Stability of a tachyon braneworld

Autor(es)

German, Gabriel ; Herrera-Aguilar, Alfredo ; Martorano Kuerten, Andre ; Malagon-Morejon, Dagoberto ; da Rocha, Roldao

• Tipo de documento: Artigo Científico
• Fonte: Journal of Cosmology and Astroparticle Physics; v. N/A, n. 1, p. 24-pg., 2016-01-01.

Resumo

Within the braneworld paradigm the tachyonic scalar field has been used to generate models that attempt to solve some of the open problems that physics faces nowadays, both in cosmology and high energy physics as well. When these field configurations arc produced by the interplay of higher dimensional warped gravity with some matter content, braneworld models must prove to be stable under the whole set of small fluctuations of the gravitational and matter fields background, among other consistency tests. Here we present a complete proof of the stability under scalar perturbations of tachyonic thick braneworlds with an embedded maximally symmetric 4D space-time, revealing its physical consistency. This family of models contains a recently reported tachyonic de Sitter thick braneworld which possesses a series of appealing properties. These features encompass complete regularity, asymptotic flatness (instead of being asymptotically or AdS) even when it contains a negative bulk cosmological constant, a relevant 3-brans with dS metric which naturally arises from the full set of field equations of the 5D background (it is not imposed), qualitatively describing the inflationary epochs of our Universe, and a graviton spectrum with a single zero mode bound state that accounts for the 41) graviton localised on the brave and is separated from the continuum of Kaluza-Klein massive graviton excitations by a mass gap. The presence of this mass gap in the graviton spectrum makes the extra-dimensional corrections to Newton's law decay exponentially. Gauge vector fields with a single massless bound state in its mass spectrum are also localised on this braneworld model a fact that allows us to recover the Coulomb's law of our 11) world. All these properties of the above referred tachyonic braneworld together with the positive stability analysis provided in this work, constitute a firm step towards the construction of realistic cosmological models within the braneworld paradigm. (AU)

• Processo FAPESP: 15/10270-0 - Correspondência fluido / gravidade e aplicações
• Beneficiário: Roldão da Rocha
• Modalidade de apoio: Auxílio à Pesquisa - Regular