Brane Cosmic String Compactification in Brans-Dicke Theory

The search of an alternative compactification of extra dimensions is a very interesting tool to analyze the hierarchy problem in string theory. Among other physical implications they provide a beautiful scenario of our universe insering it on a brane [1, 2]. In the RandallSundrum (RS) model there are two 3-branes in a quite glance orbifold with Z2 symmetry in five dimensions [3]. A warp factor in the metric shows how this type of model can help us with the hierarchy problem, and beyond it, the model is a 5 −D realization of Horava-Witten solution [4]. Many physical effects related to the extra dimensions can be calculated using the standard brane-world gravity [5]. However, from the point of view of topological defects, these models use global domain walls to generate the branes [6]. But cosmologists call our attention to cosmological problems related to global defect like domain walls [7]. In this vein an interesting alternative (global strings) was given in [9] that provides in six dimensions all the necessary structure; three-brane plus transverse space.