Abstract
I review the problem of dark energy focussing on cosmological constant as the candidate and discuss what it tells us regarding the nature of gravity. Section 1 briefly overviews the currently popular “concordance cosmology” and summarizes the evidence for dark energy. It also provides the observational and theoretical arguments in favour of the cosmological constant as a candidate and emphasizes why no other approach really solves the conceptual problems usually attributed to cosmological constant. Section 2 describes some of the approaches to understand the nature of the cosmological constant and attempts to extract certain key ingredients which must be present in any viable solution. In the conventional approach, the equations of motion for matter fields are invariant under the shift of the matter Lagrangian by a constant while gravity breaks this symmetry. I argue that until the gravity is made to respect this symmetry, one cannot obtain a satisfactory solution to the cosmological constant problem. Hence cosmological constant problem essentially has to do with our understanding of the nature of gravity. Section 3 discusses such an alternative perspective on gravity in which the gravitational interaction—described in terms of a metric on a smooth spacetime—is an emergent, long wavelength phenomenon, and can be described in terms of an effective theory using an action associated with normalized vectors in the spacetime. This action is explicitly invariant under the shift of the matter energy momentum tensor T ab → T ab + Λ gab and any bulk cosmological constant can be gauged away. Extremizing this action leads to an equation determining the background geometry which gives Einstein’s theory at the lowest order with Lanczos–Lovelock type corrections. In this approach, the observed value of the cosmological constant has to arise from the energy fluctuations of degrees of freedom located in the boundary of a spacetime region.
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de Bernardis P. et al. (2000). Nature 404: 955
Balbi A. et al. (2000). Ap. J. 545: L1
Hanany S. et al. (2000). Ap. J. 545: L5
Pearson T.J. et al. (2003). Astrophys. J. 591: 556
Bennett C.L. et al. (2003). Astrophys. J. Suppl. 148: 1
Spergel D.N. et al. (2003). ApJS 148: 175
Mason B.S. et al. (2003). Astrophys. J. 591: 540
Spergel, D.N., et al.: astro-ph/0603449
Percival W.J. et al. (2002). Mon. Not. Roy. Astron. Soc. 337: 1068
Percival W.J. et al. (2001). MNRAS 327: 1297
Wang X. et al. (2002). Phys. Rev. 65: 123001
Padmanabhan T. and Sethi S (2001). Ap. J. 555: 125, [astro-ph/0010309]
Sarkar S. (1996). Rept. Prog. Phys. 59: 1493
Freedman W. et al. (2001). Astrophys. J. 553: 47
Mould J.R. et al. (2000). Astrophys. J. 529: 786
Padmanabhan T. (2006). Advanced topics in cosmology: a pedagogical introduction. AIP Conf. Proc. 843: 111–166, [astro-ph/0602117]
Padmanabhan T. (2005). Understanding our universe: current status and open issues. In: Ashtekar, A. (eds) 100 Years of Relativity—Space–time Structure: Einstein and Beyond, pp 175–204. World Scientific, Singapore, [gr-qc/0503107]
Kazanas D. (1980). Ap. J. Lett. 241: 59
Starobinsky A.A. (1979). JETP Lett. 30: 682
Starobinsky A.A. (1980). Phys. Lett. B91: 99
Guth A.H. (1981). Phys. Rev. D23: 347
Linde A.D. (1982). Phys. Lett. B108: 389
Albrecht A. and Steinhardt P.J. (1982). Phys. Rev. Lett. 48: 1220
Narlikar J.V. and Padmanabhan T. (1991). Ann. Rev. Astron. Astrophys. 29: 325
Alabidi, L., Lyth, D.H.: astro-ph/0510441
Hawking S.W. (1982). Phys. Lett. B115: 295
Starobinsky A.A. (1982). Phys. Lett. B117: 175
Guth A.H., Pi S.-Y. (1982). Phys. Rev. Lett. 49: 1110
Bardeen J.M. et al. (1983). Phys. Rev. D28: 679
Abbott L.F., Wise M.B. (1984). Nucl. Phys. B244: 541
Sriramkumar L., Padmanabhan T. (2005). Phys. Rev. D71: 103512 [gr-qc/0408034]
Padmanabhan T. (1988). Phys. Rev. Lett. 60: 2229
Padmanabhan T., Seshadri T.R., Singh T.P. (1989). Phys. Rev. D39: 2100
Smoot G.F. et al. (1992). Ap. J. 396: L1
Padmanabhan T., Narasimha D. (1992). MNRAS 259: 41P
Efstathiou G. et al. (1992). MNRAS 258: 1
Zeldovich Ya.B. (1970). Astron. Astrophys. 5: 84
Gurbatov S.N. et al. (1989). MNRAS 236: 385
Brainerd T.G. et al. (1993). Astrophys. J. 418: 570
Bagla J.S., Padmanabhan T. (1994). MNRAS 266: 227, [gr-qc/9304021]
Bagla J.S., Padmanabhan T. (1997). MNRAS 286: 1023, [astro-ph/9605202]
Padmanabhan T., Engineer S. (1998). Ap. J. 493: 509, [astro-ph/9704224]
Engineer S. et al. (2000). MNRAS 314: 279, [astro-ph/9812452]
Padmanabhan T. (1990). Phys. Rept. 188: 285
Padmanabhan T. (1989). Astrophys. J. Supp. 71: 651
Tatekawa, T.: [astro-ph/0412025]
Hamilton A.J.S. et al. (1991). Ap. J. 374: L1
Nityananda R., Padmanabhan T. (1994). MNRAS 271: 976, [gr-qc/9304022]
Padmanabhan T. (1996). MNRAS 278: L29, [astro-ph/9508124];astro-ph/0512077
Padmanabhan T. et al. (1996). Ap. J. 466: 604, [astro-ph/9506051]
Munshi D. et al. (1997). MNRAS 290: 193, [astro-ph/9606170]
Bagla J.S. et al. (1998). Ap. J. 495: 25, [astro-ph/9707330]
Kanekar N. et al. (2001). MNRAS 324: 988, [astro-ph/0101562]
Padmanabhan T., Ray S. (2006). Mon. Not. Roy. Astron. Soc. Lett. 372: L53–L57, [astro-ph/0511596]
Bagla, J.S.: astro-ph/0411043
Bagla J.S., Padmanabhan T. (1997). Pramana 49: 161–192, [astro-ph/0411730]
Efstathiou G. et al. (1990). Nature 348: 705
Ostriker J.P., Steinhardt P.J. (1995). Nature 377: 600
Bagla J.S., Padmanabhan T., Narlikar J.V. (1996). Comments Astrophys. 18: 275, [astro-ph/9511102]
Perlmutter S.J. et al. (1999). Astrophys. J. 517: 565
Reiss A.G. et al. (1998). Astron. J. 116: 1009
Tonry J.L. et al. (2003). ApJ 594: 1
Barris B.J. et al. (2004). Astrophys. J. 602: 571
Reiss A.G. et al. (2004). Astrophys. J. 607: 665
Astier P. et al. (2006). Astron. Astrophys. 447: 31, [astro-ph/0510447]
Padmanabhan T. and Roy Choudhury T. et al. (2003). MNRAS 344: 823, [astro-ph/0212573]
Roy Choudhury T. and Padmanabhan T. (2005). Astron. Astrophys. 429: 807, [astro-ph/0311622]
Jassal H.K. et al. (2005). Phys. Rev. D 72: 103503, [astro-ph/0506748]
Nesseris S. and Perivolaropoulos L. (2007). JCAP 0702: 025
Gong, Y., Wang, A.: arXiv:0705.0996
Lazkoz, R., et al.: arXiv:0704.2606
Gong, Y., et al.: astro-ph/0703583
Rosenfeld R. (2007). Phys. Rev. D75: 083509
Rapetti D. (2007). Mon. Not. Roy. Astron. Soc. 375: 1510
Sen, A.A., Scherrer, R.J.: astro-ph/0703416
Shafieloo, A.: astro-ph/0703034
Cattoen, C., Visser, M.: gr-qc/0703122
Padmanabhan T. (2003). Phys. Rept. 380: 235, [hep-th/0212290]
Padmanabhan T. (2005). Curr. Sci. 88: 1057, [astro-ph/0411044]
Nobbenhuis, S.: gr-qc/0609011
Alcaniz, J.S.: astro-ph/0608631
Hannestad S. (2006). Int. J. Mod. Phys. A21: 1938
Perivolaropoulos L. (2006). AIP Conf. Proc. 848: 698
Copeland E.J. et al (2006). Int. J. Mod. Phys. D15: 1753
Dolgov, A.D.: hep-ph/0606230
Peebles P.J.E. and Ratra B. (2003). Rev. Mod. Phys. 75: 559
Sahni V. and Starobinsky A. (2000). Int. J. Mod. Phys. D9: 373
Fuzfa, A., Alimi, J.-M.: astro-ph/0611284
Lima, J.A.S., et al.: astro-ph/0611007
Das, A., et al.: gr-qc/0610097
Fabris, J.C., et al.: gr-qc/0609017
Gannouji, R., et al.: astro-ph/0606287
Gao, C.J., et al.: astro-ph/0605682
Grande, J., et al.: gr-qc/0604057
Nojiri, S., Odintsov, S.D.: hep-th/0601213;hep-th/0606025
Panotopoulos, G.: astro-ph/0606249
Carneiro, S., et al.: astro-ph/0605607
Johri, V.B., Rath, P.K.: astro-ph/0603786
Wang, M.: hep-th/0601189
Wei H. et al (2005). Phys. Rev. D72: 123507
Capozziello, S.: astro-ph/0508350
Polarski D. and Ranquet A. (2005). Phys. Lett. B627: 1
Andrianov A.A. et al (2005). Phys. Rev. D72: 043531
Stefancic, H.: astro-ph/0504518
Sola J. and Stefancic H. (2006). Mod. Phys. Lett. A21: 479
Sola J. and Stefancic H. (2005). Phys. Lett. B624: 147
Sahlen, M., et al.: astro-ph/0506696
Huang, Z.-Y., et al.: astro-ph/0511745
Guo, Z.K., Ohta, N., Zhang, Y.Z.: astro-ph/0505253
Nojiri, S., Odintsov, S.D.: hep-th/0506212; hep-th/0408170
Godlowski W. et al. (2004). Ap. J. 605: 599, astro-ph/0604327
Cardone V.F. et al. (2004). Phys. Rev. D69: 083517
Neupane I.P. (2004). Class. Quant. Grav. 21: 4383
Bento, M.C., et al.: astro-ph/0407239
DeBenedictis, A., et al.: gr-qc/0402047
Axenides, M., Dimopoulos, K.: hep-ph/0401238
Maia, M.D., et al.: astro-ph/0403072
Alcaniz, J.S.: astro-ph/0312424
Li X.-Z. et al. (2003). Int. J. Mod. Phys. A18: 5921
Steinhardt P.J. (2003). Phil. Trans. Roy. Soc. Lond. A361: 2497
Sen S. and Seshadri T.R. (2003). Int. J. Mod. Phys. D12: 445
Gonzalez-Diaz P.F. (2003). Phys. Lett. B562: 1
de Putter, R., Linder, E.V.: arXiv:0705.0400
Movahed, M.S., et al.: astro-ph/0701339
Li, H., et al.: astro-ph/0601007
Chimento L.P. and Feinstein A. (2004). Mod. Phys. Lett. A 19: 761
Scherrer R.J. (2004). Phys. Rev. Lett. 93: 011301
Gonzalez-Diaz, P.F.: hep-th/0408225
Chimento L.P. (2004). Phys. Rev. D69: 123517
Bertolami, O.: astro-ph/0403310
Lazkoz, R.: gr-qc/0410019
Alcaniz, J.S., Lima, J.A.S.: astro-ph/0308465
Malquarti M. et al. (2003). Phys. Rev. D67: 123503
Padmanabhan T. (2002). Phys. Rev. D 66: 021301, [hep-th/0204150]
Padmanabhan T. and Choudhury T.R. (2002). Phys. Rev. D 66: 081301, [hep-th/0205055]
Bagla J.S. et al. (2003). Phys. Rev. D 67: 063504, [astro-ph/0212198]
Shao, Y., et al.: gr-qc/0703112
Zamarias, V.: hep-th/0610063
Ren, J., et al.: astro-ph/0610266
Fang, W., et al.: hep-th/0606033
Calcagni, G., Liddle, A.R.: astro-ph/0606003
Sen, A.A.: gr-qc/0604050
Singh, H.: hep-th/0608032; hep-th/0505012
Das A. et al. (2005). Phys. Rev. D72: 043528
Aref’eva, I.Ya., et al.: astro-ph/0505605; astro-ph/0410443
Aguirregabiria, J.M., Lazkoz, R.: hep-th/0402190
Kim, C., et al.: hep-th/0404242
Herrera, R., et al.: astro-ph/0404086
Ghodsi, A., Mosaffa, A.E.: hep-th/0408015
Liu, D.J., Li, X.Z.: astro-ph/0402063
Gorini V. et al. (2004). Phys. Rev. D 69: 123512
Sami M. et al. (2004). Pramana 62: 765
Steer D.A. (2004). Phys. Rev. D70: 043527
Raul L., Abramo W. and Finelli F. (2003). Phys. Lett. B575: 165
Frederic L. and Peet A.W. (2003). JHEP 0304: 048
Sami M. (2003). Mod. Phys. Lett. A18: 691
Kim C.J. et al. (2003). Phys. Lett. B552: 111
Shiu G. and Wasserman I. (2002). Phys. Lett. B541: 6
Choudhury D. et al. (2002). Phys. Lett. B544: 231
Frolov A.V. et al. (2002). Phys. Lett. B545: 8
Gibbons G.W. (2002). Phys. Lett. B537: 1
Ellis G.F.R. and Madsen M.S. (1991). Class. Quan. Grav. 8: 667
Schunck F.E. and Mielke E.W. (1994). Phys. Rev. D50: 4794
Jassal H.K. et al. (2005). MNRAS 356: L11–L16, [astro-ph/0404378]; [astro-ph/0601389]
Lapchinsky V.G. and Rubakov V.A. (1979). Acta Phys. Polon. B10: 1041
Hartle J.B. (1988). Phys. Rev. D37: 2818
Hartle J.B. (1988). D 38: 2985
Padmanabhan T. (1989). Class. Quan. Grav. 6: 533
Singh T.P. and Padmanabhan T. (1989). Ann. Phys. 196: 296
Padmanabhan T. (1989). Phys. Rev. D39: 2924
Padmanabhan T. and Singh T.P. (1990). Class. Quan. Grav. 7: 441
Hallwell J.J. (1989). Phys. Rev. D39: 2912
Padmanabhan T. and Roy Choudhury T. (2000). Mod. Phys. Lett. A 15: 1813, [gr-qc/0006018]
Snyder H.S. (1947). Phys. Rev. 71: 38
DeWitt B.S. (1964). Phys. Rev. Lett. 13: 114
Yoneya T. (1976). Prog. Theor. Phys. 56: 1310
Padmanabhan T. (1985). Ann. Phys. (N.Y.) 165: 38
Padmanabhan T. (1987). Class. Quantum Grav. 4: L107
Ashtekar A. et al. (1992). Phys. Rev. Lett. 69: 237
Padmanabhan T. (1997). Phys. Rev. Lett. 78: 1854, [hep-th/9608182]
Padmanabhan T. (1998). Phys. Rev. D57: 6206
Srinivasan K. et al. (1998). Phys. Rev. D 58: 044009, [gr-qc/9710104]
Calmet X. (2004). Phys. Rev. Lett. 93: 211101, [hep-th/0505144]
Fontanini M. et al. (2006). Phys. Lett. B 633: 627, [hep-th/0509090]
Garay L.J. (1995). Int. J. Mod. Phys. A10: 145
Gibbons G.W. and Hawking S.W. (1977). Phys. Rev. D15: 2738
Padmanabhan T. (2004). Mod. Phys. Lett. A 19: 2637, [gr-qc/0405072]
Padmanabhan, T.: Lecture at the Plumian 300—The Quest for a Concordance Cosmology and Beyond Institute of Astronomy, Cambridge, UK, July 2004; [astro-ph/0510492]
Bjorken, J.D.: astro-ph/0404233 (2004)
Padmanabhan T. (2006). Gravity: A new holographic perspective (Lecture at the International Conference on Einstein’s Legacy in the New Millennium, Puri, India, Dec, 2005). Int. J. Mod. Phys. D 15, 1659–1675, [gr-qc/0606061]
Padmanabhan T. (2005). Class.Quan.Grav. 22: L107–L110, [hep-th/0406060]
Padmanabhan T. (2002). Class. Quan. Grav. 19: L167, [gr-qc/0204020]
Sorkin D. (1997). Int. J. Theor. Phys. 36: 2759
Djorgovski, S.G., Gurzadyan, V.G.: astro-ph/0610204
Volovik, G.E.: gr-qc/0405012
Lindesay, J.V., et al.: astro-ph/0412477
Myung, Y.S.: hep-th/0412224
Barrow, J.D.: gr-qc/0612128
Elizalde, E., et al.: hep-th/0502082
Padmanabhan T. (2005). Brazilian J. Phys. (Special Issue) 35: 362, [gr-qc/0412068]
Padmanabhan T. (2004). Class. Quan. Grav. 21: L1, [gr-qc/0310027]
Padmanabhan T. (2003). Gen. Rel. Grav. 35: 2097
Padmanabhan T. (2002). Gen. Rel. Grav. 34: 2029, [gr-qc/0205090]
Mottola, E., Vaulin, R.: gr-qc/0604051
Cremades, D., et al.: hep-th/0608174
Erdem, R.: hep-th/0410063
Hooft, G.’t., Nobbenhuis, S.: gr-qc/0602076
Kaplan, D.E., Sundrum, R.: hep-th/0505265
Antoniadis, I., et al.: gr-qc/0612068
Mottola E. (1985). Phys. Rev. D31: 754
Tsamis N.C. and Woodard R.P. (1993). Phys. Lett. B301: 351
Elizalde E. and Odintsov S.D. (1994). Phys. Lett. B321: 199
Elizalde E. and Odintsov S.D. (1994). Phys. Lett. B333: 331
Lindesay, J.V., Noyes, H.P.: astro-ph/0508450
Wang, S.: gr-qc/0606109
Qi, S.: hep-th/0505109
Padmanabhan T. and Chitre S.M. (1987). Phys. Lett. A 120: 433
Baum E. (1983). Phys. Lett. B 133: 185
Padmanabhan T. (1984). Phys. Lett. A104: 196
Hawking S.W. (1984). Phys. Lett. B134: 403
Coleman S. (1988). Nucl. Phys. B310: 643
Mongan T. (2001). Gen. Rel. Grav. 33: 1415, [gr-qc/0103021]
Mongan T. (2003). Gen. Rel. Grav. 35: 685
Wu, Q., et al.: arXiv:0705.1006
Myung, Y.S.: gr-qc/0702032
Simpson, F.: astro-ph/0609755
Gong, Y., Zhang, Y.-Z.: hep-th/0505175; astro-ph/0502262; hep-th/0412218
Zhang, X., Wu, F.-Q.: astro-ph/0506310
Hu, M.G., Meng, X.-H.: astro-ph/0511615
Shapiro I.L. (2003). J. Sola, Phys. Lett. B 574: 149–155, [astro-ph/0303306]
Shapiro I.L. and Sola J. (2000). Phys. Lett. B475: 236
Shapiro, I.L., et al.: hep-ph/0410095
Espana-Bonet C. (2003). Phys. Lett. B574: 149
Espana-Bonet C. (2004). JCAP 0402: 006
Bauer, F.: gr-qc/0501078; gr-qc/0512007
Shapiro I.L. (2002). J. Sola, JHEP 0202: 006
Sola, J., Stefancic, H.: astro-ph/0505133
Alcaniz J.S. and Lima J.A.S. (2005). Phys. Rev. D 72: 063516, [astro-ph/0507372]
Alcaniz J.S. and Lima J.A.S. (2003). Phys. Rev. D67: 043502
Bauer F. (2005). Class. Quant. Grav. 22: 3533
Buchert, T.: gr-qc/0612166
Buchert T. (2000). Gen. Rel. Grav. 32: 105
Buchert T. (2001). Gen. Rel. Grav. 33: 1381
Ellis G.F.R. and Buchert T. (2005). Phys. Lett. A347: 38
Zalaletdinov R.M. (1992). Gen. Rel. Grav. 24: 1015
Paranjape, A., Singh, T.P.: gr-qc/0703106
Paranjape A. and Singh T.P. (2006). Class. Quant. Grav. 23: 6955
Ishibashi A. and Wald R.M. (2006). Class. Quant. Grav. 23: 235–250
Rasanen, S.: JCAP 0402 (2004) 003
Losic B. and Unruh W.G. (2005). Phys. Rev. D72: 123510
Hirata C.M. and Seljak U. (2005). Phys. Rev. D72: 083501
Kolb, E.W., et al.: astro-ph/0506534; hep-th/0503117
Padmanabhan T. (1987). Gen. Rel. Grav. 19: 927
Jha S. et al. (2007). Astrophys. J. 659: 122
Conley, A., et al.: arXiv:0705.0367v1
Dolgov, A.D.: In: Gibbons, G.W., Hawking, S.W., Sikkos, S.T.C. (eds.) The very early universe: proceeding of the 1982 Nuffield Workshop at Cambridge. Cambridge University Press, p. 449 (1982)
Barr S.M. (1987). Phys. Rev. D36: 1691
Ford L.H. (1987). Phys. Rev. D35: 2339
Hebecker A. and Wetterich C. (2000). Phy. Rev. Lett. 85: 3339
Hebecker, A.: hep-ph/0105315
Singh T.P. and Padmanabhan T. (1988). Int. J. Mod. Phys. A3: 1593
Sami M. and Padmanabhan T. (2003). Phys. Rev. D 67: 083509, hep-th/0212317
Einstein, A.: Siz. Preuss. Acad. Scis. (1919), translated in The Principle of Relativity, by edited by Einstein, A., et al. (Dover, New York, 1952)
van der Bij J.J. et al. (1982). Physica A116: 307
Wilczek F. (1984). Phys. Rep. 104: 111
Zee, A.: High energy physics. In: Kursunoglu, B., Mintz, S.C., Perlmutter, A. (eds.) Proceedings of the 20th Annual Orbis Scientiae, Coral Gables (1983). Plenum, New York (1985)
Buchmuller W. and Dragon N. (1988). Phys. Lett. B207: 292
Unruh W.G. (1989). Phys. Rev. D40: 1048
Mahajan, G., et al.: astro-ph/0604265
Fulling S.A. (1973). Phys. Rev. D7: 2850
Unruh W.G. (1976). Phys. Rev. D14: 870
DeWitt, B.S.: In: Hawking, S.W., Israel, W. (eds.) General Relativity: An Einstein Centenary Survey, pp. 680–745. Cambridge University Press (1979)
Padmanabhan T. (1985). Class. Quan. Grav. 2: 117
Srinivasan K. et al. (1999). Phys. Rev. D 60: 24007, [gr-qc/9812028]
Sriramkumar L. et al. (2002). Int. J. Mod. Phys. D 11: 1, [gr-qc/9903054]
Padmanabhan, T.: From gravitons to gravity: myths and reality.(2004). [gr-qc/0409089]
Padmanabhan T. (2006). Gravity’s immunity from vacuum: the holographic structure of semiclassical action. Third prize essay; Gravity Essay Contest 2006. Gen. Rel. Grav. 38: 1547–1552
Padmanabhan T. (2006). Int. J. Mod. Phys. D 15: 2029, [gr-qc/0609012]
Sakharov A.D. (1968). Sov. Phys. Dokl. 12: 1040
Jacobson T. (1995). Phys. Rev. Lett. 75: 1260
Padmanabhan T. (2002). Mod. Phys. Lett. A 17: 1147, [hep-th/0205278]
Padmanabhan T. (2004). Int. J. Mod. Phys. D 13: 2293–2298, [gr-qc/0408051]
Padmanabhan, T.: 18, 2903 (2003). [hep-th/0302068]
Padmanabhan T. (2004). Class. Quan. Grav. 21: 4485, [gr-qc/0308070]
Volovik G.E. (2001). Phys. Rept. 351: 195
Volovik, G.E.: gr-qc/0604062
Volovik G.E. (2003). The universe in a helium droplet. Oxford University Press, Oxford
Huang, C.-G., Sun, J.-R.: gr-qc/0701078
Makela, J.: gr-qc/0701128
Padmanabhan T. (1998). Phys. Rev. Lett. 81: 4297, [hep-th/9801015]
Padmanabhan T. (1999). Phys. Rev. D. 59: 124012, [hep-th/9801138] and references therein
Padmanabhan T. (2005). Phys. Rept. 406: 49, [gr-qc/0311036]
Padmanabhan T. (2002). Mod. Phys. Lett. A 17: 923, [gr-qc/0202078]
Padmanabhan T. (2002). Class. Quan. Grav. 19: 5387, [gr-qc/0204019]
Zhou, J., et al.: arXiv:0705.1264
Cai, R.-G., Cao, L.-M.: [gr-qc/0611071]
Akbar, M., Cai, R.-G.: [hep-th/0609128]
Akbar, M.: [hep-th/0702029]
Kothawala, D., Sarkar, S., Padmanabhan, T.: Einstein’s equations as a thermodynamic identity: the cases of stationary axis-symmetric horizons and evolving spherically symmetric horizons. gr-qc/0701002
Padmanabhan, T.: Plenary talk at the Albert Einstein Century International Conference, Paris, 18–22 July 2005, AIP Conf. Proc. 861, 858–866, [astro-ph/0603114]
Padmanabhan T. (2005). Int. J. Mod. Phys D 14: 2263–2270, [gr-qc/0510015]
Paranjape A., Sarkar S. and Padmanabhan T. (2006). Phys. Rev. D 74: 104015, [hep-th/0607240]
Akbar, M., Cai, R.-G.: gr-qc/0612089
Ge, X.-H.: hep-th/0703253
Sheykhi, A., et al.: hep-th/0701198
Allemandi, G., et al.: gr-qc/0308019
Mukhopadhyay A. and Padmanabhan T. (2006). Phys. Rev. D 74: 124023, [hep-th/0608120]
Padmanabhan T. and Paranjape A. (2007). Phys. Rev. D 75: 064004, [gr-qc/0701003]
Lanczos C. (1932). Z. Phys. 73: 147
Lanczos C. (1938). Ann. Math. 39: 842
Lovelock D. (1971). J. Math. Phys. 12: 498
York J.W. (1972). Phys. Rev. Lett. 28: 1082
Gibbons G.W. and Hawking S.W. (1977). Phys. Rev. D15: 2752–2756
Wald R.M. (1993). Phys. Rev. D48: 3427
Iyer V. and Wald R.M. (1995). Phys. Rev. D52: 4430–4439
Padmanabhan T. and Singh T.P. (1987). Class. Quan. Grav. 4: 1397
Bombelli L. et al. (1986). Phys. Rev. D34: 373
Srednicki M. (1993). Phys. Rev. Lett. 71: 666
Brustein R. et al. (2002). Phys. Rev. D65: 105013
Yarom, A., Brustein, R.: hep-th/0401081
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Padmanabhan, T. Dark energy and gravity. Gen Relativ Gravit 40, 529–564 (2008). https://doi.org/10.1007/s10714-007-0555-7
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DOI: https://doi.org/10.1007/s10714-007-0555-7