Characterization of Maximizers for Sums of the First Two Eigenvalues of Sturm-Liouville Operators

This paper establishes the existence and uniqueness of a non-negative, piecewise smooth, and symmetric potential in L1L^1 that maximizes the sum of the first two Dirichlet eigenvalues for Sturm-Liouville operators, demonstrating that its nonzero part is determined by the solution to the pendulum equation via measure differential equations and weak^* convergence.

Gang Meng, Yuzhou Tian, Bing Xie, Meirong Zhang2026-03-09🔢 math

STAR Beyond Diagonal RISs with Amplification: Modeling and Optimization

This paper proposes a physically consistent signal model and an alternating optimization framework for downlink sum-rate maximization in STAR beyond-diagonal RISs with per-element amplification, achieving substantial performance gains over conventional passive systems while ensuring hardware feasibility and passivity.

Chandan Kumar Sheemar, Giovanni Iacovelli, Wali Ullah Khan, George C. Alexandropoulos, Stefano Tomasin, Symeon Chatzinotas2026-03-09🔢 math

Oort's conjecture on automorphisms of generic supersingular abelian varieties

This paper proves Oort's conjecture that the automorphism group of a generic principally polarized supersingular abelian variety in characteristic pp is {±1}\{\pm 1\}, except for the specific cases of genus 2 or 3 with p=2p=2, while also providing an explicit description of the a=1a=1-locus in the corresponding Rapoport-Zink space and establishing analogous results for supersingular pp-divisible groups.

Eva Viehmann2026-03-09🔢 math