Non-unitarity of the leptonic mixing matrix in the TeV-scale type-I seesaw model

The non-unitarity effects in leptonic flavor mixing are regarded as one of the generic features of the type-1 seesaw model. Therefore, we explore these effects in the TeV-scale type-1 seesaw model, and show that there exist non-trivial correlations among the non-unitarity parameters, stemming from the typical flavor structure of the low-scale seesaw model. In general, it follows from analytical discussions and numerical results that all the six non-unitarity parameters are related to three model parameters, while the widely studied parameters eta(e tau) and eta(mu tau) cannot be phenomenologically significant simultaneously.