Theory of Higgs to tau tau signatures at the LHC

In this report, selected topics of tau leptons are collected in view of the high-energy collider experiments and the Higgs-boson search. Those topics include decay modes, tau-jet tagging, collinear approximation and the tau polarization. Using these unique properties of tau leptons, it is possible to observe various properties of the Higgs boson or the associated scalars in the extended Higgs models at the LHC.