Notes: Chapter 15c: The Bilateral Cosmos

Chapter notes for “Chapter 15c: The Bilateral Cosmos”

Notes

¹ Gaztañaga, E., Kumar, K. S., & Marto, J. (2026). “A new understanding of Einstein-Rosen bridges.” Classical and Quantum Gravity, 43, 015023. arXiv:2512.20691. DOI: 10.1088/1361-6382/ae3044.

² Barbour, J., Koslowski, T., & Mercati, F. (2014). “Identification of a gravitational arrow of time.” Physical Review Letters, 113, 181101. arXiv:1409.0917. See also Barbour, J. (2020). The Janus Point: A New Theory of Time. Basic Books. Entaxy is introduced in Barbour, J., Koslowski, T., & Mercati, F. (2015), “Entropy and the Typicality of Universes,” arXiv:1507.06498, which describes it as scale-invariant and decreasing as the observable universe evolves away from the Janus point of maximum disorder.

³ Boyle, L., Finn, K., & Turok, N. (2018). “CPT-Symmetric Universe.” Physical Review Letters, 121, 251301. arXiv:1803.08928.

⁴ Boyle, L. & Turok, N. (2022). “The Big Bang, CPT, and neutrino dark matter.” Annals of Physics, 438, 168767. arXiv:1803.08930.

⁵ Maldacena, J. & Susskind, L. (2013). “Cool horizons for entangled black holes.” Fortschritte der Physik, 61(9), 781–811. arXiv:1306.0533.

⁶ Barbour, J., Koslowski, T., & Mercati, F. (2016). “Janus Points and Arrows of Time.” arXiv:1604.03956.

⁷ Einstein, A. & Rosen, N. (1935). “The particle problem in the general theory of relativity.” Physical Review, 48(1), 73–77.

⁸ Einstein, A., Podolsky, B., & Rosen, N. (1935). “Can quantum-mechanical description of physical reality be considered complete?” Physical Review, 47(10), 777–780.

⁹ Coppo, A., Pranzini, N., & Verrucchi, P. (2026). “Quantum model for black holes and clocks.” arXiv:2601.07437. A bipartite quantum system modeling a test particle near a Schwarzschild horizon and Hawking radiation satisfies exactly the Page-Wootters clock conditions.

¹⁰ Ladghami, Y., Lobo, F.S.N., Ouali, T. et al. (2026). “Timelike Entanglement Entropy of Hawking Radiation.” arXiv:2602.06833. Reveals periodic “timelike Page times” — transitions in the temporal entanglement structure between a black hole’s interior and its emitted radiation.

¹¹ Egan, C.A. & Lineweaver, C.H. (2010). “A Larger Estimate of the Entropy of the Universe.” Astrophysical Journal, 710, 1825–1834. Supermassive black holes dominate the cosmic entropy budget (~10¹⁰⁴ of ~10¹⁰⁴ total).

¹² Penrose, R. (1979). “Singularities and Time-Asymmetry.” In General Relativity: An Einstein Centenary Survey, ed. S.W. Hawking & W. Israel. Cambridge University Press. The Weyl curvature hypothesis: low Weyl curvature at the Big Bang, increasing via gravitational clumping toward black holes, drives the arrow of time.

¹³ Castro-Ruiz, E., Giacomini, F. & Brukner, Č. (2020). “Entanglement of quantum clocks through gravity.” Proceedings of the National Academy of Sciences, 117(6), 2890–2895. arXiv:1908.10165. Gravitational time dilation entangles quantum clocks — gravity itself triggers the Page-Wootters mechanism.

¹⁴ Pikovski, I., Zych, M., Costa, F. & Brukner, Č. (2015). “Universal decoherence due to gravitational time dilation.” Nature Physics, 11, 668–672. arXiv:1311.1095. Gravitational time dilation universally decoheres composite quantum systems, producing classicality without environmental interaction.

¹⁵ Susskind, L. (2016). “Computational complexity and black hole horizons.” Fortschritte der Physik, 64, 24–43. arXiv:1402.5674. ER bridge interior growth corresponds to quantum computational complexity growth. Refined by Brown, A.R. et al., Physical Review D 93 (2016): 086006. Confirmed non-perturbatively by Iliesiu, L.V., Mezei, M. & Sárosi, G., JHEP 2022:73.

¹⁶ Jacobson, T. (1995). “Thermodynamics of spacetime: The Einstein equation of state.” Physical Review Letters, 75, 1260–1263. Derives Einstein’s field equations from thermodynamics of local Rindler horizons. Updated in Jacobson (2016), Physical Review Letters 116, 201101, using entanglement entropy.

¹⁷ Calcinari, A. & Gielen, S. (2025). “Relational dynamics and Page-Wootters formalism in group field theory.” Quantum, 9:1610. Applies Page-Wootters to discrete quantum spacetime, deriving an expanding universe from matter-clock correlations — demonstrating the mechanism works cosmologically.

¹⁸ Hutsemékers, D. et al. (2014). “Alignment of quasar polarizations with large-scale structures.” Astronomy & Astrophysics, 572, A18. Spin axes of supermassive black holes align parallel to host large-scale structures over gigaparsec scales (<1% probability of random occurrence). Confirmed at radio wavelengths by Pelgrims, V. & Hutsemékers, D. (2016), Astronomy & Astrophysics, 585, A32.

¹⁹ NANOGrav Collaboration (Agazie, G. et al.) (2023). “The NANOGrav 15 yr Data Set: Evidence for a Gravitational-wave Background.” Astrophysical Journal Letters, 951, L8. Stochastic gravitational wave background at nanohertz frequencies from 68 pulsars, consistent with merging supermassive black hole binaries. Confirmed by EPTA, PPTA, and CPTA.

²⁰ Lee, J. et al. (2019). “Mysterious Coherence in Several-megaparsec Scales between Galaxy Rotation and Neighbor Motion.” Astrophysical Journal, 884, 104. Galaxy rotation correlates with neighbor motions out to 6 Mpc — far beyond direct gravitational interaction.

²¹ Wang, P. et al. (2021). “Possible observational evidence for cosmic filament spin.” Nature Astronomy, 5, 839–845. Coherent vortical motion in stacked cosmic filaments — the largest known rotating structures. See also Tudorache, M. N. et al. (2025). “A 15 Mpc rotating galaxy filament at redshift z = 0.032.” MNRAS, 544(4), 4306–4316. doi:10.1093/mnras/staf2005.

²² Hutsemékers, D. et al. (2014), quoted in ESO Press Release eso1438. See also Zhao, Y. et al. (2025), arXiv:2503.10841, finding observed filament alignment sometimes exceeds simulation predictions — suggesting either systematics or genuine excess beyond tidal torque theory.

²³ Alternative mechanisms proposed for gigaparsec-scale alignment: Arun, K. et al. (2010), “Cosmic magnetism from electroweak strings,” Physical Review Letters 105, 161301 (primordial magnetic fields); Shurtleff, R. (2018), International Journal of Modern Physics D 27, 1850094 (cosmic string networks); Hutsemékers, D. et al. (2008), arXiv:0809.3088 (pseudoscalar-photon mixing as propagation effect). None is established.

²⁴ Olsen, C. et al. (2021). “Star Formation Histories from Spectral Energy Distributions and Color–Magnitude Diagrams Agree: Evidence for Synchronized Star Formation in Local Volume Dwarf Galaxies over the Past 3 Gyr.” Astrophysical Journal, 913, 45. Thirty-six Local Volume dwarf galaxies show coordinated star formation across several megaparsecs.

²⁵ Meurer, G.R., Zheng, Z., & de Blok, W.J.G. (2018). “Cosmic clocks: a tight radius–velocity relationship for HI-selected galaxies.” Monthly Notices of the Royal Astronomical Society, 476(2), 1624–1636. HI-selected galaxies of widely varying size rotate at their outermost radii with similar angular velocity — approximately once per gigayear.

²⁶ Müller, O., Pawlowski, M.S., Lelli, F. et al. (2021). “The coherent motion of Cen A dwarf satellite galaxies remains a challenge for ΛCDM cosmology.” Astronomy & Astrophysics, 645, L5. Twenty-one of 28 Centaurus A dwarf satellites share coherent orbital motion (0.2–0.3% probability in simulations). The anomaly is contested. Sawala, T. et al. (2023). “The Milky Way’s plane of satellites is consistent with ΛCDM.” Nature Astronomy, 7, 481–491, argue the best-known such plane is a transient alignment rather than a stable structure. A rival reading takes the Centaurus A plane’s members to be tidal dwarf galaxies condensed from the debris of the galaxy’s major merger roughly two billion years ago, a merger whose aftermath JWST/MIRI observations resolve in the nucleus (arXiv:2607.04942). Tidal dwarfs would inherit co-rotation from a single debris stream, yet they should carry almost no dark matter, so this rescue is itself a departure from standard cosmology. The chapter draws only on the observed coherence; the explanation remains open.

²⁷ Martín-Navarro, I. et al. (2021). “Anisotropic satellite galaxy quenching modulated by supermassive black hole activity.” Nature, 594, 187–190. arXiv:2106.04587. Satellite quenching patterns correlate with AGN activity timing and axis orientation, with effects on satellites outside the direct outflow path.

²⁸ Bennett, M. et al. (2002). “Huygens’s clocks.” Proceedings of the Royal Society A, 458, 563–579. Modern analysis of Huygens’ 1665 observation that pendulum clocks on a shared beam spontaneously synchronize.

²⁹ Kingsbury, L. et al. (2019). “Correlated Neural Activity and Encoding of Behavior across Brains of Socially Interacting Animals.” Cell, 178(2), 429–446. See also Hasson, U. et al. (2012). “Brain-to-Brain Coupling.” Trends in Cognitive Sciences, 16(2), 114–121. Neural oscillations synchronize between interacting individuals via shared social substrate.

³⁰ Lopez, A.M. et al. (2021). “A Giant Arc on the Sky.” 238th AAS Meeting. A coherent crescent of galaxies spanning 3.3 billion light-years at z~0.8 — nearly three times the theoretical upper limit under the cosmological principle.

³¹ Minami, Y. & Komatsu, E. (2020). “New Extraction of the Cosmic Birefringence from the Planck 2018 Polarization Data.” Physical Review Letters, 125, 221301. arXiv:2011.11254. Original detection at 2.4σ; improved to 3.6σ by Eskilt & Komatsu (2022), Physical Review D, 106, 063503; confirmed by ACT (Diego-Palazuelos & Komatsu, 2025, arXiv:2509.13654) reaching ~7σ combined. The Chern-Simons coupling explicitly breaks parity; if the field has a time-dependent vacuum expectation value, the violation extends to CPT. See Chapter 12.