Why study Carnatic Music Theory?
For a beginner learning instruments like Veena, knowledge of notes speeds up the learning process. At a more advanced level, a knowledge of the structure of a Raagam can help to sing a piece for which there is no recording but notation is available.
A Rasika can enjoy music whether he knows the theory or not, but most of the time a Carnatic music Rasika wants to find the Raagam of a song he hears! Or he would like to know, how one Raagam differs from another. He could be given examples of songs but an explanation based on notes and nuances would help a lot.
The program Rasika part of Rasika-Gaayaka-Sishya Carnatic Music Software package (works with Windows OS) was aimed at satisfying these needs. Books do not help as they have no audio. Even if an audio CD comes with a book it is quite difficult for the listener to correlate the two. A Computer helps to give a combined Text-Visual-Audio view.
The descriptions are based on my six decades of experience with Carnatic Music (as a student, amateur musician, teacher and above all Rasika), extensive reading including old books (like Sangeetha Ratnaakara, Chaturdandiprakaasika, Raagavibodham etc.) and analysing using computer techniques. The ideas may differ from the standard texts in books. Though I can justify my ideas, if you are appearing for some examination, stick to the definitions and descriptions in the books prescribed as part of your syllabus.