排序方式: 共有33条查询结果,搜索用时 31 毫秒
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We investigate the Laplacian on a smooth bounded open set Rn with Wentzell-Robin boundary condition $\beta u+\frac{\partial u}{\partial \nu} + \Delta u=0$ on the boundary . Under the assumption $\memb$ C() with $\geq$ 0 , we prove that generates a differentiable positive contraction semigroup on $C(\bar{\Omega})$ and study some monotonicity properties and the asymptotic behaviour. 相似文献
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Giorgio Metafune Diego Pallara 《Journal of Mathematical Analysis and Applications》2011,377(1):170-179
Given a second-order elliptic operator on Rd, with bounded diffusion coefficients and unbounded drift, which is the generator of a strongly continuous semigroup on L2(Rd) represented by an integral, we study the time behavior of the integral kernel and prove estimates on its decay at infinity. If the diffusion coefficients are symmetric, a local lower estimate is also proved. 相似文献
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Summary We prove that, when X is one of the Banach spaces lp (1p ) or c0, then every infinite-dimensional complemented subspace of XN (resp. X(N)) is isomorphic to one of the following spaces: (, X, × X, XN (resp. , X, X, X(N)). Therefore, XN and X(N) are primary. We also give some consequences and related results.The second author acknowledges partial support from the Italian Ministero della Pubblica Istruzione. 相似文献
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Giorgio Metafune Diego Pallara 《Proceedings of the American Mathematical Society》2002,130(6):1779-1786
We give estimates on the bottom of the essential spectrum of Schrödinger operators in .
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Chill R.; Fasangova E.; Metafune G.; Pallara D. 《Journal London Mathematical Society》2005,71(3):703-722
The sector of analyticity of the OrnsteinUhlenbeck semigroupis computed on the space := Lp (RN; µ) with respect to its invariant measure µ.If A= + Bx· denotes the generator of the OrnsteinUhlenbecksemigroup, then the angle 2 of the sector of analyticity in is /2 minus the spectral angleof BQ, Q being the matrix determining the Gaussian measure µ.The angle of analyticity in is then given by the formula
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We show that the Fréchet-Sobolev spaces C(ℝ) ∩ L
p
(ℝ) and C
k
(ℝ) ∩ L
p
(ℝ) are not isomorphic for p ≠ 2 and k ∈ ℕ.
Research supported by the Italian MURST. 相似文献
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We study global regularity properties of invariant measures associated with second order differential operators in RN. Under suitable conditions, we prove global boundedness of the density, Sobolev regularity, a Harnack inequality and pointwise upper and lower bounds. 相似文献