20,719 research outputs found
Torsion-Adding and Asymptotic Winding Number for Periodic Window Sequences
In parameter space of nonlinear dynamical systems, windows of periodic states
are aligned following routes of period-adding configuring periodic window
sequences. In state space of driven nonlinear oscillators, we determine the
torsion associated with the periodic states and identify regions of uniform
torsion in the window sequences. Moreover, we find that the measured of torsion
differs by a constant between successive windows in periodic window sequences.
We call this phenomenon as torsion-adding. Finally, combining the torsion and
the period adding rules, we deduce a general rule to obtain the asymptotic
winding number in the accumulation limit of such periodic window sequences
Detectability of the First Cosmic Explosions
We present a fully self-consistent simulation of a synthetic survey of the
furthermost cosmic explosions. The appearance of the first generation of stars
(Population III) in the Universe represents a critical point during cosmic
evolution, signaling the end of the dark ages, a period of absence of light
sources. Despite their importance, there is no confirmed detection of
Population III stars so far. A fraction of these primordial stars are expected
to die as pair-instability supernovae (PISNe), and should be bright enough to
be observed up to a few hundred million years after the big bang. While the
quest for Population III stars continues, detailed theoretical models and
computer simulations serve as a testbed for their observability. With the
upcoming near-infrared missions, estimates of the feasibility of detecting
PISNe are not only timely but imperative. To address this problem, we combine
state-of-the-art cosmological and radiative simulations into a complete and
self-consistent framework, which includes detailed features of the
observational process. We show that a dedicated observational strategy using
per cent of total allocation time of the James Webb Space
Telescope mission can provide us up to detectable PISNe per year.Comment: 9 pages, 8 figures. Minor corrections added to match published
versio
Accuracy of a teleported trapped field state inside a single bimodal cavity
We propose a simplified scheme to teleport a superposition of coherent states
from one mode to another of the same bimodal lossy cavity. Based on current
experimental capabilities, we present a calculation of the fidelity that can be
achieved, demonstrating accurate teleportation if the mean photon number of
each mode is at most 1.5. Our scheme applies as well for teleportation of
coherent states from one mode of a cavity to another mode of a second cavity,
both cavities embedded in a common reservoir.Comment: 4 pages, 2 figures, in appreciation for publication in Physical
Review
Utilização de herbicidas no controle de plantas indesejáveis em pastagem natural.
A aplicação de herbicidas sob a pastagem natural, tanto para o estabelecimento de pastagens cultivadas através do plantio direto, como no controle de plantas indesejáveis tem crescido nos últimos anos. A pesquisa, até o presente momento não dispõe de informações seguras para recomendar tal procedimento. O efeito de herbicidas sobre uma vegetação natural tão diversificada e rica em espécies forrageiras tem sido uma das maiores interrogantes neste processo.bitstream/item/55664/1/ct24-1999.pd
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