$c$ is pretty cool. In two-dimensional critical theories, we are surrounded by it: it appears in the Virasoro central charge, the Stefan-Boltzmann constant, the conformal 'anomaly', the entanglement entropy, and at the endpoints of the Zamolodchikov $C$-function - and, of course, it doesn't appear on the string worldsheet. I will explain these appearances and the tight relationships between them, and discuss how we might use $c$ to chart and classify the space of CFTs and QFTs.
Junior Strings is a seminar series where DPhil students present topics of common interest that do not necessarily overlap with their own research area. This is primarily aimed at PhD students and post-docs but everyone is welcome.