Zobrazeno 1 - 10
of 1 050
pro vyhledávání: '"Seelmann A"'
Autor:
Alphonse, Paul, Seelmann, Albrecht
We prove time-pointwise quantitative unique continuation estimates for the evolution operators associated to (fractional powers of) the Baouendi--Grushin operators on the cylinder $\mathbb{R}^d \times \mathbb{T}^d$. Corresponding spectral inequalitie
Externí odkaz:
http://arxiv.org/abs/2401.17782
Autor:
Seelmann, Albrecht
Publikováno v:
Oper. Matrices 18 (2024), 191--203
The relative distance between eigenvalues of the compression of a not necessarily semibounded self-adjoint operator to a closed subspace and some of the eigenvalues of the original operator in a gap of the essential spectrum is considered. It is show
Externí odkaz:
http://arxiv.org/abs/2309.07032
Autor:
Gabel, Fabian, Seelmann, Albrecht
Publikováno v:
Arch. Math. 122 (2024), 227--239
A final-state observability result in the Banach space setting for non-autonomous observation problems is obtained that covers and extends all previously known results in this context, while providing a streamlined proof that follows the established
Externí odkaz:
http://arxiv.org/abs/2307.10716
Publikováno v:
J. Math. Anal. Appl. 535 (2024) 128101
We develop a Logvinenko--Sereda theory for one-dimensional vector-valued self-adjoint operators. We thus deliver upper bounds on $L^2$-norms of eigenfunctions -- and linear combinations thereof -- in terms of their $L^2$- and $W^{1,2}$-norms on small
Externí odkaz:
http://arxiv.org/abs/2304.10441
Autor:
Alphonse, Paul, Seelmann, Albrecht
We prove quantitative spectral inequalities for the (anisotropic) Shubin operators on the whole Euclidean space, thus relating for functions from spectral subspaces associated to finite energy intervals their $L^2$-norm on the whole space to the $L^2
Externí odkaz:
http://arxiv.org/abs/2212.10842
Publikováno v:
Partial Differ. Equ. Appl. 5, 7 (2024)
We prove a spectral inequality (a specific type of uncertainty relation) for Schr\"odinger operators with confinement potentials, in particular of Shubin-type. The sensor sets are allowed to decay exponentially, where the precise allowed decay rate d
Externí odkaz:
http://arxiv.org/abs/2206.08682
Publikováno v:
J Fourier Anal Appl 29, 11 (2023)
We establish a family of uncertainty principles for finite linear combinations of Hermite functions. More precisely, we give a geometric criterion on a subset $S\subset \RR^d$ ensuring that the $L^2$-seminorm associated to $S$ is equivalent to the fu
Externí odkaz:
http://arxiv.org/abs/2201.11703
Autor:
Dicke, Alexander, Seelmann, Albrecht
Publikováno v:
Archiv der Mathematik 119, 413-425 (2022)
In this note, an alternative approach to establish observability for semigroups based on their smoothing properties is presented. The results discussed here are closely related to those recently obtained in [arXiv:2112.01788], but the current proof a
Externí odkaz:
http://arxiv.org/abs/2201.09781
Publikováno v:
ESAIM: COCV, 29 (2023) 80
We prove observability and null-controllability for quadratic parabolic differential equations. The sensor set is allowed to be sparse and have finite volume if the generator has trivial singular space $S$. In the case of generators with singular spa
Externí odkaz:
http://arxiv.org/abs/2201.02370
Publikováno v:
In Journal of Mathematical Analysis and Applications 1 July 2024 535(1)
