Intelligent Design: On the Emulation of Cosmological Simulations
  Simulation design is the choice of locations in parameter space at which
simulations are to be run and is the first step in building an emulator capable
of quickly providing estimates of simulation results for arbitrary locations in
the parameter space. We introduce an alteration to the "OALHS" design used by
Heitmann et al. (2006) that reduces the number of simulation runs required to
achieve a fixed accuracy in our case study by a factor of two. We also compare
interpolation procedures for emulators and find that interpolation via Gaussian
Process models and via the much-easier-to-implement polynomial interpolation
have comparable accuracy. A very simple emulation-building procedure consisting
of a design sampled from the parameter prior distribution, combined with
interpolation via polynomials also performs well. Although our primary
motivation is efficient emulators of non-linear cosmological N-body
simulations, in an appendix we describe an emulator for the CMB temperature
power spectrum publicly available as computer code.
