Core-collapse supernovae and neutron-star mergers produce copious amount of neutrinos, which impact evolution of these astrophysical sites as well as the element synthesis they may host. Collective oscillations of these neutrinos represent emergent nonlinear flavor evolution phenomena instigated by neutrino-neutrino interactions in astrophysical environments with sufficiently high neutrino densities. In this talk, after a brief introduction, A.B. Balantekin of the University of Wisconsin-Madison will show that neutrinos exhibit interesting entanglement behavior in simplified models of those oscillations. H will aslo describe attempts to study this behavior using classical and quantum computers.