  In this proceedings contribution I review recent work in kinetic theory which
demonstrates that, for system undergoing Bjorken expansion, there exists an
attractor in all moments of the one-particle distribution function. I discuss
how this attractor emerges in both exact solutions obtained in relaxation time
approximation (RTA) and the effective kinetic theory approach to
high-temperature quantum chromodynamics (QCD). The QCD effective kinetic theory
collisional kernel used includes both elastic (2 <-> 2) and LPM-resummed
inelastic (2 <-> 1) contributions. The results obtained indicate that a
pseudothermal attractor exists in both RTA and QCD kinetic theory and that
their respective attractors can be extended to early times when the system is
far from equilibrium. Finally, I discuss how knowledge of the QCD effective
kinetic theory attractor can be used to assess different hydrodynamic
freeze-out prescriptions used in heavy-ion phenomenology. The results obtained
show that improved freeze-out prescriptions such as anisotropic hydrodynamics
perform better in conditions corresponding to those generated in
high-multiplicity pA and pp collisions, e.g. short lifetime and high inverse
Reynolds number.
