Frame-like Actions for Massless Mixed-Symmetry Fields in Minkowski space

A frame-like action for arbitrary mixed-symmetry bosonic massless fields in Minkowski space is constructed. The action is given in a simple form and consists of two terms for a field of any spin. The fields and gauge parameters are certain tensor-valued differential forms. The formulation is based on the unfolded form of equations for mixed-symmetry fields.Comment: 25 pages; replaced with revised versio

Transverse Invariant Higher Spin Fields

It is shown that a symmetric massless bosonic higher-spin field can be described by a traceless tensor field with reduced (transverse) gauge invariance. The Hamiltonian analysis of the transverse gauge invariant higher-spin models is used to control a number of degrees of freedom.Comment: 12 pages, no figures. The general proof and the example of a spin-3 adde

Unfolding Mixed-Symmetry Fields in AdS and the BMV Conjecture: I. General Formalism

We present some generalities of unfolded on-shell dynamics that are useful in analysing the BMV conjecture for mixed-symmetry fields in constantly curved backgrounds. In particular we classify the Lorentz-covariant Harish-Chandra modules generated from primary Weyl tensors of arbitrary mass and shape, and in backgrounds with general values of the cosmological constant. We also discuss the unfolded notion of local degrees of freedom in theories with and without gravity and with and without massive deformation parameters, using the language of Weyl zero-form modules and their duals.Comment: Corrected typos, references added, two figures, some remarks and two subsections added for clarit

Geometric Formulation for Partially Massless Fields

The manifestly gauge invariant formulation for free symmetric partially massless fields in $(A)dS_d$ is given in terms of gauge connections and linearized curvatures that take values in the irreducible representations of $(o(d-1,2)) o(d,1)$ described by two-row Young tableaux, in which the lengths of the first and second row are, respectively, associated with spin and depth of partial masslessness.Comment: LaTeX, 42 pages. Published in Nucl. Phys.

Unfolding Mixed-Symmetry Fields in AdS and the BMV Conjecture: II. Oscillator Realization

Following the general formalism presented in arXiv:0812.3615 -- referred to as Paper I -- we derive the unfolded equations of motion for tensor fields of arbitrary shape and mass in constantly curved backgrounds by radial reduction of Skvortsov's equations in one higher dimension. The complete unfolded system is embedded into a single master field, valued in a tensorial Schur module realized equivalently via either bosonic (symmetric basis) or fermionic (anti-symmetric basis) vector oscillators. At critical masses the reduced Weyl zero-form modules become indecomposable. We explicitly project the latter onto the submodules carrying Metsaev's massless representations. The remainder of the reduced system contains a set of Stueckelberg fields and dynamical potentials that leads to a smooth flat limit in accordance with the Brink--Metsaev--Vasiliev (BMV) conjecture. In the unitary massless cases in AdS, we identify the Alkalaev--Shaynkman--Vasiliev frame-like potentials and explicitly disentangle their unfolded field equations.Comment: 67 pages, typos corrected, clarifying comments adde

Thermal conductivity performance of nanoporous plate for high-power LED lighting and power electronics

Comparative results of measurements of the thermal resistance of a new nanoporous material based on aluminium oxide are presented. Low-cost high-heat-conducting printed circuit boards for high-power LEDs, LED lighting devices and power electronics on the basis of the presented material have been developed and manufactured. Comparison of a set of performances of nanoporous aliminium oxide and aluminium nitride ceramics demonstrate advantages of the material developed. Its thermal characteristics is inferior to the AlN ceramics by 30%, but the cost of the proposed material is lower by almost four times. © 2019 IOP Publishing Ltd. All rights reserved