8,081 research outputs found

    Vertex Operators in 4D Quantum Gravity Formulated as CFT

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    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

    Recursion Relations in Liouville Gravity coupled to Ising Model satisfying Fusion Rules

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    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

    Making a Universe

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    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 dd-dimensional universe having the topology Dd D^d is created numerically in terms of a simplicial manifold with dd-simplices as the building blocks. The space coordinates of a universe are identified on the boundary surface Sd1 S^{d-1} , and the time coordinate is defined along the direction perpendicular to Sd1 S^{d-1} . 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 S2 S^2 -surface formed as the last scattering surface in the S3 S^3 universe.Comment: 27pages,18figures,using jpsj.st

    Teleportation and entanglement distillation in the presence of correlation among bipartite mixed states

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    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

    Role of covalency in the ground state properties of perovskite ruthenates: A first principle study using local spin density approximations

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    We investigate the electronic structure of SrRuO3 and CaRuO3 using full potential linearized augmented plane wave method within the local spin density approximations. The ferromagnetic ground state in SrRuO3 could exactly be described in these calculations and the calculated spin magnetic moment is found to be close to the experimentally observed values. Interestingly, the spin polarized calculations for CaRuO3 exhibit large spin moment as observed in the experiments but the magnetic ground state has higher energy than that in the non-magnetic solution. Various calculations for different structural configurations indicate that Ca-O covalency plays the key role in determining the electronic structure and thereby the magnetic ground state in this system.Comment: 8 figure

    Assessing the Medical Emergency Preparedness of Dental Faculty, Residents, and Practicing Periodontists: An Exploratory Study

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    With the increased number of elderly and medically compromised individuals receiving dental care and the presence of systemic comorbidities and associated treatment modalities in this patient population, it is imperative that dentists be prepared to manage a variety of medical emergencies. The aim of this study was to assess the knowledge of and preparedness to manage common medical emergencies of cohorts of practicing periodontists, specialty residents, and faculty members, both for comparative purposes and as an aid to refining a dental school’s standardized case scenarios. The study, conducted in 2017, was designed for four groups of randomly selected participants with at least 20 in each group; the actual number of voluntary participants was 28 private practice periodontists, 22 residents in specialty programs, 21 specialist faculty members, and 24 general practice faculty members. Participants were asked to evaluate ten clinical emergency cases and identify the diagnosis and indicated intervention for each. Groups were also evaluated for differences among correct responses for each case. Overall, there were no statistically significant differences for number of correct diagnoses or interventions among the four groups. However, several cases had varying degrees of incorrect diagnoses and management across all groups. Participants who had recently graduated or were still in school were able to treat cases appropriately more often than the other participants. Further refinement of cases to assess provider preparedness to correctly diagnose and manage medical emergencies is needed, specifically establishing case-specific features and addressing areas of potential confusion before the cases are used for educational purposes

    Uso do SIG para estimar o potencial de distribuição geográfica de pragas quarentenárias em função de variáveis climáticas.

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    Praga quarentenária é uma praga de importância econômica potencial para uma área com risco de sua introdução, mas não presente? ou presente, mas não amplamente distribuído na área e estando oficialmente controlado. Um Sistema de Informações Geográficas pode ser utilizado como ferramenta na análise de risco de pragas a fim de avaliar o seu potencial de introdução e de dispersão em uma área após o seu estabelecimento. O objetivo deste estudo foi determinar o potencial de distribuição geográfica de duas espécies quarentenárias, a mosca oriental das frutas (Bactrocera dorsalis), e o mal seco (Deuterophoma tracheiphila ), no estado de São Paulo, com base em variáveis climáticas e a utilização da ferramenta de SIG. Como resultado deste estudo, ambas as pragas quarentenárias indicaram potencial de introdução e dispersão no estado de São Paulo

    Non-linear Structures in Non-critical NSR String

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    We investigate the Ward identities of the \W_{\infty} symmetry in the super-Liouville theory coupled to the super-conformal matter of central charge c^M=12(pq)2/pq{\hat c}_M = 1-2(p-q)^2 /pq. The theory is classified into two chiralities. For the positive chirality, all gravitationally dressed scaling operators are generated from the q1q-1 gravitational primaries by acting one of the ring generators in the R-sector on them repeatedly. After fixing the normalizations of the dressed scaling operators, we find that the Ward identities are expressed in the form of the {\it usual} \W_q algebra constraints as in the bosonic case: \W^{(k+1)}_n \tau =0, (k=1,,q1; nZ1k)(k=1,\cdots,q-1 ;~ n \in {\bf Z}_{\geq 1-k}), where the equations for even and odd nn come from the currents in the NS- and the R-sector respectively. The non-linear terms come from the anomalous contributions at the boundaries of moduli space. The negative chirality is defined by interchanging the roles of pp and qq. Then we get the \W_p algebra constraints.Comment: 22 pages, Latex file, YITP/U-94-16, UT-Komaba/94-1
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