5,200 research outputs found
Vertex Operators in 4D Quantum Gravity Formulated as CFT
We study vertex operators in 4D conformal field theory derived from quantized
gravity, whose dynamics is governed by the Wess-Zumino action by Riegert and
the Weyl action. Conformal symmetry is equal to diffeomorphism symmetry in the
ultraviolet limit, which mixes positive-metric and negative-metric modes of the
gravitational field and thus these modes cannot be treated separately in
physical operators. In this paper, we construct gravitational vertex operators
such as the Ricci scalar, defined as space-time volume integrals of them are
invariant under conformal transformations. Short distance singularities of
these operator products are computed and it is shown that their coefficients
have physically correct sign. Furthermore, we show that conformal algebra holds
even in the system perturbed by the cosmological constant vertex operator as in
the case of the Liouville theory shown by Curtright and Thorn.Comment: 26 pages, rewrote review part concisely, added explanation
Inflammation, Diet, and Depression
Although it is well established that inflammation contributes to cardiovascular disease (CVD), this thesis considers the potential for dietary-induced inflammation to also play a role in the development of depression. Even though the association between inflammation and depression was initially proposed over 100 years ago, treatment of depression has focused on psychopharmacological and psychotherapy. In addition to the increases in the chronic diseases that are the leading causes of death, including CVD, diabetes, and several forms of cancer, consumption of meat, dairy, and highly processed foods have also increased dramatically in recent decades. The resulting Standard American Diet (S.A.D.) is highly inflammatory and is known to play a significant role in the etiology of CVD. In contrast, a whole food, plant-based (WFPB) diet reduces the body’s inflammatory response. Recognizing there are many factors contributing to these complex conditions, is it possible that a WFPB diet that has been shown to prevent, and in some instances, reverse CVD also has the potential to play an important role in reducing the suffering of those diagnosed with depression
Recursion Relations in Liouville Gravity coupled to Ising Model satisfying Fusion Rules
The recursion relations of 2D quantum gravity coupled to the Ising model
discussed by the author previously are reexamined. We study the case in which
the matter sector satisfies the fusion rules and only the primary operators
inside the Kac table contribute. The theory involves unregularized divergences
in some of correlators. We obtain the recursion relations which form a closed
set among well-defined correlators on sphere, but they do not have a beautiful
structure that the bosonized theory has and also give an inconsistent result
when they include an ill-defined correlator with the divergence. We solve them
and compute the several normalization independent ratios of the well-defined
correlators, which agree with the matrix model results.Comment: Latex, 22 page
Teleportation and entanglement distillation in the presence of correlation among bipartite mixed states
The teleportation channel associated with an arbitrary bipartite state
denotes the map that represents the change suffered by a teleported state when
the bipartite state is used instead of the ideal maximally entangled state for
teleportation. This work presents and proves an explicit expression of the
teleportation channel for the teleportation using Weyl's projective unitary
representation of the space of 2n-tuples of numbers from Z/dZ for integers d>1,
n>0, which has been known for n=1. This formula allows any correlation among
the n bipartite mixed states, and an application shows the existence of
reliable schemes for distillation of entanglement from a sequence of mixed
states with correlation.Comment: 12 pages, 1 figur
p-norms of histogram of oriented gradients for X-ray images
Lebesgue spaces (Lp over Rn) play a significant role in mathematical analysis. They are widely used in machine learning and artificial intelligence to maximize performance or minimize error. The well-known histogram of oriented gradients (HOG) algorithm applies the 2-norm (Euclidean distance) to detect features in images. In this paper, we apply different p-norm values to identify the impact that changing these norms has on the original algorithm. The aim of this modification is to achieve better performance in classifying X-ray medical images related to of COVID-19 patients. The efficiency of the p-HOG algorithm is compared with the original HOG descriptor using a support vector machine implemented in Python. The results of the comparisons are promising, and the p-HOG algorithm shows greater efficiency in most cases
Making a Universe
For understanding the origin of anisotropies in the cosmic microwave
background, rules to construct a quantized universe is proposed based on the
dynamical triangulation method of the simplicial quantum gravity. A
-dimensional universe having the topology is created numerically in
terms of a simplicial manifold with -simplices as the building blocks. The
space coordinates of a universe are identified on the boundary surface , and the time coordinate is defined along the direction perpendicular
to . Numerical simulations are made mainly for 2-dimensional
universes, and analyzed to examine appropriateness of the construction rules by
comparing to analytic results of the matrix model and the Liouville theory.
Furthermore, a simulation in 4-dimension is made, and the result suggests an
ability to analyze the observations on anisotropies by comparing to the scalar
curvature correlation of a -surface formed as the last scattering
surface in the universe.Comment: 27pages,18figures,using jpsj.st
Temperature dependence of modified CNO nuclear reaction rates in dense stellar plasmas
We study the dependence of the CNO nuclear reaction rates on temperature, in
the range of K, the typical range of temperature evolution from
a Sun-like star towards a white dwarf. We show that the temperature dependence
of the CNO nuclear reaction rates is strongly affected by the presence of
non-extensive statistical effects in the dense stellar core. A very small
deviation from the Maxwell-Boltzmann particle distribution implies a relevant
enhancement of the CNO reaction rate and could explain the presence of heavier
elements (e.g. Fe, Mg) in the final composition of a white dwarf core. Such a
behavior is consistent with the recent experimental upper limit to the fraction
of energy that the Sun produces via the CNO fusion cycle.Comment: Presented at NEXT2003 (Second International Conference on "News and
Expectations in Thermostatistics"), Villasimius (Cagliari)- Italy in 21-28
September 2003. 7 pages including 3 figure
Impact of Tributyltin and Triphenyltin on Ivory Shell (Babylonia japonica) Populations
We histopathologically examined gonads and chemically determined organotin compounds in tissues of the ivory shell, Babylonia japonica. Imposex (a superimposition of male-type genital organs on females) occurred in approximately 80–90% of B. japonica specimens that we examined, with the penis and vas deferens both well developed. No oviduct blockage by vas deferens formation was observed. Ovarian spermatogenesis and suppressed ovarian maturation were observed in the females that exhibited imposex, although no histopathological abnormalities were found in males. Tissue distributions of organotin compounds [tributyltin (TBT), triphenyltin (TPhT), and their metabolites] were different for butyltins and phenyltins; a remarkably high accumulation of TBT was observed in the ctenidium, osphradium, and heart, whereas high concentrations of TPhT were detected in the ovary and digestive gland. More than one-third of TBT accumulated in the digestive glands of both males and females, followed by the testis, ctenidium, muscle, and heart tissues in males and in the muscle, ovary, ctenidium, and head tissues (including the central nervous system ganglia) in females. In both males and females, more than half of total TPhT accumulated in the digestive glands, followed by the gonads. The next highest values were in the muscle, ctenidium, and heart tissues in males and in the muscle, oviduct, and head tissues in females. Both TBT and TPhT concentrations in the gonads were positively correlated with penis length in females. Our findings strongly suggest that reproductive failure in adult females accompanied by imposex, possibly induced by TBT and TPhT from antifouling paints, may have caused the marked decline of B. japonica populations in Japan
Efeito das mudanças climáticas sobre a duração da fase lagarta do curuquerê-do-algodoeiro no nordeste brasileiro.
Resumo: Este trabalho teve como objetivo avaliar o impacto das mudanças climáticas no desenvolvimento de uma das mais importantes pragas desfolhadoras do algodão no Nordeste brasileiro, o curuquerê-do-algodoeiro Alabama argillacea (Hübner) na fase larval, utilizando Sistema de Informações Geográficas. A ocorrência do curuquerê-do-algodoeiro foi estimada empregando-se o modelo de desenvolvimento proposto por Kasten Junior e Parra (1984). Foram elaborados mapas que simulam a duração em dias da fase larval do inseto para o Nordeste no período de referência (1961-1990) e nas condições climáticas futuras projetadas pelo IPCC, nos períodos de 2011-2040, 2041-2070, 2071-2100, no cenário A2. Os resultados indicam que no futuro, de um modo geral, haverá uma diminuição da duração em dias da fase larval, implicando em aumento nas populações do curuquerê-do-algodoeiro, comparado ao período de 1961 a 1990 no Nordeste. Abstract: The objective of this study was to evaluate the impact of the climate change on the development of one of the most important cotton leaf defoliator pest in the Brazilian Northeast, the leafworm Alabama argillacea (Hübner) in larval stage, using Geographic Information System. The occurrence of leaf worm on cotton was estimated using the model of development proposed by Kasten Junior and Parra (1984). Maps were prepared to simulate the duration in days of the leafworm on cotton larval stage, to the Northeast in the reference period (1961-1990) and future climate conditions projected by the IPCC for the periods of 2011-2040, 2041-2070, 2071 - 2100, A2 scenario. The results indicate that in the future, generally, there will be a decrease in the duration in days of the larval stage implying the increase of the population of the cotton leafworm compared to the period of 1961 to 1990 in the Northeast region
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