Yi-Cen Ma

collaborators

7 papers

math.CV2026

A Proof of the Koumandos--Ruscheweyh Conjecture

Yicen Ma

We prove the Koumandos--Ruscheweyh conjecture for every $0 < ρ \leq 1$ . If $ν (ρ)$ is the unique root in $(0, 1]$ of $\int_{0}^{(1 + ρ) π} t^{μ - 1} sin (t - ρ π) d t = 0$ , then $(1-z)^ρs_n^μ…

math.CO2026

A Proof of the Third and Cubic Borwein Conjectures

Yicen Ma

We establish the coefficient sign patterns in the Third Borwein conjecture and the modulus-three Cubic Borwein conjecture. The analytic arguments apply for $n \geq 1750$ and $n \geq 500$ …

math.FA2026

Hyponormality of Generalized Cesàro Matrices of Every Positive Integer Order

Yicen Ma

For a positive integer $m$ and a real parameter $α > - 1$ , consider the generalized Cesàro matrix on $ℓ^{2} (N_{0})$ with entries $m (n - j + 1)_{m - 1} / (n + α + 1)_{m}$ for $j \leq n$ . We giv…

math.FA2026

Affine Anchors and Cylinder Obstructions in the Three-Dimensional Tingley Problem

Yicen Ma

Let $X$ be a three-dimensional real Banach space and let $f : S_{X} \to S_{Y}$ be a surjective isometry. We study the propagation of an affine formula for $f$ on a relatively open part of…

math.FA2026

A proof of the Fong--Tsui conjecture

Mohamed Amine Aouichaoui, Fuad Kittaneh, Yicen Ma

We prove that a bounded operator $T$ on a complex Hilbert space is self-adjoint whenever $|T|\leq|\re T|$, as conjectured by Fong and Tsui \cite{FT}.

math.FA2026

A General Proof of the Fong-Tsui Conjecture

Yicen Ma

We present a general proof of the Fong-Tsui conjecture for bounded operators on arbitrary complex Hilbert spaces. Specifically, we show that $∣ T ∣ \leq ∣ Re T ∣$ implies t…

math.FA2026

Vector-Carleson, Calderón, and Poisson-Atomic Criteria for Generalized Hilbert Operators on $H^{p}$ , $p > 2$

Yicen Ma

Let $H_{g} f (z) = \int_{0}^{1} f (t) g^{'} (t z), d t$ , and let $2 < p < \infty$ . Set $t = 2 p / (p - 2)$ and $X_{j} = 2^{- j / p^{'}} Δ_{j} g^{'}$ , where $Δ_{j}$ is the hard dyadic Taylor projection. We prove that $\…

A Proof of the Koumandos--Ruscheweyh Conjecture

A Proof of the Third and Cubic Borwein Conjectures

Hyponormality of Generalized Cesàro Matrices of Every Positive Integer Order

Affine Anchors and Cylinder Obstructions in the Three-Dimensional Tingley Problem

A proof of the Fong--Tsui conjecture

A General Proof of the Fong-Tsui Conjecture

Vector-Carleson, Calderón, and Poisson-Atomic Criteria for Generalized Hilbert Operators on Hp, p>2

Vector-Carleson, Calderón, and Poisson-Atomic Criteria for Generalized Hilbert Operators on $H^{p}$ , $p > 2$