Abstract
By viewing space-time as a continuum elastic medium and introducing an entropy functional for its elastic deformations, T. Padmanabhan has shown that general relativity emerges from varying the functional and that the latter suggests holography for gravity and yields the Bekenstein-Hawking entropy formula. In this paper we extend this idea to Riemann-Cartan space-times by constructing an entropy functional for the elastic deformations of space-times with torsion. We show that varying this generalized entropy functional permits to recover the full set of field equations of the Cartan-Sciama-Kibble theory. Our generalized functional shows that the contributions to the on-shell entropy of a bulk region in Riemann-Cartan space-times come from the boundary as well as the bulk and hence does not suggest that holography would also apply for gravity with spin in space-times with torsion. It is nevertheless shown that for the specific cases of Dirac fields and spin fluids the system does become holographic. The entropy of a black hole with spin is evaluated and found to be in agreement with Bekenstein-Hawking formula.
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References
Bekenstein, J.D.: Lett. Nuovo Cimento 4, 737 (1972)
Bekenstein, J.D.: Phys. Rev. D 7, 2333 (1973)
Hawking, S.W.: Nature 248, 30 (1974)
Hawking, S.W.: Commun. Math. Phys. 43, 199 (1975)
t’ Hooft, G.: arXiv:gr-qc/9310026
Susskind, L.: J. Math. Phys. 36, 6377 (1995). arXiv:hep-th/9409089
Cartan, É.: Ann. Éc. Norm. 40, 325 (1923)
Kibble, T.W.B.: J. Math. Phys. 2, 212 (1961)
Sciama, D.W.: In: Recent Developements in General Relativity, p. 415. Pergamon, Oxford (1962)
Sakharov, A.D.: Dokl. Akad. Nauk SSSR 177, 70 (1967)
Sakharov, A.D.: Sov. Phys. Dokl. 12, 1040 (1968)
Clifford, W.: Mathematical Papers. MacMillan, New York (1968)
Kleinert, H.: Gauge Fields in Condensed Matter, Vol. II: Stress and Defects. World Scientific, Singapore (1989)
Kokarev, S.S.: Nuovo Cimento B 113, 1339 (1998). arXiv:gr-qc/0010005v1
Malyshev, C.: Ann. Phys. 286, 249 (2000)
Tartaglia, A.: Gravit. Cosmol. 1, 335 (1995). arXiv:gr-qc/0410145v1
Tartaglia, A., Capone, M., Radicella, N.: International Conference on Problems of Practical Cosmology, St. Petersburg, Russia, 23–27 June 2008
Tartaglia, A., Radicella, N.: Class. Quantum Gravity 27, 035001 (2010). arXiv:0903.4096 [gr-qc]
Edelen, D.G.B.: Int. J. Theor. Phys. 33, 1315 (1994)
Letelier, P.S.: Class. Quantum Gravity 12, 471 (1995)
Puntigam, R.A., Soleng, H.H.: Class. Quantum Gravity 14, 1129 (1997)
Padmanabhan, T.: Int. J. Mod. Phys. D 13, 2293 (2004). arXiv:gr-qc/0408051v1
Padmanabhan, T.: Braz. J. Phys. 35, 362 (2005). arXiv:gr-qc/0412068v3
Padmanabhan, T.: Int. J. Mod. Phys. D 15, 2029 (2006). arXiv:gr-qc/0609012v2
Hammad, F.: Int. J. Theor. Phys. 49, 1055 (2010)
De Sabbata, V., Gasperini, M.: Introduction to Gravitation. World Scientific, Singapore (1985)
De Sabbata, V., Sivaram, C.: Spin and Torsion in Gravitation. World Scientific, Singapore (1994)
Hehl, F.W., von der Heyde, P., Kerlick, G.D., Nester, J.M.: Rev. Mod. Phys. 48, 393 (1976)
Ortín, T.: Gravity and Strings. Cambridge Univ. Press, Cambridge (2004)
Weyssenhoff, J., Raabe, A.: Acta Phys. Pol. 9, 7 (1947)
Halbwachs, F.: Theorie relativiste des fluids à spin. Gauthier-Villars, Paris (1960)
Burinskii, A.: Phys. Rev. D 70, 086006 (2004). arXiv:hep-th/0406063
Cognola, G.: Phys. Rev. D 57, 6292 (1998). arXiv:gr-qc/9710118
Wald, R.: General Relativity. The University of Chicago Press, Chicago (1984)
De Sabbata, V., Gasperini, M.: Lett. Nuovo Cimento 27, 289 (1980)
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An erratum to this article is available at http://dx.doi.org/10.1007/s10773-013-1806-x.
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Hammad, F. An Entropy Functional for Riemann-Cartan Space-Times. Int J Theor Phys 51, 362–373 (2012). https://doi.org/10.1007/s10773-011-0913-9
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DOI: https://doi.org/10.1007/s10773-011-0913-9