158 articles – 1995 Notices  [english version]
 HAL : hal-00716540, version 1
 arXiv : 0809.2013
 Code Bibliographique ADS : 2009JHEP...03..091B
 Journal of High Energy Physics 03 (2009) 091
 Dirac Born Infeld (DBI) cosmic strings
 E. Babichev1, P. Brax, C. Caprini2, J. Martin3, D.A. Steer4
 (03/2009)
 Motivated by brane physics, we consider the non-linear Dirac-Born-Infeld (DBI) extension of the Abelian-Higgs model and study the corresponding cosmic string configurations. The model is defined by a potential term, assumed to be of the mexican hat form, and a DBI action for the kinetic terms. We show that it is a continuous deformation of the Abelian-Higgs model, with a single deformation DBI parameter depending on a dimensionless combination of the scalar coupling constant, the vacuum expectation value of the scalar field at infinity, and the brane tension. By means of numerical calculations, we investigate the profiles of the corresponding DBI-cosmic strings and prove that they have a core which is narrower than that of Abelian-Higgs strings. We also show that the corresponding action is smaller than in the standard case suggesting that their formation could be favoured in brane models. Moreover we show that the DBI-cosmic string solutions are non-pathological everywhere in parameter space. Finally, in the limit in which the DBI model reduces to the Bogomolnyi-Prasad-Sommerfield (BPS) Abelian-Higgs model, we find that DBI cosmic strings are no longer BPS: rather they have positive binding energy. We thus argue that, when they meet, two DBI strings will not bind with the corresponding formation of a junction, and hence that a network of DBI strings is likely to behave as a network of standard cosmic strings. On the other hand, we also find that, if the BPS condition is no longer satisfied and the coupling constant is less than twice the charge squared of the scalar field, DBI strings can change their behaviour from type I to type II depending on the DBI parameter.
 équipe(s) de recherche : APC - THEORIE
 Domaine : Physique/Physique des Hautes Energies - Théorie
 Lien vers le texte intégral : http://fr.arXiv.org/abs/0809.2013
 hal-00716540, version 1 http://hal.archives-ouvertes.fr/hal-00716540 oai:hal.archives-ouvertes.fr:hal-00716540 Contributeur : Danièle Steer <> Soumis le : Mardi 10 Juillet 2012, 17:09:41 Dernière modification le : Mercredi 1 Août 2012, 13:27:37