5 problems

Optimality conjecture. The bound

Let $\bm H_n=\bm W_{pq}^{n}(\bm W_{pq}^{n})^{\top}$ be the matrix from Theorem, where $\bm W_q^n=\bm V_{\perp}^{n_2}\otimes\bm U_{\perp}^{n_1}$ forms a concentrated sequence of sem…

Let TIHT denote the tensor iterative hard thresholding algorithm, and consider its recovery performance as the number of epochs increases. TIHT epoch requirement conjecture. The TI…

Let $\Pi_{k,\mathcal{A}}(\cdot)$ denote the projection operator onto the model class with sparsity or complexity level $k$ and structure $\mathcal{A}$. In the theory under discussi…

Let $\tau$ be the momentum parameter in the accelerated iterative hard thresholding method, and suppose that its use produces “ripples” in the function values. Adaptive-momentum co…