{"work":{"id":"50c4dfef-4115-4e86-9c22-ac7fd06f6b09","openalex_id":null,"doi":null,"arxiv_id":"1208.2701","raw_key":null,"title":"Revising the Halofit Model for the Nonlinear Matter Power Spectrum","authors":null,"authors_text":"R","year":2012,"venue":"astro-ph.CO","abstract":"Based on a suite of state-of-the-art high-resolution $N$-body simulations, we revisit the so-called halofit model (Smith et al. 2003) as an accurate fitting formula for the nonlinear matter power spectrum. While the halofit model has been frequently used as a standard cosmological tool to predict the nonlinear matter power spectrum in a universe dominated by cold dark matter, its precision has been limited by the low-resolution of $N$-body simulations used to determine the fitting parameters, suggesting the necessity of improved fitting formula at small scales for future cosmological studies. We run high-resolution $N$-body simulations for 16 cosmological models around the Wilkinson Microwave Anisotropy Probe (WMAP) best-fit cosmological parameters (1, 3, 5, and 7 year results), including dark energy models with a constant equation of state. The simulation results are used to re-calibrate the fitting parameters of the halofit model so as to reproduce small-scale power spectra of the $N$-body simulations, while keeping the precision at large scales. The revised fitting formula provides an accurate prediction of the nonlinear matter power spectrum in a wide range of wavenumber ($k \\leq 30h$\\,Mpc$^{-1}$) at redshifts $0 \\leq z \\leq 10$, with 5% precision for $k\\leq1 h$ Mpc$^{-1}$ at $0 \\leq z \\leq 10$ and 10% for $1 \\leq k\\leq 10 h$ Mpc$^{-1} $ at $0 \\leq z \\leq 3$. We discuss the impact of the improved halofit model on weak lensing power spectra and correlation functions, and show that the improved model better reproduces ray-tracing simulation results.","external_url":"https://arxiv.org/abs/1208.2701","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-05-23T17:45:45.894150+00:00","pith_arxiv_id":"1208.2701","created_at":"2026-05-12T08:31:26.131425+00:00","updated_at":"2026-05-23T17:45:45.894150+00:00","title_quality_ok":true,"display_title":"Takahashi, M","render_title":"Takahashi, M"},"hub":{"state":{"work_id":"50c4dfef-4115-4e86-9c22-ac7fd06f6b09","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":12,"external_cited_by_count":null,"distinct_field_count":2,"first_pith_cited_at":"2020-05-11T17:49:03+00:00","last_pith_cited_at":"2026-05-13T13:55:32+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":"2026-05-31T21:32:53.802653+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":4},{"context_role":"method","n":4}],"polarity_counts":[{"context_polarity":"background","n":4},{"context_polarity":"use_method","n":4}],"runs":{},"summary":{},"graph":{},"authors":[]}}