# Program for Birkhoff-Gustavson normal form for N degrees of freedom - BIRKHOFF 1.2

## Description

Abstract A REDUCE program to calculate the Birkhoff-Gustavson normal form of a Hamiltonian system with N degrees of freedom is presented. The potential of the system should be a polynomial in coordinates and momenta. The program enables the calculation of the approximate integrals of motion up to a given order in powers of coordinates and momenta. Title of program: BIRKHOFF version 1.2 Catalogue Id: ACLL_v1_0 Nature of problem In classical as well as in quantum mechanics one wishes to obtain the properties of the solutions of equations of motion without actually solving the equations of motion explicitly. The Birkhoff-Gustavson normal form approach is a means of finding the approximate constants of motion of a hamiltonian system with polynomial potential, if they exist. Versions of this program held in the CPC repository in Mendeley Data ACLL_v1_0; BIRKHOFF version 1.2; 10.1016/0010-4655(93)90025-8 This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)