Jacob's ladders, the structure of the Hardy–Littlewood integral and some new class of nonlinear integral equations

In this paper we obtain new formulae for short and microscopic parts of the Hardy–Littlewood integral, and the first asymptotic formula for the sixth-order expression $|\zeta(\frac12+i\varphi _1(t))|^4|\zeta(\frac 12+it)|^2$. These formulae cannot be obtained in the theories of Balasubramanian, Heath-Brown and Ivić.