3 papers
math.DG2026
Toric gravitational instantons with four fixed points
Lars Andersson, Mattias Dahl, Gustav Nilsson
We classify the simply connected toric gravitational instantons whose torus action has four fixed points. They are the hyperkähler multi-Eguchi--Hanson and multi-Taub--NUT metrics…
math.DG2026
On the Geroch conjecture for toric gravitational instantons
Lars Andersson, Mattias Dahl, Gustav Nilsson
Geroch conjectured that the local solutions of the vacuum Einstein equations with two commuting Killing fields and vanishing twist constants are generated from flat space by an inf…
gr-qc2024
Mode Stability of Hermitian Instantons
Lars Andersson, Bernardo Araneda, Mattias Dahl
In this note, we prove the Riemannian analog of black hole mode stability for Hermitian, non-self-dual gravitational instantons which are either asymptotically locally flat (ALF) a…