Hùng Việt Chu

activity

20232026

most citedOn Schreier-type Sets, Partitions, and Compositions

1 citations · 1 across the 7 of their papers we have counts for

collaborators

7 papers

math.CO2026

Schreier Sets of Intervals, Super-Schreier Sets, and Catalan Numbers

Hung Viet Chu, Mariam Khaduri, Moiz M. Khokhar +1

A finite nonempty set $F \subset N$ is Schreier if $min F \geq ∣ F ∣$ . First, we prove a linear recurrence relation and compute initial counts for Schreier sets consisting of i…

math.CO2025

Linear Recurrences of Generalized Schreier Sets Revisited

Hung Viet Chu, Zachary Louis Vasseur

For $p, q \in N$ , a finite nonempty set $F$ is said to be $(p, q)$ -Schreier (or maximal $(p, q)$ -Schreier, respectively) if $q min F \geq p ∣ F ∣$ (or $q min F = p ∣ F ∣$ , respective…

math.FA2025

Lower-Order Refinements of Greedy Approximation

Kevin Beanland, Hung Viet Chu, Thomas Schlumprecht +1

For two countable ordinals $α$ and $β$ , a basis of a Banach space $X$ is said to be $(α, β)$ -quasi-greedy if it is 1) quasi-greedy, 2) $S_{α}$ -unconditional but not $\mathc…

math.CO2024

Weighted Schreier-type Sets and the Fibonacci Sequence

Hung Viet Chu, Zachary Louis Vasseur

For a finite set $A \subset N$ and $k \in N$ , let $ω_{k} (A) = \sum_{i \in A, i \neq = k} 1$ . For each $n \in N$ , define $$a_{k, n}\ =\ |\{E\subset \mathbb{N}\,:\, E…

math.FA2024

Higher Order Tsirelson Spaces and their Modified Versions are Isomorphic

Hung Viet Chu, Thomas Schlumprecht

We prove that for every countable ordinal $ξ$ , the Tsirelson's space $T_{ξ}$ of order $ξ$ , is naturally, i.e., via the identity, $3$ -isomorphc to its modified version. For the first…

math.CO2023★ 1 cited

On Schreier-type Sets, Partitions, and Compositions

Kevin Beanland, Hung Viet Chu

A nonempty set $A \subset N$ is $ℓ$ -strong Schreier if $min A ⩾ ℓ ∣ A ∣ - ℓ + 1$ . We define a set of positive integers to be sparse if either the set has at most t…

math.NT2023

A Threshold for the Best Two-term Underapproximation by Egyptian Fractions

Hung Viet Chu

Let $G$ be the greedy algorithm that, for each $θ \in (0, 1]$ , produces an infinite sequence of positive integers $(a_{n})_{n = 1}^{\infty}$ satisfying $\sum_{n=1}^\infty 1/a_n =…