四费米理论大N极限中能量-动量张量的显式构造
Explicit construction of the energy-momentum tensor in the large N limit of a four-Fermi theory
- University of Nova Gorica（新戈里察大学）
- Department of Physics and Astronomy, The University of Iowa（爱荷华大学物理与天文系）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文利用精确重整化群在2<D<4维欧几里得空间中构造四费米理论大N极限下的能量-动量张量，证明其满足Ward-Takahashi恒等式并揭示临界理论的共形不变性。
AI中文摘要：
利用精确重整化群（泛函RG）形式，我们在2 < D < 4维欧几里得空间中，在大N极限下构造了四费米理论的能量-动量张量，其中N是狄拉克场的数目。能量-动量张量是狄拉克场的泛函，其截断依赖性由精确RG方程控制。在零截断极限下，该泛函约化为具有单个能量-动量张量插入的单粒子不可约有效作用量。在有限截断下，能量-动量张量满足平移不变性的Ward-Takahashi恒等式，其反对称部分由旋转不变性决定。我们还通过推导相应的Ward-Takahashi恒等式，证明了临界理论是共形不变的。
英文摘要：
Using the exact renormalization group (functional RG) formalism, we construct the energy-momentum tensor of a four-Fermi theory in the Euclidean space of dimensions 2 < D < 4 in the large N limit, where N is the number of Dirac fields. The energy-momentum tensor is a functional of the Dirac fields, and its cutoff dependence is controlled by the exact RG equation. In the zero cutoff limit the functional reduces to the one-particle-irreducible effective action with a single insertion of the energy-momentum tensor. At a finite cutoff the energy-momentum tensor satisfies the Ward-Takahashi identity for translation invariance, and its antisymmetric part is determined by rotation invariance. We also show that the critical theory is conformally invariant by deriving the corresponding Ward-Takahashi identity.
