Reconsidering the role of bright and dark gravitational-wave standard sirens for cosmology
Abstract
Gravitational-wave (GW) standard sirens have emerged as powerful probes of cosmic expansion. They are commonly divided into two classes: bright sirens, observed in coincidence with an electromagnetic (EM) counterpart, and dark sirens, detected without one. Bright sirens have often been considered the main avenue for precision cosmology; however, following the latest observing run of the LIGO-Virgo-KAGRA (LVK) collaboration, the estimates of merger rates of compact objects involving neutron stars (NSs) have decreased. In this Letter, we reconsider the role that bright and dark sirens will play in precision cosmology. We demonstrate that bright sirens, although detected in small numbers, will play a crucial role in achieving the precision needed to address the Hubble tension, primarily by breaking the degeneracy between the Hubble constant (H0) and the matter density parameter (Ωm) inherent to dark sirens. Alternatively, we show that dark sirens alone can resolve the H0 tension when supplemented with an external prior on Ωm. Furthermore, we present a self-consistent statistical framework for GW cosmology with bright and dark sirens, which have traditionally been treated as independent populations although they originate from the same underlying population of black holes (BHs) and NSs. Finally, we find that treating bright and dark sirens as independent populations will not significantly bias GW cosmology in the next LVK observing runs, but can lead to a biased reconstruction of the low-mass end of the mass spectrum.
Related
- Cosmology beyond standard sirens: cross-correlation of gravitational waves and neutral hydrogen intensity mapping
- A gaussian-process reconstruction of gravitational-wave friction from dark standard sirens
- A multiprobe ΛCDM consistency analysis with gravitational-wave standard sirens
- The Impact of Inclination, Redshift, and Mass Ratio Selection on Cosmological Constraints from Bright Sirens Beyond Conventional Fisher Approximations
- LISA bright sirens as a tiebreaker among cosmologies in tension
BibTeX
@misc{colombo2026reconsidering,
title = {{Reconsidering the role of bright and dark gravitational-wave standard sirens for cosmology}},
author = {Alberto Colombo and Sonia Triscari-Benimavò and Simone Mastrogiovanni},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.12053},
eprint = {2609.12053},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.12053},
}
RIS
TY - UNPB
TI - Reconsidering the role of bright and dark gravitational-wave standard sirens for cosmology
AU - Alberto Colombo
AU - Sonia Triscari-Benimavò
AU - Simone Mastrogiovanni
PY - 2026
DA - 2026/09/10
PB - arXiv
DO - 10.48550/arxiv.2609.12053
UR - https://arxiv.org/abs/2609.12053
AB - Gravitational-wave (GW) standard sirens have emerged as powerful probes of cosmic expansion. They are commonly divided into two classes: bright sirens, observed in coincidence with an electromagnetic (EM) counterpart, and dark sirens, detected without one. Bright sirens have often been considered the main avenue for precision cosmology; however, following the latest observing run of the LIGO-Virgo-KAGRA (LVK) collaboration, the estimates of merger rates of compact objects involving neutron stars (NSs) have decreased. In this Letter, we reconsider the role that bright and dark sirens will play in precision cosmology. We demonstrate that bright sirens, although detected in small numbers, will play a crucial role in achieving the precision needed to address the Hubble tension, primarily by breaking the degeneracy between the Hubble constant (H_0) and the matter density parameter (Ω_m) inherent to dark sirens. Alternatively, we show that dark sirens alone can resolve the H_0 tension when supplemented with an external prior on Ω_m. Furthermore, we present a self-consistent statistical framework for GW cosmology with bright and dark sirens, which have traditionally been treated as independent populations although they originate from the same underlying population of black holes (BHs) and NSs. Finally, we find that treating bright and dark sirens as independent populations will not significantly bias GW cosmology in the next LVK observing runs, but can lead to a biased reconstruction of the low-mass end of the mass spectrum.
ER -