Well, Mr. CrankyPants. I was talking in terms that everyone can understand. I deeply apologize for confusing you. When you politely requested that I get to the theme of the thread, I did exactly that. The theme is "Do you believe in gravity?"
No amount of name-calling on your part can hide the fact that you are not answering any of my questions.
No need to shout Mr. Nums. The quantum froth problem is much much more theoretically difficult than the problem you are referring to. 10 or 11 dimensional spaces you know.
So, you wish to discuss a theory involving n-dimensions when no experimental verification of it is even possible at this time?
10 or 11 dimensions, indeed!
But if you are worried about high velocity of expansion, I will try to be real terse so you won't fall asleep and hit your head on your keyboard. Yes, what is also in vogue these days on the gee whiz science news is dark matter and dark energy, which complicates the big picture a bit, and seems to be a repulsive force. But not to worry, the lambda constant was worked by A. Einstein long ago, and now we have a use for it.
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Einstein inserted the cosmological constant to derive a steady state universe. Without it, space-time geometry would be spherical, and nothing would stop the universe from contracting on itself.
Lambda is just a parameter built into the theory. Albert overreacted when he put it in, and was a bit hasty, but now it's useful.
All terms of the field equation represent a particular parameter.
Do you even know what you are saying or are you just trying to be amusing for mare's benefit?
Here, you might want to refresh your memory:
http://en.wikipedia.org/wiki/Cosmological_constant
The cosmological constant has the same effect as an
intrinsic energy density of the vacuum, ρvac (and an associated pressure). In this context it is commonly defined with a proportionality factor of 8π: Λ = 8πρvac, where modern unit conventions of general relativity are followed (otherwise factors of G and c would also appear). It is common to quote values of energy density directly, though still using the name "cosmological constant".
Other than the gravity due to mass and energy, no other 'parameter' affects the geometry of space-time except lambda.
You might want to recall this too:
In lieu of the cosmological constant, cosmologists often quote the ratio between the energy density due to the cosmological constant and the
critical density of the universe. This ratio is usually called ΩΛ. In a
flat universe ΩΛ corresponds to the fraction of the energy density of the Universe which is associated with the cosmological constant.
Cosmologists even have a sense of humor, giving a paradoy of critical density that is originally associated with nuclear explosions. It is 'critical' because it is the value
necessary to derive a flat space-time geometry of the universe, the one we are living in right now.
Any small deviation from this critical density would immediately result in either a spherical or psuedo-spherical (saddle-shaped) geometry which, in turn immediately results in either a big crunch or the universe 'escaping' itself.
To say 'today, it is useful' is an understatement of monumental proportions. The fact that the universe is expanding at an accelerating rate only means that the cosmological constant is doing so even against the tendency of gravity.
It doesn't complicate the mathematics of the theory any more than the theory was quite a few decades ago.
You have einstein to thank for that. His genius comes from the sublime beauty of its simplicity. It doesn't get much simpler than E=mc^2, does it?
It doesn't violate Lorentz invariance. The expansion of the cosmos beyond the speed of light? - not to worry. Local measurements of the speed of light will always be,... well, the speed of light, no faster and no slower.
Of course it does.
The speed of light does not just 'appear' to be so. It is so in
ANY AND ALL reference frames. It is a
UNIVERSAL SPEED LIMIT.
You keep mentioning 'local' as if there was some other reference frame in which something can go faster than the speed of light. I hate to break the news to you but, in relativity, there ain't.
The notion that space can somehow expand a couple of thousand times the speed of light, or inflationary cosmology, was contrived to give an explanation to the horizon problem. And this particular solution gives rise to more problems than it solves.
Gravitons don't do much of anything let alone contract space, until they figure out how they might work. The theory is still not much better than scribblings on napkins during a working lunch.
Space can expand beyond the speed of light. It gives an event horizon that you can see whenever you stand on your roof and strain your eyes to see radiation at a couple of degrees from absolute zero. Don't wear sunglasses. BTW gravity propagates at the speed of light, if that's a question people are worrying about.
Sigh.
The original problem is that there is something fundamentally wrong with gravity as an 'instantaneous action from a distance'. After all, there must be some sort of intermediary between a cause and its effect. A light source emits electro-magnetic waves 'bundled up' as photons to give the sensation of light. And because nothing can travel faster than c, so does these photons.
For gravity, it was 'theorized' that it propagates via gravitons. And gravity (hence gravitons, being the intermediary particle to it), by gr, serves to curve space-time.
Now, you say that the gravitons are unable to go faster than light but its effect, the expansion/contraction of space-time, can go faster than light.
To put it simply, the effect is vastly overtaking its cause. I may have a mere undergraduate degree but I think you need to explain this a little better than a vague and cursory mention of 'local measurements'