Effective approach to top-quark decay and FCNC processes at NLO accuracy

The top quark is expected to be a probe to new physics beyond the standard model. Thanks to the large number of top quarks produced at the Tevatron and the LHC, various properties of the top quark can now be measured accurately. An effective field theory allows us to study the new physics effects in a model-independent way, and to this end accurate theoretical predictions are required. In this talk we will discuss some recent results on top-quark decay processes as well as flavor-changing processes, based on the effective field theory approach.