Kṛṣṇa Daivajña

The man in the middle with white turban and casting the horoscope is believed to be Kṛṣṇa Daivajña. Kṛṣṇa Daivajña was a 16th-17th century Indian astrologer-astronomer-mathematician from Varanasi patronized by the Mughal Emperor Jahangir. As a mathematician Kṛṣṇa Daivajña is best known for his elaborate commentary on Bhaskara II's (c. 1114–1185) Bījagaṇita and, as an astrologer, his fame rested on his commentary on Śrīpati's (c. 1019 – 1066) Jātakapaddhati. These commentaries contain not only detailed explanations of the text being commented upon, but also the rationales of the various rules and often additional original material. He has also composed an original work by name Chādakanirṇaya dealing with eclipses.

Kṛṣṇa Daivajña's family originally lived in Dadhigrama in the Vidarbha region; his father moved his family to Varanasi and took residence there. Kṛṣṇa Daivajña's father was Ballāla and his grandfather was Trimalla. He had five brothers of whom Ranganātha was known for his commentary Guḍharthaprāśikā on Suryasiddhanta. Several of his nephews, these include Munīśvara, Gadādhara and Nārāyaṇa, have composed reputed works on astrology and astronomy. He studied under Viṣṇu, a pupil of Nṛsiṃha who was a pupil and nephew of Gaṇeśa Daivajna the author of Grahalāghava.

Works

Bījapallava: Commentary on Bhāskara II's Bījagaṇita

Among Kṛṣṇa Daivajña's various commentaries, the more widely known and studied one is his commentary called Bījapallava (also called Kalpālatāvatāra, Bījānkura and Nāvāakura) on Bījagaṇita. The commentary is in Sanskrit prose and contains more details than that are generally given in other conventional commentaries. T. Hayashi, a Japanese historian of Indian mathematics, in his forward to the critical edition of Bījapallava, writes: ". . . he [Kṛṣṇa Daivajña] goes on to discuss the mathematical contents in great detail, giving proofs (upapattis) for the rules and step-by-step solutions for the examples; but when the solution is easy, he merely refers to Bhaskara's auto-commentary. His discussions, often in the form of disputations between an imaginary opponent and himself, go deep into the nature of important mathematical concepts such as negative quantity, zero and unknown quantity, into the raison d'être of particular steps of the algorithms, and into various conditions for solubility of the mathematical problems treated in the Bijaganita."