4 papers
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…
Sobolev trace inequalities on John domains and its applications
Weicong Su, Yi Ru-Ya Zhang
We prove that a trace inequality holds for John domains satisfying where denotes the measure-theoret…
Carrot John domains in variational problems
Weicong Su, Yi Ru-Ya Zhang
In this paper, we explore carrot John domains within variational problems, dividing our examination into two distinct sections. The initial part is dedicated to establishing the lo…
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…