Multipoint correlators in multifield cosmology

关于超共形线缺陷的多点Ward恒等式

On multipoint Ward identities for superconformal line defects

本文重新审视超共形线缺陷中的Ward恒等式，通过拓扑约束推导多点关联函数的恒等式，并以1/2-BPS算子和位移多重态为例验证。

Wilson线缺陷CFT的微扰bootstrap：多点关联函数

Perturbative bootstrap of the Wilson-line defect CFT: Multipoint correlators

本文通过微扰bootstrap方法研究了Wilson线缺陷CFT的多点关联函数，在大$N$和弱耦合下推导了新解析结果，并展示了非微扰约束对五点和六点函数的决定作用。

Multipoint correlators of conformal field theories: implications for quantum critical transport

We compute three-point correlators between the stress-energy tensor and conserved currents of conformal field theories (CFTs) in 2+1 dimensions. We first compute the correlators in the large-flavor-number expansion of conformal gauge theories and then do the computation using holography. In the holographic approach, the correlators are computed from an effective action on 3+1 dimensional anti-de Sitter space (AdS_4) proposed by Myers et al., and depend upon the co-efficient, γ, of a four-derivative term in the action. We find a precise match between the CFT and the holographic results, thus fi…

Multipoint correlators in the Abelian sandpile model

We revisit the calculation of height correlations in the two-dimensional Abelian sandpile model by taking advantage of a technique developed recently by Kenyon and Wilson. The formalism requires to equip the usual graph Laplacian, ubiquitous in the context of cycle-rooted spanning forests, with a complex connection. In the case at hand, the connection is constant and localized along a semi-infinite defect line (zipper). In the appropriate limit of a trivial connection, it allows one to count spanning forests whose components contain prescribed sites, which are of direct relevance for height co…

Operator Product Expansion of Inflationary Correlators and Conformal Symmetry of de Sitter

We study the multifield inflationary models where the cosmological perturbation is sourced by light scalar fields other than the inflaton. The corresponding perturbations are both scale invariant and special conformally invariant. We exploit the operator product expansion technique of conformal field theories to study the inflationary correlators enjoying the symmetries present during the de Sitter epoch. The operator product expansion is particularly powerful in characterizing inflationary correlation functions in two observationally interesting limits, the squeezed limit of the three-point c…

雕琢多场宇宙学对撞机景观

Carving out the Multifield Cosmological Collider Landscape

本文证明多场暴胀在双谱压缩极限中普遍产生几乎局域的宇宙学对撞机信号，并揭示大场数下标度维度趋向幺正性边界，源于极值统计与随机矩阵普适性。

量子场论中的解析方法：从环积分到缺陷关联函数

Analytical methods in Quantum Field Theories: from loop integrals to defect correlators

本论文研究了量子场论中通过费曼积分和对称性减少计算缺陷关联函数所需积分的方法，并识别出计算这些关联函数所需的积分类别。

威尔逊线缺陷共形场论（CFT）中的关联函数

Correlators on the Wilson Line Defect CFT

本研究针对N=4超对称杨-米尔斯理论中的威尔逊线共形缺陷，提出弱耦合下计算标量插入算符多点关联函数的高效算法，推导相关微扰结果与非微扰约束，定义一维梅林振幅并提取CFT数据。

Single Particle Operators and their Correlators in Free $\mathcal{N}=4$ SYM

We consider a set of half-BPS operators in $\mathcal{N}=4$ super Yang-Mills theory which are appropriate for describing single-particle states of superstring theory on AdS${}_5 \times S^5$. These single-particle operators are defined to have vanishing two-point functions with all multi-trace operators and therefore correspond to admixtures of single- and multi-traces. We find explicit formulae for all single-particle operators and for their two-point function normalisation. We show that single-particle $U(N)$ operators belong to the $SU(N)$ subspace, thus for length greater than one they are s…

Evolution of Non-Gaussian Hydrodynamic Fluctuations

In the context of the search for the QCD critical point using non-Gaussian fluctuations, we obtain the evolution equations for non-Gaussian cumulants to the leading order of the systematic expansion in the magnitude of thermal fluctuations. We develop a diagrammatic technique in which the leading order contributions are given by tree diagrams. We introduce a Wigner transform for multipoint correlators and derive the evolution equations for three- and four-point Wigner functions for the problem of nonlinear stochastic diffusion with multiplicative noise.

关于 AdS${}_2$ 中 $n$ 点 Witten 图的注记

Notes on $n$-point Witten diagrams in AdS${}_2$

本文利用留数定理等基本方法在 AdS$_2$ 中计算了标量 $n$ 点接触 Witten 图及 Yang-Mills 拓扑关联函数，显式计算了交换图，并微扰验证了 $\mathcal{N}$=4 SYM 中的多点 Ward 恒等式。