Treatment of theory uncertainties for Higgs measurements and searches at ATLAS

As the integrated luminosity recorded by the LHC experiments increases, systematic uncertainties play an ever more important role in Higgs boson measurements and searches. Several measurements are already limited by systematic uncertainties. Among these, theory uncertainties on the signal and background modeling play an important role. This talk discusses a few examples of analyses where theory uncertainties play an important role, and shows how these uncertainties are assessed and implemented in the analyses.