activity
20082026
most citedUniversality of covariance matrices

155 citations · 955 across the 56 of their papers we have counts for

collaborators

69 papers

math.PR2026

On the Pseudo-Mixing of Kac's Walk

Natesh S. Pillai, Aaron Smith, Vinod Vaikuntanathan

Motivated by a conjecture of Vaikuntanathan and Zamir, we study the pseudo-mixing of Kac's walk on : whether short trajectories are indistinguishable from Haar meas…

math.PR2026

Kac's walk on rotation matrices mixes in steps

Natesh S. Pillai, Aaron Smith

Kac's walk on the rotation group, introduced by Hastings in 1970, is an important high-dimensional Markov chain with applications in statistical physics, statistics, cryptography,…

math.ST2026

Microergodicity implies orthogonality of Matérn fields on bounded domains in

Natesh S. Pillai

Matérn random fields are one of the most widely used classes of models in spatial statistics. The fixed-domain identifiability of covariance parameters for stationary Matérn Gaussi…

stat.ME2025

A Heavily Right Strategy for Statistical Inference with Dependent Studies in Arbitrary Dimensions

Tianle Liu, Xiao-Li Meng, Natesh S. Pillai

We leverage recent advances in heavy-tail approximations for global hypothesis testing with dependent studies to construct approximate confidence regions without modeling or estima…

stat.CO2024

No Free Lunch for Stochastic Gradient Langevin Dynamics

Natesh S. Pillai, Aaron Smith, Azeem Zaman

As sample sizes grow, scalability has become a central concern in the development of Markov chain Monte Carlo (MCMC) methods. One general approach to this problem, exemplified by t…

cs.LG2024

Privacy-Preserving Race/Ethnicity Estimation for Algorithmic Bias Measurement in the U.S

Saikrishna Badrinarayanan, Osonde Osoba, Miao Cheng +4

AI fairness measurements, including tests for equal treatment, often take the form of disaggregated evaluations of AI systems. Such measurements are an important part of Responsibl…

stat.CO2024

Policy Gradients for Optimal Parallel Tempering MCMC

Daniel Zhao, Natesh S. Pillai

Parallel tempering is a meta-algorithm for Markov Chain Monte Carlo that uses multiple chains to sample from tempered versions of the target distribution, enhancing mixing in multi…

math.ST2023★ 3 cited

Towards Understanding the Dynamics of Gaussian-Stein Variational Gradient Descent

Tianle Liu, Promit Ghosal, Krishnakumar Balasubramanian +1

Stein Variational Gradient Descent (SVGD) is a nonparametric particle-based deterministic sampling algorithm. Despite its wide usage, understanding the theoretical properties of SV…

stat.CO2022

Optimal Scaling for the Proximal Langevin Algorithm in High Dimensions

Natesh S. Pillai

The Metropolis-adjusted Langevin (MALA) algorithm is a sampling algorithm that incorporates the gradient of the logarithm of the target density in its proposal distribution. In an…

stat.ME2021★ 4 cited

A Bayesian Gaussian Process for Estimating a Causal Exposure Response Curve in Environmental Epidemiology

Boyu Ren, Xiao Wu, Danielle Braun +2

Motivated by environmental policy questions, we address the challenges of estimation, change point detection, and uncertainty quantification of a causal exposure-response function…

stat.CO2020★ 5 cited

No Free Lunch for Approximate MCMC

James E. Johndrow, Natesh S. Pillai, Aaron Smith

It is widely known that the performance of Markov chain Monte Carlo (MCMC) can degrade quickly when targeting computationally expensive posterior distributions, such as when the sa…

math.PR2020

Universality and least singular values of random matrix products: a simplified approach

Rohit Chaudhuri, Vishesh Jain, Natesh S. Pillai

In this note, we show how to provide sharp control on the least singular value of a certain translated linearization matrix arising in the study of the local universality of produc…

stat.CO2020★ 3 cited

Rate-optimal refinement strategies for local approximation MCMC

Andrew D. Davis, Youssef Marzouk, Aaron Smith +1

Many Bayesian inference problems involve target distributions whose density functions are computationally expensive to evaluate. Replacing the target density with a local approxima…

cs.DS2020

Fast and memory-optimal dimension reduction using Kac's walk

Vishesh Jain, Natesh S. Pillai, Ashwin Sah +2

In this work, we analyze dimension reduction algorithms based on the Kac walk and discrete variants. (1) For points in , we design an optimal Johnson-Lindenstra…

stat.CO2018★ 13 cited

Unbiased estimation of log normalizing constants with applications to Bayesian cross-validation

Maxime Rischard, Pierre E. Jacob, Natesh Pillai

Posterior distributions often feature intractable normalizing constants, called marginal likelihoods or evidence, that are useful for model comparison via Bayes factors. This has m…

math.PR2018★ 4 cited

Simple Conditions for Metastability of Continuous Markov Chains

Oren Mangoubi, Natesh S. Pillai, Aaron Smith

A family of Markov chains is said to exhibit with if its spectral gap (or some other…

math.PR2018★ 17 cited

Does Hamiltonian Monte Carlo mix faster than a random walk on multimodal densities?

Oren Mangoubi, Natesh S. Pillai, Aaron Smith

Hamiltonian Monte Carlo (HMC) is a very popular and generic collection of Markov chain Monte Carlo (MCMC) algorithms. One explanation for the popularity of HMC algorithms is their…

stat.AP2018★ 6 cited

Bias correction in daily maximum and minimum temperature measurements through Gaussian process modeling

Maxime Rischard, Natesh Pillai, Karen A. McKinnon

The Global Historical Climatology Network-Daily database contains, among other variables, daily maximum and minimum temperatures from weather stations around the globe. It is long…

stat.AP2017★ 12 cited

Diagnosing missing always at random in multivariate data

Iavor Bojinov, Natesh Pillai, Donald Rubin

Models for analyzing multivariate data sets with missing values require strong, often unassessable, assumptions. The most common of these is that the mechanism that created the mis…

math.PR2017

Mixing Times for a Constrained Ising Process on the Two-Dimensional Torus at Low Density

Natesh S Pillai, Aaron Smith

We study a kinetically constrained Ising process (KCIP) associated with a graph and density parameter ; this process is an interacting particle system with state space $\{ 0…

math.ST2017

Designs for estimating the treatment effect in networks with interference

Ravi Jagadeesan, Natesh Pillai, Alexander Volfovsky

In this paper we introduce new, easily implementable designs for drawing causal inference from randomized experiments on networks with interference. Inspired by the idea of matchin…

stat.ME2017

Optimal Scaling of the MALA algorithm with Irreversible Proposals for Gaussian targets

Michela Ottobre, Natesh S. Pillai, Konstantinos Spiliopoulos

It is well known in many settings that reversible Langevin diffusions in confining potentials converge to equilibrium exponentially fast. Adding irreversible perturbations to the d…

stat.ME2016★ 4 cited

A Divide and Conquer Strategy for High Dimensional Bayesian Factor Models

Gautam Sabnis, Debdeep Pati, Barbara Engelhardt +1

We propose a distributed computing framework, based on a divide and conquer strategy and hierarchical modeling, to accelerate posterior inference for high-dimensional Bayesian fact…

stat.CO2016

Parallel local approximation MCMC for expensive models

Patrick Conrad, Andrew Davis, Youssef Marzouk +2

Performing Bayesian inference via Markov chain Monte Carlo (MCMC) can be exceedingly expensive when posterior evaluations invoke the evaluation of a computationally expensive model…