of Non-zero $\theta_{13}$ and Super-WIMP Dark Matter'
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Introduction
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Non-zero but tiny neutrino mass and large leptonic mixing have become a well established fact by now, thanks to several experimental efforts in the last two decades [@Fukuda:2001nk; @Ahmad:2002jz; @Ahmad:2002ka; @Abe:2008aa; @Abe:2011sj; @Abe:2011fz; @An:2012eh; @Ahn:2012nd; @Adamson:2013ue]. For a review of neutrino mass and mixing, please see [@Tanabashi:2018oca]. Among these experiments, the relatively new ones namely, the T2K [@Abe:2011sj], the Double Chooz [@Abe:2011fz], the Daya Bay [@An:2012eh], the RENO [@Ahn:2012nd] and the MINOS [@Adamson:2013ue] have not only reconfirmed the fact that neutrinos oscillate by making the measurements of mass squared differences and mixing angles more precise, but also discovered a non-zero value of of reactor mixing angle $\theta_{13}$ which was thought to be almost vanishing earlier. For a recent global fit of neutrino oscillation data, we refer to [@deSalas:2017kay; @Esteban:2018azc]. Apart from neutrino oscillation experiments, cosmology experiment like Planck also constrains the neutrino sector by putting an upper bound on the sum of absolute neutrino masses $\sum_i \lvert m_i \rvert < 0.11$ eV [@Aghanim:2018eyx]. As indicated by these global fits, in spite of these experimental developments, there still remains several unknowns in the neutrino sector like the nature of neutrinos: Dirac 