2,857 research outputs found
Anomalous dimensions from rotating open strings in AdS/CFT
We propose a new entry within the dictionary of the AdS/CFT duality at strong
coupling: in the limit of a large spin or a large R-charge, the anomalous
dimension of the gauge theory operator dual to a semiclassical rotating string
is proportional to the string proper length. This conjecture is motivated by a
generalization to strings of the rule for computing anomalous dimensions of
massive particles and supergravity fields in the anti-de Sitter space. We show
that this proportionality holds for a rotating closed string in global AdS
space, representing a high spin operator made of fields in the adjoint
representation. It is also valid for closed strings rotating in
(representing operators with large R-charge), for closed strings with multiple
AdS spin, and for giant magnons. Based on this conjecture, we calculate the
anomalous dimension of operators made of fields in the fundamental
representation, associated with high spin mesons, and which are represented by
rotating open strings attached to probe D7-branes. The result is a logarithmic
dependence upon the spin, , similar to the
closed string case. We show that the operator properties --- anomalous
dimension and spin --- are obtained from measurements made by a local observer
in the anti-de Sitter space. For the open string case, this ensures that these
quantities are independent of the mass scale introduced by the D7-branes (the
quark mass), as expected on physical grounds. In contrast, properties of the
gauge theory states, like the energy, correspond to measurements by a gauge
theory observer and depend upon the mass scale --- once again, as expected.Comment: V2: two related references include
Slow dynamics in cylindrically confined colloidal suspensions
We study bidisperse colloidal suspensions confined within glass
microcapillary tubes to model the glass transition in confined cylindrical
geometries. We use high speed three-dimensional confocal microscopy to observe
particle motions for a wide range of volume fractions and tube radii. Holding
volume fraction constant, we find that particles move slower in thinner tubes.
The tube walls induce a gradient in particle mobility: particles move
substantially slower near the walls. This suggests that the confinement-induced
glassiness may be due to an interfacial effect.Comment: Submitted to AIP conference proceedings for "Slow Dynamics in Complex
Systems" (Sendai, Japan, Dec. 2012
Observations on the Law of Implied Warranty of Quality in Missouri: 1960
Recent cases indicate a strengthened and extended law of implied warranty of quality in Missouri. Two of these cases deserve close consideration: Ross v. Philip Moris Co., 164 F. Supp. 683 (W.D. Mo. 1958), modified, No. 9494, W.D. Mo., Oct. 22, 1959; Midwest Game Co. v. M.F.A. Milling Co., 320 S.W. 2d 547 (Mo. 1959)
Friction pull plug welding: chamfered heat sink pull plug design
Friction Pull Plug Welding (FPPW) is a solid state repair process for defects up to one inch in length, only requiring single sided tooling (OSL) for usage on flight hardware. Experimental data has shown that the mass of plug heat sink remaining above the top of the plate surface after a weld is completed (the plug heat sink) affects the bonding at the plug top. A minimized heat sink ensures complete bonding of the plug to the plate at the plug top. However, with a minimal heat sink three major problems can arise, the entire plug could be pulled through the plate hole, the central portion of the plug could be separated along grain boundaries, or the plug top hat can be separated from the body. The Chamfered Heat Sink Pull Plug Design allows for complete bonding along the ISL interface through an outside diameter minimal mass heat sink, while maintaining enough central mass in the plug to prevent plug pull through, central separation, and plug top hat separation
Friction pull plug welding: top hat plug design
Friction Pull Plug Welding is a solid state repair process for defects up to one inch in length, only requiring single sided tooling, or outside skin line (OSL), for preferred usage on flight hardware. The most prevalent defect associated with Friction Pull Plug Welding (FPPW) was a top side or inside skin line (ISL) lack of bonding. Bonding was not achieved at this location due to the reduction in both frictional heat and welding pressure between the plug and plate at the end of the weld. Thus, in order to eliminate the weld defects and increase the plug strength at the plug `top` a small `hat` section is added to the pull plug for added frictional heating and pressure
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