text: The namesake factor of this phenomenon is raised to the power of either two or three plus the spectralindex in the equation for relativistic beaming.
full_question: The namesake factor of this phenomenon is raised to the power of either two or three plus the spectralindex in the equation for relativistic beaming. This effect causes boosting in blazars because of its strongdependence on the peak frequency. The namesake relativistic factor of this phenomenon depends only on theviewing angle and the Lorentz factor. This effect caused canal rays reflected by a concave mirror oriented at 7degrees to have slight changes to their spectral lines, as measured by Ives and Stilwell. A proof of specialrelativity is the existence of this effect's transverse form. For 10 points, name this phenomenon in whichdifferent source and receiver velocities causes the observed frequency of a wave to shift. 
first_sentence: The namesake factor of this phenomenon is raised to the power of either two or three plus the spectralindex in the equation for relativistic beaming.
raw_answer: Doppler effect [or transverse Doppler effect; or relativistic Doppler effect; prompt on special relativity] 