Singly Periodic Functions $e^{x},\cos(x),\sin(x),\tan(x), .. etc.$
Euler's identity is $$e^{i\alpha}=\cos(\alpha)+i\sin(\alpha)$$
$$e^{-i\alpha}=\cos(\alpha)-i\sin(\alpha)$$
Thus, we can express all trigonometric functions via $e^{x}$ function
$$\cos(\alpha)=\frac{e^{i\alpha}+e^{-i\alpha}}{2}$$ $$\sin(\alpha)=\frac{e^{i\alpha}-e^{-i\alpha}}{2i}$$
$$\tan(\alpha)=\frac{e^{i\alpha}-e^{-i\alpha}}{i(e^{i\alpha}+e^{-i\alpha})}$$ $$\cot(\alpha)=\frac{i(e^{i\alpha}+e^{-i\alpha})}{e^{i\alpha}-e^{-i\alpha}}$$ $$.$$ $$.$$
And also we know that periodic functions or periodic signals into the sum of a (possibly infinite) set of simple oscillating functions are can be expressed via sines and cosines (or complex exponentials). wiki reference
$$ f(x) = \frac{a_0}{2} + \sum_{n=1}^\infty \, [a_n \cos(\tfrac{2\pi nx}{P}) + b_n \sin(\tfrac{2\pi nx}{P})]\\ = \sum_{n=-\infty}^\infty c_n\cdot e^{i \tfrac{2\pi nx}{P}}$$
where $ f(x)$ is any periodic function and $P$ is period.
Elliptic functions are doubly periodic functions
The elliptic functions are inversions of the elliptic integrals. The two standard forms of these functions are known as Jacobi elliptic functions and Weierstrass elliptic functions.
Jacobi elliptic functions arise as solutions to differential equations of the form
$$ y''(x)=A+By(x)+Cy^2(x)+Dy^3(x)$$
and Weierstrass elliptic functions arise as solutions to differential equations of the form
$$ y''(x)=A+By(x)+Cy^2(x)$$
My questions:
Can we express all doubly periodic functions as one of doubly periodic function similarly as we do in singly periodic functions?
Is there any research on such base doubly periodic function that can be used to express all type of doubly periodic functions or signals in series? Please share references If you know any.
In other words,For example:
$y(x)=e^{x}$ is a solution of $$ y'(x)=y(x)$$ and $e^{x}$ has been used as base function to express all singly Periodic Functions.
Maybe we can define a $f{(x)}$ as the solution of $$ y''(x)=1+y(x)+y^2(x)+y^3(x)$$ .$f{(x)}$ can be used to express all of other doubly periodic functions . I do not know if it is possible or not?
Thanks for answers and comments