Abstract
The next generation of ground-based gravitational-wave detectors will look much deeper into the Universe and have unprecedented sensitivities and low-frequency capabilities. Especially alluring is the possibility of detecting an early-Universe cosmological stochastic background that could provide important insights into the beginnings of our Universe and fundamental physics at extremely high energies. However, even if next-generation detectors are sensitive to cosmological stochastic backgrounds, they will be masked by more dominant astrophysical backgrounds, namely the residual background from the imperfect subtraction of resolvable compact binary coalescences (CBCs) as well as the CBC background from individually unresolvable CBCs. Using our latest knowledge of masses, rates, and delay time distributions, we present a data-driven estimate of the unresolvable CBC background that will be seen by next-generation detectors. Accounting for statistical errors and astrophysical systematics, this estimate quantifies an important piece in the CBC noise budget for next-generation detectors and can help inform detector design and subtraction algorithms. Importantly, we find that the neutron-star black-hole binary contribution to the unresolved CBC background is further comparable to the binary neutron star contribution. We compare our results with predictions for backgrounds from several cosmological sources in the literature, finding that the unresolvable background will likely be a significant impediment for many models. This motivates the need for simultaneous inference methods or other statistical techniques to detect early-Universe cosmological backgrounds.
| Original language | English (US) |
|---|---|
| Article number | 023006 |
| Journal | Physical Review D |
| Volume | 110 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jul 15 2024 |
Funding
We thank Salvatore Vitale, Emanuele Berti, Vuk Mandic, Haowen Zhong, and Vishal Baibhav for helpful discussions. We thank Amanda Farah and Philippe Landry for their help with the LVK population analyses and Sylvia Biscoveanu for her help with the NSBH population analyses and for providing PI curves for XG detectors. D.\u2009S.\u2009B. is supported by the National Science Foundation (NSF) Graduate Research Fellowship Program under Grant No. DGE-2234667. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the NSF.\u2009D.\u2009S.\u2009B. was supported by a CIERA Post-Baccalaureate Research Fellowship during the majority of this research. D.\u2009S.\u2009B. acknowledges partial support for this project from NASA through a NASA Illinois Space Grant. S.\u2009B. acknowledges support from the NSF Grant No. PHY-2207945. Z.\u2009D. is supported by the CIERA Board of Visitors Research Professorship. V.\u2009K. is partially supported through a CIFAR Senior Fellowship, a Guggenheim Fellowship, the Gordon and Betty Moore Foundation (Grant Award No. GBMF8477), and from Northwestern University, including the Daniel I. Linzer Distinguished University Professorship fund. This material is based upon work supported by NSF\u2019s LIGO Laboratory which is a major facility fully funded by the National Science Foundation. This research has made use of data obtained from the Gravitational Wave Open Science Center (gwosc.org), a service of LIGO Laboratory, the LIGO Scientific Collaboration, the Virgo Collaboration, and KAGRA. LIGO Laboratory and Advanced LIGO are funded by the United States NSF as well as the STFC of the United Kingdom, the Max-Planck-Society (MPS), and the State of Niedersachsen/Germany for support of the construction of Advanced LIGO and construction and operation of the GEO\u2009600 detector. Additional support for Advanced LIGO was provided by the Australian Research Council. Virgo is funded, through the European Gravitational Observatory (EGO), by the French Centre National de Recherche Scientifique (CNRS), the Italian Istituto Nazionale di Fisica Nucleare (INFN), and the Dutch Nikhef, with contributions by institutions from Belgium, Germany, Greece, Hungary, Ireland, Japan, Monaco, Poland, Portugal, and Spain. K.\u2009A.\u2009G.\u2009R.\u2009A. is supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan Society for the Promotion of Science (JSPS) in Japan; National Research Foundation (NRF) and Ministry of Science and ICT (MSIT) in Korea; Academia Sinica (AS) and National Science and Technology Council (NSTC) in Taiwan. The authors are grateful for computational resources provided by the LIGO Laboratory and supported by NSF Grants No. PHY-0757058 and No. PHY-0823459. Lastly, we acknowledge the efforts of the CE Consortium and ET Collaboration in the planning and development of XG GW detectors. This manuscript carries an LSC DCC number LIGO-P2300334.
ASJC Scopus subject areas
- Nuclear and High Energy Physics