Improved Concentration Bounds for Gaussian Quadratic Forms
For a wide class of monotonic functions f, we develop a Chernoff-style concentration inequality for quadratic forms Q_f ∼∑_i=1^n f(η_i) (Z_i + δ_i)^2, where Z_i ∼ N(0,1). The inequality is expressed in terms of traces that are rapid to compute, making it useful for bounding p-values in high-dimensional screening applications. The bounds we obtain are significantly tighter than those that have been previously developed, which we illustrate with numerical examples.
READ FULL TEXT