Classical and Quantum Decay of Oscillatons: Oscillating Self-Gravitating Real Scalar Field Solitons

TL;DR

This paper analyzes the classical and quantum decay processes of oscillatons, revealing that quantum decay dominates for small Gm, and provides estimates for their lifetimes and asymptotic behavior towards boson star configurations.

Contribution

It presents a detailed comparison of classical and quantum decay rates of oscillatons, including new non-perturbative and perturbative formulas, and describes their long-term evolution towards static boson star states.

Findings

Quantum decay is faster than classical decay for Gm < 39.4/ln(1/Gm^2).

Oscillatons have an extremely long lifetime, approximately 10^324 years for certain parameters.

More complex oscillatons tend to evolve into static boson star configurations.

Abstract

The oscillating gravitational field of an oscillaton of finite mass M causes it to lose energy by emitting classical scalar field waves, but at a rate that is non-perturbatively tiny for small GMm, where m is the scalar field mass: d(GM)/dt ~ -3797437.776333015 e^[-39.433795197160163/(GMm)]/(GMm)^2. Oscillatons also decay by the quantum process of the annihilation of scalarons into gravitons, which is only perturbatively small in GMm, giving by itself d(GM)/dt ~ - 0.008513223934732692 G m^2 (GMm)^5. Thus the quantum decay is faster than the classical one for Gmm < 39.4338/[ln(1/Gm^2)}-7ln(GMm)+19.9160]. The time for an oscillaton to decay away completely into free scalarons and gravitons is ~ 2/(G^5 m^11) ~ 10^324 yr (1 meV/m)^11. Oscillatons of more than one real scalar field of the same mass generically asymptotically approach a static-geometry U(1) boson star configuration with GMm = GM_0 m, at the rate d(GM/c^3)/dt ~ [(C/(GMm)^4)e^{-alpha/(GMm)}+Q(m/m_{Pl})^2(GMm)^3] [(GMm)^2-(GM_0 m)^2], with GM_0 m depending on the magnitudes and relative phases of the oscillating fields, and with the same constants C, alpha, and Q given numerically above for the single-field case that is equivalent to GM_0 m = 0.