TY - JOUR AU - Phat, Tran Huu AU - Long, Nguyen Van PY - 2007/07/14 Y2 - 2024/03/29 TI - On the loop expansion of the effective action JF - Communications in Physics JA - Comm. Phys. VL - 14 IS - 2 SE - Papers DO - 10.15625/0868-3166/14/2/10696 UR - https://vjs.ac.vn/index.php/cip/article/view/10696 SP - 65-73 AB - Based on the DeWitt formula the loop expansion of the effective action is easily established. Extending to the system with finite density we develop the in-medium DeWitt formula, which is the starting point for setting up loop expansion of the in-medium effective action. ER -