Radial action for massive particles in spherically symmetric geometries: Exact resummation at any post-Minkowskian order
Phys. Rev. D 114, 044098 – Published 28 August, 2026
DOI: https://doi.org/10.1103/rn6v-jwbz
Abstract
We compute the radial action for massive particles along hyperboliclike geodesics in various spherically symmetric spacetimes: the standard Schwarzschild spacetime, its -dimensional generalization known as Schwarzschild-Tangherlini solutions and for the D3-brane spacetimes, showing useful resummation properties in terms of special (hypergeometric, Fox-Wright) functions in the eikonal limit and generalizing previous results valid for null geodesics. As a consequence, the scattering angle can be resummed too, and we explicitly display the resummed expressions. In addition, in the more interesting situation of a Schwarzschild black hole spacetime, following the approach of the quantum Seiberg-Witten curves to the radial equation associated with a massive scalar field, we show that the quantum cycle (or, equivalently, the “renormalized angular momentum”) is simply related to the part of the radial action also in this massive case, providing fully resummed expressions. Finally, we display the explicit, expanded-form expression of the dual cycle, for which, however, no resummed expressions have been derived yet.