Works

Papers since 2020

  1. I. Antoniadis, S. Cotsakis, I. Klaoudatou, Regular braneworlds with nonlinear bulk-fluids; arXiv:2106.15669
  2. I. Antoniadis, S. Cotsakis, Geodesic incompleteness and partially covariant gravity, Universe 7(5) (2021) 126; arXiv:2102.07806
  3. S. Cotsakis and D. Trachilis,The radiation instability in modified gravity, Int. J. Mod. Phys. A36 (2021) 2150060; arXiv: 2012.05850
  4. S. Cotsakis, Onset of synchronization in coupled Mixmaster oscillators; arXiv: 2010.00298  
  5. J. D. Barrow, S. Cotsakis and D. Trachilis, The Generic Sudden Singularity in Brans-Dicke Theory, Eur. Phys. J. C 80, 1197 (2020); arXiv: 2009.01732

Selected older works

  1. J. D. Barrow and S. Cotsakis, Inflation and the Conformal Structure of Higher-Order Gravity Theories, Phys. Lett. B214 (1988) 515–518
  2. S. Cotsakis, Escape Rates for the Quiescent Self-Regenerating Universe, Phys. Lett. B328 (1994) 270–273
  3. Y. Choquet-Bruhat and S. Cotsakis, Global Hyperbolicity and Completeness. J. Geom. Phys. 43 (2002) 345–350
  4. S. Cotsakis, Global Hyperbolicity of Sliced Spaces, Gen. Rel. Grav. 36 (2004) 1183–1188
  5. S. Cotsakis and J. D. Barrow, The Dominant Balance at Cosmological Singularities, In Proceedings of the Greek Relativity Meeting NEB12, June 29-July 2, 2006, Nauplia, Greece, J. Phys. Conf. Ser. 68 (2007) 012004
  6. S. Cotsakis, Asymptotic Poincar\’e compactification and finite singularities,  Grav. Cosm. 19 (2013) 240; arXiv:1301.4778
  7. J. D. Barrow, S. Cotsakis, Geodesics at Sudden Singularities, Phys.  Rev.  D88 (2013) 067301; arXiv:1307.5005
  8. I. Antoniadis, S. Cotsakis, Ambient cosmology and spacetime singularities. Eur. Phys. J. C75 (2015) 1-12, CERN-PH-TH/2014-176, arXiv:1409.2220
  9. I. Antoniadis, S. Cotsakis, Topology of the ambient boundary and the convergence of causal curves, Mod.  Phys.  Lett.  A30 (2015) 1550161; arXiv:1505.04737
  10. J. D. Barrow, S. Cotsakis, Inflation without a trace of Lambda, Eur. Phys. J. C80 (2020) 839; arXiv:1907.02928

Older works list

  1. S. Cotsakis, Theories of Star Formation, MSc Thesis (University of Sussex Archives, 1987)
  2. J. D. Barrow and S. Cotsakis, Inflation and the Conformal Structure of Higher-Order Gravity Theories, Phys. Lett. B214 (1988) 515–518
  3. J. D. Barrow and S. Cotsakis, Chaotic Behaviour in Higher-Order Gravity Theories, Phys. Lett. B232 (1989) 172–176
  4. S. Cotsakis, Cosmological Models in Higher-Order Gravity, PhD Thesis (University of Sussex Archives, 1990)
  5. J. D. Barrow and S. Cotsakis, Self-Regenerating Inflationary universe in higher-order gravity in arbitrary dimension, Phys. Lett. B258 (1991) 299–306
  6. S. Cotsakis, Quiescent Self-Regenerating Universe. In Proceedings of the First Greek Astronomical Meeting, P. Laskarides, (ed.), Athens 1992, pp.  135-140
  7. S. Cotsakis, Chaos in the Universe: Myth or Reality? Nonlinear News 3 (1992) 25-30 (in Greek)
  8. S. Cotsakis, Conformal Transformations Single Out a Unique Measure of Distance, Phys.  Rev.  D47 (1993) 1437-1439; Erratum:  Phys.  Rev.  D49 (1994) 1145
  9. S. Cotsakis, J. Demaret, Y. de Rop and L. Querella, Mixmaster Universe in Fourth-Order Gravity Theories, Phys. Rev. D48 (1993) 4595–4603
  10. S. Cotsakis and G. Flessas, Stability of FRW Cosmology in Higher Order Gravity, Phys. Rev. D48 (1993) 3577–3584
  11. S. Cotsakis and G. Flessas, Generalized No-Hair Theorems, Phys. Lett. B319 (1993) 69–73
  12. S. Cotsakis and P. G. L. Leach, Painlev´e Analysis of the Mixmaster Universe, J. Phys. A27 (1993) 1625–1631
  13. S. Cotsakis and P. Saich, Power-Law Inflation and Conformal Transformations, Class. Quant. Grav. 11 (1994) 383–387
  14. S. Cotsakis, Escape Rates for the Quiescent Self-Regenerating Universe, Phys. Lett. B328 (1994) 270–273
  15. S. Cotsakis, P. G. L. Leach and G. Flessas, Minimally Coupled Scalar Field Wormholes, Phys. Rev. D49 (1994) 6489–6492
  16. G. Flessas, P. G. L. Leach and S. Cotsakis, Comment on a Paper Concerning Symmetries of Equations of Motion and Equivalent Lagrangians, Can. J. Phys. 72 (1994) 86–88
  17. G. Flessas, P. G. L. Leach and S. Cotsakis, On Noether’s formulation of her theorem, Can. J. Phys. 73 (1995) 543
  18. S. Cotsakis and G. Flessas, Past-Instability Conjecture and Cosmological Attractors in Generalized Isotropic Universes, Phys. Rev. D51 (1995) 4160–4168
  19. S. Cotsakis and G. Flessas, Graviton Creation and Conformal Non-Invariance in Higher Order Gravity Theories, Phys. Rev. D52 (1995) 5783–5786
  20. S. Cotsakis, Reply to Two Comments by Teyssandier and by Schmidt, Phys. Rev. D52 (1995) 6199–6200
  21. J. Miritzis and S. Cotsakis, Non-Linear Lagrangians and the Isotropy of the Universe, Phys. Lett. B383 (1996) 377–382
  22. S. Cotsakis and G. W. Gibbons, (eds.) Global Structure and Evolution in General Relativity, Springer LNP, 460 (1996)
  23. S. Cotsakis, R. Lemmer and P. G. L. Leach, Adiabatic Invariants and Mixmaster Catastrophes, Phys. Rev. D57 (1998) 4691–4698
  24. S. Cotsakis and J. Miritzis, Proof of the Cosmic No-Hair Conjecture for Some Quadratic Homogeneous Cosmologies Class. Quant. Grav. 15 (1998) 2795–2801
  25. S. Cotsakis, P.G.L. Leach and H. Pantazi Symmetries of homogeneous cosmologies, Grav. Cosm. 4 (1998) 314–325
  26. S. Cotsakis Inflation, Baby-Universes and Hawking’s Proposal, Oikonomikos Taxidromos, 5 November 1998, 118-120
  27. S. Cotsakis Mathematical problems in higher order gravity and cosmology, In Proceedings of the Eighth Marcel Grossman Meeting on General Relativity, T. Piran and R. Ruffini, eds., (World Scientific, 1999), pp.  505–507
  28. S. Cotsakis, J. Miritzis and L. Querella, Variational and conformal structure of nonlinear metric-connection gravitational lagrangians, J. Math. Phys. 40 (1999) 3063–3071
  29. S. Cotsakis, V. Ivashchuk and V. Melnikov, p-Brane Black Holes and Post-Newtonian Approximation, Grav. Cosm. 5 (1999) 52–57
  30. S. Cotsakis, G.P. Flessas, P.G.L. Leach and L. Querella, Ever-Expanding, Isotropizing, Quadratic Cosmologies, Grav.  Cosm.  6 (2000) 282– 290
  31. P.G.L. Leach, S. Cotsakis and G.P. Flessas, Symmetries, Singularities and Integrability in Complex Dynamics I: The reduction problem, J. Nonl. Math. Phys. 7 (2000) 445–479
  32. S. Cotsakis, V.R. Gavrilov and V.N. Melnikov, Integrable Spherically Symmetric p-Brane models Associated with Lie Algebras, Grav. Cosm. 6 (2000) 66–75
  33. P.G.L. Leach, S. Cotsakis and G. P. Flessas, Symmetries, Singularities and Integrability in Complex Dynamics II: Rescalings and Time-Translations in 2D Systems, J. Math. Anal. Appl. 251 (2000) 587–608
  34. J. Miritzis, P.G.L. Leach and S. Cotsakis, Symmetries, Singularities and Integrability in Complex Dynamics IV: Painlev´e Integrability of Isotropic Cosmologies, Grav. Cosm. 6 (2000) 282-290
  35. S. Cotsakis and G. W. Gibbons, (eds.)  Mathematical and Quantum Aspects of Relativity and Cosmology. Springer LNP, 537 (2000)
  36. P.G.L. Leach, S. Moyo, S. Cotsakis and R. Lemmer, Symmetries, Singularities and Integrability in Complex Dynamics III: Approximate Symmetries and Invariants, J. Nonl.  Math.  Phys.  8 (2001) 139-156
  37. P.G.L. Leach, M.C. Nucci and S. Cotsakis, Symmetries, Singularities and Integrability in Complex Dynamics V: Complete Sym- metry Groups of Certain Relativistic Spherically Symmetric Systems, J. Nonl. Math. Phys. 8 (2001) 475–490
  38. P.G.L. Leach, S. Cotsakis and J. Miritzis, Symmetries, Singularities and Integrability in Complex Dynamics VI: Painlev´e Inte- grability of FRW-Scalar Cosmologies, Grav. Cosm. 7 (2001) 311–320
  39. S. Cotsakis and P. G. L. Leach, Symmetries, Singularities and Integrability in Nonlinear Mathematical Physics and Cosmology, In Proceedings of the Fourth International Conference on Symmetries in Nonlinear Mathematical Physics, Proc. Inst. Math. N.A.S. Ukraine 43 (2002) 128-135
  40. S. Cotsakis and J. Miritzis, Algebraic Integrability of FRW-Scalar Cosmologies, In Proceedings of the Ninth Marcel Grossman Meeting on General Relativity, V. Gurzadyan, R.T. Jantzen and R. Ruffini (eds.) (World Scientific, 2002) pp. 1943-1945
  41. S. Cotsakis and J. Miritzis, Scalar-Tensor  σ-Cosmologies, In Proceedings of the Ninth Marcel Grossman Meeting on General Relativity, V. Gurzadyan, R.T. Jantzen and R. Ruffini (eds.) (World Scientific, 2002) pp. 1945-1947
  42. S. Cotsakis, Current Trends in Mathematical Cosmology, In Modern Theoretical and Observational Cosmology, S. Cotsakis and M. Plionis (eds.) (Kluwer, ASSL276, 2002), pp. 5–18
  43. S. Cotsakis and J. Miritzis, A Note on Wavemap-Tensor Cosmologies, In Modern Theoretical and Observational Cosmology, S. Cotsakis and M. Plionis (eds.), Kluwer, ASSL276, 2002, pp 67–74
  44. S. Cotsakis and P. G. L. Leach, Is Nature Generic? In Cosmological Crossroads, S. Cotsakis and E. Papantonopoulos (eds.), Springer, LNP592, 2002, pp. 3–15
  45. S. Cotsakis, Cosmological Singularities. In Cosmological Crossroads, S. Cotsakis and E. Papantonopoulos (eds.), (Springer, LNP592, 2002) pp. 59–94
  46. Y. Choquet-Bruhat and S. Cotsakis, Global Hyperbolicity and Completeness. J. Geom. Phys. 43 (2002) 345–350
  47. S. Cotsakis and E. Papantonopoulos, (eds.) Cosmological Crossroads. Springer LNP, 592 (2002)
  48. M. Plionis and S. Cotsakis, (eds.) Theoretical and Observational Cosmology. Kluwer ASSL, 276 (2002)
  49. Y. Choquet-Bruhat and S. Cotsakis, Completeness Theorems in General relativity, In Proceedings of the 10th Greek Relativity Conference, K. D. Kokkotas and N. Stergioulas  (eds.) (World Scientific, 2003)  pp. 145–149
  50. S. Cotsakis, Global Hyperbolicity of Sliced Spaces, Gen. Rel. Grav. 36 (2004) 1183–1188
  51. S. Cotsakis and I. Klaoudatou, Future Singularities of Isotropic Cosmologies, J. Geom. Phys. 55 (2005) 306–315
  52. S. Cotsakis and I. Klaoudatou, Modern Approaches to Cosmological Singularities, In Proceedings of the 11th Greek Relativity Meeting, J. Phys. Conf. Ser. 8 (2005) 150
  53. S. Cotsakis, Slice Energy and Theories of Gravitation, In Proceedings of the 11th Greek Relativity Meeting, J. Phys. Conf. Ser. 8 (2005) 39-48
  54. S. Cotsakis and I. Klaoudatou, Singular Isotropic Cosmologies and Bel-Robinson Energy. In Proceedings of the A. Einstein Century International Conference, J. -M. Alimi and A. Fu¨zfa, (eds.) (2005) pp. 842-7
  55. S. Cotsakis, The Future of Spacetime, (2005) (in Greek)
  56. S. Cotsakis and J. Miritzis, (eds.) Eleventh Conference on Recent Developments in Gravity. J. Phys. Conf. Series. 8 (2005)
  57. S. Cotsakis, Newtonian Melodies. Discovery & Science, 10 (2006) 58-65 (in Greek)
  58. S. Cotsakis, Space and Time, Gravity and Matter: Einstein’s Enigma, 6 pages (2006) (in Greek)
  59. S. Cotsakis and I. Klaoudatou, Cosmological Singularities and Bel-Robinson Energy. J. Geom. Phys. 57 (2007) 1303-1312
  60. S. Cotsakis, Future Singularities and Completeness in Cosmology, In Proceedings  of  the  Thessaloniki  Meeting  on   Cosmology   and   Gravitational Physics, N. Spyrou, N. Stergioulas and C. Tsagas (eds.), pp.  119-129
  61. S. Cotsakis and J. D. Barrow, The Dominant Balance at Cosmological Singularities, In Proceedings of the Greek Relativity Meeting NEB12, June 29-July 2, 2006, Nauplia, Greece, J. Phys. Conf. Ser. 68 (2007) 012004
  62. I. Klaoudatou and S. Cotsakis, Bel-Robinson energy and the nature of singularities in isotropic cosmologies, In Proceedings of the Greek Relativity Meeting NEB12, June 29-July 2, 2006, Nauplia, Greece, J. Phys. Conf. Ser. 68 (2007) 012010
  63. J. Miritzis and S. Cotsakis, Singularities of varying light speed cosmologies, In Proceedings of the Greek Relativity Meeting NEB12, June 29-July 2, 2006, Nauplia, Greece, J. Phys. Conf. Ser. 68 (2007) 012019
  64. S. Cotsakis and A. Tsokaros, Asymptotics of flat, radiation universes in quadratic gravity. Phys. Lett.   B651 (2007) 341-344
  65. S. Cotsakis and A. Tsokaros, Flat, radiation universes with quadratic corrections and asymptotic analysis. In Proceedings of the MG11 Meeting, H. Kleinert, R. J. Jantzen and R. Ruffini, (World Scientific, 2008), pp. 2045-7
  66. I. Antoniadis, S. Cotsakis and I. Klaoudatou, Braneworld  cosmological  singularities, In Proceedings of the MG11 Meeting, H. Kleinert, R. J. Jantzen and R. Ruffini, (World Scientific, 2008), pp. 2054-6
  67. S. Cotsakis, Talking about singularities. In Proceedings of the MG11 Meeting on General Relativity, H. Kleinert, R. J. Jantzen and R. Ruffini, (World Scientific, 2008), pp. 758-68
  68. S. Cotsakis Slice Energy in Higher-Order Gravity Theories and Conformal Transformations, Grav. Cosm. 14 (2008) 176-183
  69. J. D. Barrow, S. Cotsakis and A. Tsokaros, A General Sudden Cosmological Singularity, Class. Quant. Grav. 27 (2010) 165017
  70. I. Antoniadis, S. Cotsakis and I. Klaoudatou, Brane singularities and their avoidance, Class. Quant. Grav. 27 (2010) 235018
  71. J. D. Barrow, S. Cotsakis and A. Tsokaros, The formal construction of sudden cosmological singularities, In Proceedings of the MG12 Meeting on General Relativity, T. Damour, R. J. Jantzen and R. Ruffini, Eds. (World Scientific, 2012), pp. 1793-5
  72. S. Cotsakis and G. Kittou, Singularities in cosmologies with interacting fluids, Phys.  Lett.  B. 712 (2012) 16-21; arXiv:1202.1407
  73. I. Antoniadis, S. Cotsakis, I. Klaoudatou, Brane singularities with mixtures in the bulk, Fortschr.  Phys.  61 (2013) 20-49, arXiv:1206.0090
  74. S. Cotsakis, G. Kolionis, A. Tsokaros, The initial state of generalized radiation universes, Phys.  Lett.  B721 (2013) 1-6; arXiv:1211.5255
  75. S. Cotsakis, Structure of infinity in cosmology, Int. J. Mod. Phys. D22 (2013) 1330003; arXiv:1212.6737
  76. S. Cotsakis, Asymptotic Poincar´e compactification and finite singularities,  Grav. Cosm. 19 (2013) 240; arXiv:1301.4778
  77. J. D. Barrow, S. Cotsakis, A. Tsokaros, Series expansions and sudden singularities, in:  Proceedings of the MG13 Meeting on General Relativity, Stockholm, July 2012
  78. S. Cotsakis, G. Kittou, Limits of isotropic universes with interacting fluids, in: Proceedings of the MG13 Meeting on General Relativity, Stockholm, July 2012
  79. S. Cotsakis, G. Kolionis, A. Tsokaros, Asymptotic states of generalized universes with higher derivatives, in: Proceedings of the MG13 Meeting on General Relativity, Stockholm, July 2012
  80. S. Cotsakis, D. Trachilis, A. Tsokaros, Generic regular universes in higher order gravity theories, In: Proceedings of the MG13 Meeting on General Relativity, Stockholm, July 2012
  81. I. Antoniadis, S. Cotsakis, I. Klaoudatou, Dynamics and asymptotics of braneworlds, In:  Proceedings of the MG13 Meeting on General Relativity, Stockholm, July 2012
  82. J. D. Barrow, S. Cotsakis, Geodesics at Sudden Singularities, Phys.  Rev.  D88 (2013) 067301; arXiv:1307.5005
  83. S. Cotsakis and G. Kittou, Flat limits of curved interacting cosmic fluids, Phys.  Rev.  D88 (2013) 083514; arXiv:1307.0377
  84. I. Antoniadis, S. Cotsakis, I. Klaoudatou, Enveloping branes and braneworld singularities, Eur. Phys. J. C74 (2014) 3192; arXiv:1406.0611.
  85. I. Antoniadis, S. Cotsakis, Ambient cosmology and spacetime singularities. Eur. Phys. J. C75 (2015) 1-12, CERN-PH-TH/2014-176, arXiv:1409.2220
  86. I. Antoniadis, S. Cotsakis, Topology of the ambient boundary and the convergence of causal curves, Mod.  Phys.  Lett.  A30 (2015) 1550161; arXiv:1505.04737
  87. S. Cotsakis, S. Kadry, G. Kolionis, A. Tsokaros, Asymptotic vacua with higher derivatives, Phys.   Lett.   B755 (2016) 387-392; arXiv:1303.2234
  88. I. Antoniadis, S. Cotsakis, The large-scale structure of the ambient boundary, In: Proceedings of the Fourteenth Marcel Grossman Meeting on General Relativity, edited by M. Bianchi, R. T. Jantzen, R. Ruffini (World Scientific, Singapore, 2017); arXiv:1512.09216
  89. I. Antoniadis, S. Cotsakis, K. Papadopoulos, The causal order on the ambient boundary, Mod.  Phys.  Lett.  A31 (2016) 1650122; arXiv:1603.08117
  90. I. Antoniadis, S. Cotsakis, I. Klaoudatou, Curved branes with regular support, Eur. Phys. J. C76 (2016) 511; arXiv:1606.09453
  91. S. Cotsakis, S. Kadry, D. Trachilis, The regular state in higher-order gravity. Int. J. Mod. Phys. A31 (2016) 1650130; arXiv:1212.2412.
  92. I. Antoniadis, S. Cotsakis, Infinity in string cosmology:  A review through open problems. Int. J. Mod. Phys. D26 (2017) 1730009; arXiv:1610.01802
  93. I. Antoniadis, S. Cotsakis, The singularity problem in brane cosmology, Universe 3 (2017) 11; arXiv:1702.01908
  94. S. Cotsakis, J. Miritzis, K. Tzanni, Cosmological wave maps, Int. J. Mod. Phys. A34 (2019) 1950092; arXiv:1905.11049
  95. S. Cotsakis, I. Klaoudatou, G. Kolionis, J. Miritzis, D. Trachilis, Conformal aspects of cosmology: a review (preprint, 2019)