7 papers
Analysis of a quasilinear coupled magneto-quasistatic model: solvability and regularity of solutions
Ralph Chill, Timo Reis, Tatjana Stykel
We consider a~quasilinear model arising from dynamical magnetization. This model is described by a~magneto-quasistatic (MQS) approximation of Maxwell's equations. Assuming that the…
Note on the Kato property of sectorial forms
Ralph Chill, Sebastian Krol
We characterise the Kato property of a sectorial form , defined on a Hilbert space , with respect to a larger Hilbert space in terms of two bounded, selfadjoin…
On the numerical range of second order elliptic operators with mixed boundary conditions in
Ralph Chill, Hannes Meinlschmidt, Joachim Rehberg
We consider second order elliptic operators with real, nonsymmetric coefficient functions which are subject to mixed boundary conditions. The aim of this paper is to provide unifor…
Atomic operators in vector lattices
Ralph Chill, Marat Pliev
In this paper we introduce a new class of operators on vector lattices. We say that a linear or nonlinear operator from a vector lattice to a vector lattice is atomic i…
Interpolation of nonlinear positive or order preserving operators on Banach lattices
Ralph Chill, Alberto Fiorenza, Sebastian Krol
We study the relationship between exact interpolation spaces for positive, linear operators, for order preserving, Lipschitz continuous operators, and for positive Gagliardo-Peetre…
The bidomain problem as a gradient system
Zakaria Belhachmi, Ralph Chill
We consider a general, nonlinear version of the bidomain system. Using the gradient structure of this system, but also the notion of -subgradient, we prove wellposedness of the…