# A Lie symmetry analysis and explicit solutions of the two‐dimensional∞‐Polylaplacian

Georgios Papamikos, Tristan Pryer

Research output: Contribution to journalArticle

4 Citations (Scopus)

## Abstract

In this work we use Lie group theoretic methods and the theory of prolonged group actions to study two fully nonlinear partial differential equations (PDEs). First we consider a third order PDE in two spatial dimensions that arises as the analogue of the Euler-Lagrange equations from a second order variational principle in $L^{\infty}$. The equation, known as the $\infty$-Polylaplacian, is a higher order generalisation of the $\infty$-Laplacian, also known as Aronsson's equation. In studying this problem we consider a reduced equation whose relation to the $\infty$-Polylaplacian can be considered analogous to the relationship of the Eikonal to Aronsson's equation. Solutions of the reduced equation are also solutions of the $\infty$-Polylaplacian. For the first time we study the Lie symmetries admitted by these two problems and use them to characterise and construct invariant solutions under the action of one dimensional symmetry subgroups.
Original language English 48-64 17 Studies in Applied Mathematics 142 1 17 Sep 2018 https://doi.org/10.1111/sapm.12232 Published - 26 Dec 2018

• math-ph
• math.AP
• math.MP