Hello Fifelad-Ned Wright's tutorial will helphttp://www.astro.ucla.edu/~wright/cosmolog.htm
There are two approaches re- energy carriers and their chronologies. The CMB epoch is quite late and in terms of energy densities the universe is passing from a radiation dominant era to the subsequent matter dominated era even though the total energy may be zero. We can all agree that if the system is at perfect equilibrium then forget any expectation that one can derive any prior history as to the evolution of that system.
There is no such thing as pure energy in isolation. Two angled high energy laser beams shine through each other and they don't interact. Very occasionally, if the enrgy of the photons is enough, high frequency gamma, then an electron and a positron are created out of pure energy. Deflected in a magnetic field they leave spiral tracks.That's a fact, proved experimentally.
Accelerated electrons and positrons accelerated to 2 TeV create quark jets and ca.100 GeV quark antiquark pairs, all three generations although the electrons don't carry the colour charge.
So the world is made up of particles force fields and the carriers of the force eg. the photon of the electroweak that incorporates the electromagnetic field and gluons, both rest massless, and the electroweak W+- and Z0 very massive carriers.
Photons have the h*nu energy, particles carry E=mc2
rest mass energy. The latter ie. all particles that have mass charge carry momentum and kinetic energy.
Well before the CMB event there's the accepted theory of near perfect thermal equilibrium between particles and photons, ca 1 billion to 10 billion photons for each particle? Which particle? Even in the sun's core it takes on average 5 billion years before, via the electroweak theory before a proton flips to a neutron via the W+- interaction that involves an electron and a neutrino. The latter particle will travel through a light year of matter as dense as lead before a 50/50 probability of interaction again! At the earliest of times, still quite late on by a hundredth of the first second; there are particles largely electrons/positrons and neutrino/antineutrinos in near thermodynamic equilibrium. The kinetic energy of even these neutrinos were busily engaged in particle pair production. A real black body container has a wall . Conceptually, we can create a real or ordinary matter container with a perfect vacuum inside, ie. no particles. OK- there are vacuum fluctuations but any particle is always produced in pairs, matter and antimatter particles in pair, hence they are called virtual particles. If the energy density is great enough real particles are created from the photon emissions from the wall and the energy density depends on the T to the 4th power and distribution onthe socalled Wien's displacement law. But to make a real particle that we observe, that is stable, requires the parity violation reaction of those massive carrier particles, the W+- and the Z0 if we are interested on where the inertial property of one of the Higgs particles. These exist for ca. 10-23
second. So set against this timescale those departures from thermodynamic equilibrium 380,000year later. The creation of a particle pair at 2TeV or the new 14TeV Cern"condenses" a lot of mass energy in a small space. The departure from perfect equilibrium in an expanding space, but not so for the inner dimensions of particles needs to be extrapolated another 6 orders of magniyude for kinetic energies where the Forces of the electromagnetic field and electroweak field merge, then perhaps another 4 magnitudes higher for the strong force interactions. These energies are ten orders of magnitude beyond Cern's capabilities but still the relation holds; not pure energy but those photons and gluons exchanging energy with particles whose kinetic energies are related to that Planck relation and the distribution for lambda, ie. where the radiation peaks in relation to a temperature you can't really comprehend in the approach to the Planck Temperature. Particles and "pure" energy go hand in hand at all times and the temperature or what kind of temperature provides information about when those particles appeared. I hate to mention it but the appearance of the most abundant form of matter has a role to in its interaction with those massive bosons. Ordinary matter irrespective of form utilises the same massless carriers the photon and gluon despite the disparity of mass charge whether its electron, neutrino or quark mass charge. The neutral hybrid or Z0 is an admix that through the conceived Higgs doublet potentials confers mass not just to ordinary matter particles but also to DM, whatever that is. Given a different electric charge the W electric charged bosons would still interact with the same photon and gluon carriers to generate a new particle set whose abundance might be enhanced relative to normal matter particles at their defined appearance threshold temperatures. A lower electric charge means a lower internal energy and a greater abundance ratio for DM. By the time of the CMB event for ordinary matter, the chicken egg dilemma is possibly semantics. It's the kinetic energies of particles against photon energies that cannot be reversed since neutrino energies decoupled well before that event. Those 1 in a few thousandths departures from equilibrium, tiny as they are and subject to some error? are why those vacuum fluctuations in the first 10-23
second mean there is still a story to be discovered. Perfect equilibrium would mean any discussion earlier than ca. 380,000 years post BB would be futile to contemplate, apart from an experimental neutrino background temperature corroboration with the 40% lower temperature viz. CMB temperature from theory. It's remarkable that the predicted Higgs mass comes in at similar mass to the W and Z0 carriers, not as a consequence to the discrepancy in the weak mixing angle , now that the more hugely top quark was determined, but that the discrepancy is to wholly account for the Z0 mass . In nature, where one measures the ratio between particle pairs of different parity, it could be a left to right hand form of a molecule, those ratios are numerically similar, by that I mean an equilibrium ratio of 1 to 1 or 10/1 etc not many orders of magnitude different. The alledged DM/OM ratio is ca. 5 to 1. That cries out to me that the temperatures are similar and that inner symmetry energy differences are minor ie. several eV's not millions eV. Why are the W , and Z0 so similar and by inference the mass of the Higgs? It isn't on! There's another route to the neutral interaction whose minimal interaction vertex gives rise to the DM Z0, as well as the inferred Higgs. It's the same Z0 perhaps. That's not to say that the Higgs isn't there.
Mass charge particle differentials are huge ; isospin and hypercharge are essentially constant. What else can change, the gravitational carrier; perhaps not. There's only onething left that can change if one assumes that the ratio of the alpha and g interaction are constant for the mixing angle formula ie. conserved. That's the electric charge. Were there two routes to Z0 then the equibrium ratio would be ca. 7.4 for the universal DM/OM ratio, ca. half decaying over a timescale of 13.7 billion years. So its not just as NGC Bill mentions as another but crucially anyother process one can rather might conceive. Regardless of how one defines the temperature of the process, the temperature doesn't matter, they are basically identical. Why wasn't the DM/OM ratio vastly different, look at the huge isotope variations; with DM it's a small number ratio that is saying - look here we have a partner in common. There are three infact, but a common Z0 in relation to identical and the same photon and g massless carriers. What might be the mass difference between a Wdelta-
and a W-
? minimal! But for an electrondelta-
the mass difference is large. It would mean there's a weakly charged less massive electron out there, in addition to a full suite of all alloparticles differing only in electric charge; with common identical photon, gluons and the neutral weak force carrier Z0, two allo W's and the same alloquark suite, and same neutrinos. This is smaller than the supersymm doubling for normal matter by the way.
Apologies for DM p p pschychosis.
Basically, chronology comes first. Prior to CMB the particles and their momenta and kinetic energies with huge photon and neutrino excesses are there. Think of the particles as the walls. It's unidirectional towards the future although the Higgs needs a backwards in time component that can confuse things but support Eigen's assertion since kinetic energy is always positive either forwards or backwards in time.