2,142 research outputs found
Hill's Equation with Random Forcing Parameters: Determination of Growth Rates through Random Matrices
This paper derives expressions for the growth rates for the random 2 x 2
matrices that result from solutions to the random Hill's equation. The
parameters that appear in Hill's equation include the forcing strength and
oscillation frequency. The development of the solutions to this periodic
differential equation can be described by a discrete map, where the matrix
elements are given by the principal solutions for each cycle. Variations in the
forcing strength and oscillation frequency lead to matrix elements that vary
from cycle to cycle. This paper presents an analysis of the growth rates
including cases where all of the cycles are highly unstable, where some cycles
are near the stability border, and where the map would be stable in the absence
of fluctuations. For all of these regimes, we provide expressions for the
growth rates of the matrices that describe the solutions.Comment: 22 pages, 3 figure
Control of Heliothis spp. (Lepidoptera: Noctuidae) larvae on flue- cured tobacco in north Queensland
In trials on tobacco in northern Queensland in 1972-76, sprays of 0.025% methomyl and 0.05% monocrotophos were effective against larvae of Heliothis spp. Other promising insecticides were 0.1% acephate, 0.05% carbofuran, 0.75% chlorpyrifos, 0.06% endosulfan, 0.075% mephosfolan, 0.03% permethrin, 0.06% prothiofos and sulprofos, 0.03% fenpropathrin, and a mixture of 0.05% chlordimeform hydrochloride with 0.05% Bacillus thuringiensis
Designing Good Partial Coverage Satellite Constellations
Design of satellite constellations providing partial coverage of certain ground regions is becoming more important as small low-altitude satellites receive increased attention. The purpose of this study is to develop the procedures necessary for deriving the best constellations for partial coverage
A Field Range Bound for General Single-Field Inflation
We explore the consequences of a detection of primordial tensor fluctuations
for general single-field models of inflation. Using the effective theory of
inflation, we propose a generalization of the Lyth bound. Our bound applies to
all single-field models with two-derivative kinetic terms for the scalar
fluctuations and is always stronger than the corresponding bound for slow-roll
models. This shows that non-trivial dynamics can't evade the Lyth bound. We
also present a weaker, but completely universal bound that holds whenever the
Null Energy Condition (NEC) is satisfied at horizon crossing.Comment: 16 page
Universality and Lepton Flavor Violation in Upsilon Decays at CLEO
I present two analyses done with the CLEOIII detector at CESR. The first is a
search for the Lepton Flavor Violating decay Upsilon to mu tau, with
preliminary results, and the second constrains Lepton Universality in Upsilon
to tau tau relative to Upsilon to mu mu. This second analysis, whose results
are final, has dramatically improved uncertainties relative to other such
measurements, and is also the first observation of the decay Upsilon(3S) to tau
tau. A limit is also set on the involvement of a CP odd Higgs in the decay of
the Upsilon(1S) to tau pairs.Comment: 8 pages, 5 figures, to appear in proceedings of The 9th International
Workshop on Tau-Lepton Physics, Tau0
Quantization of Field Theories Generalizing Gravity-Yang-Mills Systems on the Cylinder
Pure gravity and gauge theories in two dimensions are shown to be special
cases of a much more general class of field theories each of which is
characterized by a Poisson structure on a finite dimensional target space. A
general scheme for the quantization of these theories is formulated. Explicit
examples are studied in some detail. In particular gravity and gauge theories
with equivalent actions are compared. Big gauge transformations as well as the
condition of metric nondegeneracy in gravity turn out to cause significant
differences in the structure of the corresponding reduced phase spaces and the
quantum spectra of Dirac observables. For gravity coupled to SU(2) Yang
Mills the question of quantum dynamics (`problem of time') is addressed. [This
article is a contribution to the proceedings (to appear in LNP) of the 3rd
Baltic RIM Student Seminar (1993). Importance is attached to concrete examples.
A more abstract presentation of the ideas underlying this article (including
new developments) is found in hep-th/9405110.]Comment: 26, pages, TUW-94-
Inflationary cosmology in the central region of String/M-theory moduli space
The "central" region of moduli space of M- and string theories is where the
string coupling is about unity and the volume of compact dimensions is about
the string volume. Here we argue that in this region the non-perturbative
potential which is suggested by membrane instanton effects has the correct
scaling and shape to allow for enough slow-roll inflation, and to produce the
correct amplitude of CMB anisotropies. Thus, the well known theoretical
obstacles for achieving viable slow-roll inflation in the framework of
perturbative string theory are overcome. Limited knowledge of some generic
properties of the induced potential is sufficient to determine the simplest
type of consistent inflationary model and its predictions about the spectrum of
cosmic microwave background anisotropies: a red spectrum of scalar
perturbations, and negligible amount of tensor perturbations.Comment: 9 pages, 1 figur
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