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Grand unification, the neutron electric dipole moment and galaxy formation

Abstract

Grand Unified Theories (GUTs) provide a possible solution to the long-standing cosmological problem of the apparent asymmetry between matter and antimatter1–9. We have argued recently10 that in a class of GUTs one may relate the baryon asymmetry to certain contributions to the neutron electric dipole moment, dn. In the absence of cancellations due to an unforeseen symmetry, we thereby obtain a qualitative cosmological lower limit on dn. We emphasize here that the experimental upper limit on dn and the present cosmological baryon-to-photon ratio (nB/nγ) can be used to limit the amount of extra entropy generated after baryosynthesis. This restriction on entropy generation becomes quite severe if, as we argue here on the basis of explicit GUTs, dn is actually considerably larger than our previous cosmological lower bound. As an application of our restriction of entropy generation, we establish an upper limit on shear in the early Universe.

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References

  1. Sakharov, A. Zh. eksp. teor. Fiz. 5, 32 (1967); 76, 1172 (1979).

    CAS  Google Scholar 

  2. Kuzmin, V. A. Zh. eksp. teor. Fiz. 13, 335 (1970).

    Google Scholar 

  3. Ignatiev, A. Yu., Krasnikov, N. V., Kuzmin, V. A. & Tavkhelidze, A. N. Phys. Lett. 76B, 436 (1978).

    Article  Google Scholar 

  4. Yoshimura, M. Phys. Rev. Lett. 41, 381 (1978); E42, 746 (1979); Phys. Lett. 88B, 294 (1979).

    Article  ADS  Google Scholar 

  5. Dimopoulos, S. & Susskind, L. Phys. Rev. D18, 4500 (1978); Phys. Lett. 81B, 416 (1979).

    ADS  CAS  Google Scholar 

  6. Toussaint, D., Treiman, S. B., Wilczek, F. & Zee, A. Phys. Rev. D19, 1036 (1979).

    ADS  CAS  Google Scholar 

  7. Ellis, J., Gaillard, M. K. & Nanopoulos, D. V. Phys. Lett. 80B, 360 (1979); E82B, 464 (1979).

    Article  Google Scholar 

  8. Weinberg, S. Phys. Rev. Lett. 42, 850 (1979).

    Article  ADS  CAS  Google Scholar 

  9. Nanopoulos, D. V. & Weinberg, S. Phys. Rev. D20, 2484 (1979).

    ADS  CAS  Google Scholar 

  10. Ellis, J., Gaillard, M. K., Nanopoulos, D. V. & Rudaz, S. Phys. Lett. 99B, 101 (1980).

    Article  Google Scholar 

  11. Turner, M. S. & Schramm, D. N. Nature 279, 303 (1979).

    Article  ADS  CAS  Google Scholar 

  12. Press, W. Phys. Scripta 21, 702 (1980).

    Article  ADS  CAS  Google Scholar 

  13. Silk, J. The Cosmic Microwave Background Radiation (University of California, Berkeley preprint, 1980).

    MATH  Google Scholar 

  14. Peebles, P. J. E. The Large-scale Structure of the Universe (Princeton University Press, New Jersey, 1980).

    Google Scholar 

  15. Fabbri, R., Guidi, I., Melchiori, F. & Natale, V. Phys. Rev. Lett. 44, 1563 (1980).

    Article  ADS  CAS  Google Scholar 

  16. Boughn, S. P., Cheng, E. S. & Wilkinson, D. T. Astrophys. J. Lett. 243, 113 (1981).

    Article  ADS  Google Scholar 

  17. Silk, J. & Wilson, M. L. Astrophys. J. Lett. 244, 37 (1981).

    Article  ADS  Google Scholar 

  18. Smoot, G. F., Gorenstein, M. V. & Muller, R. A. Phys. Rev. Lett. 34, 898 (1977).

    Article  ADS  Google Scholar 

  19. Barrow, J. D. & Turner, M. S. Nature 291, 469 (1981).

    Article  ADS  Google Scholar 

  20. Bond, J. R., Kolb, E. W. & Silk, J. The Generation of Isothermal Perturbations in the Very Early Universe (University of California, Berkeley preprint, 1981).

    Google Scholar 

  21. Guth, A. H. Phys. Rev. D23, 347 (1981).

    ADS  CAS  Google Scholar 

  22. Bais, F. A. & Rudaz, S. Nucl. Phys. B170, (FS1), 507 (1980).

    Article  ADS  Google Scholar 

  23. Ellis, J., Gaillard, M. K. & Nanopoulos, D. V. Phys. Lett. 90B, 253 (1980).

    Article  Google Scholar 

  24. Schramm, D. N. Preprint EFI-81-03 (Enrico Fermi Institute, 1981).

  25. Barrow, J. D. Mon. Not. R. astr. Soc. 175, 359 (1976).

    Article  ADS  CAS  Google Scholar 

  26. Olson, D. W. & Silk, J. Astrophys. J. 226, 50 (1978).

    Article  ADS  CAS  Google Scholar 

  27. Altarev, I. S. et al. Preprint 636 (Leningrad Nuclear Physics Institute, 1981).

  28. Witten, E. Nucl. Phys. B177, 477 (1981).

    Article  ADS  MathSciNet  Google Scholar 

  29. Guth, A. H. & Weinberg, E. J. Phys. Rev. Lett. 45, 1131 (1980).

    Article  ADS  CAS  Google Scholar 

  30. Ellis, J. & Gaillard, M. K. Nucl. Phys. B150, 141 (1979).

    Article  ADS  Google Scholar 

  31. Ellis, J., Gaillard, M. K. & Nanopoulos, D. V. Unification of the Fundamental Particle Interactions (eds Ferrara, S., Ellis, J. & van Nieuwenhuizen, P.) 461 (Plenum, New York, 1980).

    Book  Google Scholar 

  32. Barr, S., Segrè, G. & Weldon, H. A. Phys. Rev. D20, 2494 (1979).

    ADS  CAS  Google Scholar 

  33. Segrè, G. & Turner, M. S. Phys. Lett. 99B, 399 (1981).

    Article  Google Scholar 

  34. Harvey, J. A., Kolb, E. W., Reiss, D. B. & Wolfram, S. Preprint CALT 68–815 (Caltech, 1981).

  35. Krasnikov, N. V. Yad. Fiz. 28, 549 (1978).

    CAS  Google Scholar 

  36. Hung, P. Q. Phys. Rev. Lett. 42, 873 (1979).

    Article  ADS  Google Scholar 

  37. Politzer, H. D. & Wolfram, S. Phys. Lett. 82B, 242 (1979); E83B, 421 (1979).

    Article  Google Scholar 

  38. Buras, A. J., Ellis, J., Gaillard, M. K. & Nanopoulos, D. V. Nucl. Phys. B135, 66 (1978).

    Article  ADS  Google Scholar 

  39. Nanopoulos, D. V. & Ross, D. A. Nucl. Phys. B157, 273 (1979).

    Article  ADS  Google Scholar 

  40. Ignatiev, V. A., Kuzmin, V. A. & Shaposhnikov, M. E. Zh. eksp. teor. Fiz. 30, 726 (1979).

    Google Scholar 

  41. Yildiz, A. & Cox, P. H. Phys. Rev. D21, 906 (1980).

    Article  ADS  CAS  Google Scholar 

  42. Georgi, H. & Jarlskog, C. Phys. Lett. 86B, 297 (1979).

    Article  Google Scholar 

  43. Georgi, H. & Nanopoulos, D. V. Nucl. Phys. B159, 16 (1979).

    Article  ADS  Google Scholar 

Download references

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Ellis, J., Gaillard, M., Nanopoulos, D. et al. Grand unification, the neutron electric dipole moment and galaxy formation. Nature 293, 41–43 (1981). https://doi.org/10.1038/293041a0

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