Grand unification, the neutron electric dipole moment and galaxy formation

John Ellis, Mary K. Gaillard, D. V. Nanopoulos, Serge Rudaz

Research output: Contribution to journalArticle

10 Citations (Scopus)

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, d n 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.

Original languageEnglish (US)
Pages (from-to)41-43
Number of pages3
JournalNature
Volume293
Issue number5827
DOIs
StatePublished - Dec 1 1981

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galactic evolution
electric moments
electric dipoles
grand unified theory
dipole moments
neutrons
entropy
baryons
constrictions
asymmetry
cancellation
universe
shear
photons
symmetry

Cite this

Grand unification, the neutron electric dipole moment and galaxy formation. / Ellis, John; Gaillard, Mary K.; Nanopoulos, D. V.; Rudaz, Serge.

In: Nature, Vol. 293, No. 5827, 01.12.1981, p. 41-43.

Research output: Contribution to journalArticle

Ellis, J, Gaillard, MK, Nanopoulos, DV & Rudaz, S 1981, 'Grand unification, the neutron electric dipole moment and galaxy formation', Nature, vol. 293, no. 5827, pp. 41-43. https://doi.org/10.1038/293041a0
Ellis, John ; Gaillard, Mary K. ; Nanopoulos, D. V. ; Rudaz, Serge. / Grand unification, the neutron electric dipole moment and galaxy formation. In: Nature. 1981 ; Vol. 293, No. 5827. pp. 41-43.
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