The methods of the theory function of several complex variable in the combinatorial analysis.
Main publications:
A. P. Lyapin, S. Chandragiri, “Generating functions for vector partition functions and a basic recurrence relation”, Journal of Difference Equations and Applications, 25:7 (2019), 1052–1061
A. P. Lyapin, T. Cuchta, “Sections of a generating series of a solution to a difference equation in a simplicial cone”, The Bulletin of Irkutsk State University. Series Mathematics, 42 (2022), 75–89
S. S. Akhtamova, V. S. Alekseev, A. P. Lyapin, “Discrete Generating Functions”, Mathematical Notes, 114:6 (2023), 1087–1093
S. S. Akhtamova, T. Cuchta, A. P. Lyapin, “An Approach to Multidimensional Discrete Generating Series”, Mathematics, 12:1 (2024), 143