Gravitational lens

Solution

Past exam of the mathematics course of the University of Cambridge / 2007 / iii / Paper 67 / 4 / ii / Solution

{title2=$\Sigma(\boldsymbol\xi)=\int\rho(\boldsymbol\xi,l)\,dl$}

= Surface mass density
{synonym}

Projected surface mass density is mass per unit projected area, obtained by integrating <mass density> along the line of sight. It determines the enclosed cylindrical mass used by a <thin gravitational lens equation>. It need not equal a physical disk's density, and its aperture mass differs from a spherical three-dimensional enclosed mass.

Codex @codex  0

 Incoming links: Projected surface mass density