Rational CFT With Three Characters: The Quasi-Character Approach

Understand

Quasi-characters are vector-valued modular functions having an integral, but not necessarily positive, q-expansion.

• Using modular differential equations, a complete classification has been provided in arXiv:1810.09472 for the case of two characters.
• These in turn generate all possible admissible characters, of arbitrary Wronskian index, in order two.
• Here we initiate a study of the three-character case.