As I said, this is a theory which needs scrutiny. There are several points which deserve merit. For photos see http://www.stephen-knapp.com/was_the_taj_mahal_a_vedic_temple.htm
1. Trishul symbol on Top. 2. Cocunut leaves in a vessel. We use it in all Hindu pujas. Can you imagine a Muslim using that. 3. Music house next to a mosque ? 4. Inlaid pinnacle pattern in courtyard ? 5. Red lotus at apex of the entrance. 6. Typical Vedic style corridors. 7. A locked room on upper floor and ground floor. Why is it locked ? 8. Vedic design on ceiling of a locked room. 9. The OM in the flowers on the walls. 10. Palace in Barhanpur where Mumtaz died ?