Abstract:   

Tree-level unitarity and renormalizability are believed to be equivalent in field theories. No counter-example is known in relativistic field theories. However, the question whether the equivalence holds true for more generic field theories, such as non-relativistic theories is obscure. In this talk, I will discuss the equivalence between tree-level unitarity and renormalizability and show that the equivalence holds true in Lifshitz (non-relativistic) scalar field theory. It can be inferred that tree-level unitarity is useful to investigate renormalizability in a large class field theories, such as Horava-Lifshitz gravity.