🔢 mathematics

A counterexample to the complex polynomial Koebe radius conjecture

This paper disproves the 2018 complex-coefficient polynomial Koebe radius conjecture by constructing a specific normalized cubic polynomial that is univalent on a neighborhood of the unit disk yet omits a point with a modulus strictly smaller than the conjectured radius, thereby establishing a strict separation between real and complex cubic Koebe radii and proving that degree three is the minimal degree for such a counterexample.

Aran S. Ziegler2026-10-26
🔢 mathematics

A novel parallel approach for solving some free boundary value problems

This paper presents a novel unified parallel framework for solving general obstacle and free boundary value problems by establishing theoretical convergence for both direct and indirect iterative methods, extending these approaches to higher dimensions via directional splitting and time-stepping, and validating their efficacy through applications in constrained quadratic programming and image deblurring.

Amboru Yalamanda, Peeyush Singh2026-10-23
🔢 mathematics

The Geometric Product of í µí² Vectors: a Grade-Spectrum Theorem, Exact Second Moments, and a Two-Scale Cut-off for Random Versors

This paper establishes a comprehensive geometric product theorem that expresses the squared coordinates and grade-wise energy distribution of Clifford algebra versors as determinants of their associated orthogonal maps, revealing deep connections to Krawtchouk transforms, spin-group reconstruction, and random walk mixing times on the orthogonal group.

Balasaheb B. Waphare2026-10-23
🔢 mathematics

A Two-Stage Finite Element Approach for High-precision Guaranteed Lower Eigenvalue Bounds

This paper proposes a new two-stage finite element algorithm that employs high-order elements on graded meshes to generate rigorous lower eigenvalue bounds as sharp as standard high-order upper bounds, effectively closing a long-standing gap in accuracy and significantly outperforming existing methods like Crouzeix--Raviart in terms of computational efficiency.

Xuefeng LIU, Michael Plum2026-10-21