  We compute three-body nuclear forces at short distances by using the nuclear
matrix model of holographic QCD proposed in our previous paper with P. Yi. We
find that the three-body forces at short distances are repulsive for (a)
aligned three neutrons with averaged spins, and (b) aligned
proton-proton-neutron / proton-neutron-neutron. These indicate that in dense
states of neutrons such as cores of neutron stars, or in Helium-3 / tritium
nucleus, the repulsive forces are larger than the ones estimated from two-body
forces only.
