Awaking the Vacuum in Relativistic Stars

Abstract

Void of any inherent structure in classical physics, the vacuum has revealed to be incredibly crowded with all sorts of processes in relativistic quantum physics. Yet, its direct effects are usually so subtle that its structure remains almost as evasive as in classical physics. Here, in contrast, we report on the discovery of a novel effect according to which the vacuum is compelled to play an unexpected central role in an astrophysical context. We show that the formation of relativistic stars may lead the vacuum energy density of a quantum field to an exponential growth. The vacuum-driven evolution which would then follow may lead to unexpected implications for astrophysics, while the observation of stable neutron-star configurations may teach us much on the field content of our Universe.

Quantization of unstable linear scalar fields in static spacetimes

“…This equation implies that all ψ (n) t in Eq. (75) are null for n odd, while for n even they can be expressed in terms of symmetrized tensor products of ψ (2) t . Hence, the only equation we must care about is…”

“…[14], we interpret ψ (2) t in the left-hand side of Eq. (78) as a map from H to H. Then, the identification of ψ (2) t with the operator ε t is consistent if the former is symmetric, i.e., if…”

“…A concrete realization of this claim was given in Ref. [2], where the appearance of the instability was studied in the spacetime of a compact object. The scenario in which the spacetime is generated by a spheroidal shell was considered in Ref.…”

Quantum versus classical instability of scalar fields in curved backgrounds

“…References [1][2][3][4] analyzed the case of a quantum fieldΦ, which satisfies Eq. (1), being stable on ðR 4 ; η ab Þ but unstable on ðR 4 ; g ab Þ.…”

“…Particular astrophysically inspired realizations of this mechanism were explored in Refs. [2,3]. As the instability sets in, the system is driven to a new equilibrium state, generically inducing a burst of free scalar particles [4].…”