activity
20242026
collaborators

9 papers

gr-qc2026

Rotating near-horizon extreme geometries in quadratic gravity

Breno L. Giacchini, Ivan Kolář

Rotating near-horizon extreme solutions of quadratic gravity are analyzed combining power series expansions and numerical calculations. Restricting to geometries with symmetries of…

gr-qc2026

Conical singularity in spacetimes with NUT is observer-dependent

Ivan Kolář, Pavel Krtouš, Maciej Ossowski

We discuss the issue of defining and measuring conical deficits (conicity) in spacetimes with the torsion singularity such as the Misner string in Taub--NUT spacetime. We propose a…

gr-qc2026

Carroll black holes in (A)dS and their higher-derivative modifications

Poula Tadros, Ivan Kolář

We define the Carrollian black holes corresponding to the limit of Schwarzschild-(A)dS spacetime and its higher-derivative counterpart known as Schwarzschild-Bach-(A)dS spacetime,…

gr-qc2026

Uniqueness of Galilean and Carrollian limits of gravitational theories and application to higher derivative gravity

Poula Tadros, Ivan Kolář

We show that the seemingly different methods used to derive non-Lorentzian (Galilean and Carrollian) gravitational theories from Lorentzian ones are equivalent. Specifically, the p…

gr-qc2026

Carrollian limit of quadratic gravity

Poula Tadros, Ivan Kolář

We study the Carrollian limit of the (general) quadratic gravity in four dimensions. We find that in order for the Carrollian theory to be a modification of the Carrollian limit of…

gr-qc2025

Symmetry reduction of gravitational Lagrangians

Guillermo Frausto, Ivan Kolář, Tomáš Málek +1

We analyze all possible symmetry reductions of Lagrangians that yield fully equivalent field equations for any 4-dimensional metric theory of gravity. Specifically, we present a co…