- Comparative religion
- Immigrant religions
- Religious diversity
- Religion and health
Selected published works
The Faith Next Door: American Christians and Their New Religious Neighbors (Oxford University Press, 2009).
"Immigrant Parochial Schools: Religion, Morality, Citizenship," in Children and Childhood in American Religions (Rutgers University Press, 2009).
The Boundaries of Knowledge in Buddhism, Christianity, and Science, editor (Vandenhoeck and Ruprecht, 2008).
Buddhists, Hindus, and Sikhs in America: A Short History, co-author (Oxford University Press, 2007).
Sacred Assemblies and Civic Engagement: How Religion Matters for America's Newest Immigrants, co-author (Rutgers University Press, 2007).