@**article**{RISC6643,author = {J. Blümlein and C. Schneider and M. Saragnese},

title = {{Hypergeometric Structures in Feynman Integrals}},

language = {english},

abstract = {Hypergeometric structures in single and multiscale Feynman integrals emerge in a wide class of topologies.
Using integration-by-parts relations, associated master or scalar integrals have to be calculated. For this
purpose it appears useful to devise an automated method which recognizes the respective (partial) differential
equations related to the corresponding higher transcendental functions. We solve these equations through
associated recursions of the expansion coefficient of the multivalued formal Taylor series. The expansion
coefficients can be determined using either the package {tt Sigma} in the case of linear difference equations
or by applying heuristic methods in the case of partial linear difference equations. In the present context a
new type of sums occurs, the Hurwitz harmonic sums, and generalized versions of them. The code {tt HypSeries}
transforming classes of differential equations into analytic series expansions is described. Also partial
difference equations having rational solutions and rational function solutions of Pochhammer symbols are
considered, for which the code {tt solvePartialLDE} is designed. Generalized hypergeometric
functions, Appell-,~Kamp'e de F'eriet-, Horn-, Lauricella-Saran-, Srivasta-, and Exton--type functions
are considered. We illustrate the algorithms by examples.},

journal = {Annals of Mathematics and Artificial Intelligence},

volume = { 91},

number = {5},

pages = {591--649},

isbn_issn = {ISSN 1573-7470},

year = {2023},

note = {arXiv:2111.15501 [math-ph]},

refereed = {yes},

keywords = {hypergeometric functions, symbolic summation, expansion, partial linear difference equations, partial linear differential equations},

length = {59},

url = {https://doi.org/10.1007/s10472-023-09831-8}

}