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Classification of classical and non-local symmetries of fourth-order nonlinear evolution equations
In this paper, we consider group classification of local and quasi-local
symmetries for a general fourth-order evolution equations in one spatial
variable. Following the approach developed by Zhdanov and Lahno, we construct
all inequivalent evolution equations belonging to the class under study which
admit either semi-simple Lie groups or solvable Lie groups. The obtained lists
of invariant equations (up to a local change of variables) contain both the
well-known equations and a variety of new ones possessing rich symmetry. Based
on the results on the group classification for local symmetries, the group
classification for quasi-local symmetries of the equations is also given.Comment: LaTeX, 60 page
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