Lambda and mu-symmetries

TL;DR

This paper extends the concept of lambda-symmetries from ordinary differential equations to partial differential equations and systems, providing a geometric framework and generalization of these symmetries.

Contribution

It offers a geometric characterization of lambda-prolongations and generalizes lambda-symmetries to PDEs and systems, broadening their applicability.

Findings

Geometric characterization of lambda-prolongations

Generalization of lambda-symmetries to PDEs

Extension to systems of equations

Abstract

Lambda-symmetries of ODEs were introduced by Muriel and Romero, and discussed by C. Muriel in her talk at SPT2001. Here we provide a geometrical characterization of lambda-prolongations, and a generalization of these -- and of lambda-symmetries -- to PDEs and systems thereof.