{"paper":{"title":"Limits on anisotropy in the nanohertz stochastic gravitational-wave background","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.CO","gr-qc"],"primary_cat":"astro-ph.HE","authors_text":"A. Lassus, A. Petiteau, A. Possenti, A. Sesana, A. Vecchio, B. Stappers, C. G. Bassa, C. M. F. Mingarelli, C. Tiburzi, D. J. Champion, D. Perrodin, G. Desvignes, G. H. Janssen, G. Theureau, I. Cognard, J. P. W. Verbiest, J. R. Gair, J. W. T. Hessels, K. Liu, L. Guillemot, L. Lentati, M. B. Purver, M. Burgay, M. Kramer, P. A. Rosado, P. Brem, P. Lazarus, R. Karuppusamy, R. N. Caballero, R. Smits, R. van Haasteren, S. A. Sanidas, S. Babak, S. Os{\\l}owski, S. R. Taylor","submitted_at":"2015-06-29T20:00:19Z","abstract_excerpt":"The paucity of observed supermassive black hole binaries (SMBHBs) may imply that the gravitational wave background (GWB) from this population is anisotropic, rendering existing analyses sub-optimal. We present the first constraints on the angular distribution of a nanohertz stochastic GWB from circular, inspiral-driven SMBHBs using the $2015$ European Pulsar Timing Array data [Desvignes et al. (in prep.)]. Our analysis of the GWB in the $\\sim 2 - 90$ nHz band shows consistency with isotropy, with the strain amplitude in $l>0$ spherical harmonic multipoles $\\lesssim 40\\%$ of the monopole value."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1506.08817","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}