Aspects of Dimensional Deconstruction and Neutrino Physics

Abstract: The existence of at or curved extra spatial dimensions provides new insights into several of the problems which face the Standard Model of particle physics, including the gauge hierarchy problem, the smallness of neutrino masses, and the dark matter problem. However, higher-dimensional gauge theories are not renormalizable and can only be considered as low-energy effective theories, with limited applicability. Dimensional deconstruction provides a class of manifestly gauge invariant possible ultraviolet completions of higher-dimensional gauge theories, formulated within conventional quantum eld theory. In dimensional deconstruction, the fundamental theory is a four-dimensional quantum eld theory and extra spatial dimensions are generated dynamically at low energies. In this thesis, we study di erent applications of dimensional deconstruction in the contexts of neutrino masses, mixing and oscillations, Kaluza{Klein dark matter, and e ective eld theories for discretized higher-dimensional gravity. A different possibility to understand the smallness of neutrino masses is provided by the see-saw mechanism. This is a genuinely four-dimensional mechanism, where the light neutrino masses are induced by the addition of heavy right-handed Majorana neutrinos or by other heavy degrees of freedom, such as scalar SU(2)L triplet elds. It has the attractive feature of simultaneously providing a mechanism for generating the observed baryon asymmetry of the Universe. We study in this context a specific left-right symmetric see-saw model.