Finding The Lie Symmetries of Some First-Order Odes Via Induced Characteristic (original) (raw)

How to obtain Lie point symmetries of PDEs

Journal of Mathematics and Computer Science

In this research, we have studied how to obtain Lie point symmetries of a partial differential equation (PDEs) of second order. We have also studied some PDEs' applications as one-dimensional and two-dimensional heat equations. We have used Manale's formula for solving second-order ordinary differential equations to determine new symmetries. Burgers equation has been studied, and Lie point symmetries have been obtained for these equations.

Ju l 2 00 0 First order ODEs , Symmetries and Linear Transformations

2000

An algorithm for solving first order ODEs, by systematically determining symmetries of the form [ξ = F (x), η = P (x) y +Q(x)]-where ξ ∂/∂x+η ∂/∂y is the symmetry generator-is presented. To these linear symmetries one can associate an ODE class which embraces all first order ODEs mappable into separable through linear transformations {t = f (x), u = p(x) y + q(x)}. This single ODE class includes as members, for instance, 78% of the 552 solvable first order examples of Kamke's book. Concerning the solving of this class, a restriction on the algorithm being presented exists only in the case of Riccati type ODEs, for which linear symmetries always exist but the algorithm will succeed in finding them only partially.

Symmetries of linear ordinary differential equations

Journal of Physics A: Mathematical and General, 1997

We discuss the Lie symmetry approach to homogeneous, linear, ordinary di erential equations in an attempt to connect it with the algebraic theory of such equations. In particular we pay attention to the elds of functions over which the symmetry vector elds are de ned and, by de ning a noncharacteristic Lie subalgebra of the symmetry algebra, are able to establish a general description of all continuous symmetries. We use this description to rederive a classical result on di erential extensions for second order equations.

New symmetries from old: exploiting lie algebra structure to determine infinitesimal symmetries of differential equations

1993

We give a method for using explicitly known Lie symmetries of a system of differential equations to help find more symmetries of the system. A Lie (or infinitesimal) symmetry of a system of differential equations is a transformation of its dependent and independent variables, depending on continuous parameters, which maps any solution of the system to another solution of the same systkun. Infinitesimal Lie symmetries of a system of differential equations arise as solutions of a related system of linear homogeneous partial differential equations called infinitesimal determining equations. The importance of symmetries in applications has prompted the development of many software packages to derive and attempt to integrate infinitesimal determining equations. For a. given system of differential equations we usually have a priori explicit knowledge of many symmetries of the system because of their simple form or the physical origin of the system. Current methods for finding symmetries d...

Lie symmetries of first order neutral differential equations

Journal of Applied Mathematics and Computational Mechanics

In this paper we extend the method of obtaining symmetries of ordinary differential equations to first order non-homogeneous neutral differential equations with variable coefficients. The existing method for delay differential equations uses a Lie-Bäcklund operator and an Invariant Manifold Theorem to define the operators which are used to obtain the infinitesimal generators of the Lie group. In this paper, we adopt a different approach and use Taylor's theorem to obtain a Lie type invariance condition and the determining equations for a neutral differential equation. We then split this equation in a manner similar to that of ordinary differential equations to obtain an over-determined system of partial differential equations. These equations are then solved to obtain corresponding infinitesimals, and hence desired equivalent symmetries. We then obtain the symmetry algebra admitted by this neutral differential equation.

First-order Ordinary Differential Equations, Symmetries and Linear Transformations1

We present an algorithm for solving first-order ordinary differential equations, by systematically determining symmetries of the form [ξ = F (x), η = P (x) y + Q(x)], where ξ ∂/∂x + η ∂/∂y is the symmetry generator. To these linear symmetries one can associate an ordinary differential equation class which embraces all first-order equations mappable into separable ones through linear transformations {t = f (x), u = p(x) y + q(x)}. This single class includes as members, for instance, 429 of the 552 solvable first-order examples of Kamke's book. Concerning the solution of this class, a restriction on the algorithm being presented exists, only in the case of Riccati equations, for which linear symmetries always exist, but the algorithm will only partially succeed in finding them.

First-order ordinary differential equations, symmetries and linear transformations

2003

We present an algorithm for solving first-order ordinary differential equations, by systematically determining symmetries of the form [ξ = F (x), η = P (x) y + Q(x)], where ξ ∂/∂x + η ∂/∂y is the symmetry generator. To these linear symmetries one can associate an ordinary differential equation class which embraces all first-order equations mappable into separable ones through linear transformations {t = f (x), u = p(x) y + q(x)}. This single class includes as members, for instance, 429 of the 552 solvable first-order examples of Kamke's book. Concerning the solution of this class, a restriction on the algorithm being presented exists, only in the case of Riccati equations, for which linear symmetries always exist, but the algorithm will only partially succeed in finding them.

Differential Forms for Finding Symmetries of Differential Equations

An application of geometry in differential equations is considered. This article reviews the use of differential forms and Lie derivatives to find symmetries of differential equations. An outline of the method is given, followed by examples and references to recent papers using the method.

Solutions of systems of ordinary differential equations using invariants of symmetry groups

AIP Conference Proceedings, 2019

We investigate the use of invariants of the admitted Lie groups of transformation in finding solutions of the systems of ordinary differential equations (ODEs). Bluman's theorem (1990) of invariant solutions of ODEs is extended for systems of ODEs. Differential invariants of a Lie group are used in reducing order of the given system. Examples are given to illustrate the methods.

Reductions of PDEs to first order ODEs, symmetries and symbolic computation

Communications in Nonlinear Science and Numerical Simulation, 2015

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights • Two methods to reduce ODEs to generalized Abel or elliptic equations are provided. • New exact solutions for well-known PDEs are obtained. • Computer algebra codes for obtaining the reduced equations are included.