Commun. Math. Phys. 390, 169–192 (2022)

Digital Object Identifier https://doi.org/10.1007/s00220-021-04291-9

We correct some errors in [CTW22].

The first one is concerned with Proposition 3.3. The constant \(C'\) should actually be \(C'' = (1+|k|)^\frac{\beta +1}{2}\sqrt{\frac{C}{|k|(\beta +1)}}\) instead of \(C' = \sqrt{\frac{C}{k(\beta +1)}}\). This does not affect the main results of the paper, because we only need that there is such a constant, and we do not need the specific dependence on k. On the other hand, this specific dependence could be useful for other purposes.

The previous value of \(C'\) works for \(\phi _k\) with \(k>0\), but for \(\phi _{-k}\) there is a sign mistake at the commutation relation between \(\phi _{-k}\) and \(L_0\) in the last displayed formula of the proof.

To see that the corrected \(C''\) work for \(-k\) (in the assumption k and \(-k\) needs to be exchanged but it results in the same inequality) for \(\Psi _n\) a generic vector in \(V_n\), we calculate

$$\begin{aligned} \Vert \phi _{-k}(L_0 + \mathbbm {1})^{-\frac{\beta +1}{2}}\Psi _n\Vert ^2&=\Vert \phi _{-k}(n + \mathbbm {1})^{-\frac{\beta +1}{2}}\Psi _n\Vert ^2 \\&\le (1 + k)^{\beta +1}\Vert \phi _{-k}(n + \mathbbm {1} + k)^{-\frac{\beta +1}{2}}\Psi _n\Vert ^2 \\&= (1 + k)^{\beta +1}\Vert (L_0 + \mathbbm {1})^{-\frac{\beta +1}{2}}\phi _{-k}\Psi _n\Vert ^2 \\&\le (1 + k)^{\beta +1}\Vert (L_0 + \mathbbm {1})^{-\frac{\beta +1}{2}}\phi _{-k}\Vert ^2 \cdot \Vert \Psi _n\Vert ^2 \\&\le (1 + k)^{\beta +1}\Vert \phi _{k}(L_0 + \mathbbm {1})^{-\frac{\beta +1}{2}}\Vert ^2 \cdot \Vert \Psi _n\Vert ^2 \\&\le (1 + k)^{\beta +1}(C')^2 \Vert \Psi _n\Vert ^2. \end{aligned}$$

As \(\phi _{-k}(L_0 + \mathbbm {1})^{-\frac{\beta +1}{2}}\Psi _n\) are mutually orthogonal for different n, for a general \(\Psi \) we obtain \(\Vert \phi _{-k}(L_0 + \mathbbm {1})^{-\frac{\beta +1}{2}}\Psi \Vert ^2 \le (1 + k)^{\beta +1}(C')^2 \Vert \Psi \Vert ^2\), which is what we had to prove with \(C'' = (1+k)^{\frac{\beta +1}{2}}\sqrt{\frac{C}{k(\beta + 1)}}\).

In addition, in Proposition 3.2, Theorem 3.5, Lemma 3.6, Theorem 3.7, the fields \(\phi \) etc. should be assumed to be hermitian. Note however that in a unitary vertex operator algebra every primary field \(\phi \) with conformal dimension d is equal to \(\phi _1 + i \phi _2\) with \(\phi _1\) and \(\phi _2\) hermitian primary fields of the same dimension d.