Building Intution: Spherical Collapse

• follow overdense "subuniverse" (Gunn & Gott (1972))

Quantifying Cosmic Density Fields: I

• observational reality:
  • Planck CMB sky
  • 2dF galaxy survey slice
  • SDSS galaxies and quasars
• counts in cells
• density contrast

Spherical Collapse Revisited

• nonlinear density contrast evolution
• linearized evolution
• forecasting strutures: critical linearized density