2019/01/24 by Daniela Pérez, Gustavo E. Romero, Luciano Combi +3
Physics and Astronomy · #Astrophysical Phenomena and Observations #Black Holes and Theoretical Physics #Classical mechanics #Conformal map #Cosmology #Cosmology and Gravitation Theories #Dark energy #Einstein #Einstein field equations #Equations of motion #General relativity #Geodesic #Geometry #Gravitation #Gravitational singularity #Massless particle #Mathematical physics #Metric expansion of space #Physics #Quantum mechanics #Schwarzschild metric #Schwarzschild radius #Solving the geodesic equations #Spacetime #Theoretical physics #Universe #astro-ph.CO #gr-qc
paper · pdf · doi:10.1088/1361-6382/ab0189
15 pages, 12 figures, accepted for publication in Classical and Quantum Gravity
openalex publication_date 2019/01/24 · arxiv created 2019/01/28 · arxiv updated 2019/01/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Abstract There are several solutions of Einstein field equations that describe an inhomogeneity in an expanding universe. Among these solutions, the McVittie metric and its generalizations have been investigated through decades, though a full understanding of them is still lacking. In this note, we explore the trajectories of photons and massive particles in generalized McVittie spacetimes. In the case of massless particles, we show that no circular orbits are possible for those models that admit cosmological singularities. We also analyze the trajectory of particles for a specific generalized McVittie spacetime that is conformal to the Schwarzschild metric. By integrating the equations of motion in the Newtonian approximation, we show that particles behave in quite distinctive ways in different cosmological black hole solutions. We conclude that the analysis of the geodetic motion in inhomogeneous expanding metrics can help to discriminate those solutions that represent real cosmological black holes in the universe.