CMB — Cosmic Microwave Background Simulator

🌌 CMB Power Spectrum

The CMB is relic radiation from 380,000 years after the Big Bang. Its temperature fluctuations encode the acoustic oscillations of the early baryon-photon plasma.

🎛 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

🔭 View

📐 Current model

1st peak ℓ

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2nd peak ℓ

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Sound horizon

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T₀

2.725 K

ℹ️ Physics

Before recombination the baryon-photon fluid oscillated as sound waves. The power spectrum C_ℓ shows peaks (compressions) and troughs (rarefactions) at harmonics of the sound horizon r_s.

Increasing Ω_b boosts odd peaks (compression) relative to even ones. Increasing Ω_c suppresses all peaks via the early ISW effect. Lower H₀ shifts all peaks to smaller ℓ.