37 research outputs found
Burchnall-Chaundy polynomials for matrix ODOs and Picard-Vessiot Theory
Burchnall and Chaundy showed that if two ODOs , with analytic
coefficients commute there exists a polynomial with complex
coefficients such that , called the BC-polynomial. This polynomial
can be computed using the differential resultant for ODOs. In this work we
extend this result to matrix ordinary differential operators, MODOs. Matrices
have entries in a differential field , whose field of constants is
algebraically closed and of zero characteristic. We restrict to the case of
order one operators , with invertible leading coefficient. A new
differential elimination tool is defined, the matrix differential resultant. It
is used to compute the BC-polynomial of a pair of commuting MODOs and
proved to have constant coefficients. This resultant provides the necessary and
sufficient condition for the spectral problem to
have a solution. Techniques from differential algebra and Picard-Vessiot theory
allow us to describe explicitly isomorphisms between commutative rings of MODOs
and a finite product of rings of irreducible algebraic curves
Burchnall鈥揅haundy polynomials for matrix ODOs and Picard鈥揤essiot theory
Burchnall and Chaundy showed that if two ordinary differential operators (ODOs) P, Q with analytic coefficients commute then there exists a polynomial f(位, 渭) with complex coefficients such that f(P, Q) = 0, called the BC-polynomial. This polynomial can be computed using the differential resultant for ODOs. In this work we extend this result to matrix ordinary differential operators, MODOs. Our matrices have entries in a differential field K, whose field of constants C is algebraically closed and of zero characteristic. We restrict to the case of order one operators P, with invertible leading coefficient. We define a new differential elimination tool, the matrix differential resultant. We use it to compute the BC-polynomial f of a pair of commuting MODOs, and we also prove that it has constant coefficients. This resultant provides the necessary and sufficient condition for the spectral problem PY = 位Y, QY = 渭Y to have a solution. Techniques from differential algebra and Picard鈥揤essiot theory allow us to describe explicitly isomorphisms between commutative rings of MODOs C[P, Q] and a finite product of rings of irreducible algebraic curvesPID2021-124473NB-I0