论文标题
来自非扰动重新归如此的$ O(N)$模型的关键指数的分析性
Analyticity of critical exponents of the $O(N)$ models from nonperturbative renormalization
论文作者
论文摘要
我们在衍生产品扩展中采用二阶功能性重归其化组框架来研究$ o(n)$模型,以不断改变现场组件$ n $和空间维度$ d $。在$(d,n)$平面中的一条线上,我们特别解决了有关关键指数$ν$和$η$的非分析行为的Cardy-Hamber预测,该预测通过了点$(2,2)$。通过$η(d,n)$和$ν{ - 1}(d,n)$的直接数值评估,以及对功能固定点配置文件的分析,我们以$(d,n)$平面中的两个方案之间的交叉形式清楚地指示了这一行的形式,但是,这些$(d,n)$平面的证据,但是没有不连续的或sikular first和sickular first和section section derivitions $ d $ d $ d $ d $ d $ d $ d $ d $ d = dd = d d $ d dd> d $ d = dd = d of。 $η(d,n)$和$ν{ - 1}(d,n)$的计算衍生物对于$ d \ to 2 $ to 2 $和$ n \ to 2 $变得越来越大,只有在此限制中,$η(d,n)$和$ν$和$ν^{-1}(-1}(-1}(d,n)$ as a g y US yous yous vent Ivernynannanaly nonananalyallynanalyally nonananalyalyally nonanalyalaly ys nonananalyalyalyalyalyalyallyallyally ys nonanalyalaly。通过扫描RG转换的二级特征值的依赖性$ n $,对于$ d> 2 $,我们没有发现其消失的迹象,正如Cardy-Hamber场景所预期的那样。对于$ d $接近3的维度,即使是跨界界的签名,也没有签名,即以预期形式的非分析性形式的交叉及其存在。
We employ the functional renormalization group framework at the second order in the derivative expansion to study the $O(N)$ models continuously varying the number of field components $N$ and the spatial dimensionality $d$. We in particular address the Cardy-Hamber prediction concerning nonanalytical behavior of the critical exponents $ν$ and $η$ across a line in the $(d,N)$ plane, which passes through the point $(2,2)$. By direct numerical evaluation of $η(d,N)$ and $ν^{-1}(d,N)$ as well as analysis of the functional fixed-point profiles, we find clear indications of this line in the form of a crossover between two regimes in the $(d,N)$ plane, however no evidence of discontinuous or singular first and second derivatives of these functions for $d>2$. The computed derivatives of $η(d,N)$ and $ν^{-1}(d,N)$ become increasingly large for $d\to 2$ and $N\to 2$ and it is only in this limit that $η(d,N)$ and $ν^{-1}(d,N)$ as obtained by us are evidently nonanalytical. By scanning the dependence of the subleading eigenvalue of the RG transformation on $N$ for $d>2$ we find no indication of its vanishing as anticipated by the Cardy-Hamber scenario. For dimensionality $d$ approaching 3 there are no signatures of the Cardy-Hamber line even as a crossover and its existence in the form of a nonanalyticity of the anticipated form is excluded.