{"work":{"id":"1dc1aaca-b80f-4a36-9fb0-bc147c21bd31","openalex_id":null,"doi":null,"arxiv_id":"1012.2879","raw_key":null,"title":"Tracking the precession of compact binaries from their gravitational-wave signal","authors":null,"authors_text":"P","year":2010,"venue":"gr-qc","abstract":"We present a simple method to track the precession of a black-hole-binary system, using only information from the gravitational-wave (GW) signal. Our method consists of locating the frame from which the magnitude of the $(\\ell=2,|m|=2)$ modes is maximized, which we denote the \"quadrupole-aligned\" frame. We demonstrate the efficacy of this method when applied to waveforms from numerical simulations. In the test case of an equal-mass nonspinning binary, our method locates the direction of the orbital angular momentum to within $(\\Delta \\theta, \\Delta \\phi) = (0.05^{\\circ},0.2^{\\circ})$. We then apply the method to a $q = M_2/M_1 = 3$ binary that exhibits significant precession. In general a spinning binary's orbital angular momentum $\\mathbf{L}$ is \\emph{not} orthogonal to the orbital plane. Evidence that our method locates the direction of $\\mathbf{L}$ rather than the normal of the orbital plane is provided by comparison with post-Newtonian (PN) results. Also, we observe that it accurately reproduces similar higher-mode amplitudes to a comparable non-spinning (and therefore non-precessing) binary, and that the frequency of the $(\\ell=2,|m|=2)$ modes is consistent with the \"total frequency\" of the binary's motion. The simple form of the quadrupole-aligned waveform will be useful in attempts to analytically model the inspiral-merger-ringdown (IMR) signal of precessing binaries, and in standardizing the representation of waveforms for studies of accuracy and consistency of source modelling efforts, both numerical and analytical.","external_url":"https://arxiv.org/abs/1012.2879","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-05-22T08:54:45.290310+00:00","pith_arxiv_id":"1012.2879","created_at":"2026-05-10T15:00:31.206146+00:00","updated_at":"2026-05-22T08:54:45.290310+00:00","title_quality_ok":true,"display_title":"Hannam, S.Husa, andP","render_title":"Hannam, S.Husa, andP"},"hub":{"state":{"work_id":"1dc1aaca-b80f-4a36-9fb0-bc147c21bd31","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":12,"external_cited_by_count":null,"distinct_field_count":1,"first_pith_cited_at":"2019-05-22T18:00:11+00:00","last_pith_cited_at":"2026-05-20T18:51:46+00:00","author_build_status":"not_needed","summary_status":"needed","contexts_status":"needed","graph_status":"needed","ask_index_status":"not_needed","reader_status":"not_needed","recognition_status":"not_needed","updated_at":"2026-05-29T20:00:22.635672+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":4},{"context_role":"method","n":3}],"polarity_counts":[{"context_polarity":"background","n":4},{"context_polarity":"use_method","n":3}],"runs":{},"summary":{},"graph":{},"authors":[]}}