Advances in Astronomy
Volume 2009 (2009), Article ID 632064, 7 pages
doi:10.1155/2009/632064
Research Article

Quantum Theory, Noncommutative Gravity, and the Cosmological Constant Problem

T. P. Singh

Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India

Received 22 January 2009; Accepted 11 November 2009

Academic Editor: Zdzislaw E. Musielak

Copyright © 2009 T. P. Singh. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Linked References

  1. T. P. Singh, “Quantum mechanics on a noncommutative geometry,” Bulgarian Journal of Physics, vol. 33, no. 3, pp. 217–229, 2006.
  2. T. P. Singh, “Quantum measurement and quantum gravity: many-worlds or collapse of the wavefunction?” Journal of Physics: Conference Series, vol. 174, Article ID 012024, 19 pages, 2009. View at Publisher · View at Google Scholar
  3. T. P. Singh, “Noncommutative gravity, a ‘no strings attached’ quantum-classical duality, and the cosmological constant puzzle,” General Relativity and Gravitation, vol. 40, no. 10, pp. 2037–2042, 2008. View at Publisher · View at Google Scholar · View at Scopus
  4. K. Lochan and T. P. Singh, in preparation.
  5. R. D. Sorkin, “Is the cosmological “constant” a nonlocal quantum residue of discreteness of the causal set type?” in Proceedings of the 13th International Symposium on Particles, Strings, and Cosmology (PASCOS '07), pp. 142–153, London, UK, November 2007. View at Publisher · View at Google Scholar
  6. M. Ahmed, S. Dodelson, P. B. Greene, and R. Sorkin, “Everpresent Λ,” Physical Review D, vol. 69, no. 10, Article ID 103523, 8 pages, 2004. View at Publisher · View at Google Scholar · View at Scopus
  7. J. D. Barrow, “Strong constraint on ever-present Λ,” Physical Review D, vol. 75, no. 6, Article ID 067301, 3 pages, 2007. View at Publisher · View at Google Scholar · View at Scopus
  8. T. Padmanabhan, “Why do we observe a small but nonzero cosmological constant?” Classical and Quantum Gravity, vol. 19, no. 17, pp. L167–L173, 2002. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  9. T. Padmanabhan, “Vacuum fluctuations of energy density can lead to the observed cosmological constant,” Classical and Quantum Gravity, vol. 22, no. 17, pp. L107–L112, 2005. View at Publisher · View at Google Scholar · View at MathSciNet · View at Scopus
  10. S. Doplicher, K. Fredenhagen, and J. E. Roberts, “The quantum structure of spacetime at the Planck scale and quantum fields,” Communications in Mathematical Physics, vol. 172, no. 1, pp. 187–220, 1995. View at Publisher · View at Google Scholar · View at Scopus