  In a large transverse field, there is an energy cost associated with flipping
spins along the axis of the field. This penalty can be employed to relate the
transverse-field Ising model in a large field to the XY model in no field (when
measurements are performed at the right stroboscopic times). We describe the
details for how this relationship works and, in particular, we also show under
what circumstances it fails. We examine wavefunction overlap between the two
models and observables, such as spin-spin Green's functions. In general, the
mapping is quite robust at short times, but will ultimately fail if the run
time becomes too long. There is also a trade-off between the length of time one
can run a simulation out to and the time jitter of the stroboscopic
measurements that must be balanced when planning to employ this mapping.
