The Cosmic Microwave Background Does Not Require a Singular Big Bang: A Hot Dense Phase in Singularity-Free Cosmology

The cosmic microwave background is usually seen as decisive proof of the Big Bang. This paper distinguishes two claims: the CMB proves a past hot dense phase but does NOT prove an initial singularity. It fully acknowledges the strength of the standard data — the FIRAS blackbody spectrum, the acoustic peaks, and the rise of temperature with redshift — which require a hot, dense, thermalizing medium (so “emission in transparent space” is rejected). But a hot dense phase is not a singularity: singularity-free (“bouncing”) cosmologies produce such a phase without t=0, and so can the author’s self-replication program. Thus the CMB is consistent with singularity-free cosmology; only the singular beginning is challenged. Viability and falsification conditions are given.