[3] M. Jamil et al, Eur.Phys.J.C59:907-912,2009 [4] M.S. Morris and K.S. Thorne, Am. J. Phys. 56 (1988) 395 [5] R.R. Caldwell, Phys. Lett. B 545 (2002) 23 [6] R.R. Caldwell et al, Phys. Rev. Lett. 91 (2003) 071301 [7] A. DeBenedicitis et al, Phys. Rev. D 78 (2008) 104003 [8] S. Sushkov, Phys. Rev. D 71 (2005) 043520 [9] O.B. Zaslavskii, Phys. Rev. D 72 (2005) 061303 [10] P.K.F. Kuhfittig, Class. Quantum. Grav. 23 (2006) 5853 [11] M. Cataldo et al, Phys.Rev.D78:104006,2008 [12] S. Carlip, Quantum Gravity in 2+1 dimensions, (Cambridge University Press, 1998) [13] F. Rahaman et al., Phys. Scr. 76 (2007) 56 [14] E.A.L. Rubio, Rev. Col. Fis. 40,2 (2008) 222-224 [arXiv:0707.0900] [15] W.T. Kim et al, Phys. Rev. D 70 (2004) 044006 [16] M.S.R. Delgaty and R.B. Mann, Int.J.Mod.Phys. D4 (1995) 231-246 [17] S. Chakraborty and T. Bandyopadhyay, Phys.Rev.D75:064027,2007 [18] M. Banados, C. Teitelboim and J. Zanelli, Phys. Rev. Lett. 69 (1992) 1849 [19] M. Banados, M. Henneaux, C. Teitelboim and J. Zanelli, Phys. Rev. D 48 (1993) 1506 [20] F. Rahaman et al, arXiv:0808.2927 [astro-ph] [21] P.K.F. Kuhfittig, Gen. Relativ. Gravit. 41 (2009) 1485 [22] S. Chakraborty and T. Bandyopadhyay, Astrophys. Space Sci. 317:209-212,2008 [23] F.S.N. Lobo, Phys.Rev.D75:064027,2007 7