What is the fine-grained topic of the following text: During his stay in the United States, he is simultaneously inspired by the abstract expressionism that was dominating the art world at the time and by surrealism, as it had been reinterpreted and exploited by the American artists, particularly under the influence of Arshile Gorky. Only return the topic.
Influence of American Abstract Expressionism and Surrealism on a Foreign Artist.