many thanks to Prof. M and Prof. S for sharing it. of course, many congrats and thanks to ictp and the ictp lectrurer
https://www.ictp-saifr.org/ads-cft2023/
in this second part of the lecture some review discussions on kruskal diagram, carter-penrose diagram, cp diagram of collapsing star forming into a blackhole
https://youtu.be/4gWt3v0Wac0?list=PLg0_ydgtbHGH0FIZzD97RVU8K0DA9vI-Q
picking up the pieces from my old exercise notes then going to DS and ADS space
take note: difference between spacetime indices and gauge indices