A construction of vertex algebra bundles on logarithmic smooth curves

We present a construction of vertex algebra bundles and spaces of conformal blocks over families of logarithmic smooth curves. This work generalizes some earlier results by Frenkel and Ben-Zvi on vertex algebra bundles over complex smooth algebraic curves. We establish a weaker version of the propagation of vacua, and compute the space of conformal blocks over a typical example of a nodal curve.