Self Gravity with FFT

Self-Gravity with FFT

Poisson's equation is solved using FFT assuming periodic BCs in all directions.

Regression Test (Jeans tests)

> cd tst/regression/
> ./run_tests.py grav

Example

> ./configure.py --prob=poisson -fft --grav=fft
> cd bin
> ./athena -i ../inputs/hydro/athinput.poisson