All Questions
Tagged with dark-energy universe
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Dark energy and conservation of energy in General relativity [duplicate]
i know that conservation of energy in general relativity has been discussed multiple times here at PE, a popular explanation on the topic is Sean Carroll's blog "Energy is not conserved" ...
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Is Dark Energy Taking Over?
First question, trying to keep it simple 😃
Because it's constant it grows in magnitude as the universe expands, whereas normal matter does not? Is this accurate as far as we know?
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The speed of expansion of space in big freeze
In the case of big freeze, space expansion will be accelerating and there appears to be a lot of different phenomena occurring. However, in the case of big rip, the expansion is super-accelerating so ...
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What exactly do astrophysicists mean when they say that the universe is expanding at an accelerated rate? [duplicate]
What exactly do astrophysicists mean when they say that the universe is expanding at an accelerated rate? Assuming that the universe is a sphere, do they mean that the radius of the universe increases ...
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What is the estimated velocity of expansion at the beginning of the Dark Energy era?
Approximately 7.5 billion year ago Dark energy began to accelerate the expansion of the universe. Data has shown us that up until that time the universe was decelerating in its expansion velocity. ...
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The size of the universe and the scale factor of $\Lambda$CDM model
I wonder is there a relation between the size of the universe and the scale factor calculated by solving Friedmann equations.
I mean if the volume of the universe nowadays is a round $V= 10^{78} m^3$, ...
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The values of the universe’s scale factor at the different eras of the universe’s evolution
I’m reading this paper:
A unified geometric description of the Universe....
In Fig. (1) they show the different values of the universe’s scale factor at the different eras of the universe’s time ...
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What is the exact ratio of dark energy to mass?
I need to know the exact ratio between mass and dark energy (total dark energy in the universe / total mass in the universe). I could only find it to 2 decimal points (0.68). I need this to make this ...
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Shape of the universe as dark energy starts to dominate
We say that the universe has a particular shape (flat, sphere or saddle) depending on what the ratio between the average energy density and the critical energy density is, something we call $\Omega$.
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How could the universe be spatially flat on average, if all forms of energy have positive spatial curvature?
EDIT: I stated the current understanding wrong, thanks Koschi for the comment.
In the $\Lambda$CDM model, it's said that the vacuum energy pretty much "balances" the baryonic matter, such ...
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What is the dark energy & dark matter? [duplicate]
Can anyone explain to me simply what is the dark energy or what is the dark matter. I have been trying to understand it deeply. but I somehow failed.
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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 ...
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Is the present (total) pressure in the universe negative?
I read from cosmological books that the pressure associated with the dark energy component, which is responsible for the accelerating expansion of the universe, is negative. Is the total pressure of ...
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What is the equation that tells us that the universe is expanding?
Well I know that the universe is expanding, but is there any equation or letter or simply just an expression that tells us that the universe is expanding...
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Does the Hubble constant measured for huge distances mean it is not the actual Hubble constant but a very old one?
I am citing Wikipedia about Hubble constant....
"Hubble constant is most frequently quoted in (km/s)/Mpc, thus giving the speed in km/s of a galaxy 1 megaparsec (3.09×1019 km) away, and its value ...
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