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Ruben Manvelyan

Publications and source records attributed to Ruben Manvelyan.

29 records · Page 2Linked to original sources
arXiv2007

Generalized Curvature and Ricci Tensors for a Higher Spin Potential and the Trace Anomaly in External Higher Spin Fields in AdS_{4} Space

The curvature of a higher spin potential as constructed in a previous article of the same authors arXiv:0705.3528 is applied to the analysis of the linearized trace anomaly obtained from the quadratic part of the effective action for a conformally coupled scalar with linearized interaction with the external higher spin fields arXiv:hep-th/0602067. The spin is restricted to four to profit from technical simplifications but without reducing the problem in principle. The issue includes the calculation of all Ricci tensors as multiple traces of the curvature, the derivation of all primary and secondary Bianchi identities, expressing all Ricci tensors as differential operators applied to the Fronsdal term, calculating the Weyl variation of these, and showing finally that Weyl variations of integrals over contracted squares of Ricci tensors can be used to eliminate the anomaly completely. This peculiarity is discussed in detail. As tools we use the formalism of bisymmetric tensor fields whose space is equipped with a local bilinear invariant form, the *-form.

hep-th↗
arXiv2007

Conformal invariant powers of the Laplacian, Fefferman-Graham ambient metric and Ricci gauging

The hierarchy of conformally invariant k-th powers of the Laplacian acting on a scalar field with scaling dimensions $Δ_{(k)}=k-d/2$, k=1,2,3 as obtained in the recent work [1] is rederived using the Fefferman-Graham d+2 dimensional ambient space approach. The corresponding mysterious "holographic" structure of these operators is clarified. We explore also the d+2 dimensional ambient space origin of the Ricci gauging procedure proposed by A. Iorio, L. O'Raifeartaigh, I. Sachs and C. Wiesendanger as another method of constructing the Weyl invariant Lagrangians. The corresponding \emph{gauged} ambient metric, Fefferman-Graham expansion and extended Penrose-Brown-Henneaux transformations are proposed and analyzed.

hep-th↗
arXiv2007

The Generalized Curvature and Christoffel Symbols for a Higher Spin Potential in AdS_{d+1} Space

The generalized curvature tensor and Christoffel symbols are determined in AdS_{d+1} background by a modified ansatz of the de Wit - Freedman type by imposing gauge invariance. The resulting set of recurrence relations and difference equations is solved. The Riemann curvature tensor is derived by antisymmetrization. All results are presented as finite power series in the inverse AdS radius and are unique. The fourth order, which is complete for fields up to spin five, is calculated explicitly. Higher orders can be obtained with the same method.

hep-th↗
arXiv2007

Conformal coupling of the scalar field with gravity in higher dimensions and invariant powers of the Laplacian

The hierarchy of conformally coupled scalars with the increasing scaling dimensions $Δ_{k}=k-d/2$, $k=1,2,3,... $ connected with the $k$-th Euler density in the corresponding space-time dimensions $d\geq 2k$ is proposed. The corresponding conformal invariant Lagrangian with the $k$-th power of Laplacian for the already known cases $k=1,2$ is reviewed, and the subsequent case of $k=3$ is completely constructed and analyzed.

hep-th↗
arXiv2006

The structure of the trace anomaly of higher spin conformal currents in the bulk of $AdS_{4}$

The two-point function of the conserved traceless spin-$\ell$ currents which are constructed from the scalar field $σ(z)$ is evaluated and renormalized by a dimensional regularization procedure. The anomaly is managed to arise only in the trace part. To isolate this trace anomaly it is sufficient to analyze only the maximum singular part of the two-point function and its trace terms to leading order. The corresponding part of the effective action which is quadratic in the trace of the higher spin field is explicitly given. For the spin-2 field which is identical with the gravitational field the results known from the literature are reproduced.

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arXiv2006

The masses of gauge fields in higher spin field theory on the bulk of $AdS_{4}$

A local gauge invariant interaction Lagrangian for two gauge fields of spin $\ell$ and $\ell-2$ $(\ell>2)$ and the scalar field is defined. It gives rise to one-loop corrections to the gauge field propagator. The loop function contains the Goldstone boson propagator for gauge symmetry breaking. The proportionality factor in front of this propagator is the mass squared of the gauge boson.

hep-th↗
arXiv2006

The quantum one loop trace anomaly of the higher spin conformal conserved currents in the bulk of $AdS_{4}$

An analysis of the structure and singularities of the one loop two point function of the higher spin traceless and conserved currents constructed from the single scalar field in $AdS$ space is presented. The detailed renormalization procedure is constructed and the quantum violation of the traceless Ward identity is investigated. The connection with the one loop effective action for higher spin gauge fields is discussed.

hep-th↗
arXiv2005

The off-shell behaviour of propagators and the Goldstone field in higher spin gauge theory on $AdS_{d+1}$ space

A detailed analysis of the structure and gauge dependence of the bulk-to-bulk propagators for the higher spin gauge fields in $AdS$ space is performed. The possible freedom in the construction of the propagators is investigated and fixed by the correct boundary behaviour and correspondence to the representation theory results for the $AdS$ space isometry group. The classical origin of the Goldstone mode and its connection with the gauge fixing procedure is considered.

hep-th↗
arXiv2004

The group approach to AdS space propagators: A fast algorithm

In this letter we show how the method of [4] for the calculation of two-point functions in d+1-dimensional AdS space can be simplified. This results in an algorithm for the evaluation of the two-point functions as linear combinations of Legendre functions of the second kind. This algorithm can be easily implemented on a computer. For the sake of illustration, we displayed the results for the case of symmetric traceless tensor fields with rank up to l=4.

hep-th↗
arXiv2003

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.

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