Details
| Original language | English |
|---|---|
| Article number | 083038 |
| Number of pages | 17 |
| Journal | Physical Review D |
| Volume | 109 |
| Issue number | 8 |
| Publication status | Published - 30 Apr 2024 |
Abstract
The stochastic gravitational wave background for pulsar timing arrays is often modeled by a Gaussian ensemble which is isotropic and unpolarized. However, the Universe has a discrete set of polarized gravitational wave sources at specific sky locations. Can we trust that the Gaussian ensemble is an accurate description To investigate this, we explicitly construct an ensemble containing N individual binary sources with circular orbits. The orbital inclination angles are randomly distributed, hence the individual sources are elliptically polarized. We then compute the first two moments of the Hellings and Downs correlation, as well as the pulsar-averaged correlation mean and (cosmic) variance. The first moments are the same as for a previously studied ensemble of circularly polarized sources. However, the second moments, and hence the variances, are different for the two ensembles. While neither discrete source model is exactly described by a Gaussian ensemble, we show that in the limit of large N, the differences are small.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Nuclear and High Energy Physics
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In: Physical Review D, Vol. 109, No. 8, 083038, 30.04.2024.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Pulsar timing array source ensembles
AU - Allen, Bruce
AU - Valtolina, Serena
N1 - Publisher Copyright: © 2024 authors. Published by the American Physical Society.
PY - 2024/4/30
Y1 - 2024/4/30
N2 - The stochastic gravitational wave background for pulsar timing arrays is often modeled by a Gaussian ensemble which is isotropic and unpolarized. However, the Universe has a discrete set of polarized gravitational wave sources at specific sky locations. Can we trust that the Gaussian ensemble is an accurate description To investigate this, we explicitly construct an ensemble containing N individual binary sources with circular orbits. The orbital inclination angles are randomly distributed, hence the individual sources are elliptically polarized. We then compute the first two moments of the Hellings and Downs correlation, as well as the pulsar-averaged correlation mean and (cosmic) variance. The first moments are the same as for a previously studied ensemble of circularly polarized sources. However, the second moments, and hence the variances, are different for the two ensembles. While neither discrete source model is exactly described by a Gaussian ensemble, we show that in the limit of large N, the differences are small.
AB - The stochastic gravitational wave background for pulsar timing arrays is often modeled by a Gaussian ensemble which is isotropic and unpolarized. However, the Universe has a discrete set of polarized gravitational wave sources at specific sky locations. Can we trust that the Gaussian ensemble is an accurate description To investigate this, we explicitly construct an ensemble containing N individual binary sources with circular orbits. The orbital inclination angles are randomly distributed, hence the individual sources are elliptically polarized. We then compute the first two moments of the Hellings and Downs correlation, as well as the pulsar-averaged correlation mean and (cosmic) variance. The first moments are the same as for a previously studied ensemble of circularly polarized sources. However, the second moments, and hence the variances, are different for the two ensembles. While neither discrete source model is exactly described by a Gaussian ensemble, we show that in the limit of large N, the differences are small.
UR - http://www.scopus.com/inward/record.url?scp=85192055322&partnerID=8YFLogxK
U2 - 10.1103/PhysRevD.109.083038
DO - 10.1103/PhysRevD.109.083038
M3 - Article
AN - SCOPUS:85192055322
VL - 109
JO - Physical Review D
JF - Physical Review D
SN - 2470-0010
IS - 8
M1 - 083038
ER -