Exact Analytical Solutions for Modeling Cosmological Black Holes New Submission

Since the Nobel Prize-winning discovery of the universe's accelerated expansion, cosmology faces a range of unresolved problems. Our research addresses questions related to the nature of this acceleration and its impact on gravitationally bound systems. Specifically, we use exact analytical solutions of the Einstein equations to model cosmological black holes—black holes embedded in an expanding, non-empty universe. We derive and analyze new inhomogeneous solutions within the Lemaitre-Tolman-Bondi class, describing a neutral or charged black hole in a universe filled with various matter types, such as dust, electromagnetic fields, and topological defects. Additionally, we use the multi-component Kiselev solution to model a charged black hole in anisotropic fluids, representing components like a cosmological constant or cosmic strings. We examine the horizon structure of the resulting space-times to further analyze the motion of particles around these black holes, which is essential for identifying observable effects from the interplay of local gravity and cosmic expansion, as well as for testing dark matter and dark energy models in the era of precision cosmology.