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Quantum null energy condition in quenched 2D CFTs

Tanay Kibe* and Pratik Roy†

  • *Contact author: tanay.kibe@wits.ac.za
  • †Contact author: roy.pratik92@gmail.com
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Phys. Rev. D 111, 126009 – Published 16 June, 2025

DOI: https://doi.org/10.1103/2p7v-f28f

Abstract

The quantum null energy condition (QNEC) is a lower bound on the expectation value of the null-null component of the energy-momentum tensor in terms of null variations of the entanglement entropy. A stronger version of the QNEC (the primary QNEC) is expected to hold in 1+1 dimensional conformal field theories (CFT). QNEC has been shown to impose nontrivial quantum thermodynamic restrictions on irreversible entropy production in quenches in 1+1 dimensional holographic CFTs. It is therefore natural to study if QNEC imposes similar bounds in other quench setups. In this paper we study QNEC in the Calabrese-Cardy global and local joining quenches using standard CFT techniques. In the global quench we show that the primary QNEC must hold at sufficiently early times and find that it imposes bounds on the four point correlators of twist fields in a boundary state. This is a constraint on the set of boundary states that satisfy the primary QNEC. Furthermore, we find that a violation of the primary QNEC implies a violation of the averaged null energy condition (ANEC) in a conformally transformed frame. In the local quench we find similar bounds on four point correlators from both the primary and the usual QNEC.

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References (43)

  1. T. Faulkner, T. Hartman, M. Headrick, M. Rangamani, and B. Swingle, in Snowmass 2021 (2022); arXiv:2203.07117.
  2. A. C. Wall, Phys. Rev. Lett. 118, 151601 (2017).
  3. R. Landauer, IBM J. Res. Dev. 5, 183 (1961).
  4. R. Landauer, Phys. Today 44, No. 5, 23 (1991).
  5. D. Reeb and M. M. Wolf, New J. Phys. 16, 103011 (2014).
  6. R. Bousso, Z. Fisher, S. Leichenauer, and A. C. Wall, Phys. Rev. D 93, 064044 (2016).
  7. R. Bousso, Z. Fisher, J. Koeller, S. Leichenauer, and A. C. Wall, Phys. Rev. D 93, 024017 (2016).
  8. T. A. Malik and R. Lopez-Mobilia, Phys. Rev. D 101, 066028 (2020).
  9. J. Koeller and S. Leichenauer, Phys. Rev. D 94, 024026 (2016).
  10. S. Balakrishnan, T. Faulkner, Z. U. Khandker, and H. Wang, J. High Energy Phys. 09 (2019) 020.
  11. F. Ceyhan and T. Faulkner, Commun. Math. Phys. 377, 999 (2020).
  12. S. Hollands and R. Longo, arXiv:2503.04651.
  13. T. Kibe, A. Mukhopadhyay, and P. Roy, Phys. Rev. Lett. 128, 191602 (2022).
  14. A. Banerjee, T. Kibe, N. Mittal, A. Mukhopadhyay, and P. Roy, Phys. Rev. Lett. 129, 191601 (2022).
  15. T. Kibe, A. Mukhopadhyay, and P. Roy, J. High Energy Phys. 04 (2025) 096.
  16. S. Deffner and E. Lutz, Phys. Rev. Lett. 105, 170402 (2010).
  17. A. C. Wall, Phys. Rev. D 85, 024015 (2012).
  18. P. Calabrese and J. L. Cardy, J. Stat. Mech. (2005) P04010.
  19. P. Calabrese and J. Cardy, J. Stat. Mech. (2017) P10004.
  20. P. Calabrese and J. L. Cardy, J. Stat. Mech. (2004) P06002.
  21. P. Calabrese and J. Cardy, J. Phys. A 42, 504005 (2009).
  22. M. Mezei and J. Virrueta, arXiv:1909.00919.
  23. D. M. Hofman and J. Maldacena, J. High Energy Phys. 05 (2008) 012.
  24. J.-M. Stéphan and J. Dubail, J. Stat. Mech. (2011) P08019.
  25. G. Klinkhammer, Phys. Rev. D 43, 2542 (1991).
  26. W. R. Kelly and A. C. Wall, Phys. Rev. D 90, 106003 (2014); 91, 069902(E) (2015).
  27. T. Faulkner, R. G. Leigh, O. Parrikar, and H. Wang, J. High Energy Phys. 09 (2016) 038.
  28. T. Hartman, S. Kundu, and A. Tajdini, J. High Energy Phys. 07 (2017) 066.
  29. P. Kravchuk and D. Simmons-Duffin, J. High Energy Phys. 11 (2018) 102.
  30. C. J. Fewster, K. D. Olum, and M. J. Pfenning, Phys. Rev. D 75, 025007 (2007).
  31. P. Calabrese, J. Cardy, and E. Tonni, J. Stat. Mech. (2009) P11001.
  32. M. Banados, AIP Conf. Proc. 484, 147 (1999).
  33. A. C. Wall, Classical Quantum Gravity 31, 225007 (2014).
  34. F. Sanches and S. J. Weinberg, Phys. Rev. D 94, 084034 (2016).
  35. B. Grado-White, D. Marolf, and S. J. Weinberg, J. High Energy Phys. 01 (2021) 009.
  36. A. Banerjee and P. Roy, J. High Energy Phys. 10 (2024) 064.
  37. K. Saraswat, arXiv:2501.15024.
  38. D. Bernard and B. Doyon, J. Stat. Mech. (2016) 064005.
  39. J. Erdmenger, D. Fernandez, M. Flory, E. Megias, A.-K. Straub, and P. Witkowski, J. High Energy Phys. 10 (2017) 034.
  40. N. Lashkari, J. High Energy Phys. 01 (2019) 059.
  41. M. Moosa, P. Rath, and V. P. Su, J. High Energy Phys. 01 (2021) 064.
  42. P. Roy, Phys. Rev. D 108, 045010 (2023).
  43. W. M. Koo and H. Saleur, Nucl. Phys. B426, 459 (1994).

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Phys. Rev. D 111, 126009– Published 16 June, 2025
  • Received 16 April 2025
  • Accepted 3 June 2025
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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. Funded by SCOAP3.

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