Gaberdiel and Gopakumar recently proposed that the tensionless limit ofstring theory on $AdS_3 \times S^3 \times T^4$ takes the form of a higher spintheory with a gauge algebra that is referred to as the higher spin square. Inthis note, we formulate the linearized Vasiliev-type equations which describe amatter field coupled to the higher spin square. We study the particle spectrumof this field and show that it accounts for the entire untwisted sector of thedual symmetric orbifold CFT, thereby confirming a conjecture by Gaberdiel andGopakumar. In doing so, we pinpoint the group-theoretic data which determinethe spectrum of a matter field coupled to a general higher spin algebra, whichwe illustrate by revisiting the theory based on the $hs[1/2]$ algebra.
Given a set of differential forms on an odd-dimensional noncommutativemanifold valued in an internal associative algebra H, we show that the mostgeneral cubic covariant Hamiltonian action, without mass terms, is controlledby an Z_2-graded associative algebra F with a graded symmetric nondegeneratebilinear form. The resulting class of models provide a natural generalizationof the Frobenius-Chern-Simons model (FCS) that was proposed in arXiv:1505.04957as an off-shell formulation of the minimal bosonic four-dimensional higher spingravity theory. If F is unital and the Z_2-grading is induced from a Kleinoperator that is outer to a proper Frobenius subalgebra, then the action can bewritten on a form akin to topological open string field theory in terms of asuperconnection valued in the direct product of H and F. We give a new model ofthis type based on a twisting of C[Z_2 x Z_4], which leads to self-dualcomplexified gauge fields on AdS_4. If F is 3-graded, the FCS model can betruncated consistently as to zero-form constraints on-shell. Two examplesthereof are a twisting of C[(Z_2)^3] that yields the original model, and theClifford algebra Cl_2n which provides an FCS formulation of the bosonicKonstein--Vasiliev model with gauge algebra hu(4^{n-1},0).
The $sp(2M)$ invariant unfolded system is considered in the periodictwistor-like spinor space. Complete set of non-trivial charges corresponding tothe global symmetry compatible with the periodicity conditions is constructed.Residual infinite-dimensional symmetry is realized in terms of the star-productalgebra. It is shown that charges associated with integrations over differentcycles are related by particular higher-spin symmetry transformations.
The application of MEMS devices is one of the recent trends in sensor technology. However, traditional silicon MEMS have some intrinsic limitations, when applied to the monitoring of high temperature/high humidity processes. Thin ceramic films of alumina, zirconia or LTCC fixed on rigid frame made of the same ceramic material in combination with ink and aerosol jet printing of functional materials (heaters, temperature, pressure, gas sensitive elements) provides a cheap, flexible, and high-performance alternative for silicon MEMS devices used as gas sensors, gas flowmeters, lambda probes, bolometric matrices for automotive and general application.
Gamma-ray haloes can exist around galaxies due to the interaction of escapinggalactic cosmic rays with the surrounding gas. We have searched for such a haloaround the nearby giant spiral Andromeda galaxy M31 using almost 7 years ofFermi LAT data at energies above 300 MeV. The presence of a diffuse gamma-rayhalo with total photon flux $2.6\pm 0.6\times 10^{-9}$ cm$^{-2}$~s$^{-1}$,corresponding to a luminosity (0.3-100 GeV) of $(3.2\pm 0.6)\times 10^{38}$ ergs$^{-1}$ (for a distance of 780~kpc) was found at a 5.3$\sigma$ confidencelevel. The halo form does not correspond to the extended baryonic HI disc ofM31, as would be expected in hadronic production of gamma photons from cosmicray interaction, nor it is spherically symmetric, as could be in the case ofdark matter annihilation. The best-fit halo template corresponds to two 6-7.5kpc bubbles symmetrically located perpendicular to the M31 galactic disc,similar to the 'Fermi bubbles' found around the Milky Way centre, whichsuggests the past activity of the central supermassive black hole or astar-formation burst in M31.
AT was supported by the Federal Ministry for Education and Research through the Sofja Kovalevskaya Award of Alexander von Humboldt Foundation. This work was supported in part by Russian Foundation for Basic Research grants 14-02-00111, 14-02-00245, 16-02-00021, from the Ministry of Education and Science of the Russian Federation in the framework of Increase Competitiveness Program of NUST «MISiS» (№ К2-2015-075 and № K4-2015-020) and by Act 211 of the Government of Russian Federation, agreement № 02.A03.21.0006. EAZ, JW and RK acknowledge support by the Excellence Initiative of the German Federal Government and States. PL thanks EPSRC (EP/K503162/1) for partial support of a studentship to IM and the Leverhulme Trust for the award of a post-doctoral fellowship (RPG-2013-343) to LC. SK is grateful for the funding by SSP1458 of the DFG.