Abstract
We study the problem of estimation of Nγ (θ) = ∑di=1 | θi|γ for γ > 0 and of the lγ -norm of θ for γ ≥ 1 based on the observations yi = θi + εξi, i = 1, . . ., d, where θ = (θ1, . . ., θd) are unknown parameters, ε > 0 is known, and ξi are i.i.d. standard normal random variables. We find the non-asymptotic minimax rate for estimation of these functionals on the class of s-sparse vectors θ and we propose estimators achieving this rate.
| Original language | English |
|---|---|
| Pages (from-to) | 1989-2020 |
| Number of pages | 32 |
| Journal | Bernoulli |
| Volume | 26 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 1 Aug 2020 |
| Externally published | Yes |
Keywords
- Functional estimation
- Nonsmooth functional
- Norm estimation
- Polynomial approximation
- Sparsity