In this article, we propose an adaptive grid based on mesh equidistribution principle for two-parameter convection-diffusion boundary value problems with continuous and discontinuous data. A numerical algorithm based on an upwind finite difference operator and an appropriate adaptive grid is constructed. Truncation errors are derived for both continuous and discontinuous problems. Parameter uni...

We investigate a technique to transform linear two-parameter eigenvalue problem into nonlinear (NEP). The transformation stems from an elimination of one the equations in problem, by considering it as (standard) generalized problem. characterize equivalence between original and nonlinearized theoretically show how use computationally. Special cases can be interpreted reversed companion lineariz...

The concept of the hafnian first appeared in works on
 quantum field theory by E. R. Caianiello. However, it also has
 an important combinatorial property: adjacency
 matrix undirected weighted graph is equal to the
 total sum weights perfect matchings this graph.
 In general, use limited complexity
 its computation. paper, we present a method for exact calculation...