A0785
Title: CP factor model for dynamic tensors
Authors: Yuefeng Han - University of Notre Dame (United States) [presenting]
Abstract: Observations in various applications are frequently represented as a time series of multidimensional arrays, called tensor time series, preserving the inherent multidimensional structure. A factor model approach is presented, in a form similar to tensor CP decomposition, to the analysis of high-dimensional dynamic tensor time series. As the loading vectors are uniquely defined but not necessarily orthogonal, it is significantly different from the existing tensor factor models based on Tucker-type tensor decomposition. The model structure allows for a set of uncorrelated one-dimensional latent dynamic factor processes, making it much more convenient to study the underlying dynamics of the time series. A new high-order projection estimator is proposed for such a factor model, utilizing the special structure and the idea of the higher-order orthogonal iteration procedures commonly used in the Tucker-type tensor factor model and general tensor CP decomposition procedures. Theoretic al investigation provides statistical error bounds for the proposed methods, which shows the significant advantage of utilizing the special model structure.