Inequalities Involving Core, Corona, and Critical Sets in General Graphs

This paper confirms two conjectures by establishing that the sum of the sizes of the union and intersection of all maximum independent sets is bounded by $2\alpha(G)plusthenumberofvertexdistinctoddcycles,whilethecorrespondingsumforcriticalindependentsetsisboundedby plus the number of vertex-distinct odd cycles, while the corresponding sum for critical independent sets is bounded by 2\alpha(G)$, thereby unifying these results into a comprehensive chain of inequalities involving core, corona, nucleus, and diadem sets.

Adrián Pastine, Kevin PereyraThu, 12 Ma🔢 math

Optimal Spectral Bounds for Antipodal Graphs

This paper establishes that for a set of nn points in the plane with diameter at most 1, the ratio of pairs with distance ε\leq \varepsilon to pairs with distance 1ε\geq 1-\varepsilon is bounded below by ε1/2+o(1)\varepsilon^{1/2+o(1)}, thereby improving upon Steinerberger's previous ε3/4+o(1)\varepsilon^{3/4+o(1)} bound and nearly confirming the conjectured asymptotic behavior.

Samuel KorskyThu, 12 Ma🔢 math

Central limit theorems for high dimensional lattice polytopes: symmetric edge polytopes

This paper establishes the first central limit theorems for the number of edges and unimodular triangulation edges in symmetric edge polytopes generated by Erdős–Rényi random graphs in high dimensions, utilizing the discrete Malliavin–Stein method to derive precise asymptotics and identify an atypical fluctuation regime where variance cancellation occurs.

Torben Donzelmann, Martina Juhnke, Benedikt Rednoß, Christoph ThäleThu, 12 Ma🔢 math

Polynomial-size encoding of all cuts of small value in integer-valued symmetric submodular functions

This paper presents a polynomial-size representation and a corresponding polynomial-time construction algorithm for the family of all sets with a fixed value kk in integer-valued symmetric submodular functions, thereby generalizing low-rank structure theorems from graph cut-rank functions to broader connectivity functions and enabling efficient solutions to cardinality-constrained minimization problems.

Sang-il Oum, Marek SokołowskiThu, 12 Ma🔢 math

Extremal problems in uniformly dense hypergraphs and digraphs

This paper establishes a novel connection between digraph extremal problems and uniform Turán densities of 3-graphs to provide verifiable conditions for determining specific density values, including identifying new classes of 3-graphs with densities such as (r1)/r(r-1)/r, (r1)2/r2(r-1)^2/r^2, and $4/27,whilealsoofferingasimplifiedprooffortheexistenceof3graphswithdensity, while also offering a simplified proof for the existence of 3-graphs with density 1/27$.

Hao Lin, Guanghui Wang, Wenling Zhou, Yiming ZhouThu, 12 Ma🔢 math