Notes on Theta Dependence in Holographic Yang-Mills

Understand

Effects of the theta parameter are studied in Witten's model of holographic 4d Yang-Mills, where theta is the coefficient of the CP-breaking topological term.

• First, the gravity background, including the full backreaction of the RR form dual to the theta parameter, is revisited.
• Then, a number of observables are computed holographically: the ground-state energy density, the string tension, the 't Hooft loop, the light scalar glueball mass, the baryon mass scale, the critical temperature for deconfinement - and thus the whole (T, theta) phase diagram - and the entanglement entropy.
• A simple rule is provided to derive the theta corrections to (at least) all the CP-neutral observables of the model.