Introduction to Extra Dimensions and Thick Braneworlds

Abstract

In this review, we give a brief introduction on the aspects of some extra dimension models and the five-dimensional thick brane models in extended theories of gravity. First, we briefly introduce the Kaluza-Klein theory, the domain wall model, the large extra dimension model, and the warped extra dimension models. Then some thick brane solutions in extended theories of gravity are reviewed. Finally, localization of bulk matter fields on thick branes is discussed.

Thick branes with inner structure in mimetic gravity

“…For more recent work on thick brane see Refs. [40][41][42][43][44][45][46][47][48][49][50] or [51] for a review.…”

Localization of five-dimensional Elko spinors with non-minimal coupling on thick branes

“…As the same as the localization mechanism of the Dirac fermion field on brane considered in [42], the action of a five-dimensional massless Elko spinor with non-minimal coupling to background scalars is written as…”

“…More a e-mail: liuyx@lzu.edu.cn details about various kinds of thick branes could be found in Refs. [28,42].…”

“…In Ref. [42], a general coupling between the five-dimensional Dirac fermion and the background scalar fields is introduced, which includes the non-minimal coupling between the Dirac fermion and the scalar fields. Inspired by this, in this paper, we will introduce this new type of coupling, i.e., the non-minimal coupling f (φ)L Elko between the five-dimensional Elko spinor and the background scalar field, where f (φ) is a function of the backgound scalar field and L Elko is the Lagrangian of the five-dimensional Elko spinor.…”

Localization of U(1) gauge vector field on flat branes with five-dimension (asymptotic) AdS5 spacetime

“…Needless appending extra terms in the standard action the gravity can be localized on branes [1][2][3] as well as scalar fields [4]. The localization of fermions can be realized by introducing the usual Yukawa coupling [5] (or by another form of coupling [6]) with background scalar field in thick brane models [7][8][9][10][11][12][13]. The localization of U(1) gauge field is more complex than above two fields, especially, in Randall-Sundrum (RSII) like model [2].…”