6 papers
Sign-Rank, Index, and List Replicability: Connections and Separations
Ari Blondal, Hamed Hatami, Pooya Hatami +2
In learning theory, the sign-rank of a binary concept class captures the smallest dimension in which it can be represented by points and halfspaces. Despite tremendous interest, lo…
Tight list replicability bounds via a novel sphere covering theorem
Ari Blondal, Hamed Hatami, Pooya Hatami +2
In recent years, list replicability has emerged as a framework for formalizing reproducibility in learning theory. A central question is how the required list size relates to the a…
Simplicial covering dimension of extremal concept classes
Ari Blondal, Hamed Hatami, Pooya Hatami +2
Dimension theory is a branch of topology concerned with defining and analyzing dimensions of geometric and topological spaces in purely topological terms. In this work, we adapt th…
Borsuk-Ulam and Replicable Learning of Large-Margin Halfspaces
Ari Blondal, Hamed Hatami, Pooya Hatami +2
We prove that the list replicability number of -dimensional -margin half-spaces satisfies \[ \frac{d}{2}+1 \le \mathrm{LR}(H^d_γ) \le d, \] which grows with dimension. This…
Stability and List-Replicability for Agnostic Learners
Ari Blondal, Shan Gao, Hamed Hatami +1
Two seminal papers--Alon, Livni, Malliaris, Moran (STOC 2019) and Bun, Livni, and Moran (FOCS 2020)--established the equivalence between online learnability and globally stable PAC…
Constant-Cost Communication is not Reducible to k-Hamming Distance
Yuting Fang, Mika Göös, Nathaniel Harms +1
Every known communication problem whose randomized communication cost is constant (independent of the input size) can be reduced to -Hamming Distance, that is, solved with a con…