P. Ha

activity

20172020

most citedNon-integrated defect relations for the Gauss map of a complete minimal surface with finite total curvature in

R^{m}

1 citations · 1 across the 2 of their papers we have counts for

collaborators

7 papers

math.CO2020

Progress on sufficient conditions for a graph to have a spanning $k -$ ended tree

Pham Hoang Ha

In 1998, Broersma and Tuinstra [J. Graph Theory \textbf{29} (1998), 227-237] proved that if $G$ is a connected graph satisfying $σ_{2} (G) \geq ∣ G ∣ - k + 1$ then $G$ has a spanning $k -$ en…

math.CO2018

A note on independence number, connectivity and $k$ -ended tree

Pham Hoang Ha

A $k$ -ended tree is a tree with at most $k$ leaves. In this note, we give a simple proof for the following theorem. Let $G$ be a connected graph and $k$ be an integer ( $k \geq 2$ ).…

math.CO2018

A note on spanning trees of connected $K_{1, t}$ -free graphs whose stems have a few leaves

Pham Hoang Ha, Dang Dinh Hanh

Let $T$ be a tree, a vertex of degree one is called a leaf. The set of leaves of $T$ is denoted by $L e a f (T)$ . The subtree $T - L e a f (T)$ of $T$ is called the stem of $T$ and denoted b…

math.CO2018

Spanning trees with at most 2 branch vertices in claw - free graphs

Pham Hoang Ha, Dang Dinh Hanh

In this article, we will prove that if $G$ is a connected claw-free graph and either $σ_{6} (G) \geq ∣ G ∣ - 5$ or $σ_{7} (G) \geq ∣ G ∣ - 2$ , here $σ_{k} (G)$ is the minimmum degree sum of $k$ indep…

math.CO2018

Spanning trees with at most 4 leaves in $K_{1, 5} -$ free graphs

Yuan Chen, Pham Hoang Ha, Dang Dinh Hanh

In 2009, Kyaw proved that every $n$ -vertex connected $K_{1, 4}$ -free graph $G$ with $σ_{4} (G) \geq n - 1$ contains a spanning tree with at most $3$ leaves. In this paper, we prove an ana…

math.CO2018

Spanning trees in a Claw-free graph whose stems have at most $k$ branch vertices

Pham Hoang Ha

Let $T$ be a tree, a vertex of degree one and a vertex of degree at least three is called a leaf and a branch vertex, respectively. The set of leaves of $T$ is denoted by $L e a f (T)$ …

Progress on sufficient conditions for a graph to have a spanning k−ended tree

A note on independence number, connectivity and k-ended tree

A note on spanning trees of connected K1,t​-free graphs whose stems have a few leaves

Spanning trees with at most 2 branch vertices in claw - free graphs

Spanning trees with at most 4 leaves in K1,5​−free graphs

Spanning trees in a Claw-free graph whose stems have at most k branch vertices

Progress on sufficient conditions for a graph to have a spanning $k -$ ended tree

A note on independence number, connectivity and $k$ -ended tree

A note on spanning trees of connected $K_{1, t}$ -free graphs whose stems have a few leaves

Spanning trees with at most 4 leaves in $K_{1, 5} -$ free graphs

Spanning trees in a Claw-free graph whose stems have at most $k$ branch vertices