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Werner Ruehl

Publications and source records attributed to Werner Ruehl.

29 records · Page 2Linked to original sources

The group approach to AdS space propagators

We show that AdS two-point functions can be obtained by connecting two points in the interior of AdS space with one point on its boundary by a dual pair of Dobrev's boundary-to-bulk intertwiners and integrating over the boundary point.

hep-th↗

Fractional Multi-Trace Fields of N=4 SYM_4 from AdS/CFT

We prove inductively that every k-trace operator of SO(6)_R irrep with Young tableau partition {r_1,r_2,r_3}, constructed out of k chiral primaries in the twenty dimensional SO(6)_R irrep, leads to a quasi primary field with protected conformal dimension. Our argument is based on perturbative evaluations of certain four point functions up to order 1/N^2.

hep-th↗

The construction of trigonometric invariants for Weyl groups and the derivation of corresponding exactly solvable Sutherland models

Trigonometric invariants are defined for each Weyl group orbit on the root lattice. They are real and periodic on the coroot lattice. Their polynomial algebra is spanned by a basis which is calculated by means of an algorithm. The invariants of the basis can be used as coordinates in any cell of the coroot space and lead to an exactly solvable model of Sutherland type. We apply this construction to the $F_4$ case

math-ph↗

Is it possible to construct exactly solvable models?

We develop a constructive method to derive exactly solvable quantum mechanical models of rational (Calogero) and trigonometric (Sutherland) type. This method starts from a linear algebra problem: finding eigenvectors of triangular finite matrices. These eigenvectors are transcribed into eigenfunctions of a selfadjoint Schrödinger operator. We prove the feasibility of our method by constructing a new "$AG_3$ model" of trigonometric type (the rational case was known before from Wolfes 1975). Applying a Coxeter group analysis we prove its equivalence with the $B_3$ model. In order to better understand features of our construction we exhibit the $F_4$ rational model with our method.

hep-th↗

Exactly solvable dynamical systems in the neighborhood of the Calogero model

The Hamiltonian of the $N$-particle Calogero model can be expressed in terms of generators of a Lie algebra for a definite class of representations. Maintaining this Lie algebra, its representations, and the flatness of the Riemannian metric belonging to the second order differential operator, the set of all possible quadratic Lie algebra forms is investigated. For N=3 and N=4 such forms are constructed explicitly and shown to correspond to exactly solvable Sutherland models. The results can be carried over easily to all $N$.

hep-th↗

The critical O($N$) $σ$-model at dimension $2<d<4$: Hardy-Ramanujan distribution of quasi-primary fields and a collective fusion approach

The distribution of quasiprimary fields of fixed classes characterized by their O$(N)$ representations $Y$ and the number $p$ of vector fields from which they are composed at $N=\infty$ in dependence on their normal dimension $[δ]$ is shown to obey a Hardy-Ramanujan law at leading order in a $\frac{1}{N}$-expansion. We develop a method of collective fusion of the fundamental fields which yields arbitrary \qps and resolves any degeneracy.

hep-th↗

Critical O(N) - vector nonlinear sigma - models: A resume of their field structure

The classification of quasi - primary fields is outlined. It is proved that the only conserved quasi - primary currents are the energy - momentum tensor and the O(N) - Noether currents. Derivation of all quasi - primary fields and the resolution of degeneracy is sketched. Finally the limits d=2 and d=4 of the space dimension are discussed. Whereas the latter is trivial the former is only almost so.

hep-th↗