Abbott, RobertAbbott, T DAbraham, SAcernese, FaustoAckley, KAdams, AAdams, CAdhikari, Rana XAdya, VaishaliAffeldt, CAgathos, MAltin, PaulEichholz, JohannesForsyth, PerryKapasi, DishaKijbunchoo, NutsineeMcClelland, DavidMcManus, DavidMcRae, TerryScott, Susan M.Slagmolen, BramWade, AndrewWard, RobertWette, KarlYap, Min JetToyra, Daniel2023-05-052023-05-052470-0010http://hdl.handle.net/1885/289888Gravitational waves enable tests of general relativity in the highly dynamical and strong-field regime. Using events detected by LIGO-Virgo up to 1 October 2019, we evaluate the consistency of the data with predictions from the theory. We first establish that residuals from the best-fit waveform are consistent with detector noise, and that the low- and high-frequency parts of the signals are in agreement. We then consider parametrized modifications to the waveform by varying post-Newtonian and phenomenological coefficients, improving past constraints by factors of ∼2; we also find consistency with Kerr black holes when we specifically target signatures of the spin-induced quadrupole moment. Looking for gravitational-wave dispersion, we tighten constraints on Lorentz-violating coefficients by a factor of ∼2.6 and bound the mass of the graviton to mg≤1.76×10-23 eV/c2 with 90% credibility. We also analyze the properties of the merger remnants by measuring ringdown frequencies and damping times, constraining fractional deviations away from the Kerr frequency to δf^220=0.03-0.35+0.38 for the fundamental quadrupolar mode, and δf^221=0.04-0.32+0.27 for the first overtone; additionally, we find no evidence for postmerger echoes. Finally, we determine that our data are consistent with tensorial polarizations through a template-independent method. When possible, we assess the validity of general relativity based on collections of events analyzed jointly. We find no evidence for new physics beyond general relativity, for black hole mimickers, or for any unaccounted systematics.The authors gratefully acknowledge the support of the United States National Science Foundation (NSF) for the construction and operation of the LIGO Laboratory and Advanced LIGO as well as the Science and Technology Facilities Council (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 GEO600 detector. Additional support for Advanced LIGO was provided by the Australian Research Council. The authors gratefully acknowledge the Italian Istituto Nazionale di Fisica Nucleare (INFN), the French Centre National de la Recherche Scientifique (CNRS) and the Netherlands Organization for Scientific Research, for the construction and operation of the Virgo detector and the creation and support of the EGO consortiumapplication/pdfen-AU© 2021 American Physical Society202110.1103/PhysRevD.103.1220022022-02-13