{"paper":{"title":"Overview and status of BICEP Array's BA4-90/150 CMB polarimeter","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.IM","authors_text":"A. C. Weber, A. D. Turner, A. Fortes, A. Greathouse, A. G. Vieregg, A. J. Cukierman, A. Patel, A. R. Polish, A. Schillaci, A. Soliman, A. Steiger, A. Wandui, B. Cantrall, B. D. Elwood, B. Schmitt, B. Singari, B. Steinbach, C. A. Bischoff, C. D. Reintsema, C. Giannakopoulos, C. Kuo, C. Pryke, C. Tucker, C. Verg\\`{e}s, C. Yu, C. Zhang, D. Barkats, D. Beck, D. C. Goldfinger, E. Denison, H. Hui, H. T. Nguyen, H. Yang, J. A. Grayson, J. Connors, J. Cornelison, J. H. Kang, J. Hubmayr, J. J. Bock, J. M. Kovac, J. P. Filippini, J. R. Cheshire IV, J. Willmert, K. D. Irwin, K. G. Megerian, K. Lasko, K. Lau, K. L. Thompson, K. S. Karkare, L. Duband, L. Minutolo, L. Moncelsi, L. Zeng, M. A. Echter, M. Amiri, M. A. Petroff, M. Crumrine, M. Eiben, M. Gao, M. Halpern, M. Izquierdo Poza, M. Lautzenhiser, M. Salatino, N. Goeckner-Wald, N. Maher, P. A. R. Ade, P. K. Grimes, R. Basu Thakur, R. O'Brient, R. Sudiwala, S. C. Mackey, S. Fatigoni, S. Gratton, S. Henderson, S. Kefeli, S. N. Paine, S. Zhang, T. D. Hoang, T. Liu, T. Prouve, T. Romand, T. St. Germaine, V. Buza, W. L. K. Wu, Y. Nakato, Z. Ahmed","submitted_at":"2026-08-07T23:34:55Z","abstract_excerpt":"The inflation paradigm postulates a period of rapid expansion in the early Universe, which would generate gravitational waves. These tensor perturbations would produce a faint B-mode signature in the polarization of the cosmic microwave background (CMB), but this signal is orders of magnitude weaker than that from the CMB's other anisotropy and that from astrophysical foregrounds. Placing more-stringent upper limits on this signal or making a definitive detection thus requires exceptional control over instrument and measurement systematics, in addition to extremely-deep maps. The fourth BICEP "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2608.07817","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2608.07817/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}