TY - GEN T1 - Upper Limits on the Isotropic Gravitational-Wave Background from Advanced LIGO's and Advanced Virgo's Third Observing Run T2 - arXiv PY - 2021/01/28 AU - The LIGO Scientific Collaboration AU - the Virgo Collaboration AU - the KAGRA Collaboration AU - Abbott R AU - Abbott TD AU - Abraham S AU - Acernese F AU - Ackley K AU - Adams A AU - Adams C AU - Adhikari RX et al ED - DO - DOI: 10.48550/arxiv.2101.12130 Y2 - 2025/10/08 ER -