4 papers
Topological axion states in magnetic insulator MnBiTe with the quantized magnetoelectric effect
Dongqin Zhang, Minji Shi, Tongshuai Zhu +3
Topological states of quantum matter have attracted great attention in condensed matter physics and materials science. The study of time-reversal-invariant (TRI) topological states…
Intrinsic data depth for Hermitian positive definite matrices
Joris Chau, Hernando Ombao, Rainer von Sachs
Nondegenerate covariance, correlation and spectral density matrices are necessarily symmetric or Hermitian and positive definite. The main contribution of this paper is the develop…
Intrinsic wavelet regression for curves of Hermitian positive definite matrices
Joris Chau, Rainer von Sachs
Intrinsic wavelet transforms and wavelet estimation methods are introduced for curves in the non-Euclidean space of Hermitian positive definite matrices, with in mind the applicati…
Functional mixed effects wavelet estimation for spectra of replicated time series
Joris Chau, Rainer von Sachs
Motivated by spectral analysis of replicated brain signal time series, we propose a functional mixed effects approach to model replicate-specific spectral densities as random curve…