Almost periodic functions serve as a powerful conceptual framework in analysing differential equations whose coefficients or forcing terms exhibit recurrent behaviour over time.

Ching Chou, Weakly Almost Periodic Functions and Almost Convergent Functions on a Group, Transactions of the American Mathematical Society, Vol. 206 (May, 1975), pp. 175-200 ...

Every non-zero complex homomorphism of the almost periodic functions on an abelian group is induced by the Fourier transform. A Plancherel formula for almost periodic functions and a necessary ...

Modern Periodic Law states that properties of elements are a periodic function of their atomic number. Q. How does the electronegativity of elements relate to their metallic or non-metallic character?