报告题目：String amplitudes and field theory amplitudes

报告人：张勇 博士（中国科学院理论物理研究所）

报告时间：2019年1月7日（周一）下午14：30  

报告地点：物理学院新楼D-502

报告摘要：

We present an integration-by-parts reduction of any massless tree-level string correlator to an equivalence class of logarithmic functions, which can be used to define a field-theory amplitude via a Cachazo-He-Yuan (CHY) formula. The string amplitude is then shown to be the double copy of the field-theory one and a special disk/sphere integral. The construction is generic as it applies to any correlator that is a rational function of correct SL(2) weight. By applying the reduction to open bosonic/heterotic strings, we get a closed-form CHY integrand for the (DF )2 + YM + φ3 theory.

邀请人：杜一剑副教授