IMA Journal of Applied Mathematics Advance Access originally published online on February 14, 2007
IMA Journal of Applied Mathematics 2007 72(2):191-205; doi:10.1093/imamat/hxm001
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-symmetries and nonlocal symmetries of exponential type
Department of Mathematics, University of Cadiz, 11510 Puerto Real, Spain
** Email: concepcion.muriel{at}uca.es
| Abstract |
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Nonlocal symmetries generated by type I hidden symmetries are identified as specific 
-symmetries of an nth-order ordinary differential equation. The general method of reduction associated to these 
-symmetries allows us to give explicit transformations to reduce the order if n > 1. As a consequence, we give a complete classification of the equations of arbitrary order that admit this kind of nonlocal symmetries. We illustrate these results with several equations that have no Lie point symmetries. For n = 1, the method provides the linearization of first-order equations. This is applied to some examples of Riccati equations and Abel equations of the second kind.
Keywords: ordinary differential equations; hidden symmetries; 
-symmetries.
Received on 6 July 2006. accepted on 27 November 2006.