Original sentence: Redshift according to various physical models can be due to three different effects:
Edited sentence: Compton scattering ,.Raman scattering.Redshift according to various physical models can be due to several different effects that may be split into two groups:.There are also a number of causes of frequency-dependent redshift of spectral lines.These redshift mechanisms are sometimes called Doppler-like redshifts since their spectra are indistinguishable.These redshift mechanisms are sometimes called non-Doppler redshifts , non-Cosmological redshifts , or intrinsic redshifts.They include Brillouin scattering  ,.This use of the term 'redshift' is in less common usage, and will not be discussed further in this article.Wolf effect ,.and other theories such as tired light theories