| Title: |
Exploring the gauge flexibility of the linear-in-spin effective-one-body Hamiltonian at the 5.5 post-Newtonian order |
| Authors: |
Placidi, Andrea; Sebastiani, Luca; Grignani, Gianluca |
| Contributors: |
Ministero dell’Università e della Ricerca; Università degli Studi di Perugia; European Research Council |
| Source: |
Physical Review D ; volume 113, issue 8 ; ISSN 2470-0010 2470-0029 |
| Publisher Information: |
American Physical Society (APS) |
| Publication Year: |
2026 |
| Description: |
We derive the gauge-general expressions of the two gyro-gravitomagnetic functions entering the spin-orbit sector of the effective-one-body (EOB) Hamiltonian up to the fifth-and-half post-Newtonian (5.5PN) order. Our results include both local and nonlocal-in-time contributions, providing the most general analytical formulation of the linear-in-spin conservative dynamics within the EOB framework. These expressions are then employed to compute two gauge-invariant observables for quasicircular orbits: the binding energy and the fractional periastron advance. We also use them to compare two spin gauge choices: the well-known Damour-Jaranowski-Schäfer (DJS) gauge, in which the gyro-gravitomagnetic functions are independent of the orbital angular momentum, and the alternative anti-DJS (or ) gauge, designed to reproduce in the test-mass limit the spin-orbit interaction of a spinning test particle in a Kerr background. For a circular, equal-mass, equal-spin binary, our analysis indicates that the gauge provides a slightly improved description of the inspiral dynamics, suggesting potential advantages for its use in future EOB waveform models. |
| Document Type: |
article in journal/newspaper |
| Language: |
English |
| DOI: |
10.1103/435y-8241 |
| DOI: |
10.1103/435y-8241/fulltext |
| Availability: |
https://doi.org/10.1103/435y-8241; https://link.aps.org/article/10.1103/435y-8241; http://harvest.aps.org/v2/journals/articles/10.1103/435y-8241/fulltext |
| Rights: |
https://creativecommons.org/licenses/by/4.0/ |
| Accession Number: |
edsbas.FDD2B737 |
| Database: |
BASE |