Notes: Chapter 14b: The Cosmic Web: Voids, Sheets, and Coordination

Chapter notes for “Chapter 14b: The Cosmic Web: Voids, Sheets, and Coordination”

Notes

¹ Diana Scognamiglio, Gavin Leroy, and David Harvey et al., “An ultra-high-resolution map of (dark) matter,” Nature Astronomy, 26 January 2026. DOI: 10.1038/s41550-025-02763-9.

² eRASS1 catalog: A. Merloni et al., “The SRG/eROSITA All-Sky Survey: The first X-ray catalog,” A&A 682 (2024): A34. The Abell 3667–3651 filament: J. Dietl et al., “Discovery of a >13 Mpc long X-ray filament,” A&A 691 (2024): A286.

³ HyeongHan Kim et al., “Weak-lensing detection of intracluster filaments in the Coma cluster,” Nature Astronomy 8 (2024): 377–386.

⁴ Zhang, X., Bulbul, E., et al., “The SRG/eROSITA all-sky survey. X-ray emission from the warm-hot phase gas in long cosmic filaments,” A&A 691 (2024): A234. DOI: 10.1051/0004-6361/202450933.

⁵ eROSITA cluster cosmology results are reported across multiple companion papers to the eRASS1 data release (A. Merloni et al., Astronomy & Astrophysics 682, 2024).

⁶ D. Hutsemékers et al., “Alignment of quasar polarizations with large-scale structures,” A&A 572 (2014): A18.

⁷ Gregory, S.A. and Thompson, L.A., “The Coma/A1367 supercluster and its environs,” The Astrophysical Journal 222 (1978): 784-799.

⁸ Kirshner, R.P., Oemler, A. Jr., Schechter, P.L., and Shectman, S.A., “A million cubic megaparsec void in Bootes,” The Astrophysical Journal Letters 248 (1981): L57-L60.

⁹ Neyrinck, M.C., “ZOBOV: a parameter-free void-finding algorithm,” Monthly Notices of the Royal Astronomical Society 386 (2008): 2101-2109.

¹⁰ Pisani, A., Sutter, P.M., Hamaus, N., et al., “Counting voids to probe dark energy,” Physical Review D 92 (2015): 083531; Verza, G., Pisani, A., Carbone, C., Hamaus, N., and Guzzo, L., “The Void Size Function in Dynamical Dark Energy Cosmologies,” JCAP 2019:12 (2019): 040; Bos, E.G.P., van de Weygaert, R., Dolag, K., and Pettorino, V., “The darkness that shaped the void,” MNRAS 426:1 (2012): 440–461.

¹¹ Sutter, P.M., Lavaux, G., Wandelt, B.D., and Weinberg, D.H., “A first application of the Alcock-Paczynski test to stacked cosmic voids,” The Astrophysical Journal 761 (2012): 187.

¹² Void galaxy properties: Void Galaxy Survey (C. M. Moorman et al., MNRAS 458, 2016: 394–406); CAVITY project (J. Domínguez-Gómez et al., A&A 680, 2023: A111); CO-CAVITY molecular gas survey (J. Romero-Gómez et al., A&A 692, 2024). The TNG300 simulation (MNRAS 528, 2024) confirms the evolutionary delay mechanism.

¹³ Zucker, Catherine, Goodman, Alyssa A., Alves, João, et al., “Star formation near the Sun is driven by expansion of the Local Bubble,” Nature 601 (2022): 334-337.

^13a Koll, Dominik, Korschinek, Gunther, Faestermann, Thomas, et al., “Interstellar ⁶⁰Fe in Antarctica,” Physical Review Letters 123 (2019): 072701.

^13b Koll, Dominik, et al., “Local Interstellar Cloud Structure Imprinted in Antarctic Ice by Supernova ⁶⁰Fe,” Physical Review Letters (2026). DOI: 10.1103/nxjq-jwgp.

^13c Kreckel, K., Egorov, O. V., Drory, N., et al., “SDSS-V LVM: Verifying what, and where, the ‘Galactic Center’ Lobe is,” Astronomy & Astrophysics 710, A205 (2026). DOI: 10.1051/0004-6361/202659505. arXiv:2604.16601. Comparing ionized-gas reddening against 3D dust maps places the shell at roughly 2 kiloparsecs (the Galactic center lies at about 8); [N II] kinematics show a uniform velocity within 5 km/s of rest, with no expansion signature or Galactic-center rotation gradient. The authors identify Barnard’s Loop as a possible analog and themselves propose the “Greatly Confused Loop” rereading.

¹⁴ DESI Collaboration (A.G. Adame et al.), “DESI 2024 VI: Cosmological Constraints from BAO,” JCAP 2025:02. arXiv:2404.03002.

¹⁵ Indranil Banik and Vasileios Kalaitzidis, “Testing the local void hypothesis using baryon acoustic oscillation measurements over the last twenty years,” MNRAS 540, no. 1 (2025): 545–561. arXiv:2501.17934. Originally characterized in Keenan, Barger, and Cowie, The Astrophysical Journal 775, no. 1 (2013): 62.

¹⁶ Indranil Banik, Harry Desmond, Vasileios Kalaitzidis, and Sergij Mazurenko, “The local void model for the Hubble and BAO tensions,” arXiv:2602.03928 (2026).

¹⁷ Hierarchical void scaling: N. Hamaus, A. Pisani, P. M. Sutter, et al., Physical Review Letters 117 (2016): 091302; Shim, J. and Park, C., MNRAS 527 (2024).

¹⁹ S. Granett, M. C. Neyrinck, and I. Szapudi, “An imprint of superstructures on the microwave background,” The Astrophysical Journal Letters 683 (2008): L99–L102. For recent approaches: A. Kovács et al., arXiv:2510.16799 (2025).

²⁰ S. Contarini, G. Verza, and A. Pisani, “The era of precision cosmology with voids,” arXiv:2601.14362 (2026).

²¹ L. M. Krauss and G. D. Starkman, “Life, the Universe, and Nothing,” ApJ 531 (2000): 22–30; F. C. Adams and G. Laughlin, “A dying universe,” Rev. Mod. Phys. 69 (1997): 337–372.

²² DESIVAST void catalogs: Hernan Rincon et al., The Astrophysical Journal 982 (2025): 38.

²³ David L. Wiltshire, “Average observational quantities in the timescape cosmology,” Physical Review D 80 (2009): 123512. arXiv:0912.4563.

²⁴ R. Y. Lane, D. L. Wiltshire, et al., “Cosmological tests of the timescape chronology,” MNRAS 535 (2024): 3606–3631. arXiv:2404.15750.

²⁵ R. Mackenzie, T. Shanks, M. N. Bremer, et al., “Evidence against a supervoid causing the CMB Cold Spot,” MNRAS 505 (2021): 2853–2869. arXiv:2112.07699.

^25a Thomas Buchert, “On average properties of inhomogeneous fluids in general relativity,” General Relativity and Gravitation 32 (2000): 105–125. arXiv:gr-qc/9906015.

²⁶ Ewoud Wempe, Amina Helmi, et al., “The mass distribution in and around the Local Group,” Nature Astronomy, 27 January 2026. BORG with 169 Gadget-4 resimulations. Sheet ~30 Mly, central plane ~2× cosmic average density. Local Group halo mass: 3.3 ± 0.6 × 10¹² M☉.

²⁷ Dan P. Marrone et al., “Galaxy growth in a massive halo in the first billion years of cosmic history,” Nature, 6 December 2017. DOI: 10.1038/nature24629.

²⁸ Andreas Koch and Eva K. Grebel, “The Anisotropic Distribution of M31 Satellite Galaxies,” The Astronomical Journal 131(3), 1405–1415 (2006).

²⁹ Rodrigo A. Ibata et al., “A vast, thin plane of co-rotating dwarf galaxies orbiting the Andromeda galaxy,” Nature 493, 62–65 (2013).

^29b A third such plane orbits Centaurus A: Oliver Müller, Marcel S. Pawlowski, Federico Lelli et al., “The coherent motion of Cen A dwarf satellite galaxies remains a challenge for ΛCDM cosmology,” Astronomy & Astrophysics 645, L5 (2021). The tidal-debris alternative is the standing rival account for all three systems; it explains the co-rotation naturally while predicting dark-matter-poor satellites, its own departure from standard cosmology. Tuomas Sawala et al., “The Milky Way’s plane of satellites is consistent with ΛCDM,” Nature Astronomy 7, 481–491 (2023) argue the Milky Way plane is a transient alignment. The debate is unresolved.

³⁰ Andrew C. Fabian, “Observational Evidence of Active Galactic Nuclei Feedback,” Annual Review of Astronomy and Astrophysics 50, 455–489 (2012).

³¹ Brian R. McNamara and Paul E.J. Nulsen, “Mechanical Feedback from Active Galactic Nuclei in Galaxies, Groups, and Clusters,” New Journal of Physics 14, 055023 (2012).

³² Jason Tumlinson, Molly S. Peeples, and Jessica K. Werk, “The Circumgalactic Medium,” Annual Review of Astronomy and Astrophysics 55, 389–432 (2017).

³³ Daniel Anglés-Alcázar et al., “The cosmic baryon cycle and galaxy mass assembly in the FIRE simulations,” MNRAS 470(4), 4698–4719 (2017).

³⁴ Rebekah J. Wright et al., “The baryon cycle in modern cosmological hydrodynamical simulations,” MNRAS 532(3), 3417–3440 (2024).

³⁵ Simone M. Weinmann et al., “Properties of galaxy groups in the Sloan Digital Sky Survey — I,” MNRAS 366(1), 2–28 (2006).

³⁶ Guinevere Kauffmann et al., “A re-examination of galactic conformity,” MNRAS 430(2), 1447–1456 (2013).

³⁷ Andrew Pontzen and Fabio Governato, “How supernova feedback turns dark matter cusps into cores,” MNRAS 421(4), 3464–3471 (2012).

³⁸ Arianna Di Cintio et al., “The dependence of dark matter profiles on the stellar-to-halo mass ratio,” MNRAS 437, 415–423 (2014).

³⁹ Simon J. Lilly et al., “Gas Regulation of Galaxies,” The Astrophysical Journal 772, 119 (2013).

⁴⁰ Yingjie Peng and Roberto Maiolino, “From haloes to Galaxies — I,” MNRAS 443(4), 3643 (2014).

⁴¹ Tessa Vernstrom et al., “Discovery of magnetic fields along stacked cosmic filaments,” MNRAS 505(3), 4178–4196 (2021).

⁴² G. V. Pignataro, S. P. O’Sullivan, A. Bonafede, et al., “Detection of Magnetic Fields in Superclusters of Galaxies,” Astronomy and Astrophysics 696 (2025): A203. DOI: 10.1051/0004-6361/202553709.

⁴³ François Schweizer, “Merger-Induced Starbursts,” in Starbursts, Astrophysics and Space Science Library, vol. 329 (2005).

⁴⁴ Ekta A. Shah et al., “The Merger-Starburst Connection Across Cosmic Times,” MNRAS 516, 4922–4935 (2022).

⁴⁵ Markus J. Aschwanden, “Order out of Randomness: Self-Organization Processes in Astrophysics,” Space Science Reviews 214, 55 (2018).

Chapter 13: The Cosmic Web: Voids, Sheets, and Coordination The Deeper Law