
(Euler's formula) expresses sinusoids as the odd or even terms of the series

, where even powers of

become

. This is generalized by replacing

with

(an independent direction, not a complex cyclotomic number) to give

, with

(See Multi-Phase Power-Sinusoids 3 for details.)
Summing every

term of this series, starting with the

, gives

separate phases (each multiplied by a direction

). The sums of the

terms of

grow exponentially unless

. This growth can be eliminated by including a normalizing factor, replacing

by

, with

. The amplitude

is set to 1/2 so that the difference between odd (or even) phases matches the amplitude of

(or

).
Mathematica expresses roots of unity as complex cyclotomic numbers. This is generalized to multiple independent

roots of unity (these occur in some Clifford and Hoop algebras). This does not cause problems at this level as

and

can be calculated as

and

.
Multi-Phase Power Sinusoids 2: Differential Equations shows multi-phase power-sinusoids as solutions to banded sets of differential equations. Their period is greater than

unless

. The period is

for

and 6, and

(half spin) for

.
Multi-Phase Power-Sinusoids 3: Exponential Series demonstrates phases as the sums of every

member of the stable infinite power series

. Truncating the series introduces exponentially growing errors.
Multi-Phase Power-Sinusoids 4: Summations investigates the properties of the sums of all phases (or their absolute values for odd powers, when the sums are zero). The sum of the even powers is a constant for some small values of

(the helix identity), generalizing

and leading to some conserved properties.
Multi-Phase Power-Sinusoids 5: Helices and Pulses introduces helices and modulated pulses, showing that phases can act as orthogonal fields and multi-phase wave packets.
Multi-Phase Power-Sinusoids 6: Non-integer Powers shows that

need not be an integer, though integration then creates compactons having support over a narrow range.
The author discovered multi-phase power sinusoids in 2000. He discovered the helix identity empirically in 2001 and published a brief description in
this Google Group posting. The binomial formulation and limits were supplied by J. J. Thwaites on 26/9/2002. His lemma was extended to include harmonics by G. Gerrard in July 2011 (personal communications).