6 papers
On Minimax Optimality and Uniqueness of Fixed-Step First-Order Methods for Smooth Convex Optimization
Benjamin Grimmer, Sunghyeon Jo, Chanwoo Park
This paper considers the design of optimal fixed-step first-order methods for high-dimensional minimization of -smooth convex functions. For optimizing worst-case performance me…
An Improved Upper Bound for Multicolour Ramsey Numbers
Sunghyeon Jo
Let denote the diagonal -colour Ramsey number. We prove that there exist absolute constants such that $R_r(k)\le r^{rk}\exp\!\left(-c\frac{k}{r\log^2(2r)}\right…
The Exact Online Threshold for the Asymmetric Binary Perceptron
Sunghyeon Jo, Taekyun Lee
Let have independent standard Gaussian entries. For a fixed margin , the asymmetric binary perceptron asks for such th…
A counterexample to Haagerup's problem on subadditive weights
Ikhan Choi, Sunghyeon Jo
We construct a subadditive weight on the type I factor that preserves directed suprema but is not -weakly lower semi-continuous. This provides a counterexample to Haage…
The Sample Complexity of Fidelity Estimation to a Known Rank- Reference State Is
Gye Jin Lee, Sunghyeon Jo
We settle the sample complexity of estimating the root Uhlmann fidelity between an unknown state and a known rank- reference s…
Tighter Bounds for the Random-Offerer Mechanism in Bilateral Trade
Sunghyeon Jo
The random-offerer mechanism for bilateral trade selects the seller or the buyer uniformly and lets the selected agent make a profit-maximizing take-it-or-leave-it offer. Let $ρ_{\…