  Massive neutrinos are expected to affect the large-scale structure formation,
including the major component of solid substances, dark matter halos. How halos
are influenced by neutrinos is vital and interesting, and angular momentum (AM)
as a significant feature provides a statistical perspective for this issue.
Exploring halos from TianNu N-body cosmological simulation with the co-evolving
neutrino particles, we obtain some concrete conclusions. First, by comparing
the same halos with and without neutrinos, in contrast to the neutrino-free
case, over 89.71\% of halos have smaller halo moduli, over 71.06\% have smaller
particle-mass-reduced (PMR) AM moduli, and over 95.44\% change their
orientations of less than $0.65^\circ$. Moreover, the relative variation of PMR
modulus is more visible for low-mass halos. Second, to explore the PMR moduli
of halos in dense or sparse areas, we divide the whole box into big cubes, and
search for halos within a small spherical cell in a single cube. From the
two-level divisions, we discover that in denser cubes, the variation of PMR
moduli with massive neutrinos decreases more significantly. This distinction
suggests that neutrinos exert heavier influence on halos' moduli in compact
regions. With massive neutrinos, most halos (86.60\%) have lower masses than
without neutrinos.

Cosmology and Nongalactic Astrophysics