3 papers
math.CA2026
General duality relations for hypergeometric and basic hypergeometric series
Dmitrii Karp, Yi Zhang
Duality relations for hypergeometric functions have reappeared as an active research topic several times, with the first instances tracing back to Euler and Gauss and the latest bu…
math.CO2025
Generalized -Eulerian polynomials: zeros and hypergeometric representations with applications
Dmitrii Karp, Anna Vishnyakova
In this paper, we explore (slightly generalized) -Eulerian polynomials introduced by Stanley and frequently appearing in combinatorics. Notable special cases include the classic…
math.CA2025
Unimodality preservation by ratios of functional series and integral transforms
Dmitrii Karp, Anna Vishnyakova, Yi Zhang
An elementary, but very useful lemma due to Biernacki and Krzyż (1955) asserts that the ratio of two power series inherits monotonicity from that of the sequence of ratios of thei…