The structure of the Osborn ("Local Renormalization Group") Equation in the presence of integer dimensional irrelevant operators is studied. We argue that the consistency of the anomalous part of the generating functional requires a beta-function for the metric. The modified form of the Weyl anomalies is calculated.
Clearing the Throat: Irrelevant Operators and Finite Temperature in Large n Gauge Theory
本文研究了在有限温度T存在下,N=4超对称大nSU(n)规范理论中加入一个无关算符的问题。在超引力对偶中,算符的效应被认为对应于AdS_5 x S^5 "喉“的变形,它恢复了时空的渐近10维闵可夫斯基区域,完成了完整的D3膜解。在非零T下的系统是有趣的,因为在某些几何参数的极值处,几何形状介于一个7维球面闵可夫斯基黑洞(乘以R^3)和一个5维平面AdS史瓦西黑洞(乘以S^5)之间。我们观察到,当耦合的运营商达到一个临界值,deconfined阶段,这是表示的几何与地平线,消失的所有温度下,返回系统到一个封闭的阶段,这是表示的热化极值几何。
Irrelevant operators in a CFT modify the usual Weyl transformation of the metric. A metric beta-function turns on, which modifies the Weyl anomalies as well. In this paper, we study the relation between bulk diffeomorphisms and Weyl transformation at the boundary when a massive scalar field, which sources irrelevant operators at the boundary, is coupled to the bulk metric. Considering the effect of the backreaction generated by the scalar field, we provide a holographic description of the boundary metric beta-function and anomalies. Our results represent an additional test of the AdS/CFT corre…
Double trace deformations, that is products of two local operators, define perturbations of conformal field theories that can be studied exactly in the large-N limit. Even when the double trace deformation is irrelevant in the infrared, it is believed to flow to an ultraviolet fixed point. In this note we define the Kallen-Lehmann representation of the two-point function of a local operator O in a theory perturbed by the square of such operator. We use such representation to discover potential pathologies at intermediate points in the flow that may prevent to reach the UV fixed point. We apply…
We study Ising Field Theory (the scaling limit of Ising model near the Curie critical point) in pure imaginary external magnetic field. We put particular emphasis on the detailed structure of the Yang-Lee edge singularity. While the leading singular behavior is controlled by the Yang-Lee fixed point ($=$ minimal CFT ${\cal M}_{2/5}$), the fine structure of the subleading singular terms is determined by the effective action which involves a tower of irrelevant operators. We use numerical data obtained through the "Truncated Free Fermion Space Approach" to estimate the couplings associated with …
Nonperturbative Chiral Anomaly Cancellation and Irrelevant Operators
Università degli Studi Roma Tre, Mathematics and Physics Department(罗马第三大学数学与物理系);Università degli Studi di Roma “La Sapienza”, Physics Department(罗马第一大学物理系);SISSA, Mathematics Area(的里雅斯特国际高等研究学校数学区)
We study an $\mathcal{N}=1$ supersymmetric quantum field theory with $O(M)\times O(N)$ symmetry. Working in $3-ε$ dimensions, we calculate the beta functions up to second loop order and analyze in detail the Renormalization Group (RG) flow and its fixed points. We allow $N$ and $M$ to assume general real values, which results in them functioning as bifurcation parameters. In studying the behaviour of the model in the space of $M$ and $N$, we demarcate the region where the RG flow is non-monotonic and determine curves along which Hopf bifurcations take place. At a number of points in the space …
The $T \overline{T}$ operator provides a universal irrelevant deformation of two-dimensional quantum field theories with remarkable properties, including connections to both string theory and holography beyond $\mathrm{AdS}$ spacetimes. In particular, it appears that a $T \overline{T}$-deformed theory is a kind of new structure, which is neither a local quantum field theory nor a full-fledged string theory, but which is nonetheless under some analytic control. On the other hand, supersymmetry is a beautiful extension of Poincaré symmetry which relates bosonic and fermionic degrees of freedom. …
We analyze the thermodynamical limit of the quantum metric along critical submanifolds of theory space. Building upon various results previously known in the literature, we relate its singular behavior to normal directions, which are naturally associated with relevant operators in the renormalization group sense. We formulate these results in the language of information theory and differential geometry. We exemplify our theory through the paradigmatic examples of the XY and Haldane models, where the normal directions to the critical submanifolds are seen to be precisely those along which the m…
We use the recently developed navigator method to obtain rigorous upper and lower bounds on new OPE data in the 3d Ising CFT. For example, assuming that there are only two $\mathbb{Z}_2$-even scalar operators $ε$ and $ε'$ with a dimension below 6 we find a narrow allowed interval for $Δ_{ε'}$, $λ_{σσε'}$ and $λ_{εεε'}$. With similar assumptions in the $\mathbb{Z}_2$-even spin-2 and the $\mathbb{Z}_2$-odd scalar sectors we are also able to constrain: the central charge $c_T$; the OPE data $Δ_{T'}$, $λ_{εεT'}$ and $λ_{σσT'}$ of the second spin-2 operator; and the OPE data $Δ_{σ'}$ and $λ_{σεσ'}$…
RG Dynamics of Irrelevant Fermion Operators and the Drag Coupling Mechanism
Universitat de Barcelona(巴塞罗那大学);Universidad de Oviedo(奥维耶多大学);Instituto Universitario de Ciencias y Tecnologías Espaciales de Asturias (ICTEA)(阿斯图里亚斯宇宙科学与技术大学研究所);Institució Catalana de Recerca i Estudis Avançats (ICREA)(加泰罗尼亚高级研究学院)
We continue our study of string theory in a background that interpolates between $AdS_3$ in the infrared and a linear dilaton spacetime $R^{1,1}\times R_ϕ$ in the UV. This background corresponds via holography to a $CFT_2$ deformed by a certain irrelevant operator of dimension $(2,2)$. We show that for two point functions of local operators in the infrared CFT, conformal perturbation theory in this irrelevant operator has a finite radius of convergence in momentum space, and one can use it to flow up the renormalization group. The spectral density develops an imaginary part above a certain cri…
We construct a solvable deformation of two-dimensional theories with $(2,2)$ supersymmetry using an irrelevant operator which is a bilinear in the supercurrents. This supercurrent-squared operator is manifestly supersymmetric, and equivalent to $T\bar{T}$ after using conservation laws. As illustrative examples, we deform theories involving a single $(2,2)$ chiral superfield. We show that the deformed free theory is on-shell equivalent to the $(2,2)$ Nambu-Goto action. At the classical level, models with a superpotential exhibit more surprising behavior: the deformed theory exhibits poles in th…
We study the holographic renormalization group (RG) flow triggered by a classically marginal operator. When a marginal operator deforms a conformal field theory, it does not yield a nontrivial renormalization group flow at the classical level. At the quantum level, however, quantum corrections modify a marginal operator into one of the truly marginal, marginally relevant, and marginally irrelevant operators and can generate a nontrivial RG flow. We investigate the holographic description of a RG flow triggered by a marginal operator with quantum corrections. We look into how the physical quant…
We consider a general (beyond $T\bar T$) deformation of the 2D $O(N+1)$ $σ$-model by the irrelevant dimension-four operators. The theory deformed in this most general way is not integrable, and the $S$-matrix loses its factorization properties. We perform the all-order summation of the leading infrared logs for the $2 \to 2$ scattering amplitude and provide the exact result for the $2 \to 2$ $S$-matrix in the leading logarithmic approximation. These results can provide us with new insights into the properties of the theories deformed by irrelevant operators more general than the $T\bar T$ defo…
We study a toy model of the Kerr/CFT correspondence using string theory on AdS$_3 \times S^3$. We propose a single trace irrelevant deformation of the dual CFT generated by a vertex operator with spacetime dimensions (2,1). This operator shares the same quantum numbers as the integrable $T\bar{J}$ deformation of two-dimensional CFTs where $\bar{J}$ is a chiral $U(1)$ current. We show that the deformation is marginal on the worldsheet and that the target spacetime is deformed to null warped AdS$_3$ upon dimensional reduction. We also calculate the spectrum of the deformed theory on the cylinder…
We investigate the emergence of ${\cal N}=1$ supersymmetry in the long-range behavior of three-dimensional parity-symmetric Yukawa systems. We discuss a renormalization approach that manifestly preserves supersymmetry whenever such symmetry is realized, and use it to prove that supersymmetry-breaking operators are irrelevant, thus proving that such operators are suppressed in the infrared. All our findings are illustrated with the aid of the $ε$-expansion and a functional variant of perturbation theory, but we provide numerical estimates of critical exponents that are based on the non-perturba…