A general class of holographic theories with a nontrivial θ‐angle are analyzed. The instanton density operator is dual to a bulk axion field. We calculate the ground‐state solutions with nontrivial source, , for the axion, for both steep and soft dilaton potentials in the IR, and both in and . We find all cases to be qualitatively similar. We also calculate the spin=2, 0 glueball spectra and show that the glueball masses monotonically decrease as functions of (or θ‐angle). The slopes of glueball masses are different, generically, in different potentials. In the case of steep dilaton potentials, the glueball (masses)² turn negative before the maximum of is attained. We interpret this as a signal for a favored instanton condensation in the bulk. We also investigate strong CP‐violation in the effective glueball action.

中文翻译：

---

有限θ-角度，CP-振动，胶球光谱和强耦合不稳定性的全息理论

分析了具有非平凡θ角的一般全息理论。瞬时密度算符对体轴场是双重的。我们计算与平凡源基态的解决方案，为轴子，两个陡峭，在IR软伸缩子潜力，无论是在和。我们发现所有情况在质量上都是相似的。我们还计算了spin = 2，0胶球光谱，并证明了胶球质量作为（或θ-角度）的函数单调减少。通常情况下，胶球质量的斜率是不同的，具有不同的潜力。在陡峭的Dilaton势的情况下，胶球（质量）²在最大达到。我们将其解释为散装中有利于瞬间凝结的信号。我们还研究了有效胶球动作中强烈的CP违规行为。