• Françoise Combes
  • Patrick Boissé
  • Alain Mazure
  • Alain Blanchard
Part of the Astronomy and Astrophysics Library book series (AAL)


Cosmology rests on two hypotheses: that the universe is homogeneous and that it is isotropic, on large scales. The verification of these hypotheses is therefore essential. Homogeneity is guaranteed if it is confirmed that the universe is isotropic at all points. Observations allow us to draw conclusions about the isotropy only from our Galaxy, and this is not sufficient to prove global homogeneity. The universe may be strongly inhomogeneous but nevertheless have a spherical symmetry. An observer situated at the centre of this distribution would see an isotropic universe and conclude, falsely, that it is homogeneous. But for others, situated elsewhere, it would appear anisotropic. It is therefore useful to introduce the so-called Copernican principle, which states that we are not privileged observers in the universe. The verification of isotropy is therefore sufficient to guarantee the homogeneity of the universe.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Abbott, L. F., and So-Young Pi (editors) (1986) Inflationary Cosmology ( World Scientific, Singapore ).Google Scholar
  2. Audouze, J., and Tran Thanh Van, J. (1984) Fundamental Interactions and Cosmology (Editions Frontières, Paris).Google Scholar
  3. Balian, R., Audouze, J., and Schramm, D. N. (1980) Physical Cosmology (Les Houches Summer School, NATO, North Holland, Amsterdam).Google Scholar
  4. Burstein, J., and Feinberg, G. (editors) (1989) Cosmological Constants ( Columbia University Press, New York ).Google Scholar
  5. Decamp, D., et al. (1990) Phys. Lett. B 231, 527 (the ALEPH collaboration). Dominguez-Tenreiro, R., and Quiros, M. (1988) An Introduction to Cosmology and Particle Physics ( World Scientific, Singapore).Google Scholar
  6. Fabian, A. C., Geller, M., and Szalay, A. (1987) Large-Scale Structures in the Universe (SaasFee Advanced Course 17, Geneva Observatory, Geneva ).Google Scholar
  7. Gunn, J. E., Longair, M. S., and Rees, M. J. (1978) Observational Cosmology (Saas-Fee Advanced Course 8, Geneva Observatory, Geneva ).Google Scholar
  8. Kolb, E. W, and Turner, M. S. (1983) Annu. Rev. Nucl. Particle Sci. 33, 645.Google Scholar
  9. Kolb, E. W., and Turner, M. S. (1990) The Early Universe (Addison-Wesley, Redwood City). Mather, J. C., et al. (1990) Astrophys. J. 354 L37.Google Scholar
  10. Peebles, P. J. E. (1980) The Large Scale Structure of the Universe ( Princeton University Press, Princeton NJ).Google Scholar
  11. Peebles, P. J. E. (1993) Principles of Physical Cosmology ( Princeton University Press, Princeton NJ).Google Scholar
  12. Primack, J. R., Seckel, D., and Sadoulet, B. (1983) Annu. Rev. Nucl. Particle Sci. 33, 645.Google Scholar
  13. Raines, D. J. (1981) The Isotropic Universe ( Adam Hilger, Bristol).Google Scholar
  14. Schatzmann, E. (editor) (1973) Cargèse Lectures in Physics (Gordon and Breach, London). Smoot, G. E. et al. (1992) Astrophys. J. 396, Ll.Google Scholar
  15. Trimble, V. (1987) Annu. Rev. Astron. Astrophys. 25, 425.Google Scholar
  16. Weinberg, S. (1972) Gravitation and Cosmology (Wiley, New York).Google Scholar
  17. Yang, J., Turner, M. S., Steigman, G., Schramm, D. N., and Olive, K. A. (1984) Astrophys. J. 281, 493.ADSCrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1995

Authors and Affiliations

  • Françoise Combes
    • 1
  • Patrick Boissé
    • 2
  • Alain Mazure
    • 3
  • Alain Blanchard
    • 4
  1. 1.Observatoire de ParisDEMIRMParisFrance
  2. 2.Ecole Normale SupérieureParis Cedex 5France
  3. 3.GRAAL, Université de Montpellier IIMontpellier Cedex 5France
  4. 4.Observatoire de StrasbourgStrasbourgFrance

Personalised recommendations