14,256 research outputs found
Thermofield-Bosonization on Compact Space
We develop the construction of fermionic fields in terms of bosonic ones to
describe free and interaction models in the circle, using thermofielddynamics.
The description in the case of finite temperature is developed for both normal
modes and zero modes. The treatment extends the thermofield-bosonization for
periodic space
Collection of relevant results obtained with the ERTS-1 satellite images by the Institute for Space Research (INPE), volume 1
There are no author-identified significant results in this report
Macaque cardiac physiology is sensitive to the valence of passively viewed sensory stimuli.
Autonomic nervous system activity is an important component of affective experience. We demonstrate in the rhesus monkey that both the sympathetic and parasympathetic branches of the autonomic nervous system respond differentially to the affective valence of passively viewed video stimuli. We recorded cardiac impedance and an electrocardiogram while adult macaques watched a series of 300 30-second videos that varied in their affective content. We found that sympathetic activity (as measured by cardiac pre-ejection period) increased and parasympathetic activity (as measured by respiratory sinus arrhythmia) decreased as video content changes from positive to negative. These findings parallel the relationship between autonomic nervous system responsivity and valence of stimuli in humans. Given the relationship between human cardiac physiology and affective processing, these findings suggest that macaque cardiac physiology may be an index of affect in nonverbal animals
Simulation of Chua's Circuit by Means of Interval Analysis
The Chua's circuit is a paradigm for nonlinear scientific studies. It is
usually simulated by means of numerical methods under IEEE 754-2008 standard.
Although the error propagation problem is well known, little attention has been
given to the relationship between this error and inequalities presented in
Chua's circuit model. Taking the average of round mode towards and
, we showed a qualitative change on the dynamics of Chua's circuit.Comment: 6th International Conference on Nonlinear Science and Complexity -
S\~ao Jos\'e dos Campos, 2016, p. 1-
Canonical Transformations in a Higher-Derivative Field Theory
It has been suggested that the chiral symmetry can be implemented only in
classical Lagrangians containing higher covariant derivatives of odd order.
Contrary to this belief, it is shown that one can construct an exactly soluble
two-dimensional higher-derivative fermionic quantum field theory containing
only derivatives of even order whose classical Lagrangian exhibits chiral-gauge
invariance. The original field solution is expressed in terms of usual Dirac
spinors through a canonical transformation, whose generating function allows
the determination of the new Hamiltonian. It is emphasized that the original
and transformed Hamiltonians are different because the mapping from the old to
the new canonical variables depends explicitly on time. The violation of
cluster decomposition is discussed and the general Wightman functions
satisfying the positive-definiteness condition are obtained.Comment: 12 pages, LaTe
Pareto's Law of Income Distribution: Evidence for Germany, the United Kingdom, and the United States
We analyze three sets of income data: the US Panel Study of Income Dynamics
PSID), the British Household Panel Survey (BHPS), and the German Socio-Economic
Panel (GSOEP). It is shown that the empirical income distribution is consistent
with a two-parameter lognormal function for the low-middle income group
(97%-99% of the population), and with a Pareto or power law function for the
high income group (1%-3% of the population). This mixture of two qualitatively
different analytical distributions seems stable over the years covered by our
data sets, although their parameters significantly change in time. It is also
found that the probability density of income growth rates almost has the form
of an exponential function.Comment: Latex2e v1.6; 16 pages with 5 figure
Higher-Derivative Two-Dimensional Massive Fermion Theories
We consider the canonical quantization of a generalized two-dimensional
massive fermion theory containing higher odd-order derivatives. The
requirements of Lorentz invariance, hermiticity of the Hamiltonian and absence
of tachyon excitations suffice to fix the mass term, which contains a
derivative coupling. We show that the basic quantum excitations of a
higher-derivative theory of order 2N+1 consist of a physical usual massive
fermion, quantized with positive metric, plus 2N unphysical massless fermions,
quantized with opposite metrics. The positive metric Hilbert subspace, which is
isomorphic to the space of states of a massive free fermion theory, is selected
by a subsidiary-like condition. Employing the standard bosonization scheme, the
equivalent boson theory is derived. The results obtained are used as a
guideline to discuss the solution of a theory including a current-current
interaction.Comment: 23 pages, Late
The Distribution of the Asymptotic Number of Citations to Sets of Publications by a Researcher or From an Academic Department Are Consistent With a Discrete Lognormal Model
How to quantify the impact of a researcher's or an institution's body of work
is a matter of increasing importance to scientists, funding agencies, and
hiring committees. The use of bibliometric indicators, such as the h-index or
the Journal Impact Factor, have become widespread despite their known
limitations. We argue that most existing bibliometric indicators are
inconsistent, biased, and, worst of all, susceptible to manipulation. Here, we
pursue a principled approach to the development of an indicator to quantify the
scientific impact of both individual researchers and research institutions
grounded on the functional form of the distribution of the asymptotic number of
citations. We validate our approach using the publication records of 1,283
researchers from seven scientific and engineering disciplines and the chemistry
departments at the 106 U.S. research institutions classified as "very high
research activity". Our approach has three distinct advantages. First, it
accurately captures the overall scientific impact of researchers at all career
stages, as measured by asymptotic citation counts. Second, unlike other
measures, our indicator is resistant to manipulation and rewards publication
quality over quantity. Third, our approach captures the time-evolution of the
scientific impact of research institutions.Comment: 20 pages, 11 figures, 3 table
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