Friedrich Philipp

activity

20102023

most citedInfinite-dimensional port-Hamiltonian systems -- a system node approach

3 citations · 9 across the 8 of their papers we have counts for

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4 papers · 1 filter

math.SP2014

Spectral Points of Type $π_{+}$ and Type $π_{-}$ of Closed Operators in Indefinite Inner Product Spaces

Friedrich Philipp, Carsten Trunk

We introduce the notion of spectral points of type $π_{+}$ and type $π_{-}$ of closed operators $A$ in a Hilbert space which is equipped with an indefinite inner product. It is shown t…

math.SP2012

Local spectral theory for normal operators in Krein spaces

Friedrich Philipp, Vladimir Strauss, Carsten Trunk

Sign type spectra are an important tool in the investigation of spectral properties of selfadjoint operators in Krein spaces. It is our aim to show that also sign type spectra for…

math.SP2012★ 2 cited

Bounds on the non-real spectrum of differential operators with indefinite weights

Jussi Behrndt, Friedrich Philipp, Carsten Trunk

Ordinary and partial differential operators with an indefinite weight function can be viewed as bounded perturbations of non-negative operators in Krein spaces. Under the assumptio…

math.SP2010★ 1 cited

Local Definitizability of $T^{[]} T$ and $T T^{[]}$

Friedrich Philipp, André C. M. Ran, Michał Wojtylak

The spectral properties of two products $A B$ and $B A$ of possibly unbounded operators $A$ and $B$ in a Banach space are considered. The results are applied in the comparison of loc…

Spectral Points of Type π+​ and Type π−​ of Closed Operators in Indefinite Inner Product Spaces

Local spectral theory for normal operators in Krein spaces

Bounds on the non-real spectrum of differential operators with indefinite weights

Local Definitizability of T[∗]T and TT[∗]

Spectral Points of Type $π_{+}$ and Type $π_{-}$ of Closed Operators in Indefinite Inner Product Spaces

Local Definitizability of $T^{[]} T$ and $T T^{[]}$