A next-to-leading Luescher formula

Understand

We propose a next-to-leading Luescher-like formula for the finite-size corrections of the excited states energies in integrable theories.

• We conjecture the expressions of the corrections for both the energy and the particles' rapidities by interpreting the excited states as momenta-dependent defects.
• We check the resulting formulas in some simple relativistic model and conjecture those for the AdS5/CFT4 case.