B. F. Nielsen

activity

20152026

most citedModified Tikhonov regularization for identifying several sources

4 citations · 5 across the 8 of their papers we have counts for

collaborators

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2 papers · 1 filter

math.AP2026

A note on the convergence of the eigenvalues in a subdomain to the continuous spectrum

Miroslav Bulíček, Bjørn Fredrik Nielsen, Zdeněk Strakoš

The SIGEST paper Nielsen and Strakoš (2024) characterized the spectrum of the preconditioned operator $Δ^{- 1} [\nabla \cdot (K \nabla u)]$ in a bounded open two-dimensional domain $Ω…

math.AP2020

Generalized spectrum of second order differential operators

Tomáš Gergelits, Bjørn Fredrik Nielsen, Zdeněk Strakoš

We analyze the spectrum of the operator $Δ^{- 1} [\nabla \cdot (K \nabla u)]$ , where $Δ$ denotes the Laplacian and $K = K (x, y)$ is a symmetric tensor. Our main result shows that this s…