Perturbative Nambu-Goto strings exist in any dimension

It is part of the narrative of string theory that quantum bosonic strings only exist in dimensions. As usual, it is not as simple as that. Even in the well-known covariant quantization scheme, the Nambu-Goto string can be consistently quantized in any dimension . In the critical case the quantization just becomes particularly nice. Based… Continue reading Perturbative Nambu-Goto strings exist in any dimension

Locality in Quantum Field Theory and Hadamard point splitting

Given the title of my blog, the first post should be on locality. In Quantum Field Theory (QFT) there are two different notions of locality. The first one, also often called causality, is the requirement that measurements of observables in causally disconnected (space-like) regions do not influence each other. This is expressed in the requirement… Continue reading Locality in Quantum Field Theory and Hadamard point splitting