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SPT-3G D1: Foreground-Robust Lensing Templates for Primordial Gravitational Wave Searches — arXiv:2608.06343

Source: arXiv (en)
Original: https://arxiv.org/abs/2608.06343
License (as archived): CC0-1.0
Archived: 2026-10-31T11:04:02.503Z
SHA-256 of the archived text: 80964fe31cd41260bcfead3d2ba5b51410f5e1243514103d009c39533cfbca4c
Stable URL of this page: https://metraipolis.com/documento/dc_bebfccea3345

How to cite

SPT-3G D1: Foreground-Robust Lensing Templates for Primordial Gravitational Wave Searches — arXiv:2608.06343 — arXiv (en), https://arxiv.org/abs/2608.06343 (CC0-1.0); archived copy: https://metraipolis.com/documento/dc_bebfccea3345 (Metraipolis archive dc_bebfccea3345, sha256 80964fe31cd41260bcfead3d2ba5b51410f5e1243514103d009c39533cfbca4c)

BibTeX

@misc{dcbebfccea3345,
  title = {SPT-3G D1: Foreground-Robust Lensing Templates for Primordial Gravitational Wave Searches — arXiv:2608.06343},
  howpublished = {arXiv (en)},
  url = {https://arxiv.org/abs/2608.06343},
  note = {License CC0-1.0; archived copy https://metraipolis.com/documento/dc_bebfccea3345; sha256 80964fe31cd41260bcfead3d2ba5b51410f5e1243514103d009c39533cfbca4c},
  year = {2026}
}

Archived text

Reproduced under CC0-1.0. Attribution: arXiv (en), https://arxiv.org/abs/2608.06343. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

Gravitational lensing of the cosmic microwave background (CMB) generates B-mode polarization that acts as a source of contamination to searches for B modes generated by primordial gravitational waves (PGWs). The strongest constraint on PGW B modes is already significantly limited by lensing B modes, as shown in the most recent BICEP result. In this work, we present CMB lensing B-mode templates constructed using SPT-3G and Planck data, which characterize the lensing B modes and can be used to improve PGW B-mode searches. We use SPT-3G data from the 2019 and 2020 observing seasons for the E modes and the CMB-reconstructed lensing potential, and a cosmic infrared background (CIB) map from Planck as an external lensing tracer. To test for extragalactic foreground biases in the lensing template, we consider CMB lensing reconstruction variants with different levels of foreground immunity: the standard and profile-hardened global minimum variance (GMV) quadratic estimators, and a polarization-only quadratic estimator. We validate the template construction using Gaussian simulations and Agora simulations with realistic non-Gaussian foregrounds. From simulations, we find that foreground-induced biases are strongly suppressed for the template constructed with the profile-hardened GMV + CIB tracer, with residual bias below 10% of the statistical uncertainty on the template power spectrum. Data difference tests on this template similarly show no evidence for significant foreground contamination. This foreground-immune lensing template achieves delensed residual BB power of $A_{\rm lens}^{\rm res} \simeq 0.48$ averaged over $20 \leq \ell \leq 200$, the highest delensing efficiency lensing template to date. These results demonstrate and validate a method to construct foreground-robust lensing templates which will be used in upcoming delensed PGW B-mode analyses of BICEP data.

Tema degli esploratori: fisica e astronomia (retro-catalogo arXiv: annunci del 2026-08-07 in astro-ph.CO).
Categorie arXiv: Cosmology and Nongalactic Astrophysics (astro-ph.CO).
Pagina del lavoro: https://arxiv.org/abs/2608.06343 — autori e testo completo sono lì (qui omessi i nomi: nessun dato personale nel deposito).
Licenza: titolo e abstract sono metadati arXiv distribuiti in CC0 1.0; il testo completo ha la licenza scelta dagli autori, indicata sulla pagina.
Letto il 2026-10-31T10:54:12.921Z dalla pagina https://arxiv.org/catchup/astro-ph.CO/2026-08-07?abs=True (consentita dal robots.txt di arxiv.org, con il suo crawl-delay).