标题： 加性粒子理论在路径积分方法中的引入 显示英文标题

标题： Introduction of Additive Particle Theory for Path Integral Approaches

摘要： 路径积分方法已被用于玻色子和费米子系统。 路径积分方法在多玻色子系统中取得了成功。 然而，在多费米子系统中，由于符号问题，路径积分方法不可行。 在这封信中，我引入了加性粒子（AP）理论，以生成一种避免符号问题的近似方法。 AP 理论将一个电子视为一个弦聚合物，并向系统中添加虚拟粒子。 AP 理论是一种近似方法，但其构建目的是能够生成自由电子之间的配对分布函数以及任意温度下自由电子的态密度。 因此，当静电相互作用减弱时，AP 理论收敛到自由电子系统。 另一方面，当静电相互作用增强时，它会偏离实际系统。 显示英文摘要

摘要： Path integral approaches have been used for boson and fermion systems. The path integral approach has been successful in the many-boson system. However, in the many-fermion system, the path integral approach is not feasible due to the sign problem. In this letter, I introduce additive particle (AP) theory in order to generate an approximation method that avoids the sign problem. The AP theory considers one electron as a string polymer, and virtual particles are added into the system. The AP theory is an approximation, but it is constructed to be able to generate the pair distribution function between free electrons and the density of states of the free electrons at an arbitrary temperature. Hence, when the electrostatic interactions are decreased, the AP theory converges to the free electron system. On the other hand, it deviates from the actual system when the electrostatic interactions are increased.