Question BIG BANG EVIDENCE

[Harry Costas]

The Cosmo images show us a recycling bounce.
Small big bangs in an ever-ending story.

 

[Harry Costas]

I'm sharing these papers so that you can form your own opinion.
Expressing my opinion.
Re-cycling bangs seems the way to go.
This can be proven.
Rather than trying to explain how trillions of Galaxies formed within 13.8 billion years.

[Submitted on 29 Aug 2024]

A new approach in classical Klein-Gordon cosmology: "Small Bangs", inflation and Dark Energy​

Eleni-Alexandra Kontou, Nicolai Rothe

In this work, we analyze the cosmological model in which the expansion is driven by a classical, free Klein-Gordon field on a flat, four-dimensional Friedmann-Lemaître-Robertson-Walker spacetime. The model allows for arbitrary mass, non-zero cosmological constant and coupling to curvature. We find that there are strong restrictions to the parameter space, due to the requirement for the reality of the field values. At early cosmological times, we observe Big Bang singularities, solutions where the scale factor asymptotically approaches zero, and Small Bangs. The latter are solutions for which the Hubble parameter diverges at a finite value of the scale factor. They appear generically in our model for certain curvature couplings. An early inflationary era is observed for a specific value of the curvature coupling without further assumptions (unlike in many other inflationary models). A late-time Dark Energy period is present for all solutions with positive cosmological constant, numerically suggesting that a "cosmic no-hair" theorem holds under more general assumptions than the original Wald version which relies on classical energy conditions. The classical fields in consideration can be viewed as resembling one-point functions of a semiclassical model, in which the cosmological expansion is driven by a quantum field.

 

[Harry Costas]

The more we have research the more we learn.
What was before and how things happen after is part of the understanding.

[Submitted on 3 Sep 2024]

Investigating early and late-time epochs in f(Q) gravity​

Ameya Kolhatkar, Sai Swagat Mishra, P.K. Sahoo

In the following work, a new hybrid model of the form f(Q)=Q(1+a)+bQ20Q has been proposed and confronted using both early as well as late-time constraints. We first use conditions from the era of Big Bang Nucleosynthesis (BBN) in order to constrain the models which are further used to study the evolution of the Universe through the deceleration parameter. This methodology is employed for the hybrid model as well as a simple model of the form α1Q+α2Q0 which is found to reduce to ΛCDM. The error bar plot for the Cosmic Chronometer (CC) and Pantheon+SH0ES datasets which includes the comparison with ΛCDM, has been studied for the constrained hybrid model. Additionally, we perform a Monte Carlo Markov Chain (MCMC) sampling of the model against three datasets -- CC, Pantheon+SH0ES, and Baryon Acoustic Oscillations (BAO) to find the best-fit ranges of the free parameters. It is found that the constraint range of the model parameter (a) from the BBN study has a region of overlap with the ranges obtained from the MCMC analysis. Finally, we perform a statistical comparison between our model and the ΛCDM model using AIC and BIC method.

 

[Harry Costas]

You try to fit the model when you assume that the BBT is correct.

[Submitted on 3 Sep 2024]

Cosmology using numerical relativity​

Josu C. Aurrekoetxea, Katy Clough, Eugene A. Lim

This review is an up-to-date account of the use of numerical relativity to study dynamical, strong-gravity environments in a cosmological context. First, we provide a gentle introduction into the use of numerical relativity in solving cosmological spacetimes, aimed at both cosmologists and numerical relativists. Second, we survey the present body of work, focusing on general relativistic simulations without approximations, organised according to the cosmological history -- from cosmogenesis, through the early hot Big Bang, to the late-time evolution of universe. In both cases, we discuss the present state-of-the-art, and suggest directions in which future work can be fruitfully pursued.

 

[Harry Costas]

Read this and make up your own mind.

[Submitted on 22 Aug 2024]

Observable Signatures of No-Scale Supergravity in NANOGrav​

Spyros Basilakos, Dimitri V. Nanopoulos, Theodoros Papanikolaou, Emmanuel N. Saridakis, Charalampos Tzerefos

In light of NANOGrav data we provide for the first time possible observational signatures of Superstring theory. Firstly, we work with inflection-point inflationary potentials naturally realised within Wess-Zumino type no-scale Supergravity, which give rise to the formation of microscopic primordial black holes (PBHs) triggering an early matter-dominated era (eMD) and evaporating before Big Bang Nucleosythesis (BBN). Remarkably, we obtain an abundant production of primordial gravitational waves (PGW) at the frequency ranges of nHz, Hz and kHz and in strong agreement with Pulsar Time Array (PTA) GW data. This PGW background could serve as a compelling observational signature for the presence of quantum gravity via no-scale Supergravity.

 

[Harry Costas]

Is this evidence assumed evidence or is it just an opinion?

[Submitted on 5 Sep 2024]

RUBIES Reveals a Massive Quiescent Galaxy at z=7.3​

Andrea Weibel, Anna de Graaff, David J. Setton, Tim B. Miller, Pascal A. Oesch, Gabriel Brammer, Claudia D.P. Lagos, Katherine E. Whitaker, Christina C. Williams, Josephine F.W. Baggen, Rachel Bezanson, Leindert A. Boogaard, Nikko J. Cleri, Jenny E. Greene, Michaela Hirschmann, Raphael E. Hviding, Adarsh Kuruvanthodi, Ivo Labbé, Joel Leja, Michael V. Maseda, Jorryt Matthee, Ian McConachie, Rohan P. Naidu, Guido Roberts-Borsani, Daniel Schaerer, Katherine A. Suess, Francesco Valentino, Pieter van Dokkum, Bingjie Wang

We report the spectroscopic discovery of a massive quiescent galaxy at zspec=7.29±0.01, just ∼700Myr after the Big Bang. RUBIES-UDS-QG-z7 was selected from public JWST/NIRCam and MIRI imaging from the PRIMER survey and observed with JWST/NIRSpec as part of RUBIES. The NIRSpec/PRISM spectrum reveals one of the strongest Balmer breaks observed thus far at z>6, no emission lines, but tentative Balmer and Ca absorption features, as well as a Lyman break. Simultaneous modeling of the NIRSpec/PRISM spectrum and NIRCam and MIRI photometry (spanning 0.9−18μm) shows that the galaxy formed a stellar mass of log(M∗/M⊙)=10.23+0.04−0.04 in a rapid ∼100−200Myr burst of star formation at z∼8−9, and ceased forming stars by z∼8 resulting in logsSFR/yr−1<−10. We measure a small physical size of 209+33−24pc, which implies a high stellar mass surface density within the effective radius of log(Σ∗,e/M⊙kpc−2)=10.85+0.11−0.12 comparable to the densities measured in quiescent galaxies at z∼2−5. The 3D stellar mass density profile of RUBIES-UDS-QG-z7 is remarkably similar to the central densities of local massive ellipticals, suggesting that at least some of their cores may have already been in place at z>7. The discovery of RUBIES-UDS-QG-z7 has strong implications for galaxy formation models: the estimated number density of quiescent galaxies at z∼7 is >100× larger than predicted from any model to date, indicating that quiescent galaxies have formed earlier than previously expected.

 

[Harry Costas]

Nucleosynthesis is the process of quantum matter ejected from the center of compact cores and reforming atoms and complex matter. The BBT scientists have labeled it as the Big Bang Nucleosynthesis without evidence unless I'm missing something.​

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Big Bang Nucleosynthesis​

Ryan Cooke (Centre for Extragalactic Astronomy, Durham University)

One of the most compelling pieces of evidence of the Hot Big Bang model is the realisation and confirmation that some nuclides were created shortly after the Big Bang. This process is referred to as Big Bang nucleosynthesis (or, sometimes, primordial nucleosynthesis), and is the end-product of putting neutrons and protons in a hot, expanding Universe. Big Bang nucleosynthesis currently provides our earliest test of cosmology, and it is the only experiment currently designed that is simultaneously sensitive to all four known fundamental forces: the gravitational force, the electromagnetic force, the strong force and the weak force. Our theoretical understanding of Big Bang nucleosynthesis and the measurement of the primordial abundances together represents one of the strongest pillars of the standard cosmological model. In this chapter, we will develop an intuitive understanding of Big Bang nucleosynthesis, discuss modern calculations of this process, and provide a summary of the current state-of-the-art measurements that have been made. Overall, Big Bang nucleosynthesis is in remarkable agreement with various cosmological probes, and it is this agreement that serves to strengthen our confidence in the general picture of cosmology that we have today.