Publication:
On the electromagnetic nature of dark energy and the origin of cosmic magnetic fields

No Thumbnail Available
Full text at PDC
Publication Date
2011
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
Progress Theoretical Physics Publication Office
Citations
Google Scholar
Research Projects
Organizational Units
Journal Issue
Abstract
In this work we consider quantum electromagnetic fields in an expanding universe. We start by reviewing the difficulties found when trying to impose the Lorenz condition in a time dependent geometry. Motivated by this fact, we explore the possibility of extending the electromagnetic theory by allowing the scalar state which is usually eliminated by means of the Lorenz condition to propagate, preserving at the same time the dynamics of ordinary transverse photons. We show that the new state cannot be generated by charged currents, but it breaks conformal invariance and can be excited gravitationally. In fact, primordial quantum fluctuations produced during inflation can give rise to super-Hubble temporal electromagnetic modes whose energy density behaves as a cosmological constant. The value of the effective cosmological constant is shown to agree with observations provided inflation took place at the electroweak scale. The theory is compatible with all the local gravity tests and is free from classical or quantum instabilities. Thus we see that, not only the true nature of dark energy can be established without resorting to new physics, but also the value of the cosmological constant finds a natural explanation in the context of standard inflationary cosmology. On sub-Hubble scales, the new state generates an effective charge density which, due to the high electric conductivity of the cosmic plasma after inflation, gives rise to both vorticity and magnetic fields. Present upper limits on vorticity coming from CMB anisotropies are translated into lower limits on the present value of cosmic magnetic fields. We find that magnetic fields B(lambda) > 1 (-12) G can be typically generated with coherence lengths ranging from sub-galactic scales up to the present Hubble radius. Those fields could act as seeds for a galactic dynamo or even account for observations just by collapse and differential rotation of the protogalactic cloud.
Description
Copyright © 2011 Progress of Theoretical Physics. El Texto completo del artículo accediendo a la URL oficial o a la de arXiv.org This work has been supported by MICINN (Spain) project numbers FIS 2008-01323 and FPA 2008-00592, CAM/UCM 910309, MEC grant BES-2006-12059 and MICINN Consolider-Ingenio MULTIDARK CSD2009-00064
Unesco subjects
Keywords
Citation
1) Goldhaber A. S., Nieto M. M. Rev. Mod. Phys. 2010;82. 939[APS]. 2) Widrow L. M. Rev. Mod. Phys. 2002;74. 775[APS]. R. M. Kulsrud and E. G. Zweibel, Rep. Prog. Phys. 71 (2008),046901[IoP STACKS]. P. P. Kronberg, Rep. Prog. Phys. 57 (1994),325[CrossRef]. 3) Neronov A., Vovk VovkI. Science 2010;328. S. Ando and A. Kusenko, Astrophys. J. 722 (2010),L39[IoP STACKS]. A. Neronov, D. V. Semikoz, P. G. Tinyakov et al.,arXiv:1006.0164[e print arXiv]. 4) Jiménez J. B., Maroto A. L. Phys. Lett. 2010;686. 175[CrossRef]. 5) Higuchi A., Parker L., Wang Y. Phys. Rev. 1990;42. 4078[APS]. 6) Zhitnitsky A. R. Phys. Rev. 2010;82. 103520[APS]. N. Ohta,arXiv:1010.1339[e-print arXiv]. 7) Jiménez J. B., Maroto A. L. arXiv:1010.4513[e-print arXiv]. 8) Jiménez J. B., Maroto A. L. J. Cosmol. Astropart. Phys. 2009;03. 016[IoP STACKS]. 9) Itzykson C., Zuber J. B. Quantum Field Theory. McGraw-Hill; 1959. N. N. Bogoliubov and D. V. Shirkov, Introduction to the theory of quantized fields (Interscience Publishers, Inc., 1959). Search Google Scholar 10) Deser S. Ann. Inst. Henri Poincaré 1972;16:79. Search Google Scholar 11) Urakawa Y., Tanaka T. Prog. Theor. Phys. 2009;122. 779[PTP]. 12) Jiménez J. B., Koivisto J. B.T. S., Maroto A. L., Mota D. F. J. Cosmol. Astropart. Phys. 2009;10. 029[IoP STACKS]. 13) Will C. Theory and experiment in gravitational physics. Cambridge University Press; 1993. Search Google Scholar 14) Jiménez J. B., Maroto A. L. J. Cosmol. Astropart. Phys. 2009;02. 025[IoP STACKS]. 15) Caprini C., Ferreira P. G. J. Cosmol. Astropart. Phys. 2005;02. 006[IoP STACKS].
Collections