Bulletin of the American Physical Society
APS April Meeting 2019
Volume 64, Number 3
Saturday–Tuesday, April 13–16, 2019; Denver, Colorado
Session G16: Cosmology with Gravitational Waves
8:30 AM–10:06 AM,
Sunday, April 14, 2019
Sheraton
Room: Grand Ballroom I
Sponsoring
Units:
DAP DGRAV
Chair: Ken herner, Fermilab
Abstract: G16.00007 : Nonadiabatic universe and the cosmological constant
9:42 AM–9:54 AM
View Presentation Abstract
Presenter:
Rajendra P Gupta
(Macronix Research Corporation)
Author:
Rajendra P Gupta
(Macronix Research Corporation)
We have shown that the Hubble constant H0 embodies the information about the evolutionary nature of the cosmological constant Λ, gravitational constant G, and the speed of light c. By explicitly incorporating the nonadiabatic nature of the universe in the Friedmann equation through the evolution of the energy density, we have derived expressions for the time evolution of G/c2 (≡K) and dark energy density εΛ related to Λ. We found (dK/dt)/K = 1.8H0 and, for redshift z, εΛ,z/εΛ,0 = [0.4+0.6(1+z)-1.5]2. Since the two expressions are related, we believe that the time variation of K (and therefore that of G and c) is manifested as dark energy in cosmological models. When we adapt the standard ΛCDM model for the z dependency of εΛ rather than it being a constant, we obtain surprisingly good results fitting the SNe Ia redshift z vs distance modulus µ data. Even more significant finding is that the new ΛCDM model, when parameterized with z < 0.5 data set, yields significantly better fit to the z > 0.5 data sets than the standard ΛCDM model. Thus the new model may be considered robust and reliable enough for predicting distances of radiation emitting extragalactic redshift sources for which luminosity distance measurement may be difficult, unreliable, or no longer possible.
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