Falomir, H.; Pisani, P. A. G. Krein’s formula and heat-kernel expansion for some differential operators with a regular singularity. (English) Zbl 1103.81015 J. Phys. A, Math. Gen. 39, No. 21, 6333-6340 (2006). MSC: 81Q10 Selfadjoint operator theory in quantum theory, including spectral analysis 47A55 Perturbation theory of linear operators 47E05 General theory of ordinary differential operators (should also be assigned at least one other classification number in Section 47-XX) 58J35 Heat and other parabolic equation methods for PDEs on manifolds 58J37 Perturbations of PDEs on manifolds; asymptotics 81T16 Nonperturbative methods of renormalization applied to problems in quantum field theory PDF BibTeX XML Cite \textit{H. Falomir} and \textit{P. A. G. Pisani}, J. Phys. A, Math. Gen. 39, No. 21, 6333--6340 (2006; Zbl 1103.81015) Full Text: DOI arXiv