Paper by Pembroke student accepted to Journal of High Energy Physics

Third-year Physics & Philosophy student Bhanu Narra has recently had a single-author theoretical physics paper accepted to the prestigious Journal of High Energy Physics.

Based on his summer project and titled ‘A supersymmetric AdS3 duality’, the paper provides new insights into the symmetry between bosons and fermions in string theory. You can find the preprint here. Below Bhanu shares some more details on the insights of his paper. 

“Dualities are equivalences between physical theories which prima facie look completely different. They play an essential role in modern physical theories like quantum field theory and string theory. A simple but surprising example is T-duality: a string theory in a cylindrical universe with radius R and one with radius 1/R are completely equivalent! Consider how strange this is: if R is very large, the first universe will appear to be enormous, stretching for light years, while the other universe seems to shrink away to nothing. Yet, T-duality says that these worlds are identical! The reason this is possible in string theory, but not in particle theory, is because strings can travel around the cylinder like particles, but they can also wind around the cylinder, which a particle cannot do. Under the T-duality, these two types of strings are exchanged. 

In 2021, a new duality was found in a paper by Daniel Louis Jafferis and Elliot Schneider, titled ‘Stringy ER = EPR’, that equates a three-dimensional cylindrical universe (called AdS_3) to a universe with a hole cut through its center with winding strings that wrap around this core (figure 1.4 in this paper gives an illustration). This universe is a very useful toy model for studying the physics of black holes and entanglement in string theory. 

In my new paper, this duality is extended to include so-called supersymmetry. Supersymmetry is a symmetry that relates bosonic particles (usually force-carrying particles like photons) to fermionic particles (usually matter particles like electrons). In string theory, supersymmetry is important for the stability of the system, and in general it allows the use of powerful calculation techniques. The supersymmetric duality actually follows almost trivially from the previous duality due to some unusual properties of this system. The paper also shows how the three-dimensional duality reduces to another known two-dimensional duality upon ‘flattening’ the cylinder.”

Many congratulations to Bhanu on this incredible achievement!