3,171 research outputs found
An algorithm for computing a standard form for second-order linear q-difference equations
In this article an algorithm is presented for computing a standard form for second order linear q-difference equations. This standard form is useful for determining the q-difference Galois group and the set of Liouvillian solutions of a given equation. (C) 1997 Elsevier Science B.V.</p
Differential transcendence criteria for second-order linear difference equations and elliptic hypergeometric functions
We develop general criteria that ensure that any non-zero solution of a given
second-order difference equation is differentially transcendental, which apply
uniformly in particular cases of interest, such as shift difference equations,
q-dilation difference equations, Mahler difference equations, and elliptic
difference equations. These criteria are obtained as an application of
differential Galois theory for difference equations. We apply our criteria to
prove a new result to the effect that most elliptic hypergeometric functions
are differentially transcendental
Differential Galois Approach to the Non-integrability of the Heavy Top Problem
We study integrability of the Euler-Poisson equations describing the motion
of a rigid body with one fixed point in a constant gravity field. Using the
Morales-Ramis theory and tools of differential algebra we prove that a
symmetric heavy top is integrable only in the classical cases of Euler,
Lagrange, and Kovalevskaya and is partially integrable only in the
Goryachev-Chaplygin case. Our proof is alternative to that given by Ziglin
({\em Funktsional. Anal. i Prilozhen.}, 17(1):8--23, 1983; {\em Funktsional.
Anal. i Prilozhen.}, 31(1):3--11, 95, 1997).Comment: 31 pages, 1 figur
Nonintegrability of the two-body problem in constant curvature spaces
We consider the reduced two-body problem with the Newton and the oscillator
potentials on the sphere and the hyperbolic plane .
For both types of interaction we prove the nonexistence of an additional
meromorphic integral for the complexified dynamic systems.Comment: 20 pages, typos correcte
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