φ_ε-coordinated modules for vertex algebras

We study $\phi_\epsilon$-coordinated modules for vertex algebras, where $\phi_\epsilon$ with $\epsilon$ an integer parameter is a family of associates of the one-dimensional additive formal group. As the main results, we obtain a Jacobi type identity and a commutator formula for $\phi_\epsilon$-coordinated modules. We then use these results to study $\phi_\epsilon$-coordinated modules for vertex algebras associated to Novikov algebras by Primc.