Kurkcu, Omur Kivanc2023-10-022023-10-0220231660-54461660-5454https://doi.org/10.1007/s00009-023-02492-1https://hdl.handle.net/20.500.13091/4611For the first time via this study, the ultimate effort is inclined to numerically solve one-dimensional parabolic partial integro-differential equations with spatial-temporal delays and infinite boundary using an efficient matrix-collocation method dependent upon the orthoexponential polynomials. The method clearly actuates a novel procedure converting the unknown differential and delay terms into their matrix expansions at the collocation points, and evaluating the integral part bounded by the half-line. The existence of the singular integral part is also validated by the orthoexponential polynomial solution. In addition to these novelties, an error bound estimation is developed via a boundary property of the orthoexponential polynomials. The resulting solutions are improved via the residual error analysis. Some numerical benchmark examples are included to indicate the accuracy and validity of the method, deploying graphical and numerical instruments. It can be noticeable to conclude that the proposed method achieves both drastic and useful approximation for highly stiff problems derived from the aforementioned equations.eninfo:eu-repo/semantics/closedAccessError bound estimationmatrix-collocation methodsingularityspatial-temporal delaysNumerical-SolutionArticle10.1007/s00009-023-02492-12-s2.0-85168436483