activity
20092025
most citedThe Dirichlet-to-Neumann operator via hidden compactness

71 citations · 80 across the 7 of their papers we have counts for

collaborators

8 papers

math.SP2025

Positivity properties of the Dirichlet-to-Neumann operator on graphs

Daniel Daners, Jochen Glück, James B. Kennedy

We explore positivity properties of the semigroup generated by the negative of the Dirichlet-to-Neumann operator with real potential , defined on a subset of the vertices of a q…

math.SP2024

On the hot spots conjecture in higher dimensions

James B. Kennedy, Jonathan Rohleder

We prove a strong form of the hot spots conjecture for a class of domains in which are a natural generalization of the lip domains of Atar and Burdzy [J. Amer. Math.…

math.SP2023

Geometric spectral theory of quantum graphs

James Kennedy

These are lecture notes from a course given at the summer school "Heat kernels and spectral geometry: from manifolds to graphs" in Bregenz, Austria, 2022. They are designed to be a…

math.AP2017★ 1 cited

A toy Neumann analogue of the nodal line conjecture

J. B. Kennedy

We introduce an analogue of Payne's nodal line conjecture, which asserts that the nodal (zero) set of any eigenfunction associated with the second eigenvalue of the Dirichlet Lapla…

math.AP2013

Analytical aspects of isospectral drums

W. Arendt, A. F. M. ter Elst, J. B. Kennedy

We reexamine the proofs of isospectrality of the counterexample domains to Kac' question `Can one hear the shape of a drum?' from an analytical viewpoint. We reformulate isospectra…

math.AP2013★ 71 cited

The Dirichlet-to-Neumann operator via hidden compactness

W. Arendt, A. F. M. ter Elst, J. B. Kennedy +1

We show that to each symmetric elliptic operator of the form \[ \mathcal{A} = - \sum \partial_k \, a_{kl} \, \partial_l + c \] on a bounded Lipschitz domain …

math.AP2010★ 2 cited

Closed nodal surfaces for simply connected domains in higher dimensions

J. B. Kennedy

We give an example of a domain in dimension , homeomorphic to a ball and with analytic boundary, for which the second eigenvalue of the Dirichlet Laplacian has an eigenfu…

math.AP2009★ 6 cited

Some remarks on the isoperimetric problem for the higher eigenvalues of the Robin and Wentzell Laplacians

J. B. Kennedy

We consider the problem of minimising the th eigenvalue, , of the (-)Laplacian with Robin boundary conditions with respect to all domains in of given…