  We focus on the initial state spatial anisotropies, originating at the
thermalization stage, for central collisions in relativistic heavy-ion
collisions. We propose that a plot of the root mean square values of the flow
coefficients $\sqrt{\bar {v_n^2}} \equiv v_n^{rms}$, calculated in a lab fixed
coordinate system, for a large range of $n$, from 1 to about 30, can give
non-trivial information about the initial stages of the system and its
evolution. We also argue that for all wavelengths $\lambda$ of the anisotropy
(at the surface of the plasma region) much larger than the acoustic horizon
size $H_s^{fr}$ at the freezeout stage, the resulting values of $v_n^{rms}$
should be suppressed by a factor of order $2H_s^{fr}/\lambda$. With initial
flow being zero, we discuss the possibility that the resulting flow could show
imprints of coherent oscillations in the plot of $v_n^{rms}$ for sub-horizon
modes. For gold-gold collision at 200 GeV, these features are expected to occur
for n $\ge$ 5, with $n < 4$ modes showing supression. This has strong
similarities with the physics of the anisotropies of the cosmic microwave
background radiation (CMBR) resulting from inflationary density fluctuations in
the universe. It seems possible that the statistical fluctuations due to finite
multiplicity may not be able to mask such features in the flow data, or, at
least a non-trivial overall shape of the plot of $v_n^{rms}$ may be inferred.
In that case, the successes of analysis of CMBR anisotropy power spectrum to
get cosmological parameters can be applied for relativistic heavy-ion
collisions to learn about various relevant parameters at the early stages of
the evolving system.
