Conjecture on gradient-descent performance in overparameterized neural networks

Suppose a neural net has O(n)O(n) parameters and the input data are generic. Let FF be its loss, and define the gradient-descent algorithm by

A(θ)=θηF(θ).\mathcal{A}(\theta)=\theta-\eta\nabla F(\theta).

For an initial point θ\theta drawn randomly from a specified distribution, define

ϕA(θ)=lim infkF(Ak(θ)).\phi_{\mathcal{A}}(\theta)=\liminf_{k\rightarrow\infty}F(\mathcal{A}^k(\theta)).

Gradient-descent performance conjecture. For a proper constant η\eta, and for a random initial point drawn from a certain distribution, such as Xavier initialization,

Pr(ϕA(θ)<ϵ)>1δ,\Pr\bigl(\phi_{\mathcal{A}}(\theta)<\epsilon\bigr)>1-\delta,

where ϵ\epsilon and δ\delta are certain small constants. This informal conjecture proposes high-probability near-zero limiting loss for gradient descent in an overparameterized, generic-data regime; the source does not provide a proof or precise conditions for the constants and initialization distribution.

Sources & referencesView supporting material

Primary source

Ruoyu Sun, Dawei Li, Shiyu Liang, Tian Ding and R Srikant, “The Global Landscape of Neural Networks: An Overview”, arXiv:2007.01429 (2020).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.