Permit me to offer a different interpretation of how matter/antimatter asymmetry occurred. (And, permit to hope that you and/or other people might explore answering other aspects of your question[s], based on this interpretation.)

First a note. We may all be 'chasing' a 'non-problem.' Perhaps no evidence exists for the notion that matter and antimatter were once in balance. But, let's assume that they were once in balance. And, let's assume that nature permits some of the elementary particles that my research predicts. (See the Springer-published book, "Models for Physics of the Very Small and Very Large." See, for example, https://thomasjbuckholtz.wordpress.com/mathematical-physics/ .) Then (per section 4.5 in the book), …

Lasing by 2O bosons converted antimatter quarks into matter quarks. Lasing by W bosons converted antimatter leptons into antimatter neutrinos. Lasing by W bosons converted matter neutrinos into matter leptons.

This leaves the notion that 'cosmic background neutrinos' might exhibit more antimatter neutrinos that matter neutrinos. (Perhaps people can try to determine the extent to which such a 'prediction' is true.)

In my theory, the universe begins with particles called Savitons which are associated with electronuclear force which came into existence just after the gravity separated at Planck time. These particles are bosonic spin 1 particles similar to photons and does not carry any mass or charge. Their energy is of the order of planck energy. So the universe begins with a 100% pure kinetic energy. Savitons are produced in pairs of particles and anti-particles. Just like photon, saviton is its own anti-partcle. So the only difference between the two is the direction of their momentum. All the rest of the particles emerge out of these savitons when they collide with each other and slow down from speed of light to lower velocities and some of their own kinetic energy gets converted into mass and charge. The particles that develop charge are a very small fraction of the total number of savitons produced at planck time. These charged particles are distinguished in this theory by the name matter and anti-matter. And most of the anti-matter fermions are used up in creating matter hadrons and mesons. This is why most of our visible universe is matter dominated. This is also consistent with ALICE experiment on symmetry in nature.

http://phys.org/news/2015-09-fundamental-symmetry-nature.html

Above explanation for the predominance of matter over antimatter is possible in my theory because the universe begins with massless and chargeless particles which are savitons. Such explanation is not possible in standard model because of the absence of the quantum gravity theory in this model, the scientists are hung up with the idea that the universe began with Inflaton which could be massive bosonic particle field like Higgs Boson which gives mass to all other particles. And they don't know where this field come from. It is just there. This makes mass creation easy but then they run into problem with excess of antimatter. So the conclusion in my theory is that mass less charge less particle anti-particles pairs were produced in equal numbers at the beginning and only a small fraction of their energy got coverted into charged matter anti-matter. Therefore universe is matter dominated.

Article Periodic quantum gravity and cosmology

>  Dear Thomas,

Thank you for your interesting answer and the hints to your newly published book (cheers !). In the frame of the present question, could you give any order of magnitude for e.g. the pressure changes within the universe between 10-31 s and 10-15 s (if this kind of calculation can be made using your metamodel) ?

>  Dear Vikram,

Thanks for your kind answer and for the details on your theory. Is it possible using this theory to compute the evolution of the pressure of the universe when matter became predominant over antimatter and to state precisely when this occurred (see below) ?  

Generally speaking, my question is not primarily aimed at comparing alternative models to the big bang, how valuable they are, but rather to have more insight on what happened during baryogenesis, provided it actually took place.

Let’s make the assumption that the universe was initially well balanced in particles and antiparticles but that baryogenesis took place very quickly in view of several elements in favour : Dirac’s relativistic equation predicting antimatter, the standard model of particles (and experiments in this frame) showing that antiparticles can artificially be created all the time in laboratory experiments like in CERN facilities (e.g. pions are couples quark-antiquark), also equipment for PET and proton-therapy systematically produce positrons, etc… . In parallel to this, the standard cosmological model of expansion of the universe and quantum field theories together with symmetry assessment lead to the assumption that matter and antimatter must have been in balance in the very early universe. A kind of phase transition (symmetry break) would then have taken place very soon afterwards to explain that only matter is nowadays observed in nature (electroweak theory and Higgs boson are among the documented theories supporting baryogenesis).

Therefore, models of baryogenesis have most probably been developed in the framework of above  summarized knowledge.

So my question is limited to ask whether any of those models is (are) well accepted by a majority of cosmologists and, if the answer is yes, how it (they) can be summarized into a nutshell, with a practical emphasis on how the main parameters like pressure, temperature, energy, … would evolve with time as a consequence.

 The question is thus more focused on what occurs with the physical parameters than on framework issues like Sakharov’s conditions etc.

For instance, using the equations of FLRW-cosmology for a flat universe (k=o) and taking account of an inflationary episode and of the present accelerated expansion, one would expect (depending on the assumptions made) a variation of pressure from p = -2,13 1070 Pa to p = +6,11 1068 Pa around 5 10-24 s, a huge step indeed (*).

Does this make sense ? And what about the energy and other parameters ?

(*) The pressure would then have lowered first quickly then more slowly to become again negative after several Gyears (acceleration of the expansion) to reach the value of p0 = -5,2 1010 Pa nowadays (see : https://www.researchgate.net/post/What_is_the_value_of_the_present_pressure_in_the_universe/2)

But this is another story !

Apologies ! Positrons are used in PET-scans but only protons in proton-therapy. But, it is thought of anti-protons as an even more efficient method in the future, see e.g. :

M . Holzscheiter , N . Bassler , N . Agazaryan , G . Beyer , E . Blackmore , J . DeMarco , M , . Doser , R . Durand , O . Hartley , K . Iwamoto The biological effectiveness of antiproton irradiation.  Radiotherapy and Oncology , Volume 81 , Issue 3 , December 2006, Pages 233 – 242

Guibert:

Sorry, I do not know that I know how to compute such a pressure. You seem to be 'open' to 'more details,' so let me say a little more. And, permit to ask if you might try a calculation.

My work seems to provide a theoretical 'match' for the experimental approximate 'spatial range' for the weak interaction. (Book, table 2.9.4 and sections 2.10 and 3.8) To the extent that the match pertains for (the would-be) 2O bosons also, the interactions I posit (in my answer above) need to occur under conditions for which …

·         The densities (number of reacting fermion particles per unit volume) of leptons are high enough for interactions intermediated by W bosons to occur.

·         The densities (number of reacting fermion particles per unit volume) of antimatter quarks are high enough for interactions intermediated by non-zero-charge 2O bosons to occur.

The range of a 2O boson would be somewhat less than half the range of a W boson. Experimentally, a range for the weak interaction is somewhere around 10^(-18) meters and less than 3x10^(-17) meters.

Perhaps you can use the above to estimate a time (presumably, a fraction of a second after the instant of the big bang) by which the universe would have achieved (much of its) matter/antimatter asymmetry? I would welcome such an estimate.

Dear Guibert:

First I refer to Alexander Merle's response to your question in another thread. As he said, "what is called "pressure" in cosmology is often given in units of an energy density". In my theory critical energy density rho_c is calculated for every epoch in the tables at the back of the article. This is possible because unlike the standard model, my quantum gravity theory also gives the size of the universe at every epoch. Alexander gave a calculation for the pressure at present epoch in which I noticed few errors, please check it out. He has given a conversion factor of 9e19 Pa for converting g/cm^3 to Pascal. This factor involves mass to energy conversion with c^2 = 9e16 (m/s)^2 and a conversion factor for g/cm^3 to Kg/m^3 which is 10^3. This makes 9e19. But there is one more factor required which is 1 Pa = 0.1 Kg/m^2 (approx.). So the total conversion factor should be 9e20, Another point is that he has used a very high value for "critical density" rho_crit = 1.878e-29 g/cm^3. Generally accepted value is weight of 6 hydrogen atoms per cubic meter which is approx. 1e-29 g/cm^3. Thirdly it is not necessary to multiply with h^2 as he has done. I have used 71% dark energy instead of 68.5%. With these changes my calculations gives pressure at present epoch = -0.71 x e-29 x 9e20 = -6.39e-9 Pa. In my article, critical density shown for Graviton is close to that at the present epoch.

Regarding the existing models, I have to say that they provide information in bits and pieces and not all cosmologists agree on one single model as they do for LambdaCDM model. Your comment "how the main parameters like pressure, temperature, energy, … would evolve with time as a consequence." I have to say that only my quantum gravity model does that. Other models don't have it. The problem of sudden jump of pressure discussed by you shows positive pressure which was never there. The universe is dark energy dominated right from the beginning. Equation of state has changed from w = -1 to w = -1/0.71. So the overall pressure has been negative all along. In standard model there are separate equation for exponential inflation period and then it is switched over to general relativity. In my theory exponential expansion happens within the wave equation formalism itself. There is no separate equation.

In my opinion negative pressure of dark energy never changed to positive. It remained negative throughout, only its magnitude decreased. Dust dominated universe has zero pressure, that is why we see very small value of negative pressure due to dark energy at present epoch. Positive pressure due to radiation is very negligible anyway.

Baryogenesis is normally discussed at GUT epoch and at electroweak epoch. Symmetry breaking occurs when strong force separate from electro-nuclear force. Before this happens, Gluons must come into existence which binds the quark anti-quark pairs. In my article Gluons cannot exist before 5.33e-39 sec. as shown in the table. The quantum gravity equations cannot generate gluon parameters before this time. This indicates that strong force must have separated at this time. The corresponding critical density is 2.3e80 Kg/m^3. So the minimum pressure at this time is given by = -0.71 x 2.3e80 x 9e17 = 1.47e98 Pa. For max pressure, replace -0.71 with -1.0. (Note: I have changed the conversion factor to 9e17 because my density is in Kg/m^3.)

Simiarly for symmetry breaking at electroweak epoch, the quantum gravity equation should be able to generate gamma photon as a particle that can exist at that point. In my theory this can not happen prior to 5.4e-26 sec. after big bang. This is the earliest that I can generate electromagnetic force. This means the symmetry broke at around this time. The corresponding critical density is 6.15e59 Kg/m^3. So the minimum pressure at this time is given by =-0.71 x 6.15e59 x 9e17 = 3.93e77 Pa. For max pressure, replace -0.71 with -1.0.

Your comment "Also the energy produced by the annihilation must have gone somewhere." This problem does not exist in my theory because if the charged particles are produced in a small number to begin with then the universe is bound to remain matter dominated right from the beginning.

I think it's not excluded that the balance between matter and anti-matter is still here with us. The handedness is symmetrically free arrangement. Hence we all can be alternately matter an anti-matter. There are strong hints about dual-phase Klein bottle geometry in the universe and corresponding mechanism in spin½ particles defined by spinors. Also the entanglement could be easily explained with this kind of reverse phasing method.

Still, there obviously has been one heavy a annihilation process at early epoch. Maybe we can see annihilations also in quasars? My hypothesis for the use of all annihilation radiation is expanding the space : https://www.researchgate.net/post/Is_there_any_recent_research_that_radiation_expand_the_universe_like_dark_energy_and_the_same_time_act_as_the_cause_of_the_dark_mass_effect

Dear Esa,

Thank you for your answer with some hints on an alternative model you would like to go more thoroughly into. On this, I would just answer as Alexander Fleming, known to be extremely sparing of his words, did once after having listened to the tea-time discussions about several ongoing projects in the laboratory he worked in and having been requested for an advice. Question : “What do you think, Dr Fleming ?”. Answer : “Try”. So, just try, if nobody could sufficiently convince you to stop. You don’t know which new ideas will become the bases for breakthroughs within 50 or 100 years !

I must anyway say that I find several interesting ideas in the alternative models referred to in an amount of RG questions.  However, I feel very unfamiliar with them ! Even in front of the standard ΛCDM cosmological model which is the one I best understand, I feel poor : reason for the present RG question.  

I’d like to know as much as possible the ins and outs of what baryogenesis can tell us about the evolution of the universe in the framework of this model, before to decide to abandon it (or not) for an alternative model.

So, thanks a lot for your hints which open the mind (see also your answers to former questions) and apologies for not reacting in details at present time.