Big Ramsey degrees and the two-branching pseudotree

This paper establishes that finite chains within the two-branching countable ultrahomogeneous pseudotree possess finite big Ramsey degrees, specifically determining the degree for chains of length two to be seven, thereby presenting the first example of a countable ultrahomogeneous structure in a finite language where some finite substructures have finite big Ramsey degrees while others have infinite ones.

David Chodounský, Natasha Dobrinen, Thilo WeinertTue, 10 Ma🔢 math

On colorings of hypergraphs embeddable in Rd\mathbb{R}^d

This paper improves upon previous results by Heise et al. by proving that the weak chromatic number of kk-uniform hypergraphs arising from linearly or PL-embeddable simplicial complexes in Rd\mathbb{R}^d is infinite for most dimensions and uniformities, and further extends these findings to show that the weak chromatic number of ss-dimensional faces in triangulations of any fixed triangulable dd-manifold is infinite for all $1 \le s \le d$.

Seunghun Lee, Eran NevoTue, 10 Ma🔢 math

On intersection cohomology with torus action of complexity one, II

This paper establishes that the decomposition theorem components for contraction maps of torus actions of complexity one are intersection cohomology complexes of even codimensional subvarieties, leading to the vanishing of odd-dimensional intersection cohomology for rational complete varieties of this type and providing explicit formulas for the Betti numbers of affine trinomial hypersurfaces based on their defining equations.

Marta Agustin Vicente, Narasimha Chary Bonala, Kevin LangloisTue, 10 Ma🔢 math

Agentic Neurosymbolic Collaboration for Mathematical Discovery: A Case Study in Combinatorial Design

This paper presents a neurosymbolic collaboration between an LLM-powered agent, symbolic computation tools, and human researchers that successfully discovered and formally verified a new tight lower bound on the imbalance of Latin squares for the case n1(mod3)n \equiv 1 \pmod{3}, demonstrating the potential of AI-human partnerships in pure mathematical discovery.

Hai Xia, Carla P. Gomes, Bart Selman, Stefan SzeiderTue, 10 Ma🔢 math

The Lovász conjecture holds for moderately dense Cayley graphs

This paper proves that every large connected Cayley graph with degree at least n1cn^{1-c} for some absolute constant c>0c>0 contains a Hamilton cycle, thereby advancing the Lovász conjecture by improving previous density thresholds through a proof that utilizes an arithmetic regularity lemma tailored to Cayley graphs instead of Szemerédi's regularity lemma.

Benjamin Bedert, Nemanja Draganic, Alp Müyesser, Matías Pavez-SignéTue, 10 Ma🔢 math