activity
20182025
most citedStructure-adaptive manifold estimation

15 citations · 19 across the 7 of their papers we have counts for

collaborators

7 papers

math.ST2025

Dimension-free Bounds for Covariance Estimation with Tensor-Train Structure

Artsiom Patarusau, Nikita Puchkin, Maxim Rakhuba +1

We consider a problem of covariance estimation from a sample of i.i.d. high-dimensional random vectors. To avoid the curse of dimensionality, we impose an additional assumption on…

math.ST2025

Dimension-free bounds in high-dimensional linear regression via error-in-operator approach

Fedor Noskov, Nikita Puchkin, Vladimir Spokoiny

We consider a problem of high-dimensional linear regression with random design. We suggest a novel approach referred to as error-in-operator which does not estimate the design cova…

math.PR2023

Sharper dimension-free bounds on the Frobenius distance between sample covariance and its expectation

Nikita Puchkin, Fedor Noskov, Vladimir Spokoiny

We study properties of a sample covariance estimate given a finite sample of i.i.d. centered random elements in with the covariance matrix . We derive di…

math.ST2020

Manifold-based time series forecasting

Nikita Puchkin, Aleksandr Timofeev, Vladimir Spokoiny

Prediction for high dimensional time series is a challenging task due to the curse of dimensionality problem. Classical parametric models like ARIMA or VAR require strong modeling…

math.OC2020★ 2 cited

Reconstruction of manifold embeddings into Euclidean spaces via intrinsic distances

Nikita Puchkin, Vladimir Spokoiny, Eugene Stepanov +1

We consider the problem of reconstructing an embedding of a compact connected Riemannian manifold in a Euclidean space up to an almost isometry, given the information on intrinsic…

math.ST2019★ 15 cited

Structure-adaptive manifold estimation

Nikita Puchkin, Vladimir Spokoiny

We consider a problem of manifold estimation from noisy observations. Many manifold learning procedures locally approximate a manifold by a weighted average over a small neighborho…

stat.ML2018★ 2 cited

An adaptive multiclass nearest neighbor classifier

Nikita Puchkin, Vladimir Spokoiny

We consider a problem of multiclass classification, where the training sample is generated from the model , $1 \le…