Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Analogue black-hole horizons

Some gravitational phenomena are difficult or even impossible to observe in real spacetime. Laboratory analogues of black-hole horizons offer new perspectives on field theory effects that might help our understanding of gravitation.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: A horizon in a water flume.
Fig. 2: A horizon in a BEC flow.
Fig. 3: A horizon in an exciton-polariton device.


  1. 1.

    Unruh, W. Experimental black hole evaporation. Phys. Rev. Lett. 46, 1351–1353 (1981).

    Article  Google Scholar 

  2. 2.

    Barceló, C., Liberati, S. & Visser, M. Analogue gravity. Living Rev. Relativ. 14, 3 (2011).

    Article  Google Scholar 

  3. 3.

    Visser, M. Essential and inessential features of Hawking radiation. Int. J. Mod. Phys. D 12, 649–661 (2003).

    MathSciNet  Article  Google Scholar 

  4. 4.

    Hawking, S. Particle creation by black holes. Commun. Math. Phys. 43, 199–220 (1975).

    MathSciNet  Article  Google Scholar 

  5. 5.

    Unruh, W. Notes on black-hole evaporation. Phys. Rev. D 14, 870–892 (1976).

    Article  Google Scholar 

  6. 6.

    Jacobson, T. Black hole evaporation and ultrashort distances. Phys. Rev. D 44, 1731–1739 (1991).

    MathSciNet  Article  Google Scholar 

  7. 7.

    Unruh, W. Sonic analog of black holes and the effects of high frequencies on black hole evaporation. Phys. Rev. D 51, 2827–2838 (1995).

    MathSciNet  Article  Google Scholar 

  8. 8.

    Cardoso, V. & Pani, P. Tests for the existence of horizons through gravitational wave echoes. Nat. Astron. 1, 586–591 (2017).

    Article  Google Scholar 

  9. 9.

    Unruh, W. G. Has Hawking radiation been measured? Found. Phys. 44, 532–545 (2014).

    MathSciNet  Article  Google Scholar 

  10. 10.

    Schützhold, R. & Unruh, W. G. Gravity wave analogues of black holes. Phys. Rev. D 66, 044019 (2002).

    MathSciNet  Article  Google Scholar 

  11. 11.

    Rousseaux, G., Mathis, C., Massa, P., Philbin, T. G. & Leonhardt, U. Observation of negative-frequency waves in a water tank: a classical analogue to the Hawking effect? New J. Phys. 10, 053015 (2008).

    Article  Google Scholar 

  12. 12.

    Weinfurtner, S., Tedford, E. W., Penrice, M. C. J., Unruh, W. G. & Lawrence, G. A. Classical aspects of Hawking radiation verified in analogue gravity experiment. In Proc. 9th SIGRAV Graduate School in Contemporary Relativity and Gravitational Physics on Analogue Gravity Phenomenology Vol. 870 (ed. Faccio, D. et al.) 167–180 (Springer, 2013).

  13. 13.

    Weinfurtner, S., Tedford, E. W., Penrice, M. C. J., Unruh, W. G. & Lawrence, G. A. Measurement of stimulated Hawking emission in an analogue system. Phys. Rev. Lett. 106, 021302 (2011).

    Article  Google Scholar 

  14. 14.

    Michel, F. & Parentani, R. Probing the thermal character of analogue Hawking radiation for shallow water waves? Phys. Rev. D 90, 044033 (2014).

    Article  Google Scholar 

  15. 15.

    Euvé, L.-P., Michel, F., Parentani, R. & Rousseaux, G. Wave blocking and partial transmission in subcritical flows over an obstacle. Phys. Rev. D 91, 024020 (2015).

    Article  Google Scholar 

  16. 16.

    Coutant, A. & Weinfurtner, S. The imprint of the analogue Hawking effect in subcritical flows. Phys. Rev. D 94, 064026 (2016).

    MathSciNet  Article  Google Scholar 

  17. 17.

    Euvé, L. P., Michel, F., Parentani, R., Philbin, T. G. & Rousseaux, G. Observation of noise correlated by the Hawking effect in a water tank. Phys. Rev. Lett. 117, 121301 (2016).

    Article  Google Scholar 

  18. 18.

    Torres, T. et al. Observation of superradiance in a vortex flow. Nat. Phys. 13, 833–836 (2017).

    Article  Google Scholar 

  19. 19.

    Bekenstein, J. D. & Schiffer, M. The many faces of superradiance. Phys. Rev. D 58, 064014 (1998).

    MathSciNet  Article  Google Scholar 

  20. 20.

    Garay, L., Anglin, J., Cirac, J. & Zoller, P. Sonic analog of gravitational black holes in Bose–Einstein condensates. Phys. Rev. Lett. 85, 4643–4647 (2000).

    Article  Google Scholar 

  21. 21.

    Garay, L., Anglin, J., Cirac, J. & Zoller, P. Sonic black holes in dilute Bose–Einstein condensates. Phys. Rev. A 63, 023611 (2001).

    Article  Google Scholar 

  22. 22.

    Barceló, C., Liberati, S. & Visser, M. Towards the observation of Hawking radiation in Bose–Einstein condensates. Int. J. Mod. Phys. A 18, 3735 (2003).

    Article  Google Scholar 

  23. 23.

    Lahav, O. et al. Realization of a sonic black hole analog in a Bose–Einstein condensate. Phys. Rev. Lett. 105, 240401 (2010).

    Article  Google Scholar 

  24. 24.

    Shammass, I., Rinott, S., Berkovitz, A., Schley, R. & Steinhauer, J. Phonon dispersion relation of an atomic Bose–Einstein condensate. Phys. Rev. Lett. 109, 195301 (2012).

    Article  Google Scholar 

  25. 25.

    Schley, R. et al. Planck distribution of phonons in a Bose–Einstein condensate. Phys. Rev. Lett. 111, 055301 (2013).

    Article  Google Scholar 

  26. 26.

    Steinhauer, J. Observation of self-amplifying Hawking radiation in an analog black hole laser. Nat. Phys. 10, 864 (2014).

    Article  Google Scholar 

  27. 27.

    Corley, S. & Jacobson, T. Black hole lasers. Phys. Rev. D 59, 1–12 (1999).

    MathSciNet  Article  Google Scholar 

  28. 28.

    Tettamanti, M., Cacciatori, S. L., Parola, A. & Carusotto, I. Numerical study of a recent black-hole lasing experiment. EPL 114, 60011 (2016).

    Article  Google Scholar 

  29. 29.

    Wang, Y.-H., Jacobson, T., Edwards, M. & Clark, C. W. Mechanism of stimulated Hawking radiation in a laboratory Bose–Einstein condensate. Phys. Rev. A 96, 023616 (2017).

    Article  Google Scholar 

  30. 30.

    Steinhauer, J. & de Nova, J. R. M. Self-amplifying Hawking radiation and its background: a numerical study. Phys. Rev. A 95, 033604 (2017).

    Article  Google Scholar 

  31. 31.

    Steinhauer, J. Observation of quantum Hawking radiation and its entanglement in an analogue black hole. Nat. Phys. 12, 959 (2016).

    Article  Google Scholar 

  32. 32.

    Balbinot, R., Fabbri, A., Fagnocchi, S., Recati, A. & Carusotto, I. Nonlocal density correlations as a signature of Hawking radiation from acoustic black holes. Phys. Rev. A 78, 021603 (2008).

    Article  Google Scholar 

  33. 33.

    Carusotto, I., Fagnocchi, S., Recati, A., Balbinot, R. & Fabbri, A. Numerical observation of Hawking radiation from acoustic black holes in atomic Bose–Einstein condensates. New J. Phys. 10, 103001 (2008).

    Article  Google Scholar 

  34. 34.

    Busch, X. & Parentani, R. Quantum entanglement in analogue Hawking radiation: When is the final state non-separable? Phys. Rev. D 89, 105024 (2014).

    Article  Google Scholar 

  35. 35.

    Michel, F., Coupechoux, J.-F. & Parentani, R. Phonon spectrum and correlations in a transonic flow of an atomic Bose gas. Phys. Rev. D 94, 084027 (2016).

    Article  Google Scholar 

  36. 36.

    Finke, A., Jain, P. & Weinfurtner, S. On the observation of nonclassical excitations in Bose–Einstein condensates. New J. Phys. 18, 113017 (2016).

    Article  Google Scholar 

  37. 37.

    Leonhardt, U. Questioning the recent observation of quantum Hawking radiation. Ann. Phys. 530, 1700114 (2018).

    MathSciNet  Article  Google Scholar 

  38. 38.

    Steinhauer, J. Response to version 2 of the note concerning the observation of quantum Hawking radiation and its entanglement in an analogue black hole. Preprint at (2016).

  39. 39.

    Philbin, T. G. et al. Fiber-optical analogue of the event horizon. Science 319, 1367–1370 (2008).

    Article  Google Scholar 

  40. 40.

    Belgiorno, F., Cacciatori, S. L., Ortenzi, G., Sala, V. G. & Faccio, D. Quantum radiation from superluminal refractive-index perturbations. Phys. Rev. Lett. 104, 140403 (2010).

    Article  Google Scholar 

  41. 41.

    Rubino, E. et al. Experimental evidence of analogue Hawking radiation from ultrashort laser pulse filaments. New J. Phys. 13, 085005 (2011).

    Article  Google Scholar 

  42. 42.

    Schützhold, R. & Unruh, W. G. Comment on “Hawking radiation from ultrashort laser pulse filaments”. Phys. Rev. Lett. 107, 149401 (2011).

    Article  Google Scholar 

  43. 43.

    Belgiorno, F. et al. Belgiorno et al. reply. Phys. Rev. Lett. 107, 149402 (2011).

    Article  Google Scholar 

  44. 44.

    Unruh, W. G. & Schützhold, R. Hawking radiation from ‘phase horizons’ in laser filaments? Phys. Rev. D 86, 064006 (2012).

    Article  Google Scholar 

  45. 45.

    Liberati, S., Prain, A. & Visser, M. Quantum vacuum radiation in optical glass. Phys. Rev. D 85, 084014 (2012).

    Article  Google Scholar 

  46. 46.

    Finazzi, S. & Carusotto, I. Spontaneous quantum emission from analog white holes in a nonlinear optical medium. Phys. Rev. A 89, 053807 (2014).

    Article  Google Scholar 

  47. 47.

    Rubino, E. et al. Negative-frequency resonant radiation. Phys. Rev. Lett. 108, 253901 (2012).

    Article  Google Scholar 

  48. 48.

    Marino, F. Acoustic black holes in a two-dimensional ‘photon-fluid’. Phys. Rev. A 78, 063804 (2008).

    Article  Google Scholar 

  49. 49.

    Carusotto, I. & Ciuti, C. Quantum fluids of light. Rev. Mod. Phys. 85, 299 (2013).

    Article  Google Scholar 

  50. 50.

    Carusotto, I. & Ciuti, C. Probing microcavity polariton superfluidity through resonant Rayleigh scattering. Phys. Rev. Lett. 93, 166401 (2004).

    Article  Google Scholar 

  51. 51.

    Nguyen, H. S. et al. Acoustic black hole in a stationary hydrodynamic flow of microcavity polaritons. Phys. Rev. Lett. 114, 036402 (2015).

    Article  Google Scholar 

  52. 52.

    Vocke, D. et al. Rotating black hole geometries in a two-dimensional photon superfluid. Optica 5, 1099–1103 (2018).

    Article  Google Scholar 

  53. 53.

    Macher, J. & Parentani, R. Black/white hole radiation from dispersive theories. Phys. Rev. D 79, 124008 (2009).

    Article  Google Scholar 

  54. 54.

    Parentani, R. Constructing QFT’s wherein Lorentz invariance is broken by dissipative effects in the UV. PoS QG-Ph:031 (2007).

  55. 55.

    Robertson, S. & Parentani, R. Hawking radiation in the presence of high-momentum dissipation. Phys. Rev. D 92, 044043 (2015).

    Article  Google Scholar 

  56. 56.

    Jacobson, T. Lorentz violation and Hawking radiation. In Proc. 2nd Meeting CPT and Lorentz Symmetry 316–320 (World Scientific, Singapore, 2002).

  57. 57.

    Finazzi, S. & Parentani, R. Black-hole lasers in Bose–Einstein condensates. New J. Phys. 12, 095015 (2010).

    Article  Google Scholar 

  58. 58.

    Barbado, L. C., Barceló, C., Garay, L. J. & Jannes, G. The trans-Planckian problem as a guiding principle. J. High Energy Phys. 2011, 112 (2011).

    Article  Google Scholar 

  59. 59.

    Barceló, C., Carballo-Rubio, R. & Garay, L. J. Where does the physics of extreme gravitational collapse reside? Universe 2, 7 (2016).

    Article  Google Scholar 

  60. 60.

    Blas, D. & Sibiryakov, S. Hořava gravity versus thermodynamics: the black hole case. Phys. Rev. D 84, 124043 (2011).

    Article  Google Scholar 

Download references


I thank R. Carballo-Rubio, L. Garay and G. Jannes for comments and suggestions. Financial support was provided by the Spanish MINECO through projects FIS2014-54800-C2-1 and FIS2017-86497-C2-1 (with FEDER contribution), and by the Junta de Andalucía through the project FQM219.

Author information



Corresponding author

Correspondence to Carlos Barceló.

Ethics declarations

Competing interests

The author declares no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Barceló, C. Analogue black-hole horizons. Nat. Phys. 15, 210–213 (2019).

Download citation

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing