if and if . The function is a Riesz potential. By using Nehari manifold method, we obtain the existence of a positive ground state solution in the case of bounded potential and periodic potential, respectively. In particular, the nonlinear term includes the well-studied case and , and the less-studied case and . Moreover, it seems to be the first existence result for the case . 相似文献
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《组合设计杂志》2018,26(3):101-118
Group divisible covering designs (GDCDs) were introduced by Heinrich and Yin as a natural generalization of both covering designs and group divisible designs. They have applications in software testing and universal data compression. The minimum number of blocks in a k‐GDCD of type is a covering number denoted by . When , the values of have been determined completely for all possible pairs . When , Francetić et al. constructed many families of optimal GDCDs, but the determination remained far from complete. In this paper, two specific 4‐IGDDs are constructed, thereby completing the existence problem for 4‐IGDDs of type . Then, additional families of optimal 4‐GDCDs are constructed. Consequently the cases for whose status remains undetermined arise when and , when and , and in several small families for which one of g and u is fixed. 相似文献
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Jamil Chaker 《Mathematische Nachrichten》2019,292(11):2316-2337
We consider systems of stochastic differential equations of the form for with continuous, bounded and non‐degenerate coefficients. Here are independent one‐dimensional stable processes with . In this article we research on uniqueness of weak solutions to such systems by studying the corresponding martingale problem. We prove the uniqueness of weak solutions in the case of diagonal coefficient matrices. 相似文献
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M.M. El-Dessoky 《Journal of the Egyptian Mathematical Society》2017,25(1):28-36
The main objective of this paper is to study the global stability of the positive solutions and the periodic character of the difference equation
with positive parameters and non-negative initial conditions. Numerical examples to the difference equation are given to explain our results. 相似文献
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In this paper, we use a weighted version of Poincaré's inequality to study density and extension properties of weighted Sobolev spaces over some open set . Additionally, we study the specific case of monomial weights , showing the validity of a weighted Poincaré inequality together with some embedding properties of the associated weighed Sobolev spaces. 相似文献
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Paulo Cesar Carrião Olímpio Hiroshi Miyagaki André Vicente 《Mathematische Nachrichten》2023,296(1):130-151
In this paper, we study the exponential decay of the energy associated to an initial value problem involving the wave equation on the hyperbolic space . The space is the unit disc of endowed with the Riemannian metric g given by , where and , if and , if . Making an appropriate change, the problem can be seen as a singular problem on the boundary of the open ball endowed with the euclidean metric. The proof is based on the multiplier techniques combined with the use of Hardy's inequality, in a version due to the Brezis–Marcus, which allows us to overcome the difficulty involving the singularities. 相似文献
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Jian‐Lin Li 《Mathematische Nachrichten》2015,288(4):412-419
Let be a self‐affine measure associated with an expanding matrix and a finite digit set . We consider in this paper the spectrality of . In the case when is a compatible pair for some , a necessary condition is obtained for the spectral pair . This condition is shown to be equivalent to the known necessary conditions for the same spectral pair. Moreover, we prove that all these necessary conditions are not sufficient in the higher dimensions, but they are sufficient in the dimension one. This extends Laba‐Wang's condition for spectral pairs. 相似文献
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For every real numbers , with , the curve parametrized by valued in with components: has image contained in the CR-umbilical locus: of the ellipsoid of equation , where the CR-umbilical locus of a Levi nondegenerate hypersurface is the set of points at which the Cartan curvature of M vanishes. 相似文献
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Tomoyuki Nakatsuka 《Mathematische Nachrichten》2021,294(1):98-117
We study the existence of a time‐periodic solution with pointwise decay properties to the Navier–Stokes equation in the whole space. We show that if the time‐periodic external force is sufficiently small in an appropriate sense, then there exists a time‐periodic solution of the Navier–Stokes equation such that and uniformly in as . Our solution decays faster than the time‐periodic Stokes fundamental solution and the faster decay of its spatial derivatives of higher order is also described. 相似文献
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