Figures 4-6

*Figure 4*

Analytic decomposition ($\Omega_0=1$ scale invariant
adiabatic model). The effective temperature after
gravitational redshift dominates the primary anisotropy. Peak
heights are enhanced and modulated by baryon-photon ratio $R$
as well as experience a boost crossing the equality scale
at $\ell \approx \sqrt{3} (2 \Omega_0 H_0^2/a_{eq})^{1/2} \eta_0
\approx 400$.
The Doppler effect is smaller and out of phase with the
temperature. The ISW effect due to potential decay after recombination
is small here but can be significant for low matter content universes.
Diffusion damping cuts off the acoustic spectrum at small scales.

*Figure 5*

Driving effects. The time evolution of the potential
can enhance the amplitude of the acoustic oscillation by
driving effects. In the adiabatic case [(a) solid lines, numerical
results and
(b) heuristic picture], the potential
enhances the first compression through infall and decays leaving
the oscillator strongly displaced from the zero point. In the
(baryon) isocurvature case [(a) dashed line], the potential grows from
zero and stimulates a sine mode. The first extrema here is suppressed
due to the fact that the gravitation driving begins near
sound horizon crossing. Notice that for the first cycle of
the adiabatic and isocurvature oscillations, the gravitational
force mimics a driving force of approximately twice the natural
period.

*Figure 6*

Heights of the peaks in a scale invariant adiabatic
model. The heights of the peaks is determined
by the baryon drag and acoustic driving effects and so are sensitive
to $\Omega_b h^2$ and $\Omega_0 h^2$. Baryons increase compression
in potential wells causing the peak heights to alternate. Lower
matter content causes more potential decay driving the oscillation.