21. Most charts in an ophthalmologist s or optometrist's office will show images of varying contrast and angular frequency . 22. The index k of the frequency response corresponds to an angular frequency \ omega of 2 \ pi k / N. 23. A small radial deviation from a circular orbit of radius " r " outer will oscillate stably with an angular frequency 24. Mihalas & Weibel-Mihalas work with radiance and frequency; also Goody & Yung; Loudon uses angular frequency and radiance. 25. Here \ omega _ 0 a constant angular frequency , chosen in accordance with the characteristics of the wave field under study. 26. In the equation, " i " is the imaginary unit, and ? is the angular frequency of the wave. 27. The second equation for " ? k " is known as the dispersion relation between the angular frequency and the wavenumber. 28. The angular frequency \ omega and wavenumber k of the wave was related to the energy E and momentum p of the particle by 29. Thus, the second-order polarization at angular frequency \ omega _ 3 = \ omega _ 1 + \ omega _ 2 is 30. Versus \ omega, where \ omega and \ omega _ \ mathrm { c } are the input and cutoff angular frequencies respectively.
