collaborators

5 papers

math.NA2026

Guaranteed Lower Eigenvalue Bounds for Spectral Galerkin Methods with Application to Schrödinger Operators

Xuefeng Liu

Spectral Galerkin methods are renowned for high-precision eigenvalue approximation, yet a rigorous lower bound obtained directly from a spectral discretisation has remained unavail…

math.NA2026

Explicit Two-Sided Eigenvalue Bounds for Schrödinger Operators with Singular Potentials via Finite Element Method

Xuefeng Liu

We present, to the best of our knowledge, the first numerical algorithm for explicit, computable two-sided eigenvalue bounds for Schrödinger operators H = -Delta + V on R^N, N = 2…

math.SP2026

Sharp Dirichlet eigenvalue inequalities on triangles

Ryoki Endo, Xuefeng Liu, Phanuel Mariano

We prove sharp Dirichlet eigenvalue inequalities for planar triangles. We settle a conjecture of Laugesen and Siudeja by showing that the equilateral triangle uniquely minimizes a…

math.NA2026

Rigorous Eigenvalue Bounds for Schrödinger Operators with Confining Potentials on

Xuefeng Liu

We propose a rigorous method for computing two-sided eigenvalue bounds of the Schrödinger operator with a confining potential on . The method combines doma…

math.SP2025

The Second Dirichlet Eigenvalue is Simple on Every Non-equilateral Triangle, Part II: Nearly Equilateral Triangles

Ryoki Endo, Xuefeng Liu

This paper solves the open problem of the simplicity of the second Dirichlet eigenvalue for nearly equilateral triangles, offering a complete solution to Conjecture 6.47 posed by R…