3 papers
gr-qc2026
Exact Bachian singularity in quadratic gravity
Simon Knoska, David Kofron, Robert Svarc
For specifically coupled values of the quadratic gravity parameters, we present a fully explicit static spherically symmetric solution. It contains the central singularity surround…
gr-qc2025
Linear perturbations of Kerr black hole in quadratic gravity
Simon Knoska, David Kofron, Robert Svarc
Employing the Newman-Penrose formalism and following the classic Teukolsky-like approach, we linearise the field equations of quadratic gravity on the Kerr background and combine t…
gr-qc2025
Initial data for a deformed isolated horizon
AleÅ¡ Flandera, David KofroÅ, Tomáš Ledvinka
Within the isolated horizon formalism, we investigate a static axisymmetric space-time of a black hole influenced by matter in its neighborhood. To illustrate the role of ingredien…