Search Results - "Seelmann, Albrecht"

The Laplacian on Cartesian products with mixed boundary conditions by Seelmann, Albrecht

“…A definition of the Laplacian on Cartesian products with mixed boundary conditions using quadratic forms is proposed. Its consistency with the standard…”
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On a Minimax Principle in Spectral Gaps by Seelmann, Albrecht

“…The minimax principle for eigenvalues in gaps of the essential spectrum in the form presented by Griesemer et al. (Doc Math 4:275–283, 1999) is adapted to…”
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Notes on the subspace perturbation problem for off-diagonal perturbations by Seelmann, Albrecht

“…The variation of spectral subspaces for linear self-adjoint operators under an additive bounded off-diagonal perturbation is studied. To this end, the…”
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Uncertainty principles with error term in Gelfand–Shilov spaces by Dicke, Alexander, Seelmann, Albrecht

“…In this note, an alternative approach to establish observability for semigroups based on their smoothing properties is presented. The results discussed here…”
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A unified observability result for non-autonomous observation problems by Gabel, Fabian, Seelmann, Albrecht

“…A final-state observability result in the Banach space setting for non-autonomous observation problems is obtained that covers and extends all previously known…”
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Band Edge Localization Beyond Regular Floquet Eigenvalues by Seelmann, Albrecht, Täufer, Matthias

“…We prove that localization near band edges of multi-dimensional ergodic random Schrödinger operators with periodic background potential in L 2 ( R d ) is…”
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The Reflection Principle in the Control Problem of the Heat Equation by Egidi, Michela, Seelmann, Albrecht

“…We consider the control problem for the generalized heat equation for a Schrödinger operator on a domain with a reflection symmetry with respect to a…”
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Exhaustion approximation for the control problem of the heat or Schrödinger semigroup on unbounded domains by Seelmann, Albrecht, Veselić, Ivan

“…We consider the control problem of the heat equation on bounded and unbounded domains, and more generally the corresponding inhomogeneous equation for the…”
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Uncertainty Principle for Hermite Functions and Null-Controllability with Sensor Sets of Decaying Density by Dicke, Alexander, Seelmann, Albrecht, Veselić, Ivan

“…We establish a family of uncertainty principles for finite linear combinations of Hermite functions. More precisely, we give a geometric criterion on a subset…”
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Correction: Uncertainty Principle for Hermite Functions and Null-Controllability with Sensor Sets of Decaying Density by Dicke, Alexander, Seelmann, Albrecht, Veselić, Ivan

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An abstract Logvinenko-Sereda type theorem for spectral subspaces by Egidi, Michela, Seelmann, Albrecht

“…We provide an abstract framework for a Logvinenko-Sereda type theorem, where the classical compactness assumption on the support of the Fourier transform is…”
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Notes on the $${\sin 2 \Theta}$$ sin 2 Θ Theorem by Seelmann, Albrecht

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On an estimate in the subspace perturbation problem by Seelmann, Albrecht

“…The problem of variation of spectral subspaces for linear self-adjoint operators under an additive bounded perturbation is considered. The aim is to find the…”
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Quantitative spectral inequalities for the anisotropic Shubin operators and applications to null-controllability by Alphonse, Paul, Seelmann, Albrecht

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Sturm-Liouville problems and global bounds by small control sets and applications to quantum graphs by Egidi, Michela, Mugnolo, Delio, Seelmann, Albrecht

“…We develop a Logvinenko–Sereda theory for one-dimensional vector-valued self-adjoint operators. We thus deliver upper bounds on L2-norms of eigenfunctions –…”
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Quantitative unique continuation for spectral subspaces of Schrödinger operators with singular potentials by Dicke, Alexander, Rose, Christian, Seelmann, Albrecht, Tautenhahn, Martin

“…Recent (scale-free) quantitative unique continuation estimates for spectral subspaces of Schrödinger operators are extended to allow singular potentials such…”
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Notes on the sin2Θ Theorem by Seelmann, Albrecht

“…An analogue of the Davis-Kahan sin 2 Θ theorem from (SIAM J Numer Anal 7:1–46, 1970 ) is proved under a general spectral separation condition. This extends the…”
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On Invariant Graph Subspaces by Makarov, Konstantin A., Schmitz, Stephan, Seelmann, Albrecht

“…In this paper we discuss the problem of decomposition for unbounded 2 × 2 operator matrices by a pair of complementary invariant graph subspaces. Under mild…”
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Relative residual bounds for eigenvalues in gaps of the essential spectrum by Seelmann, Albrecht

“…Oper. Matrices 18 (2024), 191--203 The relative distance between eigenvalues of the compression of a not necessarily semibounded self-adjoint operator to a…”
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On a minimax principle in spectral gaps by Seelmann, Albrecht

“…Complex Anal. Oper. Theory 16 (2022), 29 The minimax principle for eigenvalues in gaps of the essential spectrum in the form presented by Griesemer, Lewis, and…”
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