114 citations · 767 across the 136 of their papers we have counts for
10 papers · 1 filter
Stability of square root domains associated with elliptic systems of PDEs on nonsmooth domains
Fritz Gesztesy, Steve Hofmann, Roger Nichols
We discuss stability of square root domains for uniformly elliptic partial differential operators in , with mixed boundary conditions on…
On a problem in eigenvalue perturbation theory
Fritz Gesztesy, Sergey N. Naboko, Roger Nichols
We consider additive perturbations of the type , , where and are self-adjoint operators in a separable Hilbert space and is boun…
Some Operator Bounds Employing Complex Interpolation Revisited
Fritz Gesztesy, Yuri Latushkin, Fedor Sukochev +1
We revisit and extend known bounds on operator-valued functions of the type $$ T_1^{-z} S T_2^{-1+z}, \quad z \in \ol Σ= \{z\in\bbC\,|\, \Re(z) \in [0,1]\}, $$ under various hypoth…
On Factorizations of Analytic Operator-Valued Functions and Eigenvalue Multiplicity Questions
Fritz Gesztesy, Helge Holden, Roger Nichols
We study several natural multiplicity questions that arise in the context of the Birman-Schwinger principle applied to non-self-adjoint operators. In particular, we re-prove (and e…
A Jost-Pais-type reduction of Fredholm determinants and some applications
Alan Carey, Fritz Gesztesy, Denis Potapov +2
We study the analog of semi-separable integral kernels in $\cH$ of the type {equation*} K(x,x')={cases} F_1(x)G_1(x'), & a<x'< x< b, \\ F_2(x)G_2(x'), & a<x<x'<b, {cases} {equation…
A Jost-Pais-type reduction of (modified) Fredholm determinants for semi-separable operators in infinite dimensions
Fritz Gesztesy, Roger Nichols
We study the analog of semi-separable integral kernels in of the type $$ K(x,x')=\begin{cases} F_1(x)G_1(x'), & a<x'< x< b, \\ F_2(x)G_2(x'), & a<x<x'<b, \end{cases}…