Ramanujan conjecture

Etymology
Named after.

Proper noun

 * 1)  A conjecture stating that the Ramanujan tau function given by the Fourier coefficients $τ(n)$ of the cusp form $Δ(z)$ of weight $12$ $$\Delta(z)= \sum_{n>0}\tau(n)q^n=q\prod_{n>0}\left (1-q^n \right)^{24} = q-24q^2+252q^3- 1472q^4 + 4830q^5-\cdots,$$ where $$q=e^{2\pi iz}$$, satisfies $$|\tau(p)| \leq 2p^{11/2},$$ when $$p$$ is a prime number.