Group Analysis of Differential Equations and Integrable Systems − 2018 Katarzyna Grabowska (University of Warsaw, Poland) Routh reduction as an example of Lagrangian reduction Abstract: The Routh reduction is a classical piece of analytical mechanics. It concerns systems with a special type of symmetry, namely systems having cyclic variables. It appears that Routh reduction is a very instructive example of a Lagrangian reduction, which illustrates the principal differences between Lagrangian and Hamiltonian reductions. The Lagrangian reduction relation, unlike the Hamiltonian one, involves values of generating object (Lagrangians) of systems.