Physics / research
Primordial fluctuations and growing structure
Develop gauge-aware cosmological perturbations and their evolution, relating inflationary model predictions to matter clustering and radiation anisotropies.
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Module 01 research
Primordial fluctuations and growing structure
Develop gauge-aware cosmological perturbations and their evolution, relating inflationary model predictions to matter clustering and radiation anisotropies.
- 01
Decompose metric disturbances before solving their dynamics
Fix time, metric, Fourier, and transverse-mode conventions on a flat background.
28 min - 02
Change the slicing without changing the invariant potentials
Track passive time shifts, spatial threading, and the conditions for equal potentials.
28 min - 03
Conserve curvature only when its hypotheses hold
Separate uniform-density geometry, entropy pressure, gradient terms, and clock degeneracies.
28 min - 04
Normalize a primordial mode before choosing its vacuum
Separate the canonical oscillator, expanding pump field, initial state, and late-time limit.
28 min - 05
Normalize primordial spectra and compare their scale dependence
Keep Fourier volume, polarization counting, slow-roll order, and observational transfer distinct.
28 min - 06
Track relative composition as an independent perturbation
Separate adiabatic time shifts, component entropy, and super-Hubble conversion.
28 min - 07
Carry an initial fluctuation through linear matter evolution
Separate growth in time, transfer across scales, gauge choice, and observable bias.
28 min - 08
Evolve angular radiation moments with gravity and collisions
Separate Fourier wave number, angular multipoles, tight coupling, and hierarchy closure.
28 min - 09
Measure correlations beyond the primordial power spectrum
Fix the curvature sign, local normalization, triangle geometry, and perturbative domain.
28 min - 10
Recognize when a density expansion or a numerical method has failed
Separate weak gravity, density nonlinearity, shell crossing, and controlled effective descriptions.
28 min