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Main Author: Wong, James C. C.
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2506.05423
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author Wong, James C. C.
author_facet Wong, James C. C.
contents Phantom dark energy from DESI DR2 BAO [1]-[3] and bservations of Supermassive Black Hole (SMBH) at very high redshift present two new challenges in cosmology and astrophysics. In this work, we show that both problems can be addressed by considering the possibility that any single cosmic background fluid is described by a FLRW metric with its own comoving frame, but these frames are relatively non-comoving with one another. This idea is used to model the peculiar velocities of galaxies. In Lemaitre-Tolman formulation, a solution for a particle's free fall velocity in this mixed fluid is given by adding free fall velocities due to individual fluid components. We find that the Hubble parameter in this model is consistent with Cosmic Chronometers (CC) and DESI DR2 data upto z<2.33, while matching the observed CMB acoustic angular scale constraint. We use this new solution to examine the SMBH formation timeline and find that the lapse between redshifts increases and provides sufficient cosmological time for the formation of SMBHs at high redshifts.t
format Preprint
id arxiv_https___arxiv_org_abs_2506_05423
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle An Alternative Hubble parameter: Explaining DESI data and High redshift Supermassive Black Hole
Wong, James C. C.
Astrophysics of Galaxies
Phantom dark energy from DESI DR2 BAO [1]-[3] and bservations of Supermassive Black Hole (SMBH) at very high redshift present two new challenges in cosmology and astrophysics. In this work, we show that both problems can be addressed by considering the possibility that any single cosmic background fluid is described by a FLRW metric with its own comoving frame, but these frames are relatively non-comoving with one another. This idea is used to model the peculiar velocities of galaxies. In Lemaitre-Tolman formulation, a solution for a particle's free fall velocity in this mixed fluid is given by adding free fall velocities due to individual fluid components. We find that the Hubble parameter in this model is consistent with Cosmic Chronometers (CC) and DESI DR2 data upto z<2.33, while matching the observed CMB acoustic angular scale constraint. We use this new solution to examine the SMBH formation timeline and find that the lapse between redshifts increases and provides sufficient cosmological time for the formation of SMBHs at high redshifts.t
title An Alternative Hubble parameter: Explaining DESI data and High redshift Supermassive Black Hole
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2506.05423