arXiv subjects

M. T. Mustafa

Publications and source records attributed to M. T. Mustafa.

23 records · Page 2Linked to original sources

arXiv2011

Polynomial solutions of certain differential equations arising in physics

Linear differential equations of arbitrary order with polynomial coefficients are considered. Specifically, necessary and sufficient conditions for the existence of polynomial solutions of a given degree are obtained for these equations. An algorithm to determine these conditions and to construct the polynomial solutions is given. The effectiveness of this algorithmic approach is illustrated by applying it to several differential equations that arise in mathematical physics.

math-ph↗

arXiv2010

Polynomial Solutions of Differential Equations

We show that any differential operator of the form $L(y)=\sum_{k=0}^{k=N} a_{k}(x) y^{(k)}$, where $a_k$ is a real polynomial of degree $\leq k$, has all real eigenvalues in the space of polynomials of degree at most n, for all n. The eigenvalues are given by the coefficient of $x^n$ in $L(x^{n})$. If these eigenvalues are distinct, then there is a unique monic polynomial of degree n which is an eigenfunction of the operator L- for every non-negative integer n. As an application we recover Bochner's classification of second order ODEs with polynomial coefficients and polynomial solutions, as well as a family of non-classical polynomials.

math.CA↗

arXiv2009

Sturm-Liouville Theory and Orthogonal Functions

We revisit basics of classical Sturm-Liouville theory and, as an application, recover Bochner's classification of second order ODEs with polynomial coefficients and polynomial solutions by a new argument. We also outline how a wider class of equations with polynomial solutions can be obtained by allowing the weight to become infinite at isolated points:the Jacobi equation, in general, is of this type. For higher order equations, we also give the basic analysis required for determining the weight functions and constraints on the coefficients which make the differential operator defined by the equation self adjoint for even orders and anti self adjoint in odd orders. We also give explicit examples of such equations.

math.CA↗

arXiv2009

Analytic solutions of initial-boundary-value problems of transient conduction using symmetries

Lie symmetry method is applied to find analytic solutions of initial-boundary-value problems of transient conduction in semi-infinite solid with constant surface temperature or constant heat flux condition. The solutions are obtained in a manner highlighting the systematic procedure of extending the symmetry method for a PDE to investigate BVPs of the PDE. A comparative analysis of numerical and closed form solutions is carried out for a physical problem of heat conduction in a semi-infinite solid bar made of AISI 304 stainless steel.

math.AP↗

arXiv1996

Harmonic morphisms from three-dimensional Euclidean and spherical space forms

P. Baird and the second author studied harmonic morphisms from a three-dimensional simply-connected space form to a surface and obtained a complete local and global classification of them. In this paper, we obtain a description of all harmonic morphisms from any three-dimensional Euclidean and spherical space form to a surface, namely that any such harmonic morphism is the composition of a standard harmonic morphism and a weakly conformal map. We list the standard harmonic morphisms.

dg-ga↗