activity
20112026
most citedFast Exact k-Means, k-Medians and Bregman Divergence Clustering in 1D

48 citations · 181 across the 49 of their papers we have counts for

collaborators

56 papers

cs.DS2026

The Binary Tree Mechanism is Optimal for Differentially Private Continual Counting

Konstantina Bairaktari, Kasper Green Larsen, Markus Engelund Dahl

Private continual counting is a fundamental problem in differential privacy: given a binary stream of length , where each corresponds to the contribution of one individual,…

cs.DS2023

Optimal Non-Adaptive Cell Probe Dictionaries and Hashing

Kasper Green Larsen, Rasmus Pagh, Giuseppe Persiano +3

We present a simple and provably optimal non-adaptive cell probe data structure for the static dictionary problem. Our data structure supports storing a set of n key-value pairs fr…

cs.DS2023

Sublinear Time Shortest Path in Expander Graphs

Noga Alon, Allan Grønlund, Søren Fuglede Jørgensen +1

Computing a shortest path between two nodes in an undirected unweighted graph is among the most basic algorithmic tasks. Breadth first search solves this problem in linear time, wh…

cs.DS2023

Invertible Bloom Lookup Tables with Less Memory and Randomness

Nils Fleischhacker, Kasper Green Larsen, Maciej Obremski +1

In this work we study Invertible Bloom Lookup Tables (IBLTs) with small failure probabilities. IBLTs are highly versatile data structures that have found applications in set reconc…

cs.DS2023

Super-Logarithmic Lower Bounds for Dynamic Graph Problems

Kasper Green Larsen, Huacheng Yu

In this work, we prove a unconditional lower bound on the maximum of the query time and update time for dynamic data structures supporting reachability quer…

cs.DS2023

Sparse Dimensionality Reduction Revisited

Mikael Møller Høgsgaard, Lion Kamma, Kasper Green Larsen +2

The sparse Johnson-Lindenstrauss transform is one of the central techniques in dimensionality reduction. It supports embedding a set of points in into $m=O(\vare…

cs.LG2023★ 1 cited

AdaBoost is not an Optimal Weak to Strong Learner

Mikael Møller Høgsgaard, Kasper Green Larsen, Martin Ritzert

AdaBoost is a classic boosting algorithm for combining multiple inaccurate classifiers produced by a weak learner, to produce a strong learner with arbitrarily high accuracy when g…

cs.LG2023

The Impossibility of Parallelizing Boosting

Amin Karbasi, Kasper Green Larsen

The aim of boosting is to convert a sequence of weak learners into a strong learner. At their heart, these methods are fully sequential. In this paper, we investigate the possibili…

cs.LG2022★ 3 cited

Bagging is an Optimal PAC Learner

Kasper Green Larsen

Determining the optimal sample complexity of PAC learning in the realizable setting was a central open problem in learning theory for decades. Finally, the seminal work by Hanneke…

cs.DS2022

Hierarchical Categories in Colored Searching

Peyman Afshani, Rasmus Killman, Kasper Green Larsen

In colored range counting (CRC), the input is a set of points where each point is assigned a ``color'' (or a ``category'') and the goal is to store them in a data structure such th…

cs.DS2022

Barriers for Faster Dimensionality Reduction

Ora Nova Fandina, Mikael Møller Høgsgaard, Kasper Green Larsen

The Johnson-Lindenstrauss transform allows one to embed a dataset of points in into while preserving the pairwise distance between any pair of po…

cs.DS2022

Fast Discrepancy Minimization with Hereditary Guarantees

Kasper Green Larsen

Efficiently computing low discrepancy colorings of various set systems, has been studied extensively since the breakthrough work by Bansal (FOCS 2010), who gave the first polynomia…

cs.LG2022★ 4 cited

Optimal Weak to Strong Learning

Kasper Green Larsen, Martin Ritzert

The classic algorithm AdaBoost allows to convert a weak learner, that is an algorithm that produces a hypothesis which is slightly better than chance, into a strong learner, achiev…

cs.DS2022★ 1 cited

The Fast Johnson-Lindenstrauss Transform is Even Faster

Ora Nova Fandina, Mikael Møller Høgsgaard, Kasper Green Larsen

The seminal Fast Johnson-Lindenstrauss (Fast JL) transform by Ailon and Chazelle (SICOMP'09) embeds a set of points in -dimensional Euclidean space into optimal $k=O(\vareps…

cs.DS2022★ 2 cited

Stronger 3SUM-Indexing Lower Bounds

Eldon Chung, Kasper Green Larsen

The SUM-Indexing problem was introduced as a data structure version of the SUM problem, with the goal of proving strong conditional lower bounds for static data structures vi…

cs.DS2022★ 4 cited

Towards Optimal Lower Bounds for k-median and k-means Coresets

Vincent Cohen-Addad, Kasper Green Larsen, David Saulpic +1

Given a set of points in a metric space, the -clustering problem consists of finding a set of points called centers, such that the sum of distances raised to the power o…

cs.DS2021★ 1 cited

Optimality of the Johnson-Lindenstrauss Dimensionality Reduction for Practical Measures

Yair Bartal, Ora Nova Fandina, Kasper Green Larsen

It is well known that the Johnson-Lindenstrauss dimensionality reduction method is optimal for worst case distortion. While in practice many other methods and heuristics are used,…

cs.LG2021

Compression Implies Generalization

Allan Grønlund, Mikael Høgsgaard, Lior Kamma +1

Explaining the surprising generalization performance of deep neural networks is an active and important line of research in theoretical machine learning. Influential work by Arora…

cs.CR2021

Property-Preserving Hash Functions from Standard Assumptions

Nils Fleischhacker, Kasper Green Larsen, and Mark Simkin

Property-preserving hash functions allow for compressing long inputs and into short hashes and in a manner that allows for computing a predicate $P(x_…

cs.DS2021

CountSketches, Feature Hashing and the Median of Three

Kasper Green Larsen, Rasmus Pagh, Jakub Tětek

In this paper, we revisit the classic CountSketch method, which is a sparse, random projection that transforms a (high-dimensional) Euclidean vector to a vector of dimension $(…

cs.LG2020★ 3 cited

Margins are Insufficient for Explaining Gradient Boosting

Allan Grønlund, Lior Kamma, Kasper Green Larsen

Boosting is one of the most successful ideas in machine learning, achieving great practical performance with little fine-tuning. The success of boosted classifiers is most often at…

cs.DS2020

Further Unifying the Landscape of Cell Probe Lower Bounds

Kasper Green Larsen, Jonathan Lindegaard Starup, Jesper Steensgaard

In a landmark paper, Pǎtraşcu demonstrated how a single lower bound for the static data structure problem of reachability in the butterfly graph, could be used to derive a wealth o…

cs.LG2020★ 7 cited

Near-Tight Margin-Based Generalization Bounds for Support Vector Machines

Allan Grønlund, Lior Kamma, Kasper Green Larsen

Support Vector Machines (SVMs) are among the most fundamental tools for binary classification. In its simplest formulation, an SVM produces a hyperplane separating two classes of d…

cs.DS2019

Optimal Learning of Joint Alignments with a Faulty Oracle

Kasper Green Larsen, Michael Mitzenmacher, Charalampos E. Tsourakakis

We consider the following problem, which is useful in applications such as joint image and shape alignment. The goal is to recover discrete variables $g_i \in \{0, \ldots, k-1\…