imaginary axis
Noun
Meaning
imaginary axis (plural imaginary axes)
(mathematics) The vertical line in the complex plane, every point on which corresponds to a complex number having zero real component
Examples
A more accurate description of this phase of the vault may be "the spin" because the vaulter spins around an imaginary axis from head to toe.
For a flow, it will occur when there are eigenvalues on the imaginary axis.
If this limit exists, then it may be computed by taking the limit as h → 0 along the real axis or imaginary axis; in either case it should give the same result.
Two special cases might be noted: when the original line is parallel to the real axis, the resulting spiral never closes in on itself; when the original line is parallel to the imaginary axis, the resulting spiral is a circle of some radius.