  We investigate the sensitivity of future space-based interferometers such as
LISA and DECIGO to the parameters of new particle physics models which drive a
first-order phase transition in the early Universe. We first perform a Fisher
matrix analysis on the quantities characterizing the gravitational wave
spectrum resulting from the phase transition, such as the peak frequency and
amplitude. We next perform a Fisher analysis for the quantities which determine
the properties of the phase transition, such as the latent heat and the time
dependence of the bubble nucleation rate. Since these quantities are determined
by the model parameters of the new physics, we can estimate the expected
sensitivities to such parameters. We illustrate this point by taking three new
physics models for example: (1) models with additional isospin singlet scalars
(2) a model with an extra real Higgs singlet, and (3) a classically conformal
$B-L$ model. We find that future gravitational wave observations play
complementary roles to future collider experiments in pinning down the
parameters of new physics models driving a first-order phase transition.
