Cosmic Acceleration and Dark Energy
21
4 Conclusion
The model describes a universe that evolves during all the radiation era, matter era,
and the present dark era. According to ω e f f = −0.571 + 0.238
R 0
R
, 0.333 = ω e f f i ≥
ω e f f ≥ −0.571 = ω ef f f , ω e f f f = −0.571 is the restriction on ω e f f to protect the
present accepted size ∼ 10
26 of the universe. It is a flat one as required by the
microwave background fluctuations measured by WMAP. Its expansion is consistent
with the present value of Hubble number. It is presently accelerating as established by
SCP, under the negative dark energy parameter and shift from the phase of deceleration to acceleration occurred in the past at the effective pressure parameter −0.333 as
required by Friedmann equations. The size of the universe at the shift is about 0.718
times the present value (while the CDM has a factor of 0.54). The acceleration
of the universe, according to the model in the late time is decreasing—decreases
to zero as the scale factor tends to infinite, unlike the acceleration of the standard
model which increases linearly with scale factor saving the universe from spending
an infinite amount of energy to produce infinite acceleration. The scale factor of the
universe in the late time is approximately like t
3
2 while standard cosmology has an
exponential function. And finally, it is important to see that it has the potential of
talking about the size of the dark matter parameter.
A simple effective equation of state parameter for the cosmic fluid of the form
described here can be a powerful alternative to the pressure parameter of the standard
model in the light of its strength of predicting cosmological parameters in a simpler
way. It seems the model is capable of describing the universe we are living in when
the values are fine-tuned.
References
1. A. Friedmann, Gen. Rel. Gr. 31, 1991 (1999)
2. WMAP. https://map.gsfc.nasa.gov/
3. S. Perlmutter, Ap. J. 517, 565 (1999)
4. G. Adam, Riess The. Astron. J. 116, 1009 (1998)
5. M. Peter, Garnavich ApJ. 509, 74 (2011)
6. Planck 2015 results arxiv.org/abs/1502.01589 astro-ph (0674450) (2015)
7. A.H. Guth, Phys. Rev., D 23, 347 (1980)
8. D.S. Hajdukovic, arxiv.0908.1047 To appear in Astrophysics and Space science (2016)
21
4 Conclusion
The model describes a universe that evolves during all the radiation era, matter era,
and the present dark era. According to ω e f f = −0.571 + 0.238
R 0
R
, 0.333 = ω e f f i ≥
ω e f f ≥ −0.571 = ω ef f f , ω e f f f = −0.571 is the restriction on ω e f f to protect the
present accepted size ∼ 10
26 of the universe. It is a flat one as required by the
microwave background fluctuations measured by WMAP. Its expansion is consistent
with the present value of Hubble number. It is presently accelerating as established by
SCP, under the negative dark energy parameter and shift from the phase of deceleration to acceleration occurred in the past at the effective pressure parameter −0.333 as
required by Friedmann equations. The size of the universe at the shift is about 0.718
times the present value (while the CDM has a factor of 0.54). The acceleration
of the universe, according to the model in the late time is decreasing—decreases
to zero as the scale factor tends to infinite, unlike the acceleration of the standard
model which increases linearly with scale factor saving the universe from spending
an infinite amount of energy to produce infinite acceleration. The scale factor of the
universe in the late time is approximately like t
3
2 while standard cosmology has an
exponential function. And finally, it is important to see that it has the potential of
talking about the size of the dark matter parameter.
A simple effective equation of state parameter for the cosmic fluid of the form
described here can be a powerful alternative to the pressure parameter of the standard
model in the light of its strength of predicting cosmological parameters in a simpler
way. It seems the model is capable of describing the universe we are living in when
the values are fine-tuned.
References
1. A. Friedmann, Gen. Rel. Gr. 31, 1991 (1999)
2. WMAP. https://map.gsfc.nasa.gov/
3. S. Perlmutter, Ap. J. 517, 565 (1999)
4. G. Adam, Riess The. Astron. J. 116, 1009 (1998)
5. M. Peter, Garnavich ApJ. 509, 74 (2011)
6. Planck 2015 results arxiv.org/abs/1502.01589 astro-ph (0674450) (2015)
7. A.H. Guth, Phys. Rev., D 23, 347 (1980)
8. D.S. Hajdukovic, arxiv.0908.1047 To appear in Astrophysics and Space science (2016)