  Quasicondensation in one dimension is known to occur for equilibrium systems
of hard-core bosons (HCBs) at zero temperature. This phenomenon arises due to
the off-diagonal long-range order in the ground state, characterized by a
power-law decay of the one-particle density matrix $g_1(x,y)\sim
|x-y|^{-1/2}$~--~a well-known outcome of Luttinger liquid theory. Remarkably,
HCBs, when allowed to freely expand from an initial product state (i.e.,
characterized by initial zero correlation), exhibit quasicondensation and
demonstrate the emergence of off-diagonal long-range order during
nonequilibrium dynamics. This phenomenon has been substantiated by numerical
and experimental investigations in the early 2000s. In this work, we revisit
the dynamical quasicondensation of HCBs, providing a fully analytical treatment
of the issue. In particular, we derive an exact asymptotic formula for the
equal-time one-particle density matrix by borrowing ideas from the framework of
quantum Generalized Hydrodynamics. Our findings elucidate the phenomenology of
quasicondensation and of dynamical fermionization occurring at different stages
of the time evolution, as well as the crossover between the two.
