Redshift of photons penetrating a hot plasma
  A new interaction, plasma redshift, is derived, which is important only when photons penetrate a hot, sparse electron plasma. The derivation of plasma redshift is based entirely on conventional axioms of physics. When photons penetrate a cold and dense plasma, they lose energy through ionization and excitation, Compton scattering on the individual electrons, and Raman scattering on the plasma frequency. But in sparse hot plasma, such as in the solar corona, the photons lose energy also in plasma redshift. The energy loss per electron in the plasma redshift is about equal to the product of the photon's energy and one half of the Compton cross-section per electron. In quiescent solar corona, this heating starts in the transition zone to the corona and is a major fraction of the coronal heating. Plasma redshift contributes also to the heating of the interstellar plasma, the galactic corona, and the intergalactic plasma. Plasma redshift explains the solar redshifts, the redshifts of the galactic corona, the cosmological redshifts, the cosmic microwave background, and the X-ray background. The plasma redshift explains the observed magnitude-redshift relation for supernovae SNe Ia without the big bang, dark matter, or dark energy. There is no cosmic time dilation. The universe is not expanding. The plasma redshift, when compared with experiments, shows that the photons' classical gravitational redshifts are reversed as the photons move from the Sun to the Earth. This is a quantum mechanical effect. As seen from the Earth, a repulsion force acts on the photons. This means that there is no need for Einstein's Lambda term. The universe is quasi-static, infinite, and everlasting. 
Ari Brynjolfsson