The metric expansion of the Universe

In summary, the metric expansion of space is subject to relativistic effects, making it a concept that can only be formulated within the framework of General Relativity. It is not possible to measure the expansion locally and it is generally believed that the expansion around the Milky Way and Andromeda galaxies will not be significantly different. The expansion is related to Hubble's Law and the cosmological constant, which tends to increase the expansion over time. An expression for the expansion has been derived by Friedmann-Lemaître-Robertson-Walker metric.
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espen180
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I have a few questions ragerding this topic. Any help with either question is appreciated.

Is the metric expansion subject to relativistic effects? Will we measure the expansion of space around the Milky Way to go faster than the expansion around the Andromeda Galaxy?

How is the expansion related to the cosmological constant and Hubble's Law? Has anyone been able to derive an expression for the expansion?
 
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Is the metric expansion subject to relativistic effects?
It is an extremely relativistic effect, as it is mostly "speaking of normal things in unfamiliar coordinates". IOW: outside Gerneral Relativity, you couldn't even formulate such a concept.
Will we measure the expansion of space around the Milky Way to go faster than the expansion around the Andromeda Galaxy?
Short answer: most probably no.
Longer answer: You can't measure expansion locally, the concept is useful only globally, if you regard the universe as a whole.
How is the expansion related to the cosmological constant and Hubble's Law?
Hubble's law is simply another ord for expansion of space - distances increase proportional to distance.
The cosmological constant tends to increase the expansion with time. It is a repulsive "force".
Has anyone been able to derive an expression for the expansion?
Yes, http://en.wikipedia.org/wiki/Friedmann%E2%80%93Lema%C3%AEtre%E2%80%93Robertson%E2%80%93Walker_metric" .
 
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Related to The metric expansion of the Universe

1. What is the metric expansion of the Universe?

The metric expansion of the Universe refers to the phenomenon of the increasing distance between galaxies and other celestial objects over time. It is a key aspect of the Big Bang theory, and is supported by various observations such as the redshift of light from distant galaxies.

2. How does the metric expansion of the Universe occur?

The metric expansion of the Universe is thought to be driven by dark energy, a mysterious force that is causing the expansion of the Universe to accelerate. This acceleration causes the distance between galaxies to increase over time, even though they may not be moving relative to each other.

3. Is the metric expansion of the Universe the same as the expansion of space?

Yes, the metric expansion of the Universe is often referred to as the expansion of space. This is because the expansion is happening at a fundamental level, affecting the very fabric of space itself. As the Universe expands, the space between objects also expands, leading to the observed metric expansion.

4. Is the metric expansion of the Universe happening in all directions?

Yes, the metric expansion of the Universe is happening in all directions. This is known as isotropic expansion, meaning that the expansion is happening uniformly in all directions. However, the expansion rate may vary in different regions of the Universe due to the distribution of matter and energy.

5. Will the metric expansion of the Universe continue forever?

As of now, it is believed that the metric expansion of the Universe will continue forever. This is because the accelerating expansion driven by dark energy shows no signs of slowing down. However, future discoveries and advancements in our understanding of the Universe may lead to a different conclusion.

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