Deeper Look into Short Strings
Nikolay Gromov, Saulius Valatka
TL;DR
This work advances the analytic understanding of short-operator spectra in AdS/CFT by deriving three leading strong-coupling coefficients for small SL(2) operators using Basso's slope conjecture and comparing them with existing Y-system/TBA numerics. It analyzes the folded-string (classical and one-loop) contributions, tests the exact-slope structure, and identifies inconsistencies for higher winding numbers that motivate refinements to the conjectured form. A two-loop strong-coupling prediction is presented, including a concrete case for two magnons, and the results are benchmarked against TBA data via Padé-type fits, showing notable agreement. The study emphasizes the importance of higher-precision numerical data and potential refinements in the slope framework for accurate short-operator predictions at strong coupling. Overall, the work strengthens the bridge between analytic strong-coupling predictions and numerical Y-system/TBA results in the AdS/CFT integrability program.
Abstract
Using a recent conjecture of Basso we compute three leading nontrivial coefficients in the strong coupling expansion of the anomalous dimensions of short operators in the sl2 sector of AdS/CFT. We show that our results are consistent with the numerical results obtained using the Y-system and TBA approach earlier thus providing further support to the Y-system conjecture.
