The dispersion relations allow one to then calculate the energy dependence of the real part.
The dispersion relation of phonons is also important and non-trivial.
He failed, however, to recognize the material dependence of the dispersion relation.
For small values of the dispersion relation is rather linear:
In this case the dispersion relation is linear, as in section 1.2.
The dispersion relation for this case is of a more complicated form.
Suggested a first proof of dispersion relations in quantum field theory.
In order to obtain the dispersion relation it is possible to proceed in two different ways.
The dispersion relation is not even approximately quadratic, in the large scale.
In a medium like air, where the dispersion relation is linear, i.e.