975 research outputs found
T Duality Between Perturbative Characters of and SO(32) Heterotic Strings Compactified On A Circle
Characters of and SO(32) heterotic strings involving the
full internal symmetry Cartan subalgebra generators are defined after circle
compactification so that they are T dual. The novel point, as compared with an
earlier study of the type II case (hep-th/9707107), is the appearence of Wilson
lines. Using SO(17,1) transformations between the weight lattices reveals the
existence of an intermediate theory where T duality transformations are
disentangled from the internal symmetry. This intermediate theory corresponds
to a sort of twisted compactification of a novel type. Its modular invariance
follows from an interesting interplay between three representations of the
modular group.Comment: 17 pages LateX 2E, 2 figures (eps
Negative Probability and Uncertainty Relations
A concise derivation of all uncertainty relations is given entirely within
the context of phase-space quantization, without recourse to operator methods,
to the direct use of Weyl's correspondence, or to marginal distributions of x
and p.Comment: RevTeX, 4 page
Logistic Map Potentials
We develop and illustrate methods to compute all single particle potentials
that underlie the logistic map, x --> sx(1-x) for 0<s<=4. We show that the
switchback potentials can be obtained from the primary potential through
functional transformations. We are thereby able to produce the various branches
of the corresponding analytic potential functions, which have an infinite
number of branch points for generic s>2. We illustrate the methods numerically
for the cases s=5/2 and s=10/3
Potentials Unbounded Below
Continuous interpolates are described for classical dynamical systems defined
by discrete time-steps. Functional conjugation methods play a central role in
obtaining the interpolations. The interpolates correspond to particle motion in
an underlying potential, . Typically, has no lower bound and can exhibit
switchbacks wherein changes form when turning points are encountered by the
particle. The Beverton-Holt and Skellam models of population dynamics, and
particular cases of the logistic map are used to illustrate these features.Comment: Based on a talk given 29 July 2010, at the workshop on Supersymmetric
Quantum Mechanics and Spectral Design, Centro de Ciencias de Benasque Pedro
Pascual. This version incorporates modifications to conform to the published
paper: Additional references and discussion; New section 3.2 on the Skellam
exponential model; Appendix change
Areal Theory
New features are described for models with multi-particle area-dependent
potentials, in any number of dimensions. The corresponding many-body field
theories are investigated for classical configurations. Some explicit solutions
are given, and some conjectures are made about chaos in such field theories.Comment: December 2001 "Coral Gables" conference contribution; Scientific
Workplace Late
T Duality of Perturbative Characters for Closed Bosonic and Type II String Theories
The duality properties of perturbative string characters associated with the
transverse space-time rotations are studied. T duality is achieved by suitably
integrating over the total momentum, contrary to earlier discussions. The O(8)
triality properties of the characters for critical superstrings, are derived.
This shows the existence of a third formulation (unnoticed so far to our
knowledge) equivalent to, but different from the ones of Neveu-Schwarz-Ramond,
and Green-Schwarz. Projectors in the NS and R sectors are defined in the GS
formalism. The consequences of supersymmetry are neatly derived at once for all
massive states by factorising the character of the long SUSY multiplet.Comment: 44 pages LateX 2E, 2 figures (eps
A history and analysis of hydrogen maser reliability
Hydrogen masers an integral part of the Deep Space Network, provide extremely accurate navigation about the outer planets, as well as precise location of tracking stations. Reliability of equipment over extended periods of time was considered. The Deep Space Network has a number of hydrogen masers deployed and in the test cycle, which enabled an analysis of reliability of several generations and breeds of construction. A history and analysis of hydrogen maser reliability over a three-year period was compiled several types of masers
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