824 research outputs found
Towards higher spin holography in ambient space of any dimension
We derive the propagators for higher-spin master fields in anti-de Sitter space of arbitrary dimension. A method is developed to construct the propagators directly without solving any differential equations. The use of the ambient space, where AdS is represented as a hyperboloid and its conformal boundary as a projective light-cone, simplifies the approach and makes a direct contact between boundary-to-bulk propagators and two-point functions of conserved currents
Development of detector active element based on thgem
A thick gas electron multiplier is considered for radiation-hard detectors
(hadron calorimeter). There was carried out technological and design study to
optimize the element structure. The measurements results and the next plans are
presented.Comment: 7 pages, 12 figure
On the Higher-Spin Spectrum in Large N Chern-Simons Vector Models
Chern-Simons gauge theories coupled to massless fundamental scalars or
fermions define interesting non-supersymmetric 3d CFTs that possess approximate
higher-spin symmetries at large N. In this paper, we compute the scaling
dimensions of the higher-spin operators in these models, to leading order in
the 1/N expansion and exactly in the 't Hooft coupling. We obtain these results
in two independent ways: by using conformal symmetry and the classical
equations of motion to fix the structure of the current non-conservation, and
by a direct Feynman diagram calculation. The full dependence on the 't Hooft
coupling can be restored by using results that follow from the weakly broken
higher-spin symmetry. This analysis also allows us to obtain some explicit
results for the non-conserved, parity-breaking structures that appear in planar
three-point functions of the higher-spin operators. At large spin, we find that
the anomalous dimensions grow logarithmically with the spin, in agreement with
general expectations. This logarithmic behavior disappears in the strong
coupling limit, where the anomalous dimensions turn into those of the critical
O(N) or Gross-Neveu models, in agreement with the conjectured 3d bosonization
duality.Comment: 52 pages, 7 figures. v3: Minor correction
Proximity Action theory of superconductive nanostructures
We review a novel approach to the superconductive proximity effect in
disordered normal-superconducting (N-S) structures. The method is based on the
multicharge Keldysh action and is suitable for the treatment of interaction and
fluctuation effects. As an application of the formalism, we study the subgap
conductance and noise in two-dimensional N-S systems in the presence of the
electron-electron interaction in the Cooper channel. It is shown that singular
nature of the interaction correction at large scales leads to a nonmonotonuos
temperature, voltage and magnetic field dependence of the Andreev conductance.Comment: RevTeX, 6 pages, 5 eps figures. This is a concise review of
cond-mat/0008463; to be published in the Proceedings of the conference
"Mesoscopic and strongly correlated electron systems" (Chernogolovka, Russia,
July 2000
- …