• [1]

    S. Weinberg, Gravitation and Cosmology: Principles and Applications of the General Theory of relativity (J. Wiley & Sons, New York 1972)

  • [2]

    N. D. Birrel and P. C. W. Davies, Quantum Fields in Curved Space (Cambridge University Press, Cambridge 1982)

  • [3]

    B. Carter and R. G. McLenaghan, Phys. Rev. D 19, 1093 (1979)

  • [4]

    I. I. Cotăescu, J. Phys. A: Math. Gen. 33, 9177 (2000)

  • [5]

    I. I. Cotăescu, Europhys. Lett. 86, 20003 (2009)

  • [6]

    I. I. Cotăescu, Eur. Phys. J. C 77, 485 (2017)

  • [7]

    I. I. Cotăescu, Eur. Phys. J. C 78, 95 (2018)

  • [8]

    I. I. Cotăescu, Mod. Phys. Lett. A 32, 1750223 (2017)

  • [9]

    P. Painleve, C. R. Acad. Sci. (Paris) 173, 677 (1921)

  • [10]

    A. Gullstrand, Arkiv. Mat. Astron. Fys. 16, 1 (1922)

  • [11]

    E. R. Harrison, Cosmology: The Science of the Universe (New York: Cambridge Univ. Press, 1981)

  • [12]

    E. Harrison, Astrophys. J. 403, 28 (1993)

  • [13]

    G. E. Lemaître, Ann. Soc. Sci. de Bruxelles 47A, 49 (1927)

  • [14]

    G. E. Lemaître, MNRAS 91, 483 (1931)

  • [15]

    E. Hubble, Proc. Nat. Acad. Sci. 15, 168 (1929)

  • [16]

    G. Lemaître, J. Math. Phys. (MIT) 4, 188 (1925)

  • [17]

    I. I. Cotăescu, GRG 43, 1639 (2011)

  • [18]

    I. I. Cotăescu, Mod. Phys. Lett. 38, 2150162 (2021)

  • [19]

    I. I. Cotăescu, Eur. Phys. J. C 81, 32 (2021)

  • [20]

    I. I. Cotăescu, Int. J. Mod. Phys. A 34, 1950024 (2019)

  • [21]

    I. I. Cotăescu and D. Popescu, Chinese Phys. C 44, 055104 (2020)