3 papers
math.CA2025
Confluent functions, Laguerre polynomials and their (generalized) bilinear integrals
Jan DereziÅski, Christian GaÃ, Joonas Mikael Vättö
We review properties of confluent functions and the closely related Laguerre polynomials, and determine their bilinear integrals. As is well-known, these integrals are convergent o…
math-ph2025
Propagators in curved spacetimes from operator theory
Jan DereziÅski, Christian GaÃ
We discuss two distinct operator-theoretic settings useful for describing (or defining) propagators associated with a scalar Klein-Gordon field on a Lorentzian manifold . Typica…
math-ph2024
Point potentials on Euclidean space, hyperbolic space and sphere in any dimension
Jan DereziÅski, Christian GaÃ, BÅażej Ruba
In dimensions d= 1, 2, 3 the Laplacian can be perturbed by a point potential. In higher dimensions the Laplacian with a point potential cannot be defined as a self-adjoint operator…