Grid designs

This paper investigates the existence of GG-designs (decompositions of complete graphs into edge-disjoint copies of a grid graph GG), proving that such designs exist for toroidal grids CnCnC_n \square C_n when nn is an odd prime or its square, and for the path-grid P4P4P_4 \square P_4 (which relates to scrambling Connections puzzles), while showing that P3P3P_3 \square P_3 admits no such design.

Alon Danai, Joshua Kou, Andy Latto, Haran Mouli, James ProppWed, 11 Ma🔢 math

On the Diameter of Arrangements of Topological Disks

This paper establishes that the diameter of the dual graph of an arrangement of nn topological disks is bounded by a function of nn and the maximum number of connected components in any pairwise intersection, providing a tight bound of max{2,2Δ}\max\{2, 2\Delta\} for two disks and an O(n32nΔ)O(n^3 2^n \Delta) bound for nn disks by analyzing the count of maximal faces.

Aida Abiad, Boris Aronov, Mark de Berg, Julian Golak, Alexander Grigoriev, Freija van LentWed, 11 Ma🔢 math

Complex Scaling for the Junction of Semi-infinite Gratings

This paper presents and analyzes a complex scaling-based integral equation method that enables the efficient, high-order, and exponentially accurate numerical solution of wave scattering problems involving the junction of two semi-infinite periodic structures by analytically continuing the formulation into the complex plane to overcome slow kernel decay and prove its well-posedness.

Fruzsina J. Agocs, Tristan Goodwill, Jeremy HoskinsWed, 11 Ma🔢 math