47 citations · 124 across the 33 of their papers we have counts for
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math.FA2012
The numerical range of non-negative operators in Krein spaces
Friedrich Philipp, Carsten Trunk
We define and characterize the Krein space numerical range and the Krein space co-numerical range of a non-negative operator in a Krein space. It is show…
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…