Acceleration of charges at Big Bang

AI Thread Summary
The discussion centers on the acceleration of charged particles during the Big Bang and its relation to the Cosmic Microwave Background Radiation (CMBR). It posits that if charged particles were accelerated by inflation, they should have emitted light, contributing to the CMBR we observe today. However, it is noted that massive particles did not form until after the inflationary period, and the universe became transparent to radiation only around one million years post-Big Bang. The CMBR is attributed to the annihilation of matter and antimatter, with thermal processes creating a black-body spectrum before the universe cooled and expanded. The conversation highlights the complexities of cosmic evolution and the timing of baryogenesis in relation to the observable universe.
Macro
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If charged particles; like protons and electrons and the others;
come out of the singularity then they ought to be accelerated
by inflation. If a great increase in space epxansion took place and
this is identical to "accelerating" then charged particles ought
to have radiated light. This burst of inflationary radiation is what
we see now as "Cosmic Microwave Background Radiation."
The light emitted during the inflationary epoch would be
redshifted by the inflation itself. Cosmologically speaking
expansion/inflation redshifts light. Stretching space stretches
the light traversing that space.

If we can calculate the original radiation from these accelerating
particles then by comparing their wavelength now(CMBR) we might
be able to accertain the exact duration of the "inflation." We could
know exactly how long it took place.

Anybody say differently?

Mitch Raemsch -- Light Falls --
 
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IIRC, massive particles did not form till after the inflationary period.
 
macro: Take a look at

http://cassfos02.ucsd.edu/public/tutorial/BB.html

The universe became transparent to radiation in "the era of recombination", way, way, way after inflation, somehwere around 1 million years after the big bang. The CMB dates from this era, before this era, radiation was absorbed as soon as it was emitted.
 
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Even in case that the universe would have been transparent to radiation and that there had existed charged particles at that time, if you consider the comoving reference frame in which the cosmological principle holds, there is no motion of objects (matter, charges, fields. etc.) in space.
 
pervect said:
macro: Take a look at

http://cassfos02.ucsd.edu/public/tutorial/BB.html

The universe became transparent to radiation in "the era of recombination", way, way, way after inflation, somehwere around 1 million years after the big bang. The CMB dates from this era, before this era, radiation was absorbed as soon as it was emitted.

What then is the source of the CMB radiation at 1 million years?
It has to saturate the universe from the very beginning.
 
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Macro said:
What then is the source of the CMB radiation at 1 million years?
It has to saturate the universe from the very beginning.
The source of the CMB photons is the annihilation of matter and antimatter, which existed in different amounts due to an asymmetry in the baryogenesis.
 
...matter and antimatter which formed everywhere throughout the universe from the 'plasma' that permeated the universe and was thinned/cooled by the expansion of space.
 
Macro said:
What then is the source of the CMB radiation at 1 million years?
It has to saturate the universe from the very beginning.

Here is the situation as I understand it:

http://relativity.livingreviews.org/open?pubNo=lrr-2001-2&page=articlesu9.html

4.1.1 Primordial black body effects
The black body spectrum of the isotropic background is essentially due to thermal equilibrium prior to the decoupling of ions and electrons, and few photon-matter interactions after that. At sufficiently high temperatures, prior to the decoupling epoch, matter was completely ionized into free protons, neutrons, and electrons. The CMB photons easily scatter off electrons, and frequent scattering produces a blackbody spectrum of photons through three main processes that occur faster than the Universe expands:

* Compton scattering in which photons transfer their momentum and energy to electrons if they have significant energy in the electron’s rest frame. This is approximated by Thomson scattering if the photon’s energy is much less than the rest mass. Inverse Compton scattering is also possible in which sufficiently energetic (relativistic) electrons can blueshift photons.
* Double Compton scattering can both produce and absorb photons, and thus is able to thermalize photons to a Planck spectrum (unlike Compton scattering which conserves photon number, and, although it preserves a Planck spectrum, relaxes to a Bose-Einstein distribution).
* Bremsstrahlung emission of electromagnetic radiation due to the acceleration of electrons in the vicinity of ions. This also occurs in reverse (free-free absorption) since charged particles can absorb photons. In contrast to Coulomb scattering, which maintains thermal equilibrium among baryons without affecting photons, Bremsstrahlung tends to relax photons to a Planck distribution.

So the universe was opaque before the plasma condensed into non-ionized matter, and the above processes gave it a black-body spectrum. After the formation of matter, this ~3000 degree thermal radiation has been redshifted to the ~3 degree microwave bacground we see today due to the expansion of the universe.

See also the wikipedia article

http://en.wikipedia.org/wiki/Cosmic_microwave_background
 
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What about my first point?

If there were charges to radiate during inflation the acceleration would have produced electromagnetic energy whether or not the universe was yet transparent.

You get a soup of matter/light.
 
  • #10
hellfire said:
The source of the CMB photons is the annihilation of matter and antimatter, which existed in different amounts due to an asymmetry in the baryogenesis.

When did this matter anti-matter exist?
It anhilates right off when the universe was small.
And what kind of matter does the asymmetry leave behind?
It's not the matter we observe.

what is it?
 
  • #11
According to this timeline, baryogenesis took place at 10-33 sec. after the big-bang. However, as far as I know there are proposals that postulate a later baryogenesis. The matter we observe today is made of the elementary particles that did not annihilate during that epoch.
 

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