Details
| Original language | English |
|---|---|
| Article number | 1005 |
| Journal | European Physical Journal C |
| Volume | 84 |
| Issue number | 10 |
| Publication status | Published - 7 Oct 2024 |
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.
ASJC Scopus subject areas
- Engineering(all)
- Engineering (miscellaneous)
- Physics and Astronomy(all)
- Physics and Astronomy (miscellaneous)
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In: European Physical Journal C, Vol. 84, No. 10, 1005, 07.10.2024.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Finite distance effects on the Hellings–Downs curve in modified gravity
AU - Domènech, Guillem
AU - Tsabodimos, Apostolos
N1 - Publisher Copyright: © The Author(s) 2024.
PY - 2024/10/7
Y1 - 2024/10/7
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85206372046&partnerID=8YFLogxK
U2 - 10.1140/epjc/s10052-024-13418-w
DO - 10.1140/epjc/s10052-024-13418-w
M3 - Article
AN - SCOPUS:85206372046
VL - 84
JO - European Physical Journal C
JF - European Physical Journal C
SN - 1434-6044
IS - 10
M1 - 1005
ER -