CMB Acoustic Oscillator: Baryon-Photon Plasma Waveform (2D)

🌌 Acoustic Oscillator

Before recombination the photon-baryon plasma rang like a bell: gravity compressed it, photon pressure pushed back. This animates that single-mode oscillator in conformal time for one multipole ℓ, then builds the power spectrum from it.

🎛 Cosmological parameters

Baryon density Ω_b h² 0.022 Dark matter Ω_c h² 0.120 Hubble H₀ (km/s/Mpc) 67.4 Primordial tilt n_s 0.965

🔊 Multipole ℓ (mode picked)

Multipole ℓ 220

📐 Current mode

Sound horizon r_s

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Baryon load R

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1st peak ℓ

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2nd peak ℓ

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ℹ️ Reading it

The top strip is the plasma itself — compression (red) and rarefaction (blue) breathing in place. The waveform below is Θ(η)+Ψ, the same quantity, traced through conformal time from the Big Bang (x=0) to recombination (x=1). The right panel is the power spectrum this oscillator sweeps out: raise Ω_b to see odd peaks grow over even ones, raise Ω_c to deepen the well, and lower H₀ to shift every peak to smaller ℓ.