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Let be a bounded domain satisfying a Hayman-type asymmetry condition, and let D be an arbitrary bounded domain referred to as an “obstacle”. We are interested in the behavior of the first Dirichlet eigenvalue .First, we prove an upper bound on in terms of the distance of the set to the set of maximum points of the first Dirichlet ground state of Ω. In short, a direct corollary is that if
(1)
is large enough in terms of , then all maximizer sets of are close to each maximum point of .Second, we discuss the distribution of and the possibility to inscribe wavelength balls at a given point in Ω.Finally, we specify our observations to convex obstacles D and show that if is sufficiently large with respect to , then all maximizers of contain all maximum points of . 相似文献
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In a previous work, it was shown how the linearized strain tensor field can be considered as the sole unknown in the Neumann problem of linearized elasticity posed over a domain , instead of the displacement vector field in the usual approach. The purpose of this Note is to show that the same approach applies as well to the Dirichlet–Neumann problem. To this end, we show how the boundary condition on a portion of the boundary of Ω can be recast, again as boundary conditions on , but this time expressed only in terms of the new unknown . 相似文献
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Andrei K. Lerner 《Comptes Rendus Mathematique》2018,356(1):77-80
We show that the operator norm of the composition , where M is the maximal operator and is a rough homogeneous singular integral with angular part , depends quadratically on , and that this dependence is sharp. 相似文献
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Cristhian E. Hidber Miguel A. Xicoténcatl 《Journal of Pure and Applied Algebra》2018,222(6):1478-1488
The purpose of this article is to compute the mod 2 cohomology of , the mapping class group of the Klein bottle with q marked points. We provide a concrete construction of Eilenberg–MacLane spaces and fiber bundles , where denotes the configuration space of unordered q-tuples of distinct points in and is the classifying space of the group . Moreover, we show the mod 2 Serre spectral sequence of the bundle above collapses. 相似文献
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In this article, we prove that the compact simple Lie groups for , for , for , , and admit left-invariant Einstein metrics that are not geodesic orbit. This gives a positive answer to an open problem recently posed by Nikonorov. 相似文献
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Gerd Grubb 《Journal of Functional Analysis》2018,274(9):2634-2660
This work contributes in two areas, with sharp results, to the current investigation of regularity of solutions of heat equations with a nonlocal operator P:
(*)
1) For strongly elliptic pseudodifferential operators (ψdo's) P on of order , a symbol calculus on is introduced that allows showing optimal regularity results, globally over and locally over : for , . The are anisotropic Sobolev spaces of Bessel-potential type, and there is a similar result for Besov spaces.2) Let Ω be smooth bounded, and let P equal (), or its generalizations to singular integral operators with regular kernels, generating stable Lévy processes. With the Dirichlet condition , the initial condition , and , (*) has a unique solution with . Here if , and is contained in if , but contains nontrivial elements from if (where ). The interior regularity of u is lifted when f is more smooth. 相似文献
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In this paper we define odd dimensional unitary groups . These groups contain as special cases the odd dimensional general linear groups where R is any ring, the odd dimensional orthogonal and symplectic groups and where R is any commutative ring and further the first author's even dimensional unitary groups where is any form ring. We classify the E-normal subgroups of the groups (i.e. the subgroups which are normalized by the elementary subgroup ), under the condition that R is either a semilocal or quasifinite ring with involution and . Further we investigate the action of by conjugation on the set of all E-normal subgroups. 相似文献
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Let be a Lipschitz domain and Γ be a relatively open and non-empty subset of its boundary ?Ω. We show that the solution to the linear first-order system:(1) vanishes if and . In particular, square-integrable solutions ζ of (1) with vanish. As a consequence, we prove that: is a norm if with , for some with as well as . We also give a new and different proof for the so-called ‘infinitesimal rigid displacement lemma’ in curvilinear coordinates: Let , , satisfy for some with . Then there exists a constant translation vector and a constant skew-symmetric matrix , such that . 相似文献
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Enkelejd Hashorva Oleg Seleznjev Zhongquan Tan 《Journal of Mathematical Analysis and Applications》2018,457(1):841-867
This contribution is concerned with Gumbel limiting results for supremum with centered Gaussian random fields with continuous trajectories. We show first the convergence of a related point process to a Poisson point process thereby extending previous results obtained in [8] for Gaussian processes. Furthermore, we derive Gumbel limit results for as and show a second-order approximation for for any . 相似文献
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Vladimir Shchigolev 《Journal of Algebra》2009,321(5):1453-1462
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Michael Winkler 《Journal of Differential Equations》2018,264(3):2310-2350
The chemotaxis system is considered under homogeneous Neumann boundary conditions in the ball , where and .Despite its great relevance as a model for the spontaneous emergence of spatial structures in populations of primitive bacteria, since its introduction by Keller and Segel in 1971 this system has been lacking a satisfactory theory even at the level of the basic questions from the context of well-posedness; global existence results in the literature are restricted to spatially one- or two-dimensional cases so far, or alternatively require certain smallness hypotheses on the initial data.For all suitably regular and radially symmetric initial data satisfying and , the present paper establishes the existence of a globally defined pair of radially symmetric functions which are continuous in and smooth in , and which solve the corresponding initial-boundary value problem for (?) with in an appropriate generalized sense. To the best of our knowledge, this in particular provides the first result on global existence for the three-dimensional version of (?) involving arbitrarily large initial data. 相似文献