Non-linear Representations of the Conformal Group and Mapping of Galileons

Дата и время публикации : 2013-06-12T20:00:03Z

Авторы публикации и институты :
Paolo Creminelli
Marco Serone
Enrico Trincherini

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 16 pages. v2: typos corrected (notably eq 4.5), matches JHEP version
Первичная категория: hep-th

Все категории : hep-th, astro-ph.CO, gr-qc

Краткий обзор статьи: There are two common non-linear realizations of the 4D conformal group: in the first, the dilaton is the conformal factor of the effective metric eta_{munu} e^{-2 pi}; in the second it describes the fluctuations of a brane in AdS_5. The two are related by a complicated field redefinition, found by Bellucci, Ivanov and Krivonos (2002) to all orders in derivatives. We show that this field redefinition can be understood geometrically as a change of coordinates in AdS_5. In one gauge the brane is rigid at a fixed radial coordinate with a conformal factor on the AdS_5 boundary, while in the other one the brane bends in an unperturbed AdS_5. This geometrical picture illuminates some aspects of the mapping between the two representations. We show that the conformal Galileons in the two representations are mapped into each other in a quite non-trivial way: the DBI action, for example, is mapped into a complete linear combination of all the five Galileons in the other representation. We also verify the equivalence of the dilaton S-matrix in the two representations and point out that the aperture of the dilaton light-cone around non-trivial backgrounds is not the same in the two representations.

Category: Physics