activity
20242026
collaborators

6 papers

math.ST2026

Asymptotics for likelihood ratio tests of boundary points with singular information and unidentifiable nuisance parameters

Karl Oskar Ekvall, Ola Hössjer, Matteo Bottai +1

We establish the asymptotic distribution of likelihood ratio tests (LRTs) in settings where some of the nuisance parameters are unidentifiable under the null hypothesis, parameters…

stat.CO2026

Likelihood-Based Inference with Separable Correlation Matrices

Karl Oskar Ekvall

This paper proposes methods for likelihood-based inference in multivariate linear regressions when the correlation matrix of the responses is separable; that is, it has a Kronecker…

stat.ME2025

Universal inference for variance components

Yiqiao Zhang, Karl Oskar Ekvall, Aaron J. Molstad

We consider universal inference in variance components models, focusing on settings where the parameter is near or at the boundary of the parameter set. Two cases, which are not ha…

math.ST2025

Uniform inference in linear mixed models

Karl Oskar Ekvall, Matteo Bottai

We provide finite-sample distribution approximations, that are uniform in the parameter, for inference in linear mixed models. Focus is on variances and covariances of random effec…

stat.ME2024

Fast and reliable confidence intervals for a variance component

Yiqiao Zhang, Karl Oskar Ekvall, Aaron J. Molstad

We show that confidence intervals in a variance component model, with asymptotically correct uniform coverage probability, can be obtained by inverting certain test-statistics base…

stat.ME2024

Direct covariance matrix estimation with compositional data

Aaron J. Molstad, Karl Oskar Ekvall, Piotr M. Suder

Compositional data arise in many areas of research in the natural and biomedical sciences. One prominent example is in the study of the human gut microbiome, where one can measure…