Entanglement of arbitrary spin modes in expanding universe

Pair particle creation is a well-known effect in the domain of field theory in curved space–time. The behavior of the generated entanglement due to expanding universe is very different for spin-0 and spin-1/2 particles. We study spin-1 particles in Friedmann–Robertson–Walker (FRW) space–time using Duffin–Kemmer–Petiau equation and spin-3/2 particles in FRW space–time using Rarita–Schwinger equation. We find that in expanding universe, the behavior of the generated entanglement for spin-1 particles is the same as the behavior of the generated entanglement for spin-0 particles. Also, we find that spin-3/2 and spin-1/2 particles have the same behavior for the generated entanglement in expanding universe. We conclude that the absolute values of spins do not play any role and the differences in the behavior of the generated entanglement in expanding universe are due to bosonic or fermionic properties.