Question Infinity or not infinity that is the question.

[Catastrophe]

No. Not at all.

Every person or conscious being has its own observable universe, including Persimultivons on planet Allivonterox 15 billion light years away; (et cetera). Of course, there are multiple overlaps for those living in close places and times.

Cat

 

[Harry Costas]

I understand

 

[Harry Costas]

I came across this paper, I thought it may be of interest.

[Submitted on 30 Nov 2024]

Simulating Rotating Newtonian Universes​

Balázs Pál, Tze Goh, Gábor Rácz, István Szapudi

We present the results of a novel type of numerical simulation that realizes a rotating Universe with a shear-free, rigid body rotation inspired by a Gödel-like metric. We run cosmological simulations of unperturbed glasses with various degrees of rotation in the Einstein-de Sitter and the ΛCDM cosmologies. To achieve this, we use the StePS N-body code capable of simulating the infinite Universe, overcoming the technical obstacles of classical toroidal (periodic) topologies that would otherwise prevent us from running such simulations. Results show a clear anisotropy between the polar and equatorial expansion rates with more than 1% deviation from the isotropic case for maximal rotation without closed timeline curves within the horizon, ω0≈10−3 Gyr−1; a considerable effect in the era of precision cosmology.

 

[Harry Costas]

I added this paper of interest.

[Submitted on 3 Dec 2024 (v1), last revised 26 Dec 2024 (this version, v2)]

Regular black holes from thin-shell collapse​

Pablo Bueno, Pablo A. Cano, Robie A. Hennigar, Ángel J. Murcia

We establish that regular black holes can form from gravitational collapse. Our model builds on a recent construction that realized regular black holes as exact solutions to purely gravitational theories that incorporate an infinite tower of higher curvature corrections in any dimension D≥5 [arXiv:2403.04827]. We identify a two-dimensional Horndeski theory that captures the spherically symmetric dynamics of the theories in question and use this to prove a Birkhoff theorem and obtain the generalized Israel junction conditions. Armed with these tools, we consider the collapse of thin shells of pressureless matter, showing that this leads generically to the formation of regular black holes. The interior dynamics we uncover is intricate, consisting of shell bounces and white hole explosions into a new universe. The result is that regular black holes are the unique spherically symmetric solutions of the corresponding theories and also the endpoint of gravitational collapse of matter. Along the way, we establish evidence for a solution-independent upper bound on the curvature, suggestive of Markov's limiting curvature hypothesis.