The Index of Invariance and its Implications for a Parameterized Least Squares Problem

Léopold Cambier, Rahul Sarkar

We study the problem $x_{b,\omega }:={\text{arg min}}_{x\in \mathcal{S}}\Vert (A+\omega I{)}^{-1/2}(b-Ax){\Vert }_2$, with $A=A^{\ast }$, for a subspace $\mathcal{S}$ of ${\mathbb{F}}^n$ ($\mathbb{F} = \…