Is the CMB cold spot a gate to extra dimensions?

Abstract

One of the most striking features found in the cosmic microwave background data is the presence of an anomalous cold spot (CS) in the temperature maps made by the Wilkinson Microwave Anisotropy Probe (WMAP). This CS has been interpreted as the result of the presence of a collapsing texture, perhaps coming from some early universe grand unified theory (GUT) phase transition. In this work we propose an alternative explanation based on a completely different kind of texture which appears in a natural way in a broad class of brane-world models. This type of texture, known as a brane-skyrmion, can be understood as a hole in the brane which makes it possible to pass through them along the extra-dimensional space. The typical scales needed for the proposed brane-skyrmions to correctly describe the observed CS can be as low as the electroweak scale.