  We numerically investigate global properties of rotating neutron stars using
the allowed band of QCD equations of state derived by Kurkela et al. This band
is constrained by chiral effective theory at low densities and perturbative QCD
at high densities, and is thus, in essence, a controlled constraint from
first-principles physics. Previously, this band of equations of state was used
to investigate non-rotating neutron stars only; in this work, we extend these
results to any rotation frequency below the mass-shedding limit. We investigate
mass--radius curves, allowed mass--frequency regions, radius--frequency curves
for a typical 1.4-solar-mass star, and the values of the moment of inertia of
the double pulsar PSR J0737-3039A, a pulsar whose moment of inertia may be
constrained observationally in a few years. We present limits on observational
data coming from these constraints, and identify values of
observationally-relevant parameters that would further constrain the allowed
region for the QCD equation of state. We also discuss how much this region
would be constrained by a measurement of the moment of inertial of the double
pulsar PSR J0737-3039A.
