  We study the low temperature properties of a helium-4 fluid confined in
nanopores, using large-scale Quantum Monte Carlo simulations with realistic
He-He and He-pore interactions. In the narrow-pore limit, the system can be
described by the quantum hydrodynamic theory known as Luttinger liquid theory
with a large Luttinger parameter, corresponding to the dominance of solid
tendencies and strong susceptibility to pinning by a periodic or random
potential from the pore walls. On the other hand, for wider pores, the central
region appears to behave like a Luttinger liquid with a smaller Luttinger
parameter, and may be protected from pinning by the wall potential, offering
the possibility of experimental detection of a Luttinger liquid.
