alle ore 14,30 presso la Sala Riunioni del Dipartimento di Matematica e Informatica, il Prof. Juha Pohjanpelto (Oregon State University, Corvallis, USA) terrà un seminario dal titolo:

                                                  Variational Principles for Differential Equations with; Symmetries and Conservation Laws

Abstract: The classical Noether's theorem establishes essentially a   one-to-one correspondence between the symmetries of the fundamental   integral of a variational problem and conservation laws of the   associated Euler-Lagrange equations. In this talk I will consider the   following partial converse to Noether's theorem first rigorously   formulated by Floris Takens in 1977: Suppose that a system of   differential equations is invariant under a given group of   transformations and possesses conservation laws corresponding to these   symmetries. Does it then necessarily follow that the system arises as   the Euler-Lagrange equations of some variational problem? Besides its intrinsic mathematical interest, Takens' problem has   far-reaching implications for physical field theories. In this talk I   will discuss my joint work with Ian Anderson on Takens' problem for   second order scalar equations, for systems of polynomial equations,   and for the physically interesting cases of Yang-Mills and metric   field theories. Tutti gli interessati sono invitati a partecipare Prof. Lorenzo Nicolodi