arXiv subjects

A. R. Gomes

Publications and source records attributed to A. R. Gomes.

23 records · Page 2Linked to original sources

arXiv2006

Gravity on the Bloch Brane

Bloch branes were introduced previously and are constructed in a system described by two real scalar fields coupled with gravity in (4, 1) dimensions in warped spacetime involving one extra dimension. This work investigates gravity on such thick branes with internal structure and focuses on the effects of massive graviton modes localization on the brane and to what extent they might reproduce the 4d gravity at a scale before escaping into the extra dimension. In this way gravitational measurements on the brane could reveal the existence of the extra dimension on some scales, with possible applications on brane cosmology.

hep-th↗

arXiv2005

Gravitacional field of a global defect

Global topological defects described by real scalar field in (3,1) dimensions coupled to gravity are analyzed. We consider a class of scalar potentials with explicit dependence with distance, evading Derrick's theorem and leading to defects with spherical symmetry. The analysis shows that the defects have finite energy on flat space, contrary to the observed for the global monopole. With the aim to study the gravitational field produced by such defects, after an {\it Ansatz} for the static metric with spherical symmetry, we obtain the coupled system of Einstein and field equations. On the Newtonian approximation, we numerically find that the defects have a repulsive gravitational field. This field is like one generated by a negative mass distributed on a spherical shell. In the weak gravity regime a relation between the Newtonian potential and one of the metric coefficients is obtained. The numerical analysis in this regime leads to a spacetime with a deficit solid angle on the core of the defect.

gr-qc↗

arXiv2004

Locally Localized Gravity and Geometric Transitions

In this paper we analyze the local localization of gravity in $AdS_4$ thick brane embedded in $AdS_5$ space. The 3-brane is modelled by domain wall solution of a theory with a bulk scalar field coupled to five-dimensional gravity. In addition to small four-dimensional cosmological constant, the vacuum expectation value (vev) of the scalar field controls the emergence of a localized four-dimensional quasi-zero mode. We introduce high temperature effects, and we show that gravity localization on a thick 3-brane is favored below a critical temperature $T_c$. These investigations suggest the appearance of another critical temperature $T_*,$ where the thick 3-brane engenders the geometric $AdS/M/dS$ transitions.

hep-th↗

arXiv2004

Bloch Brane

We investigate a system described by two real scalar fields coupled with gravity in (4, 1) dimensions in warped spacetime involving one extra dimension. The results show that the parameter which controls the way the two scalar fields interact induces the appearence of thick brane which engenders internal structure, driving the energy density to localize inside the brane in a very specific way.

hep-th↗

arXiv2003

Brane Structure from a Scalar Field in Warped Spacetime

We deal with scalar field coupled to gravity in five dimensions in warped geometry. We investigate models described by potentials that drive the system to support thick brane solutions that engender internal structure. We find analytical expressions for the brane solutions, and we show that they are all linearly stable.

hep-th↗