On the Dispersion Law of the Form $\varepsilon(p)=\hbar^2p^2/2m+\widetilde V(p)-\widetilde V(0)$ for Elementary Excitations of a Nonideal Fermi Gas in the Pair Interaction Approximation $(i\leftrightarrow j)$, $V(|x_i-x_j|)$

We give a derivation of the dispersion law $\varepsilon(p)=\hbar^2p^2/2m+\widetilde V(p)-\widetilde V(0)$, where $\widetilde V(p)$ is the Fourier transform of the pair interaction potential $V(r)$. (The interaction between particles $x_i$ and $x_j$ is $V(|x_i-x_j|)$.)