- Physical Review Journals
All JournalsPhysics Magazine

Physical Review D

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Open Access

Forecasting the Ly-α forest × CMB lensing bispectrum from ACT, SO, S4, and DESI

Adrien La Posta1,2 and Emmanuel Schaan3,4

PDF

Phys. Rev. D 112, 063528 – Published 16 September, 2025

DOI: https://doi.org/10.1103/9x9x-pqqm

Abstract

We forecast the sensitivity of future correlations between cosmic microwave background (CMB) lensing and the Lyman-α forest power spectrum. This squeezed-limit bispectrum probes the connection between the Lyman-α transmission and the underlying large-scale matter density field. We recover the measured signal-to-noise (SNR) ratio obtained with Planck×BOSS, and forecast a SNR of 10.3,14.8 and 20.2 for DESI combined with ACT, SO, and CMB-S4, respectively. For DESI and SO/CMB-S4, the correlation should be detectable at SNR≥5 in 5 redshift bins, useful for distinguishing our signal from several contaminants. Indeed, our forecast is affected by large theoretical uncertainties in the current modeling of the signal and its contaminants, such as continuum misestimation bias or damped-Lyman-α absorbers. Quantifying these more accurately will be crucial to enable a reliable cosmological interpretation of this observable in future measurements. We attempt to enumerate the features required in future Lyman-α forest simulations required to do so.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (45)

  1. M. Viel, G. D. Becker, J. S. Bolton, and M. G. Haehnelt, Phys. Rev. D 88, 043502 (2013).
  2. N. Palanque-Delabrouille et al., J. Cosmol. Astropart. Phys. 11 (2015) 011.
  3. N. Palanque-Delabrouille et al., J. Cosmol. Astropart. Phys. 04 (2020) 038.
  4. B. Villasenor, B. Robertson, P. Madau, and E. Schneider, Phys. Rev. D 108, 023502 (2023).
  5. N. G. Busca et al., Astron. Astrophys. 552, A96 (2013).
  6. A. Slosar et al., J. Cosmol. Astropart. Phys. 04 (2013) 026.
  7. T. Delubac et al., Astron. Astrophys. 574, A59 (2015).
  8. V. de Sainte Agathe et al., Astron. Astrophys. 629, A85 (2019).
  9. M. Blomqvist et al., Astron. Astrophys. 629, A86 (2019).
  10. H. du Mas des Bourboux et al., Astrophys. J. 901, 153 (2020).
  11. R. A. C. Croft, D. H. Weinberg, N. Katz, and L. Hernquist, Astrophys. J. 495, 44 (1998).
  12. A. Borde et al., J. Cosmol. Astropart. Phys. 07 (2014) 005.
  13. G. Rossi, N. Palanque-Delabrouille, A. Borde, M. Viel, C. Yèche, J. S. Bolton, J. Rich, and J.-M. Le Goff, Astron. Astrophys. 567, A79 (2014).
  14. A. Arinyo-i-Prats, J. Miralda-Escudé, M. Viel, and R. Cen, J. Cosmol. Astropart. Phys. 12 (2015) 017.
  15. M. S. Peeples et al., Mon. Not. R. Astron. Soc. 404, 1281 (2010).
  16. A. Garzilli, T. Theuns, and J. Schaye, Mon. Not. R. Astron. Soc. 450, 1465 (2015).
  17. A. Vallinotto, S. Das, D. N. Spergel, and M. Viel, Phys. Rev. Lett. 103, 091304 (2009).
  18. C. Doux, E. Schaan, E. Aubourg, K. Ganga, K.-G. Lee, D. N. Spergel, and J. Tréguer, Phys. Rev. D 94, 103506 (2016).
  19. W. Hu and T. Okamoto, Astrophys. J. 574, 566 (2002).
  20. A. Lewis and A. Challinor, Phys. Rep. 429, 1 (2006).
  21. A. Vallinotto, M. Viel, S. Das, and D. N. Spergel, Astrophys. J. 735, 38 (2011).
  22. C.-T. Chiang, A. M. Cieplak, F. Schmidt, and A. Slosar, J. Cosmol. Astropart. Phys. 06 (2017) 022.
  23. C.-T. Chiang, C. Wagner, F. Schmidt, and E. Komatsu, J. Cosmol. Astropart. Phys. 05 (2014) 048.
  24. Y. Li, W. Hu, and M. Takada, Phys. Rev. D 90, 103530 (2014).
  25. C. Wagner, F. Schmidt, C.-T. Chiang, and E. Komatsu, Mon. Not. R. Astron. Soc. 448, L11 (2014).
  26. C.-T. Chiang and A. Slosar, J. Cosmol. Astropart. Phys. 01 (2018) 012.
  27. E. Schaan, S. Ferraro, and D. N. Spergel, Phys. Rev. D 97, 123539 (2018).
  28. A. S. Maniyar, E. Schaan, and A. R. Pullen, Phys. Rev. D 105, 083509 (2022).
  29. H.-M. Zhu, T.-X. Mao, and U.-L. Pen, Astrophys. J. 929, 5 (2022).
  30. M. Takada and W. Hu, Phys. Rev. D 87, 123504 (2013).
  31. Y. Li, W. Hu, and M. Takada, Phys. Rev. D 89, 083519 (2014).
  32. E. Schaan, M. Takada, and D. N. Spergel, Phys. Rev. D 90, 123523 (2014).
  33. F. J. Qu et al., Astrophys. J. 962 112 (2024).
  34. M. S. Madhavacheril et al., Astrophys. J. 962 113 (2024).
  35. P. Ade et al., J. Cosmol. Astropart. Phys. 02 (2019) 056.
  36. K. N. Abazajian et al., arXiv:1610.02743.
  37. https://github.com/julienguy/simplelyaforecast
  38. N. Palanque-Delabrouille et al., Astron. Astrophys. 559, A85 (2013).
  39. D. Collaboration et al., Astron. J. 164, 207 (2022).
  40. C. Ravoux et al., Mon. Not. R. Astron. Soc. 526, 5118 (2023).
  41. H. K. Herrera-Alcantar et al., J. Cosmol. Astropart. Phys. 01 (2025) 141.
  42. A. M. Cieplak and A. Slosar, J. Cosmol. Astropart. Phys. 12 (2016) 016.
  43. A. M. Wolfe, E. Gawiser, and J. X. Prochaska, Annu. Rev. Astron. Astrophys. 43, 861 (2005).
  44. K. K. Rogers et al., Mon. Not. R. Astron. Soc. 474, 3032 (2017).
  45. A. Font-Ribera et al., J. Cosmol. Astropart. Phys. 11 (2012) 059.

Outline

Information

Phys. Rev. D 112, 063528– Published 16 September, 2025
  • Received 4 June 2024
  • Accepted 16 July 2025
Crossmark - Check for updates button
Creative Commons Logo

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation