28 citations · 46 across the 11 of their papers we have counts for
7 papers · 1 filter
Quasi-topological gravity for 4-dimensional Taub-NUT, near-horizon extreme Kerr, and swirling symmetries
Aimeric Colléaux, Ivan Kolář, Tomáš Málek
We classify 4-dimensional gravitational theories with integrability properties analogous to quasi-topological gravity, but for metrics with the symmetries of spherical, hyperbolic,…
Static spherically symmetric Kundt vacuum solutions of higher-derivative gravities
Breno L. Giacchini, Ivan Kolář, Vojtěch Pravda +1
We study static spherically symmetric Kundt solutions to the vacuum field equations of quadratic gravity with a cosmological constant, as well as specific models of six-derivative…
Canonical quantization of all minisuperspaces with consistent symmetry reductions
Poula Tadros, Ivan Kolář, Otakar Svítek
We present the quantization of all symmetry reductions of the Einstein--Hilbert Lagrangian that correctly reproduce the reduced Einstein's field equations -- i.e., characterized by…
Double Wick rotations between symmetries of Taub-NUT, near-horizon extreme Kerr, and swirling spacetimes
Aimeric Colléaux, Ivan Kolář, Tomáš Málek
We explicitly show that certain 4-dimensional infinitesimal group actions with 3-dimensional orbits are related by double Wick rotations. In particular, starting with the symmetrie…
Neglected solutions in quadratic gravity
Breno L. Giacchini, Ivan Kolář
We report on several previously overlooked families of static spherically symmetric solutions in quadratic gravity. Our main result concerns the existence of solutions whose leadin…
Black holes and other exact solutions in six-derivative gravity
Breno L. Giacchini, Ivan Kolář
We study exact static spherically symmetric vacuum solutions in generic six-derivative gravity (i.e., without assuming specific relations between the coupling constants). Using mod…
Non-local scalar fields in static spacetimes via heat kernels
Ivan Kolář
We solve the non-local equation for i) static scalar fields in static spacetimes and ii) time-dependent scalar fields in ultrastatic spacetimes. C…