activity
20242026
collaborators

31 papers

cs.LG2026

Twist Flow for Inverse Problems

Shiqin Zeng, Zijun Deng, Felix J. Herrmann

In Bayesian inverse problems, posterior sampling requires generating samples that are consistent with given observations while capturing the range of plausible solutions. Direct co…

math.CO2026

Sharp connectivity thresholds for mixed rigidity packings and improved bounds for highly connected orientations of graphs

Hanzhi Bai, Jørgen Bang-Jensen, Jin Yan

Garamvölgyi, Jordán, Király and Villányi [{{\bf Forum Math. Pi} \textbf{13} (2025), Paper No.~e11}] posed two sharp connectivity conjectures for packing rigid spanning subgraphs: o…

math.CO2026

Hitting Maximum Independent Sets in Dense and Highly Connected Graphs

Hanzhi Bai, Yufei Chang, Jin Yan

For a graph , let be the minimum cardinality of a vertex set meeting every maximum independent set of . We establish two complementary reduction principles for the Bol…

math.CO2026

An Exact Dominant Degree Condition for Transitive Tournament Factors in Digraphs

Yufei Chang, Shuo Wei, Jin Yan

Let , let denote the transitive tournament on vertices, and write . We prove that if and an -vertex digraph s…

math.CO2026

Paths with Prescribed Endpoints in Semicomplete and Locally Semicomplete Digraphs

Hanzhi Bai, Jin Yan, Jia Zhou

We study two open path problems with prescribed endpoints posed by Bang-Jensen and Gutin. The first asks for a longest -path in a semicomplete digraph. The second asks wheth…

math.CO2026

A Chvátal--Erdős type condition for supereulerian digraphs with

Zirui Liu, Jin Yan, Jia Zhou

A digraph is \textbf{supereulerian} if it contains a spanning closed trail. Let denote the maximum cardinality of a vertex set inducing no 2-cycle. In this paper, we chara…

math.CO2026

Packing and Covering Cycles Through Prescribed Vertices

Hanzhi Bai, Jin Yan

Let be a finite simple graph and let . We prove that the minimum number of vertices meeting every cycle that intersects is at most the maximum number of ve…

math.CO2026

Complexity of Arc-Decompositions involving Perfect Matchings and Cycle Factors

Hangning Liu, Jørgen Bang-Jensen, Jin Yan +1

For two digraph properties and , a -arc-decomposition of a digraph is a partition such that the spanning subdigraphs $D[A_…

math.CO2026

Spanning -subdivisions with Prescribed Path Lengths

Zhilan Wang, Shuo Wei, Jin Yan

We study spanning -subdivisions in dense graphs where the length of every subdivision path is prescribed in advance. This problem is motivated in part by a question of Pavez-Sig…

math.CO2026

Nearly balanced spanning subdivisions in dense digraphs

Zhilan Wang, Shuo Wei, Jin Yan

Pavez-Signé [Combin. Probab. Comput. 33 (2024), 121--128] conjectured a Dirac-type condition for spanning -subdivisions and asked whether the subdivision paths can additionally…

math.CO2026

Sparse spanning -strong oriented subdigraphs in split digraphs

Jia Zhou, Jørgen Bang-Jensen, Jin Yan

Jackson and Thomassen conjectured that every -strong digraph admits a spanning -strong oriented subdigraph [Ann. N. Y. Acad. Sci. 555 (1989) 402-412]. The conjecture holds f…

math.CO2026

Highly connected spanning oriented subdigraphs in generalizations of semicomplete digraphs

Jia Zhou, Jørgen Bang-Jensen, Tong Zhou +1

Let be a positive integer. Jackson and Thomassen conjectured in 1989 that there exists an integer function such that every -strong digraph admits a spanning -st…

math.CO2026

The exact total degree threshold for the square of a Hamilton cycle in digraphs

Zhilan Wang, Shuo Wei, Jin Yan

The Pósa-Seymour conjecture establishes the minimum degree threshold required to guarantee the presence of the th power of a Hamilton cycle in a graph. Following numerous partia…

math.CO2026

K-Arc-Strong Orientations Of Semicomplete Digraphs

Tong Zhou, Jørgen Bang-Jensen, Jia Zhou +1

Results by Jackson and Frank imply that every 2k-arc-strong digraph D contains a spanning k-arc-strong oriented subdigraph. This is best possible, even for very dense digraphs. A d…

cs.DM2026

Polynomial Algorithms for Minimum Degree Partitions in Semicomplete Digraphs

Hanzhi Bai, Jin Yan

A 2-partition of a digraph is a partition of its vertex set into two nonempty parts. Degree-constrained 2-partition problems are generally computationally difficult, even when the…

math.CO2026

Ramsey-Turán Type Problem for Perfect Transitive Triangle Tilings in Digraphs

Zhimin Wang, Zhilan Wang, Jin Yan

The classical Corrádi-Hajnal theorem states that for any multiple of , if is a graph with vertices and , then can be partitioned into verte…

math.CO2026

Oriented Discrepancy of The Square of Hamilton Cycles

Yufei Chang, Yangyang Cheng, Zhilan Wang +2

For an oriented graph , the oriented discrepancy problem concerns the existence of a spanning subgraph of with a large imbalance between its forward and backward edge orient…

math.CO2026

Spanning Subdivisions in Robustly Expanding Digraphs

Zhilan Wang, Jin Yan, Shuo Wei

Kühn, Osthus and Treglown [\emph{J. Combin. Theory Ser. B} \textbf{100} (2010)] proved that every sufficiently large robust outexpander with linear minimum semi-degree contains a H…

math.CO2026

An Ore-type Theorem for Oriented Discrepancy of Hamilton Cycles

Yufei Chang, Yangyang Cheng, Zhilan Wang +2

Oriented discrepancy concerns the existence of prescribed subgraphs whose edges exhibit a substantial imbalance between the two directions. The Hamilton cycle case was first invest…

math.CO2026

On the 2-Linkage Problem for Split Digraphs

Xiaoying Chen, Jørgen Bang-Jensen, Jin Yan +1

A digraph is {\bf \( k \)-linked} if for arbitary two disjoint vertex sets \(\{s_1, \ldots, s_k\}\) and \(\{t_1, \ldots, t_k\}\), there exist vertex-disjoint directed paths \(P_1,…

math.CO2025

Proof of the linkage conjecture for highly connected tournaments

Jia Zhou, Jin Yan

A digraph is -linked if for every distinct vertices in , there exist pairwise vertex-disjoint paths such…

math.CO2025

On the -linkage problem for generalizations of semicomplete digraphs

Jia Zhou, Jørgen Bang-Jensen, Jin Yan

A directed graph (digraph) is -linked if , and for any distinct vertices of , there exist vertex-disjoi…

math.CO2024

Solutions to the linkage conjecture in tournaments

Jia Zhou, Jin Yan

A digraph is -linked if for every -tuple of distinct vertices in , there exist pairwise vertex-disjoint paths $P_1,\ldots,…

math.CO2024

Spanning -subdivisions and perfect -subdivision tilings in dense digraphs

Yangyang Cheng, Zhilan Wang, Jin Yan

Given a (di)graph , we say that a (di)graph is an -subdivision if is obtained from by replacing one or more edges with internally vertex-disjoint pa…