6 papers
Polynomially Deformed Normalized Pochhammer Sequences Having Generating Functions With Only Real Non-positive Zeros
Anna Vishnyakova
For a given real number and a given real polynomial of degree it is easy to see that $ \sum_{k=0}^\infty \frac{(a)_k}{k!} P_n(k) z^…
Polynomials interpolated totally positive sequences
Anna Vishnyakova
A real sequence is called {\it totally positive} if all minors of the infinite Toeplitz matrix are nonnegative (wh…
Convolution operators preserving the set of totally positive sequences
Olga Katkova, Anna Vishnyakova
A real sequence is called {\it totally positive} if all minors of the infinite Toeplitz matrix are nonnegative (he…
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…
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…
On the number of real zeroes of a homogeneous differential polynomial and a generalization of the Hawaii conjecture
Olga Katkova, Mikhail Tyaglov, Anna Vishnyakova
For a given real polynomial we study the possible number of real roots of a differential polynomial $H_{\varkappa}[p](x) = \varkappa\left(p'(x)\right)^2-p(x)p''(x), \varkappa \…