The term Bhattacharyya angle does not appear in widely recognized scientific literature, standard textbooks, or reputable encyclopedic sources. Consequently, it is not established as a formal concept in statistics, information theory, geometry, or related fields.
Limited Discussion
The word “Bhattacharyya” originates from the Indian statistician Anil Kumar Bhattacharyya (1903–1972), who introduced several measures of similarity and divergence between probability distributions, most notably the Bhattacharyya coefficient and the Bhattacharyya distance. These measures are commonly used in pattern recognition, hypothesis testing, and signal processing.
In certain contexts, the term “angle” is employed to denote a geometric interpretation of similarity or divergence between probability distributions—for example, the Bures angle (also called the Fubini–Study angle) in quantum information theory. It is plausible that “Bhattacharyya angle” might be used informally or in niche research to refer to an angular metric derived from the Bhattacharyya coefficient or distance, analogous to how the Hellinger distance can be related to an angle via trigonometric transformations. However, no authoritative definition, formula, or standard usage has been documented in the accessible scholarly record.
Therefore, without verifiable sources establishing a precise definition, the term remains unconfirmed in the encyclopedic sense.