  We present 1/N Schwinger boson and quantum Monte Carlo calculations of the
magnetization and NMR relaxation rate for the two-dimensional ferromagnetic
Heisenberg model representing a quantum Hall system at filling factor nu=1.
Comparing the analytic and numerical calculations, we find that the SU(N)
version of Schwinger boson theory gives accurate results for the magnetization
at low temperatures, whereas the O(N) model works well at higher temperatures.
