He traveled to India in 1995, with a fellowship from the Spanish Agency for International Cooperation (AECI) and at the University of Varanasi (Banaras Hindu University, BHU), where he began his studies of Indian philosophy and culture with Catalan Sanskritist Oscar Pujol.
From India he went to Mexico, where he did his PhD at the Centre for Asian and African Studies at El Colegio de México, studying Sanskrit with Rashik Vihari Joshi.
After completing his PhD he moved to Ann Arbor (Michigan) for six years, where he did postdoctoral research at the Department of Asian Languages and Cultures of the University of Michigan, with Luis Ó. Gomez. Meanwhile, he taught Spanish, and Latin American Literature and Cinema, in the Department of Romance Languages.
Juan Arnau has made the critical editions, translated directly from Sanskrit, from the philosophical treatises of Nāgārjuna, as well as from the Bhagavad Gita and the Upanishads:
Fundamentos de la vía media (2004). (Fundamentals of the Middle Way). Direct translation from Sanskrit. Madrid: Siruela. ISBN9788478447626.
Abandono de la discusión (2006). (Leaving discussion). Direct translation from Sanskrit. Madrid: Siruela. ISBN9788478442478.
El Mulamadhyamakakarikah de Nagarjuna: la vacuidad como medio hábil (2002). Tesis doctoral. Colegio de México, Centro de Estudios de Asia y África.
Actualidad del pensamiento de Nagarjuna (2005). Colegio de México, Centro de Estudios de Asia y África.
La palabra frente al vacío. Filosofía de Nagarjuna (2005). (Language against Emptiness. Philosophy of Nagarjuna). México D.F.: Fondo de Cultura Económica. ISBN9789681675172.
Antropología del budismo (2007). (Anthropology of Buddhism). Barcelona: Kairós. ISBN978-84-7245-645-7.
Arte de probar. Ironía y lógica en India antigua (2008). (Art of proving. Irony and logic in ancient India). Madrid: Fondo de Cultura Económica. ISBN978-84-375-0621-0.
Rendir el sentido. Filosofía y traducción (2008). (Rendering sense. Philosophy and translation). Valencia: Pre-Textos. ISBN978-84-8191-865-6.
Elogio del asombro. Conversaciones con Agustín Andreu (2010). (Praise of amazement. Conversations with Agustin Andreu). Valencia: Pre-Textos. ISBN978-84-92913-18-3.
Vasubandhu / Berkeley (2011). With Carlos Mellizo. Valencia: Pre-Textos. ISBN978-84-15297-00-0.
Leyenda de Buda (2011). (Legend of the Buddha). Alianza. ISBN9788420652795.
Cosmologías de India. Védica, samkhya y budista (2012). (Cosmologies of India. Vedic Samkhya and Buddhist). Fondo de Cultura Económica. ISBN978-6071-610003.
La medicina india. Según las fuentes del Ayurveda (2013). Kairós. ISBN9788499883021.