A mathematical formula inscribed on a wall at the Maya site of Xultun in Guatemala has revealed the name of an important Maya mathematician-astronomer for the first time. Researchers suggest Sak Tahn Waax, or 'White-Chested Fox', was a scholar comparable with mathematical giants of the past.

In a study published 14 July in the journal Antiquity, Heather Hurst, an archaeologist at Skidmore College, and her colleagues describe their analysis of a mathematical text from a chamber excavated in 2011. The chamber's walls contain mathematical calculations based on astronomical calendars used to time events like royal inaugurations. Hurst suggests the chamber was a scribe workspace in the mid-eighth century AD.

The authors analyzed Text 19, an L-shaped group of eleven hieroglyphs about 10 centimetres tall. The first nine hieroglyphs encode a 2,920-day cycle divisible into Maya calendar units, tying together five Venus cycles (584 days each) and eight solar years (365 days each). The calculations also relate to Uinal (20 days), Tzolkin (260 days), Tun (360 days), and Mars years (780 days).

The penultimate hieroglyph contains a phrase meaning "so says," followed by the name Sak Tahn Waax in the final glyph, indicating authorship. Gerardo Aldana, an anthropologist at the University of California, Santa Barbara, notes this suggests mathematicians were recognized in Maya society like artists. Eric Heller, an archaeologist at USC Dornsife, says the discovery shows the Maya were intellectually curious people who did math for its own sake.