All Questions
Tagged with dark-energy cosmic-microwave-background
18
questions
1
vote
1
answer
111
views
Could the increasing anisotropy of the universe lead to an additional blueshift?
I'm contemplating the possible sources of a wavelength-shift within our universe:
The CMB had a lot more energy when it was produced (around 3000 K). Due to the expansion of the universe, it has been ...
- 63
2
votes
3
answers
189
views
Will cosmic microwave background become invisible in the future?
If my understanding of CMB and Hubble's Law is correct, then CMB photons emitted from more than ~14.4 Glyr during Recombination Epoch would not reach us. The reason is this would correspond to Hubble'...
- 131
0
votes
0
answers
50
views
$\Lambda$CDM's observations and the universe's matter content
It's known that the current value of the universe's total density parameter $\Omega_0=1$.
According to the $\Lambda$CDM model, the current density parameter of baryonic matter $\Omega_P \sim 0.04$, ...
- 395
1
vote
1
answer
104
views
Given current densities of dark energy, dark matter and normal matter in universe currently, calculate ratio of density of dark matter at CMB to now? [closed]
I stumbled upon this question while preparing for the astronomy Olympiad.
It is question #17 in this pdf.
Given that dark energy is vacuum energy, and that the densities of dark energy, dark matter ...
3
votes
2
answers
361
views
Is the commonly accepted Universe age of 13.8B years really accurate? [closed]
Hmm...challenging the error margin of a specific calculation result of a specific model based on confirmed inconsistencies is regarded as "opinion-based". Interesting. Just curious, is the ...
- 4,452
0
votes
1
answer
331
views
How is Hubble constant measured by the method of observing BAO?
How is Hubble constant measured by the method of observing BAO?By just reading some articles it seems to me a more complex method than the astronomic scale.Can this method be explained in few words to ...
- 1,815
0
votes
0
answers
73
views
Good references to start researching on dark energy knowing only graduate general relativity
I'd like to research on Dark Energy, but I only know (Schutz-Foster-Carroll) general relativity. Can anyone indicate to me some good books to start to research this topic?
I'm interested in how to ...
5
votes
3
answers
796
views
Is the "cosmological constant tension" the prime reason that we believe the expansion of the universe is accelerating?
Background: For a few years now there is significant difference in the calculation of the cosmological constant between standard candles methods and CMB methods. CMB measurement comes from a very ...
- 898
3
votes
1
answer
152
views
Could decaying dark energy solve the Hubble tension? [closed]
The redshift-based distance ladder values of the Hubble constant are higher than that inferred by the cosmic microwave background. This discrepancy in the last few years has become highly ...
- 6,531
3
votes
0
answers
107
views
Are deductions from CMB much less accurate than claimed, owing to approximations in the FLRW model?
My question concerns "timescape cosmology" and measurements of dark energy based on CMB radiation.
The background to the question is
Lawrence H. Dam, Asta Heinesen, David L. Wiltshire,
"Apparent ...
- 59.6k
1
vote
1
answer
142
views
Is dark energy just a cooling effect of CMB?
(1) Cosmic microwave background cooled down from about 3000K billions of years ago to a couple of Kelvin nowadays. (2) Adiabatic expansion causes gas (of photons in this case) to cool. (3) Dark energy ...
- 209
5
votes
2
answers
606
views
Why is the calculated Power Spectrum peak at $l=302$ different from the chart peak at $l=220$?
This is a follow-up to a really basic question I had: How is the first acoustic peak calculated in CMB? Plank quotes an angular size of the sound horizon at 0.0104, but that corresponds to an ...
user32023
10
votes
2
answers
924
views
The Redshift of the CMB vs. Dark Energy
The cosmic microwave background (CMB) radiation comprises about 98% of all electromagnetic radiation in the universe. And, from the creation of the CMB to today that electromagnetic radiation has red ...
- 161
3
votes
1
answer
281
views
What is the mix of ordinary mass vs. ordinary radiating energy in the universe?
I have seen data showing that the estimated mix of dark energy in the universe is 68.3%, the mix of dark matter is 26.8% and the mix of ordinary matter is 4.9%1. However, within "ordinary matter," ...
4
votes
2
answers
444
views
Cosmological triangle with PLANCK results
Is there an updated version of the cosmological triangle with recent PLANCK results included?
- 51