Question BIG BANG EVIDENCE

[Harry Costas]

Keep SEarching how the universe works

[Submitted on 15 Dec 2024]

Cosmic reverberations on a constrained f(Q,T)-model of the Universe​

Akanksha Singh, Shaily, J. K. Singh

In this paper, we construct an isotropic cosmological model in the f(Q,T) theory of gravity in the frame of a flat FLRW spacetime being Q the non-metricity tensor and T the trace of the energy-momentum tensor. The gravity function is taken to be a quadratic equation, f(Q,T)=ζQ2+γT, where ζ<0 and γ are the arbitrary constants. We constrain the model parameters α and H0 using the recent observational datasets: the Hubble dataset (OHD), the Pantheon dataset of 1048 points, and the joint dataset (OHD + Pantheon). The universe model transits from an early deceleration state to an acceleration in late times. This model also provides the ekpyrotic phase of the universe on the high redshift z>12.32. In this model, the Big Bang is described as a collision of branes, and thus, the Big Bang is not the beginning of time. Before the Big Bang, there is an ekpyrotic phase with the equation of state ω>>1. In late times, the undeviating Hubble measurements reduce the H0 tension in the reconstructed f(Q,T) function. Additionally, we study various physical parameters of the model. Finally, our model describes a quintessence dark energy model at later times.

 

[Harry Costas]

I take this paper with a pinch of salt.
Make your own mind about this paper.
They make up time to their own narrative.
Maybe I'm wrong.

[Submitted on 16 Dec 2024]

The Age-Thickness Relation of the Milky Way Disk: A Tracer of Galactic Merging History​

Lekshmi Thulasidharan, Elena D'Onghia, Robert Benjamin, Ronald Drimmel, Eloisa Poggio, Anna Queiroz

The prevailing model of galaxy formation proposes that galaxies like the Milky Way are built through a series of mergers with smaller galaxies over time. However, the exact details of the Milky Way's assembly history remain uncertain. In this study, we show that the Milky Way's merger history is uniquely encoded in the vertical thickness of its stellar disk. By leveraging age estimates from the value-added LAMOST DR8 catalog and the StarHorse ages from SDSS-IV DR12 data, we investigate the relationship between disk thickness and stellar ages in the Milky Way using a sample comprising Red Giants (RG), Red Clump Giants (RCG), and metal-poor stars (MPS). Guided by the IllustrisTNG50 simulations, we show that an increase in the dispersion of the vertical displacement of stars in the disk traces its merger history. This analysis reveals the epoch of a major merger event that assembled the Milky Way approximately 11.13 billion years ago, as indicated by the abrupt increase in disk thickness among stars of that age, likely corresponding to the Gaia-Sausage Enceladus (GSE) event. The data do not exclude an earlier major merger, which may have occurred about 1.3 billion years after the Big Bang. Furthermore, the analysis suggests that the geometric thick disk of the Milky Way was formed around 11.13 billion years ago, followed by a transition period of approximately 2.6 billion years leading to the formation of the geometric thin disk, illustrating the galaxy's structural evolution. Additionally, we identified three more recent events -- 5.20 billion, 2.02 billion, and 0.22 billion years ago -- potentially linked to multiple passages of the Sagittarius dwarf galaxy. Our study not only elucidates the complex mass assembly history of the Milky Way and highlights its past interactions but also introduces a refined method for examining the merger histories of external galaxies.

 

[Harry Costas]

Another paper that has to be taken with a pinch of salt.
With all the information and Deep Field Images, one cannot age the Universe to 7.8 Billion Years.
Knowing quite well there a Billions of Galaxies before the Big Bang.

So! what's cooking?


[Submitted on 17 Dec 2024]

Emergent Universe in f(Q) gravity theories​

Hamid Shabani, Avik De, Tee-How Loo

One resolution of the ancient cosmic singularity, i.e., the Big Bang Singularity (BBS), is to assume an inflationary stage preceded by a long enough static state in which the universe and its physical properties would oscillate around certain equilibrium points. The early period is referred to as the Einstein Static (ES) Universe phase, which characterizes a static phase with positive spatial curvature. A stable Einstein static state can serve as a substitute for BBS, followed by an inflationary period known as the Emergent Scenario. The initial need has not been fulfilled within the context of General Relativity, prompting the investigation of modified theories of gravity. The current research aims to find such a solution within the framework of symmetric teleparallel gravity, specifically in the trendy f(Q) theories. An analysis has been conducted to investigate stable solutions for both positively and negatively curved spatial FRW universes, in the presence of a perfect fluid, by utilizing various torsion-free and curvature-free affine connections. Additionally, we propose a method to facilitate an exit from a stable ES to a subsequent inflationary phase. We demonstrate that f(Q) gravity theories have the ability to accurately depict the emergence of the universe.