A de Sitter tachyonic braneworld revisited

Abstract

Abstract. Within the framework of braneworlds, several interesting physical effects can be described in a wide range of energy scales, starting from high-energy physics to cosmology and low-energy physics. An usual way to generate a thick braneworld model relies in coupling a bulk scalar field to higher dimensional warped gravity. Quite recently, a novel braneworld was generated with the aid of a tachyonic bulk scalar field, having several remarkable properties. It comprises a regular and stable solution that contains a relevant 3-brane with de Sitter induced metric, arising as an exact solution to the 5D field equations, describing the inflationary eras of our Universe. Besides, it is asymptotically flat, despite of the presence of a negative 5D cosmological constant, which is an interesting feature that contrasts with most of the known, asymptotically either dS or AdS models. Moreover, it encompasses a graviton spectrum with a single massless bound state, accounting for 4D gravity localized on the brane, separated from the continuum of Kaluza-Klein massive graviton modes by a mass gap that makes the 5D corrections to Newton's law to decay exponentially. Finally, gauge, scalar and fermion fields are also shown to be localized on this braneworld. In this work, we show that this tachyonic braneworld allows for a nontrivial solution with a vanishing 5D cosmological constant that preserves all the above mentioned remarkable properties with a less amount of parameters, constituting an important contribution to the construction of a realistic cosmological braneworld model. arXiv:1709.09016v1 [hep-th]

Configurational entropy and instability of tachyonic braneworld

“…Employing the replacement of the supersymmetric operators by the specific solution of the field equations, we found that tachyon braneworld in the bulk negative/zero cosmological constant is stable under scalar fluctuations, which is consistent with that in [14][15][16]. We applied similar analysis to the instability of tachyonic braneworld model in the bulk positive cosmological constant.…”

“…+k, (2.27) where the hypergeometric function 2 F 1 (a, b; c; z) is defined for |z| > 1 by the power series and a − b must not be an integer. Here, for 0 < n < 1 the tachyon field becomes real value by introducing a complex constant l. The warped factor f (x) is [15] f (x) = −n ln…”

“…A branch of models with bulk scalar fields has been recently suggested in search for tachyonic braneworld scenario with a bulk cosmological constant. It has been found that there is an exact solution for tachyonic braneworld model with/without a bulk cosmological constant [14,15] and such model is stable under scalar perturbations [15,16].…”

Localization of Elko spinor fields in tachyonic de Sitter braneworld models

“…Furthermore, the authors of Ref. [16] indicated that this tachyonic braneworld allows for a nontrivial solution with a vanishing 5D cosmological constant.…”

Dynamical tachyonic AdS/QCD and information entropy

“…[3,4,9]. Tachyonic 5D domain wall models can be implemented on smooth 5D branes [34][35][36] within the framework of cosmological inflationary scenarios [37,38]. Now we want to explore the tachyonic corrections to dynamical AdS/QCD holographic models [39], from the point of view of their underlying informational content.…”