Re: Zusammenfassung

Am 21 Feb 2008 10:00:57 GMT schrieb Norbert Dragon:

Aus welcher Not die Inflationären Modelle eine Tugend machen sollen

....ist Fachleuten wohl bekannt.

Hätte die Inflationstheorie keinen "Nutzen", dann würde man es
(z.B. mit Ockham) nicht postulieren, schlimm, dies überhaupt
erwähnen zu müssen. Z.B. hätte kein Mensch chirale Asymmetrie
eingeführt, wenn die nicht gefunden worden wäre, denn "Physiker"
hätten die Natur eben nun mal gern maximal symmetrisch.

Penrose führt Penrose in RtR aus:

"Guth put forward the 'outrageous' proposal (also previously suggested
independently, in essence, by Alexei Starobinski and Katsuoko Sato) that
if the universe were to have expanded, by a factor of, say 10^30 or perhaps
even 10^60 or more, at some period after the production of the monopoles
(though before electroweak symmetry was broken, at the time of 10^-12 s)
then the unwanted monopoles would now be so sparse that they could
easily escape detection, as was required from observation.

It was soon realized that this 'inflationary period' of extreme
exponential expansion might serve other purposes as well, having to
do with the uniformity of the universe."

Zum Horizontproblem:
..------------------
"This impossibility of the causal communication that would be required
for thermalization, in the standard model, is referred to as the horizon
problem. The effect of the period of inflation, in this respect, is
depicted in the conformal diagram of Fig. 28.5. The spacelike 3-surface
that represents the Big Bang has now been displaced to a much 'earlier'
location, so that the pasts of q and r now do intersect before reaching
the 3-surface that describes the Big Bang, so that now thermalization does
have the opportunity to take eVect, and we may now imagine that the
equality of temperatures at q and r can come about through this means."

Zum Smoothnessproblem:
..------------------
Another perceived benefit of this proposed inflationary period was that
it could provide an explanation of the remarkable uniformity of the
matter distribution and spacetime geometry, this being referred to as
the smoothness problem. The idea is that, with inXation, the initial
state of the universe might have been very irregular in detail, but
the enormous expansion of the universe during the inXationary stage
would have served to ‘iron out’ these irregularities, and a closely
FLRW universe is thereby anticipated. The inXationary viewpoint envisages
that even a 'generic' initial state would look like a smooth manifold
on a small scale, and we see this tiny smooth portion expanded out to
cosmological scales—so as to appear to be spatially flat—during the
course of the inflationary phase; see Fig. 28.6 (and compare Fig. 12.6)."

Zum Flatnessproblem:
..------------------
"But whether or not the observable universe is, on the average, actually
spatially flat, it is certainly remarkably close to being so, and this
had presented a puzzle to many cosmologists—referred to as the flatness
problem.
It is not immediate to the eye what the inflationary phase of expansion
has to do with the moving back of the Big Bang 3-surface in the conformal
diagrams, as in Fig. 28.5. It will be instructive, therefore, to examine
the particular cosmological model on which this 'inflationary phase' is
based. "

Und:

"Instead, three particular problems in the standard model of cosmology
tend to be singled out by inflationists, these all being issues that
are indeed related to the initial precision in the early universe.

They were specifically addressed in §28.4, and are referred to as the
horizon problem, the smoothness problem, and the flatness problem. In
the standard model, these issues are handled by 'fine-tuning' of the
initial Big Bang state"



"fractal sets, for example, never iron themselves out, no matter
how much they are stretched."

"whether or not we actually have inflation, the physical possibility of
an inflationary period is of no use whatever in attempts to ensure that
the evolution from a generic singularity will lead to a uniform (or
spatially flat) universe."

"The universe was very special at the Big Bang. It had to be so for
there to have been a Second Law of thermodynamics, extending right
back to the beginning. All thermalization processes depend upon the
Second Law; thus they explain neither why we have a Second Law nor
why we had a very special universe at the beginning. Moreover, all
spontaneous symmetry-breaking processes and all phase transitions
(these being needed for inXation) take place only by the good grace
of the Second Law. These processes do not explain the Second Law:
they use it. Moreover, all the serious calculations in inflationary
cosmology assume a spacetime geometry that is FLRW, or close to it,
which gives no insight as to what would happen in the generic case.
If we want to know why the universe was initially so very very
special, in its extraordinary uniformity, we must appeal to completely
different arguments from those upon which inflationary cosmology depends."

--
Jeder Glaube verblödet
.

Relevant Pages

  • God in Super Cosmos?
    ... self-reproducing universe and the version of the Steady State hypothesis ... C-field playing the part of the scalar field that drives inflation. ... appeared out of nothing at all, and contains zero energy overall, was ... quantum fluctuation so small that it only contained one monopole. ...
    (sci.physics)
  • God in Super Cosmos?
    ... self-reproducing universe and the version of the Steady State hypothesis ... C-field playing the part of the scalar field that drives inflation. ... appeared out of nothing at all, and contains zero energy overall, was ... quantum fluctuation so small that it only contained one monopole. ...
    (sci.astro)
  • why dark energy density is small
    ... Our early universe has low entropy compared to present universe. ... Sir Roger Penrose says this is a big problem for inflation theory - it's the Arrow of Time problem - why irreversible aging is in same sense as expansion of 3D space with dark energy speeding up of that cosmic expansion. ... this is precisely what we expect from the retro-causal world hologram in which 3D space at our moments of perception of our entire pocket universe on the landscape is simply a hologram image of the future 2D deSitter horizon. ... Because it has a very similar formal structure to the internal symmetry Yang-Mills quantum field operators. ...
    (sci.math)
  • why dark energy density is small
    ... Our early universe has low entropy compared to present universe. ... Sir Roger Penrose says this is a big problem for inflation theory - it's the Arrow of Time problem - why irreversible aging is in same sense as expansion of 3D space with dark energy speeding up of that cosmic expansion. ... this is precisely what we expect from the retro-causal world hologram in which 3D space at our moments of perception of our entire pocket universe on the landscape is simply a hologram image of the future 2D deSitter horizon. ... Because it has a very similar formal structure to the internal symmetry Yang-Mills quantum field operators. ...
    (sci.physics)
  • why dark energy density is small
    ... Our early universe has low entropy compared to present universe. ... Sir Roger Penrose says this is a big problem for inflation theory - it's the Arrow of Time problem - why irreversible aging is in same sense as expansion of 3D space with dark energy speeding up of that cosmic expansion. ... this is precisely what we expect from the retro-causal world hologram in which 3D space at our moments of perception of our entire pocket universe on the landscape is simply a hologram image of the future 2D deSitter horizon. ... Because it has a very similar formal structure to the internal symmetry Yang-Mills quantum field operators. ...
    (sci.astro)
Loading