科研之友
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摘要
The hypothesis is made that, at large scales where general relativity may be applied, empty space is scale invariant. This establishes a relation between the cosmological constant and the scale factor. of the scale-invariant framework. This relation brings major simplifications in the scale-invariant equations for cosmology, which contain a new term, depending on the derivative of the scale factor, that opposes gravity and produces an accelerated expansion. The displacements due to the acceleration term make a high contribution Omega(lambda) to the energy density of the universe, satisfying an equation of the form Omega(m)+ Omega(k)+ Omega(lambda) = 1. The models do not demand the existence of unknown particles. There is a family of flat models with different density parameters Omega(m) < 1. Numerical integrations of the cosmological equations for different values of the curvature and density parameter k and Wm are performed. The presence of even tiny amounts of matter in the universe tends to kill scale invariance. The point is that for Omega(m) = 0.3 the effect is not yet completely killed. Models with non-zero density start explosively with a braking phase followed by a continuously accelerating expansion. Several observational properties are examined, in particular the distances, the m-z diagram, and the Wm versus Wl plot. Comparisons with observations are also performed for the Hubble constant H-0 versus Omega(m), for the expansion history in the plot II (z)/(z+ 1) versus redshift z, and for the transition redshift from braking to acceleration. These first dynamical tests are satisfied by scale-invariant models, which thus deserve further study.
- 出版日期2017-1-10
