Before revision:  These bounds significantly improve existing results for indefinite B, reducing the the number of required samples by a factor n or even more, where n is the size of A . Even for an SPD matrix, our work improves an existing result by Roosta-Khorasani and Ascher for Rademacher vectors.
After revision:  These bounds significantly improve existing results for indefinite B, reducing the the number of required samples by a factor n or even more, where n is the size of B . Even for an SPD matrix, our work improves an existing result by Roosta-Khorasani and Ascher for Rademacher vectors.