CAO Yin is an Associate Professor in the Department of History and a Tang Zhongying Young Scholar at Tsinghua University. He has a PhD in history from the National University of Singapore and a post-doctorate from the Center for Global Asia at New York University in Shanghai. His research interests include global history, modern South Asian history, and Sino-Indian relations. He is currently focusing on the relationship between infrastructure, colonial empire, and everyday life in the global tropics in the 19th and 20th centuries. He has published a monograph, From Policemen to Revolutionaries: A Sikh Diaspora in Global Shanghai, 1885-1945 (Brill，2018), with papers in Indian Historical Review, Journal of World History, South Asia: Journal of South Asian Studies, Modern Asian Studies and other journals.