English

Adaptive estimation in symmetric location model under log-concavity constraint

Statistics Theory 2023-12-05 v2 Statistics Theory

Abstract

We revisit the problem of estimating the center of symmetry θ\theta of an unknown symmetric density ff. Although stone (1975), Eden (1970), and Sacks (1975) constructed adaptive estimators of θ\theta in this model, their estimators depend on external tuning parameters. In an effort to reduce the burden of tuning parameters, we impose an additional restriction of log-concavity on ff. We construct truncated one-step estimators which are adaptive under the log-concavity assumption. Our simulations suggest that the untruncated version of the one step estimator, which is tuning parameter free, is also asymptotically efficient. We also study the maximum likelihood estimator (MLE) of θ\theta in the shape-restricted model.

Keywords

Cite

@article{arxiv.2105.04287,
  title  = {Adaptive estimation in symmetric location model under log-concavity constraint},
  author = {Nilanjana Laha},
  journal= {arXiv preprint arXiv:2105.04287},
  year   = {2023}
}

Comments

In this version, several minor mistakes in the previous version have been corrected. You can find a detailed list of these corrections on the last page of this manuscript. To summarize, fixed algebraic mistake in Theorem 1 proof. Corrected (log n)^2 to (log n)^4 in Lemma B.12. Revised proof of Fact 4 using algebraic inequality (Fact 16)

R2 v1 2026-06-24T01:56:28.119Z