Finite distance effects on the Hellings–Downs curve in modified gravity
- verfasst von
- Guillem Domènech, Apostolos Tsabodimos
- Abstract
There is growing interest in the overlap reduction function in pulsar timing array observations as a probe of modified gravity. However, current approximations to the Hellings–Downs curve for subluminal gravitational wave propagation, say v<1, diverge at small angular pulsar separation. In this paper, we find that the overlap reduction function for the v<1 case is sensitive to finite distance effects. First, we show that finite distance effects introduce an effective cut-off in the spherical harmonics decomposition at ℓ∼1-v2kL, where ℓ is the multipole number, k the wavenumber of the gravitational wave and L the distance to the pulsars. Then, we find that the overlap reduction function in the small angle limit approaches a value given by πkLv2(1-v2)2 times a normalization factor, exactly matching the value for the autocorrelation recently derived. Although we focus on the v<1 case, our formulation is valid for any value of v.
- Organisationseinheit(en)
-
Institut für Theoretische Physik
- Externe Organisation(en)
-
Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut)
- Typ
- Artikel
- Journal
- European Physical Journal C
- Band
- 84
- ISSN
- 1434-6044
- Publikationsdatum
- 07.10.2024
- Publikationsstatus
- Veröffentlicht
- Peer-reviewed
- Ja
- ASJC Scopus Sachgebiete
- Ingenieurwesen (sonstige), Physik und Astronomie (sonstige)
- Elektronische Version(en)
-
https://doi.org/10.1140/epjc/s10052-024-13418-w (Zugang:
Offen)
https://doi.org/10.1140/epjc/s10052-024-13492-0 (Zugang: Offen)
