Who is the author of Noruznameh?

Among books and treaties ascribed to Khayyam, there is a treatise in the name of Noruznameh which has been ascribed to Khayyam since the antiquity. Mojtaba Minovi in 1312 published it in the name of Khayyam and in its introduction, he has recognized no one as worthy of the title author but Khayyam. Shortly afterwards certain individuals such as Minoverski, the renowned orientalist due to certain reasons opposed to the idea, till Mohsen Farzaneh in the article he wrote in Ayandeh magazine claimed that the author of Noruznameh is not Khayyam but is a person in the name of Kaykhosrow shirazi. While studying Jamali’s Farrokhnameh, written by Abubakr Motahar Jamali yazdi in the year 580 Hj, Farzaneh realized certain similarities in phrases of the book with that of Noruznameh which the writer quoted on the behalf of Kaykhosrow Shirazi. Based on a few similarities between the two, Farzaneh believes that the writer of Noruznameh is Kaykhosrow Shirazi but he also writes that apart from Farokhnameh he has not come across this name and that he does not know who he really is. In this article Farzaneh’s assumption has been verified and strengthened based on other lines of evidence. Kaykhosrow’s real identity was also revealed.