British journalist/writer Graham Hancock is probably the most popular of these "alternative history" researchers. Hancock has been working on the history of the civilization since the early nineties and suggested a connection between Indus-Harappan civilization and the relatively late American (South and Mesoamerica) cultures, first in his "Fingerprints of the Gods" in mid-nineties. But his 2002 work "Underworld" is particularly on Indus-Harappa culture and its possible connections with Peru and Yucatan civilizations. Of course, Graham's thesis are generally very sp...

British journalist/writer Graham Hancock is probably the most popular of these "alternative history" researchers. Hancock has been working on the history of the civilization since the early nineties and suggested a connection between Indus-Harappan civilization and the relatively late American (South and Mesoamerica) cultures, first in his "Fingerprints of the Gods" in mid-nineties. But his 2002 work "Underworld" is particularly on Indus-Harappa culture and its possible connections with Peru and Yucatan civilizations. Of course, Graham's thesis are generally very speculative and should be read with caution but he has many interesting and intriguing points as well.

Another interesting researcher is David Frawley. I think I mentioned the book which he wrote with scholars Georg Feuerstein and Shubash Kak, "In Search of the Cradle of Civilization". As well as analyzing the roots of Harappan civilization and its relations with Sumerians and Egyptians, this book tries to decode the astronomical data on the vedic texts and show the parallels between Indus and Mayan cosmologies, mathematics and calendars.

David Cruttenden's works on archaeoastronomy, especially "The Lost Star of Myth and Time" also suggests a direct connection between vedic Yugas and Mayan Calendar. John Major Jenkins, in his "2012 Mayan Cosmogenesis" pays attention to the similarities of the myths and cosmic time-spans between Indian and Mesoamerican astronomical lores. Of course there are many others and though some of them sound somewhat "very unorthodox" or "fictituous", latest archaeological researches slowly began bringing light to the subject. For example, Peruvian archaeologist Ruth Shady's discoveries at Supe Valley, the ancient city of Caral, shows surprising similarities with ancient Indus-Harappan settlements.