Quantum Monte Carlo simulations offer an unbiased means to study the static
and dynamic properties of quantum critical systems, while quantum field theory
provides direct analytical results. We study three dimensional, critical
quantum antiferromagnets by performing a combined analysis using both quantum
field theory calculations and quantum Monte Carlo data. Explicitly, we analyze
the order parameter (staggered magnetization), N\'eel temperature,
quasiparticle gaps, and the susceptibilities in the scalar and vector channels.
We connect the two approaches by deriving descriptions of the quantum Monte
Carlo observables in terms of the quasiparticle excitations of the field
theory. The remarkable agreement not only unifies the description of the static
and dynamic properties of the system, but also constitutes a thorough test of
perturbative O(3) quantum field theory and opens new avenues for the analytical
guidance of detailed numerical studies.Comment: New, improved, extended discussion throughout and in particular of
Higgs linewidth compariso
