SNe Ia Redshift in a Nonadiabatic Universe

Gupta, Ranjana

doi:10.3390/universe4100104

Cited by 16 publications

(30 citation statements)

References 18 publications

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“…The deceleration parameter q 0 has been analytically determined on the premise that expansion of the universe and the tired light phenomena are jointly responsible for the observed redshift, especially in the limit of very low redshift [36]. One could see it as if the tired light effect is superimposed on the Einstein de Sitter's matter only universe rather than the cosmological constant [37]. By equating the expressions for the proper distance of the source of the redshift for the two, one gets q 0 = −0.4.…”

Section: Evolutionary Constants Modelmentioning

confidence: 99%

Varying Physical Constants, Astrometric Anomalies, Redshift and Hubble Units

Gupta¹

2019

Galaxies

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We have developed a cosmological model by allowing the speed of light c, gravitational constant G and cosmological constant Λ in the Einstein filed equation to vary in time, and solved them for Robertson-Walker metric. Assuming the universe is flat and matter dominant at present, we obtain a simple model that can fit the supernovae 1a data with a single parameter almost as well as the standard ΛCDM model with two parameters, and which has the predictive capability superior to the latter. The model, together with the null results for the variation of G from the analysis of lunar laser ranging data determines that at the current time G and c both increase as dG/dt = 5.4GH0 and dc/dt = 1.8cH0 with H0 as the Hubble constant, and Λ decreases as dΛ/dt = −1.2ΛH0. This variation of G and c is all what is needed to account for the Pioneer anomaly, the anomalous secular increase of the moon eccentricity, and the anomalous secular increase of the astronomical unit. We also show that the Planck’s constant ħ increases as dħ/dt = 1.8ħH0 and the ratio D of any Hubble unit to the corresponding Planck unit increases as dD/dt = 1.5DH0. We have shown that it is essential to consider the variation of all the physical constants that may be involved directly or indirectly in a measurement rather than only the one whose variation is of interest.

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Section: Evolutionary Constants Modelmentioning

confidence: 99%

Varying Physical Constants, Astrometric Anomalies, Redshift and Hubble Units

Gupta¹

2019

Galaxies

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“…This model is developed by relaxing the constraint of adiabatic universe used in all the models we have considered above [23]. As per the first law of thermodynamic [14,24]:…”

Section: Einstein De Sitter (Edes-na) Model In Nonadibatic Universementioning

confidence: 99%

“…with β as the proportionality constant (not the same as in plasma cosmology-Equation 17), the proper distance of the redshifted source has been shown to be [23]:…”

Section: Einstein De Sitter (Edes-na) Model In Nonadibatic Universementioning

confidence: 99%

Weighing Cosmological Models with SNe Ia and Gamma Ray Burst Redshift Data

Gupta¹

2019

Universe

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Many models have been proposed to explain the intergalactic redshift using different observational data and different criteria for the goodness-of-fit of a model to the data. The purpose of this paper is to examine several suggested models using the same supernovae Ia data and gamma-ray burst (GRB) data with the same goodness-of-fit criterion and weigh them against the standard Lambda cold dark matter model (ΛCDM). We have used the redshift—distance modulus (z − μ) data for 580 supernovae Ia with 0.015 ≤ z ≤ 1.414 to determine the parameters for each model and then use these model parameter to see how each model fits the sole SNe Ia data at z = 1.914 and the GRB data up to z = 8.1. For the goodness-of-fit criterion, we have used the chi-square probability determined from the weighted least square sum through non-linear regression fit to the data relative to the values predicted by each model. We find that the standard ΛCDM model gives the highest chi-square probability in all cases albeit with a rather small margin over the next best model—the recently introduced nonadiabatic Einstein de Sitter model. We have made (z − μ) projections up to z = 1096 for the best four models. The best two models differ in μ only by 0.328 at z = 1096, a tiny fraction of the measurement errors that are in the high redshift datasets.

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“…where s is given by Eq. (16) and F (φ, k) is Legendres incomplete elliptic integral of the first kind,…”

Section: A New Formula For a Flat-flrw Universementioning

confidence: 99%