# Tag Info

## New answers tagged dark-matter

6

Short answer: The ratios have changed over time... drastically. This is a consequence of the expansion of our universe. Initially (and by that I mean after the conjectured inflationary epoch, which I will not consider here), radiation dominated all other forms of energy by far. However, as the universe expands---as measured by the increase of the ''scale ...

0

First have a look at my answer to Black holes and positive/negative-energy particles for some background on Hawking radiation. The pairs of virtual particles analogy is just an analogy and not what actually happens. In fact virtual particles don't really exist in the way that real particles do - see this article by Matt Strassler for more on this. But your ...

3

We need to distinguish between the concept of Dark Matter and the potential candidates that fill it's role. Dark matter, as originally posited, was just non-luminous matter that could be inferred only through gravity. As time went on, additional research shed more light on what dark matter was. Both the growth of large scale structure of the universe and ...

0

First off, to say that WIMPs are the basis of dark matter is a little misleading. It's a well motivated model that can explain Dark Matter as well as be evidence of supersymmetry, but we have no experimental evidence to support it. It's still just a theory. Another well motivated candidate are Axions which help solve the Strong CP violation. ADMX is an ...

1

There are suggestions for ways to explain the observed redshift without dark energy. One example is the suggestion that the redshift is related to light undergoing redshift as it passes through matter that is not distributed homogeneously. You say that the laws of physics don't work at the microscopic scale. This is false. Systems at the microscopic scale ...

2

Yes, it's possible and there exist papers that claim to explain many effects normally attributed to dark matter to other parts of new physics like MOND – the Modified Newtonian Gravity. They either add new fields and new local interactions or completely nonlocal interactions, or perhaps try to link these novelties with the holographic principle or other ...

0

They are 2 different concepts. According to the inflationary paradigm, the primordial fluctuations , visible with a contrast scale of $10^5$, are supposed to be the seeds of the galaxies and of the parent structures. Not all is clear but , with the informations which are available, this idea is enough credible to be intensively studied. On another hand, ...

2

The main point to grasp is that the tiny inhomogeneities seen in the CMB are too small (by a factor of 100) to grow into the structures we see today without something like "cold dark matter". The CMB was formed at the epoch when normal (baryonic) matter and the radiation filling the universe decoupled. Only at this point was normal matter free to start ...

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