That's exactly my point. There are no primordial positrons, yet we see positrons, hence there must be a method of producing positrons. The same argument applies to dark matter antiparticles. Unless I'm missing your point...
Yes, sorry I was
scatter-brained yesterday. I
started thinking I
was disagreeing
with you, but then realized
I agreed with you.
Maybe little things
will draw attention back to
Hoyle's "little" big bangs:
Cosmologists Fred Hoyle, Geoffrey Burbidge, and Jayant Narlikar have recently developed a detailed "quasi-steady state" model of the universe. As in the original model, they propose that the universe has always existed, but they abandon the idea of the continuous creation of matter, suggesting instead that a series of large creation events, or little big bangs, occurred 10 to 15 billion years ago, which caused our part of the universe to expand. Since then smaller creation events have continued to occur, producing energetic objects such as quasars and radio galaxies. However, in the future the expansion of our part of the universe will weaken, allowing the formation of new creation centers and another episode of large creation events. ... ["Cosmology and the Big Bang," By David Pratt]
Positrons created by photon-photon collisions can be a source of both rest mass and opacity. They can become dominant in astrophysical systems where the energy densities are large and particles are accelerated to relativistic energies. Examples include accreting black holes and neutron stars, relativistic jets, pulsars, gamma-ray bursts and the cosmological universe. ["Positrons in Charge: e^+e^- in Astrophysics," by E. S. Phinney (California Institute of Technology)]