Diverses teories han estat surfejant per la literatura en relació a la massa perduda com les WIMP (Weakly Interacting Massive Particles - "partícules massives que interaccionen dèbilment"), MACHO (MAssive Compact Halo Objects - "objectes massius i compactes de l' aurèola"), forats negres primordials, neutrins massius i d' altres, cadascuna amb els seus pros i els seus contres. Cap d' aquestes teories no ha estat encara acceptada per la comunitat astronòmica, bàsicament per la impossibilitat actual de contrastar unes hipòtesis contra les altres.
Several theories have surfaced in literature to account for the missing mass such as WIMP s (Weakly Interacting Massive Particles), MACHO s (MAssive Compact Halo Objects), primordial black holes, massive neutrinos, and others; each with their pros and cons. No single theory has yet been accepted by the astronomical community, because we so far lack the means to conclusively test one theory against the other.