Graph labellings and external difference families

This paper establishes a systematic framework for constructing digraph-defined external difference families by combining graph blow-up techniques with generalized vertex labellings, resulting in new combinatorial families—including the first infinite construction for specific 2-circular external difference families—and novel results on graph labellings such as α\alpha-valuations for sun graphs.

Gavin Angus, Sophie Huczynska, Struan McCartney2026-03-09🔢 math

FlexTrace: Exchangeable Randomized Trace Estimation for Matrix Functions

This paper introduces FlexTrace, a novel single-pass trace estimator that accurately computes the trace of matrix functions for large symmetric positive semi-definite matrices using only matrix-vector products with the original matrix, thereby overcoming the computational expense of existing methods that require products with the function of the matrix.

Madhusudan Madhavan, Alen Alexanderian, Arvind K. Saibaba2026-03-09🔢 math

A Lock-Free Work-Stealing Algorithm for Bulk Operations

This paper presents a specialized lock-free work-stealing queue designed for a master-worker framework in mixed-integer programming solvers that leverages restricted concurrency assumptions to support native bulk operations and achieve constant-latency push performance, significantly outperforming general-purpose implementations like C++ Taskflow in batch processing scenarios.

Raja Sai Nandhan Yadav Kataru, Danial Davarnia, Ali Jannesari2026-03-09🔢 math

Unitary and Nonunitary Representations of the Heisenberg-Weyl Lie Algebra

This paper provides a detailed Lie-algebraic analysis of the Heisenberg-Weyl Lie algebra by constructing explicit unitary intertwining operators for tensor products of its Schrödinger representations and proving that finite-dimensional irreducible representations of the symplectic Lie algebra sp2n+2(R)\mathfrak{sp}_{2n+2}(\mathbb{R}) yield a large family of finite-dimensional, nonunitary indecomposable representations when restricted to hwn\mathfrak{hw}_n.

Andrew Douglas, Hubert de Guise, Joe Repka2026-03-09🔢 math