Higher string functions, higher-level Appell functions, and the logarithmic CFT model
Oct, 2007Citations per year
Abstract: (arXiv)
We generalize the string functions C_{n,r}(tau) associated with the coset ^sl(2)_k/u(1) to higher string functions A_{n,r}(tau) and B_{n,r}(tau) associated with the coset W(k)/u(1) of the W-algebra of the logarithmically extended ^sl(2)_k conformal field model with positive integer k. The higher string functions occur in decomposing W(k) characters with respect to level-k theta and Appell functions and their derivatives (the characters are neither quasiperiodic nor holomorphic, and therefore cannot decompose with respect to only theta-functions). The decomposition coefficients, to be considered ``logarithmic parafermionic characters,'' are given by A_{n,r}(tau), B_{n,r}(tau), C_{n,r}(tau), and by the triplet \mathscr{W}(p)-algebra characters of the (p=k+2,1) logarithmic model. We study the properties of A_{n,r} and B_{n,r}, which nontrivially generalize those of the classic string functions C_{n,r}, and evaluate the modular group representation generated from A_{n,r}(tau) and B_{n,r}(tau)/ its structure inherits some features of modular transformations of the higher-level Appell functions and the associated transcendental function Phi.- string
- field theory: conformal
- mathematical methods
- transformation: modular
- algebra: W(N)
- algebra: representation
- quantum group
- algebra: SL(2)
- character
References(43)
Figures(0)