3 papers
gr-qc2025
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-qc2024
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…
gr-qc2024
Dust collapse and horizon formation in Quadratic Gravity
Luca Buoninfante, Francesco Di Filippo, Ivan Kolář +1
Quadratic Gravity supplements the Einstein-Hilbert action by terms quadratic in the spacetime curvature. This leads to a rich phase space of static, compact gravitating objects inc…