Search Results for author: Ankit Pensia

Found 22 papers, 2 papers with code

The Sample Complexity of Simple Binary Hypothesis Testing

no code implementations25 Mar 2024 Ankit Pensia, Varun Jog, Po-Ling Loh

In this paper, we derive a formula that characterizes the sample complexity (up to multiplicative constants that are independent of $p$, $q$, and all error parameters) for: (i) all $0 \le \alpha, \beta \le 1/8$ in the prior-free setting; and (ii) all $\delta \le \alpha/4$ in the Bayesian setting.

Robust Sparse Estimation for Gaussians with Optimal Error under Huber Contamination

no code implementations15 Mar 2024 Ilias Diakonikolas, Daniel M. Kane, Sushrut Karmalkar, Ankit Pensia, Thanasis Pittas

Concretely, for Gaussian robust $k$-sparse mean estimation on $\mathbb{R}^d$ with corruption rate $\epsilon>0$, our algorithm has sample complexity $(k^2/\epsilon^2)\mathrm{polylog}(d/\epsilon)$, runs in sample polynomial time, and approximates the target mean within $\ell_2$-error $O(\epsilon)$.

A Sub-Quadratic Time Algorithm for Robust Sparse Mean Estimation

no code implementations7 Mar 2024 Ankit Pensia

We study the algorithmic problem of sparse mean estimation in the presence of adversarial outliers.

Black-Box $k$-to-$1$-PCA Reductions: Theory and Applications

no code implementations6 Mar 2024 Arun Jambulapati, Syamantak Kumar, Jerry Li, Shourya Pandey, Ankit Pensia, Kevin Tian

The $k$-principal component analysis ($k$-PCA) problem is a fundamental algorithmic primitive that is widely-used in data analysis and dimensionality reduction applications.

Dimensionality Reduction

Near-Optimal Algorithms for Gaussians with Huber Contamination: Mean Estimation and Linear Regression

no code implementations NeurIPS 2023 Ilias Diakonikolas, Daniel M. Kane, Ankit Pensia, Thanasis Pittas

We study the fundamental problems of Gaussian mean estimation and linear regression with Gaussian covariates in the presence of Huber contamination.

regression

Nearly-Linear Time and Streaming Algorithms for Outlier-Robust PCA

no code implementations4 May 2023 Ilias Diakonikolas, Daniel M. Kane, Ankit Pensia, Thanasis Pittas

Our main contribution is to develop a nearly-linear time algorithm for robust PCA with near-optimal error guarantees.

Simple Binary Hypothesis Testing under Local Differential Privacy and Communication Constraints

no code implementations9 Jan 2023 Ankit Pensia, Amir R. Asadi, Varun Jog, Po-Ling Loh

For the sample complexity of simple hypothesis testing under pure LDP constraints, we establish instance-optimal bounds for distributions with binary support; minimax-optimal bounds for general distributions; and (approximately) instance-optimal, computationally efficient algorithms for general distributions.

Outlier-Robust Sparse Mean Estimation for Heavy-Tailed Distributions

no code implementations29 Nov 2022 Ilias Diakonikolas, Daniel M. Kane, Jasper C. H. Lee, Ankit Pensia

We study the fundamental task of outlier-robust mean estimation for heavy-tailed distributions in the presence of sparsity.

Gaussian Mean Testing Made Simple

no code implementations25 Oct 2022 Ilias Diakonikolas, Daniel M. Kane, Ankit Pensia

Here we give an extremely simple algorithm for Gaussian mean testing with a one-page analysis.

Robust Sparse Mean Estimation via Sum of Squares

no code implementations7 Jun 2022 Ilias Diakonikolas, Daniel M. Kane, Sushrut Karmalkar, Ankit Pensia, Thanasis Pittas

In this work, we develop the first efficient algorithms for robust sparse mean estimation without a priori knowledge of the covariance.

Communication-constrained hypothesis testing: Optimality, robustness, and reverse data processing inequalities

no code implementations6 Jun 2022 Ankit Pensia, Varun Jog, Po-Ling Loh

We show that the sample complexity of simple binary hypothesis testing under communication constraints is at most a logarithmic factor larger than in the unconstrained setting and this bound is tight.

Streaming Algorithms for High-Dimensional Robust Statistics

no code implementations26 Apr 2022 Ilias Diakonikolas, Daniel M. Kane, Ankit Pensia, Thanasis Pittas

In this work, we develop the first efficient streaming algorithms for high-dimensional robust statistics with near-optimal memory requirements (up to logarithmic factors).

Stochastic Optimization Vocal Bursts Intensity Prediction

Optimal Lottery Tickets via Subset Sum: Logarithmic Over-Parameterization is Sufficient

1 code implementation NeurIPS 2020 Ankit Pensia, Shashank Rajput, Alliot Nagle, Harit Vishwakarma, Dimitris Papailiopoulos

We show that any target network of width $d$ and depth $l$ can be approximated by pruning a random network that is a factor $O(log(dl))$ wider and twice as deep.

Robust regression with covariate filtering: Heavy tails and adversarial contamination

no code implementations27 Sep 2020 Ankit Pensia, Varun Jog, Po-Ling Loh

We study the problem of linear regression where both covariates and responses are potentially (i) heavy-tailed and (ii) adversarially contaminated.

regression

Outlier Robust Mean Estimation with Subgaussian Rates via Stability

no code implementations NeurIPS 2020 Ilias Diakonikolas, Daniel M. Kane, Ankit Pensia

We study the problem of outlier robust high-dimensional mean estimation under a finite covariance assumption, and more broadly under finite low-degree moment assumptions.

Optimal Lottery Tickets via SubsetSum: Logarithmic Over-Parameterization is Sufficient

1 code implementation14 Jun 2020 Ankit Pensia, Shashank Rajput, Alliot Nagle, Harit Vishwakarma, Dimitris Papailiopoulos

We show that any target network of width $d$ and depth $l$ can be approximated by pruning a random network that is a factor $O(\log(dl))$ wider and twice as deep.

Extracting robust and accurate features via a robust information bottleneck

no code implementations15 Oct 2019 Ankit Pensia, Varun Jog, Po-Ling Loh

We propose a novel strategy for extracting features in supervised learning that can be used to construct a classifier which is more robust to small perturbations in the input space.

Estimating location parameters in entangled single-sample distributions

no code implementations6 Jul 2019 Ankit Pensia, Varun Jog, Po-Ling Loh

In the multivariate setting, we generalize our theory to mean estimation for mixtures of radially symmetric distributions, and derive minimax lower bounds on the expected error of any estimator that is agnostic to the scales of individual data points.

regression

Deep Topic Models for Multi-label Learning

no code implementations13 Apr 2019 Rajat Panda, Ankit Pensia, Nikhil Mehta, Mingyuan Zhou, Piyush Rai

We present a probabilistic framework for multi-label learning based on a deep generative model for the binary label vector associated with each observation.

Multi-Label Learning Topic Models

Generalization Error Bounds for Noisy, Iterative Algorithms

no code implementations12 Jan 2018 Ankit Pensia, Varun Jog, Po-Ling Loh

In statistical learning theory, generalization error is used to quantify the degree to which a supervised machine learning algorithm may overfit to training data.

Learning Theory

Cannot find the paper you are looking for? You can Submit a new open access paper.