Correlation effects on Z classification of non-Hermitian topology Tsuneya Yoshida U. Tsukuba For non-Hermitian systems, a variety of novel phenomena have been reported which are induced by non-Hermitian point-gap topology. While extensive works developed the non-Hermitian topological band theory, understanding correlation effects on the non-Hermitian point-gap topology remains a significant issue to be addressed. In this talk, by analyzing a zero-dimensional toy model, we show that correlations reduce the number of possible topological states; correlations change Z classification at the non-interacting level to Z2 classification. If time allows, we will also discuss a case of one-dimensional point-gap topology.