  In the domain growth process, small structures gradually vanish, leaving
behind larger ones. We investigate spectral energy transfers in two standard
models for domain growth: (a) the {\it Cahn-Hilliard} (CH) equation with
conserved dynamics, and (b) the {\it time-dependent Ginzburg-Landau} (TDGL)
equation with non-conserved dynamics. The nonlinear terms in these equations
dissipate fluctuations and facilitate energy transfers among Fourier modes. In
the TDGL equation, only the $\phi(\mathbf{k} = 0, t)$ mode survives, and the
order parameter $\phi(\mathbf{r},t)$ approaches a uniform state with $\phi =
+1$ or $-1$. On the other hand, there is no dynamics of the $\phi(\mathbf{k} =
0, t)$ mode in the CH equation due to the conservation law, highlighting the
different dynamics of these equations.
