21,570 research outputs found
Towards a quantum field theory of primitive string fields
We denote generating functions of massless even higher spin fields "primitive
string fields" (PSF's). In an introduction we present the necessary definitions
and derive propagators and currents of these PDF's on flat space. Their
off-shell cubic interaction can be derived after all off-shell cubic
interactions of triplets of higher spin fields have become known [2],[3]. Then
we discuss four-point functions of any quartet of PSF's. In subsequent sections
we exploit the fact that higher spin field theories in are
determined by AdS/CFT correspondence from universality classes of critical
systems in dimensional flat spaces. The O(N) invariant sectors of the O(N)
vector models for play for us the role of "standard
models", for varying , they contain e.g. the Ising model for N=1 and the
spherical model for . A formula for the masses squared that break
gauge symmetry for these O(N) classes is presented for d = 3. For the PSF on
space it is shown that it can be derived by lifting the PSF on flat space
by a simple kernel which contains the sum over all spins. Finally we use an
algorithm to derive all symmetric tensor higher spin fields. They arise from
monomials of scalar fields by derivation and selection of conformal
(quasiprimary) fields. Typically one monomial produces a multiplet of spin
conformal higher spin fields for all , they are distinguished by
their anomalous dimensions (in ) or by their mass (in ). We sum
over these multiplets and the spins to obtain "string type fields", one for
each such monomial.Comment: 16 pages,Late
The critical O() -model at dimension : Hardy-Ramanujan distribution of quasi-primary fields and a collective fusion approach
The distribution of quasiprimary fields of fixed classes characterized by
their O representations and the number of vector fields from which
they are composed at in dependence on their normal dimension
is shown to obey a Hardy-Ramanujan law at leading order in a
-expansion. We develop a method of collective fusion of the
fundamental fields which yields arbitrary \qps and resolves any degeneracy.Comment: KL-TH-94/2, 21 pages (uuencoded Postscript file
The Rocketdyne Multifunction Tester. Part 2: Operation of a Radial Magnetic Bearing as an Excitation Source
The operation of the magnetic bearing used as an excitation source in the Rocketdyne Multifunction Tester is described. The tester is scheduled for operation during the summer of 1990. The magnetic bearing can be used in two control modes: (1) open loop mode, in which the magnetic bearing operates as a force actuator; and (2) closed loop mode, in which the magnetic bearing provides shaft support. Either control mode can be used to excite the shaft; however, response of the shaft in the two control modes is different due to the alteration of the eigenvalues by closed loop mode operation. A rotordynamic model is developed to predict the frequency response of the tester due to excitation in either control mode. Closed loop mode excitation is shown to be similar to the excitation produced by a rotating eccentricity in a conventional bearing. Predicted frequency response of the tester in the two control modes is compared, and the maximum response is shown to be the same for the two control modes when synchronous unbalance loading is not considered. The analysis shows that the response of this tester is adequate for the extraction of rotordynamic stiffness, damping, and inertia coefficients over a wide range of test article stiffnesses
Electron-Transport Properties of Na Nanowires under Applied Bias Voltages
We present first-principles calculations on electron transport through Na
nanowires at finite bias voltages. The nanowire exhibits a nonlinear
current-voltage characteristic and negative differential conductance. The
latter is explained by the drastic suppression of the transmission peaks which
is attributed to the electron transportability of the negatively biased plinth
attached to the end of the nanowire. In addition, the finding that a voltage
drop preferentially occurs on the negatively biased side of the nanowire is
discussed in relation to the electronic structure and conduction.Comment: 4 pages, 6 figure
Geometric Bogomolov conjecture for abelian varieties and some results for those with some degeneration (with an appendix by Walter Gubler: The minimal dimension of a canonical measure)
In this paper, we formulate the geometric Bogomolov conjecture for abelian
varieties, and give some partial answers to it. In fact, we insist in a main
theorem that under some degeneracy condition, a closed subvariety of an abelian
variety does not have a dense subset of small points if it is a non-special
subvariety. The key of the proof is the study of the minimal dimension of the
components of a canonical measure on the tropicalization of the closed
subvariety. Then we can apply the tropical version of equidistribution theory
due to Gubler. This article includes an appendix by Walter Gubler. He shows
that the minimal dimension of the components of a canonical measure is equal to
the dimension of the abelian part of the subvariety. We can apply this result
to make a further contribution to the geometric Bogomolov conjecture.Comment: 30 page
The health of banking in the Third District
Banks and banking ; Bank failures
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