Winter 2020 Series
- 9 and 16 November: Amihay Hanany, Branes and the moduli space of instantons
See the below file for a reading list and problem set.
amihay_hanany_-_9th_nov.pdf |
- 16 and 23 November: Congkao Wen, Witten diagrams and the Mellin transform in AdS/CFT
AdS/CFT duality (or more general holographic principle) represents a major advance in understanding quantum gravity, and provides powerful tools for studying strongly coupled quantum field theories. This talk will give a basic introduction to AdS/CFT duality, with the focus on the computation of Witten diagrams and their Mellin transform. Witten diagrams, which play the role of Feynman diagrams, provide the means for computing correlation functions in AdS/CFT. We will show that CFT correlation functions obtained from Witten diagrams have much simpler structures after Mellin transform. Correlators in Mellin space are very analogous to the flat-space scattering amplitudes, and they are often called Mellin amplitudes. We will demonstrate the ideas by studying a few non-trivial examples.
See the file below for a reading list and problem set.
congkao_wen_-_16th_nov.pdf |
The following are the whiteboard notes for the online lecture and problem class.
note_10_nov_2020.pdf |
note_23_nov_2020.pdf |
- 23 and 30 November: Gerard Watts, Conformal blocks in two dimensions
Conformal blocks are the building blocks of conformal field theories, the key ingredients of correlation functions and knowledge of these blocks is central to the conformal bootstrap. This lecture covers some general results before quickly specialising to two-dimensions. It discusses the implications of global conformal invariance and then the larger and more constraining Virasoro algebra symmetry. It introduces various methods of calculation including brute force, differential equations, recursion relations and closed formulae - and some aspects of bootstrap techniques.
Reading list and problem set, as well as mathematica worksheet available at:
https://www.nms.kcl.ac.uk/gerard.watts/blocks/
- 30 November and 7 December: Bogdan Stefanski, D-branes and boundary states
See the file below for a reading list and problem set.
bogdan_stefanski_30_dec.pdf |