Singularities of Green functions of the products of the Laplace type operators
Abstract
The structure of diagonal singularities of Green functions of partial differential operators of even order acting on smooth sections of a vector bundle over a Riemannian manifold is studied. A special class of operators formed by the products of secondorder operators of Laplace type defined with the help of a unique Riemannian metric and a unique bundle connection but with different potential terms is investigated. Explicit simple formulas for singularities of Green functions of such operators in terms of the usual heat kernel coefficients are obtained.
 Publication:

Physics Letters B
 Pub Date:
 February 1997
 DOI:
 10.1016/S03702693(97)005364
 arXiv:
 arXiv:hepth/9703005
 Bibcode:
 1997PhLB..403..280A
 Keywords:

 High Energy Physics  Theory
 EPrint:
 12 Pages, LaTeX, 30 KB, No Figures, submitted to Physics Letters B, Discussion of the Huygence principle is removed