  It is examined whether primordial top quarks from the Big Bang could survive
under natural conditions till present days. Hybrid quark-neutron stars, with
dense enough core to maintain the existence of top quarks, is discussed. In
this paper only final states are investigated. Zero temperature quark-lepton
matter is modelled as as a gas of non-interacting particles. Local charge
neutrality has been assumed in order to avoid volume interactions which would
not make thermodynamical treatment possible.
