Skip to main content
Log in

Some Results On Relative Entropy in Quantum Field Theory

  • Published:
Communications in Mathematical Physics Aims and scope Submit manuscript

Abstract

We prove that the mutual information for vacuum state as defined by Araki is finite for general Dirac Quantum Fields in Minkowski spacetime of any dimension. In the case of two dimensional chiral conformal field theory (CFT) we use our previous results for the free fermions to show that for a large class of chiral CFT the mutual information is finite. We also provide a direct relation between relative entropy and the index of a representation of conformal net.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Araki H.: Relative entropy of states of von Neumann algebras, I. Publ. RIMS Kyoto Univ. 11, 809–833 (1976)

    Google Scholar 

  2. Araki H.: Relative entropy of states of von Neumann algebras, II. Publ. RIMS Kyoto Univ. 13, 173–192 (1977)

    Google Scholar 

  3. Araki H.: On quasifree states of the CAR and Bogoliubov automorphisms. Publ. RIMS Kyoto Univ. 6, 385–442 (1970)

    Google Scholar 

  4. Arias, R.E., Casini, H., Huerta, M., Pontello, D.: Entropy and modular Hamiltonian for a free chiral scalar in two intervals. arXiv:1809.00026 [hep-th]

  5. Buchholz D., D’Antoni C., Longo R.: Nuclearity and thermal states in conformal field theory. Commun. Math. Phys. 270, 267–293 (2007)

    Google Scholar 

  6. Buchholz D.: Product states for local algebras. Commun. Math. Phys. 36(4), 287C304 (1974)

    Google Scholar 

  7. Calabrese P, Cardy J: Entanglement entropy and conformal field theory. J. Phys. A 42, 504005 (2009)

    Google Scholar 

  8. Carlenl, E.A.: Trace inequalities and entropy: An introductory course. In: Entropy and the quantum, vol. 529. Contemp. Math., Amer. Math. Soc., Providence, RI, (2010)

  9. Cardy J.: Some results on mutual information of disjoint regions in higher dimensions. J. Phys. A Math. Theor. 46, 285402 (2013) arXiv:1304.7985

    Google Scholar 

  10. Casini H., Huerta M.: Entanglement entropy in free quantum field theory. J. Phys. A. 42, 504007 (2009) arXiv:0905.2562

    Google Scholar 

  11. Casini H., Huerta M.: A finite entanglement entropy and the c-theorem. Phys. Lett. B. 600, 142–150 (2004) arXiv:hep-th/0405111

    Google Scholar 

  12. D’Antoni C., Hollands S.: Nuclearity, local quasiequivalence and split property for dirac quantum fields in curved spacetime. Commun. Math. Phys. 261(1), 133C159 (2006)

    Google Scholar 

  13. Dong C., Xu F.: Conformal nets associated with lattices and their orbifolds. Adv. Math. 206, 279–306 (2006)

    Google Scholar 

  14. Haag R.: Local quantum physics: fields, particles, algebras. Springer, Berlin (1992)

    Google Scholar 

  15. He, S., Numasawa, T., Takayanagi, T., Watanabe, K.: Quantum dimension as entanglement entropy in 2D CFTs. arXiv:1403.0702. https://doi.org/10.1103/PhysRevD.90.041701

  16. Hollands, S.: Relative entropy close to the edge. arXiv:1805.10006 [hep-th]

  17. Hollands, S., Sanders, K.: Entanglement measures and their properties in quantum field theory. arXiv:1702.04924

  18. Longo R.: On Landauer principle and bound for infinite systems. Commun. Math. Phys. 363, 531–560 (2018)

    Google Scholar 

  19. Longo, R.: Entropy distribution of localised states. Commun. Math. Phys. arXiv:1809.03358 (in press)

  20. Longo R., Xu F.: Comment on the Bekenstein bound. J. Geom. Phys. 130, 113–120 (2018)

    Google Scholar 

  21. Longo R., Xu F.: Relative entropy in CFT. Adv. Math. 337, 139–170 (2018)

    Google Scholar 

  22. Narnhofer H.: Entanglement, split, and nuclearity in quantum field theory. Rep. Math. Phys. 50, 307–347 (2002)

    Google Scholar 

  23. Ohya M., Petz D.: Quantum entropy and its use, theoretical and mathematical physics. Springer, Berlin (1993)

    Google Scholar 

  24. Otani, Y., Tanimoto, Y.: Towards entanglement entropy with UV cutoff in conformal nets. arXiv:1701.01186

  25. Pimsner M., Popa S.: Entropy and index for subfactors. Ann. Sci. Ec. Norm. Sup. 19, 57106 (1986)

    Google Scholar 

  26. Pressley A., Segal G.: Loop Groups. Oxford University Press, Oxford (1986)

    Google Scholar 

  27. Simon, B.: Trace Ideals and their Applications, London Mathematical Society Lecture Note Series (1979). ISBN: 9780521222860

  28. Summers S.J.: Normal product states for fermions and twisted duality for CCR and CAR type algebras with application to the Yukawa quantum field model. Commun. Math. Phys. 86, 111–141 (1982)

    Google Scholar 

  29. Witten, E.: Notes on some entanglement properties of Quantum Field Theory. arXiv:1803.04993

Download references

Acknowledgements

Part of this work was done when I participated in Pitp 2018 at Institute for Advanced Study. I would like to thank E. Witten for making my visit possible and stimulating discussions, and R. Longo for helpful comments.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Feng Xu.

Additional information

Communicated by Y. Kawahigashi

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supported in part by NSF Grant DMS-1764157.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Xu, F. Some Results On Relative Entropy in Quantum Field Theory. Commun. Math. Phys. 374, 1469–1482 (2020). https://doi.org/10.1007/s00220-019-03367-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00220-019-03367-x

Navigation