Equation Icon  ( ) ( ) ℏ- u0- --ℏ-- 2 -ℏ--2 ℏ- u0- -ℏ--- 2 -ℏ-- 2 − m q ⋅ k + c ω − 2mc2 ω + 2m k m q ⋅ k − c ω − 2mc2 ω + 2m k ( )2 − c0 ω2 + c20k2 = 0 , (279 ) c