Résultats de recherche pour « Defect Verlinde Formula »

We revisit the problem of boundary excitations at a topological boundary or junction defects between topological boundaries in non-chiral bosonic topological orders in 2+1 dimensions. Based on physical considerations, we derive a formula that relates the fusion rules of the boundary excitations, and the "half-linking" number between condensed anyons and confined boundary excitations. This formula is a direct analogue of the Verlinde formula. We also demonstrate how these half-linking numbers can be computed in explicit Abelian and non-Abelian examples. As a fundamental property of topological orders and their allowed boundaries, this should also find applications in finding suitable platforms realizing quantum computing devices.

In these notes we give an introduction to some of the concepts involved in constructing SM-like gauge theories in systems of branes at singularities of CY manifolds. These notes are an expanded version of lectures given by Herman Verlinde at the Cargese 2006 Summer School.

In rational conformal field theory, the Verlinde formula computes the fusion coefficients from the modular S-transformations of the characters of the chiral algebra's representations. Generalising this formula to logarithmic models has proven rather difficult for a variety of reasons. Here, a recently proposed formalism [1] for the modular properties of certain classes of logarithmic theories is reviewed, and refined, using simple examples. A formalism addressing fusion rules in simple current extensions is also reviewed as a means to tackle logarithmic theories to which the proposed modular formalism does not directly apply.

We establish a precise relationship between the $GΣ$ collective field theory of the double scaled SYK model and the worldsheet theory of the complex Liouville string a.k.a. sine dilaton gravity. The relationship is similar to the lightcone gauge in critical string theory, and to what transpires when we gravitationally dress to an observer in gravity: one of the Liouville fields plays the role of a dynamical clock with respect to which the second Liouville field evolves. This other Liouville field is identified with the collective field of SYK, which thus acquires a direct gravity interpretation. The relevant 2D worldsheet geometry is that of a disk with specific crosscap and FZZT boundary conditions, as deduced from the $GΣ$ formulation. We compute the CLS amplitude on this geometry and find that this coincides with the DSSYK partition function. We indicate how our results can be lifted to 3D gravity, previewing upcoming work. An outflow of our results is that physical operators of DSSYK are mapped to holonomy operators (Verlinde lines) of complex Liouville theory on the crosscap geometry, which in turn have a 3D representation in terms of line operators in 3D de Sitter gravity. We show that the partition function of SYK can be represented as the expectation value of a circular gravitational Wilson line on $\mathbb{RP}^3$ (a.k.a. elliptic 3D de Sitter space).

This work derives mutual braiding statistics of anyons from a set of axioms about entanglement entropy, which have been shown to imply the fusion rules of anyons. More specifically, the author defines the topological $S$ matrix from a quantum state and show that it satisfies the Verlinde formula.

We propose and prove the Verlinde formula for the quantization of the Higgs bundle moduli spaces and stacks for any simple and simply-connected group. This generalizes the equivariant Verlinde formula for the case of $SU(n)$ proposed previously by the second and third author. We further establish a Verlinde formula for the quantization of parabolic Higgs bundle moduli spaces and stacks. Finally, we prove that these dimensions form a one-parameter family of $1+1$-dimensional TQFT, uniquely classified by the complex Verlinde algebra, which is a one-parameter family of Frobenius algebras. We construct this one-parameter family of Frobenius algebras as a deformation of the classical Verlinde algebra for $G$.

A bstract We use the Virasoro TQFT to derive an integral identity that we view as a non-rational generalization of the Verlinde formula for the Virasoro algebra with central charge c ≥ 25. The identity expresses the Virasoro fusion kernel as an integral over a ratio of modular S-kernels on the (punctured) torus. In particular, it shows that the one-point S-kernel diagonalizes the Virasoro 6 j symbol. After carefully studying the analytic properties of this ‘Virasoro-Verlinde formula’, we present three applications. In boundary Liouville CFT, the formula ensures the open-closed duality of the boundary one-point function on the annulus. In pure 3d gravity, it provides an essential step in computing the partition function on hyperbolic 3-manifolds that fiber over the circle. Lastly, in AdS 3 /CFT 2 , the formula computes a three-boundary torus wormhole, which leads to a prediction for the statistical correlation between the density of states and two OPE coefficients in the dual large- c CFT ensemble. We conclude by discussing the implications of our result for the fusion rules in generic non-rational 2d CFTs.

Abstract Given an $$ \mathcal{N}=2 $$ N = 2 superconformal field theory, we reconsider the Schur index ℐ L (q) in the presence of a half line defect L. Recently Cordova-Gaiotto-Shao found that ℐ L (q) admits an expansion in terms of characters of the chiral algebra $$ \mathcal{A} $$ A introduced by Beem et al., with simple coefficients υ L,β (q). We report a puzzling new feature of this expansion: the q → 1 limit of the coefficients υ L,β (q) is linearly related to the vacuum expectation values 〈L〉 in U(1) r -invariant vacua of the theory compactified on S 1. This relation can be expressed algebraically as a commutative diagram involving three algebras: the algebra generated by line defects, the algebra of functions on U(1) r -invariant vacua, and a Verlindelike algebra associated to $$ \mathcal{A} $$ A . Our evidence is experimental, by direct computation in the Argyres-Douglas theories of type (A 1, A 2), (A 1, A 4), (A 1, A 6), (A 1, D 3) and (A 1, D 5). In the latter two theories, which have flavor symmetries, the Verlinde-like algebra which appears is a new deformation of algebras previously considered.

We prove a decomposition formula for Verlinde sums (rational trigonometric sums), as a discrete counterpart to the Boysal-Vergne decomposition formula for Bernoulli series. Motivated by applications to fixed point formulas in Hamiltonian geometry, we develop differential form valued version of Bernoulli series and Verlinde sums, and extend the decomposition formula to this wider context.