Vertex operator algebras (VOAs) lie at the intersection of mathematics and theoretical physics, providing a rigorous algebraic framework for two-dimensional conformal field theories (CFTs). These ...

For a row-finite graph G with no sinks and in which every loop has an exit, we construct an isomorphism between Ext(C*(G)) and coker(A—I), where A is the vertex matrix of G. If c is the class in Ext(C ...

A signed bipartite graph G(U,V) is a bipartite graph in which each edge is assigned a positive or a negative sign. The signed degree of a vertex x in G(U, V) is the number of positive edges incident ...