8,144 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
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Injectable and Spatially Patterned Microporous Annealed Particle (MAP) Hydrogels for Tissue Repair Applications.
Spatially patterned hydrogels are becoming increasingly popular in the field of regenerative medicine and tissue repair because of their ability to guide cell infiltration and migration. However, postfabrication technologies are usually required to spatially pattern a hydrogel, making these hydrogels difficult to translate into the clinic. Here, an injectable spatially patterned hydrogel is reported using hyaluronic acid (HA)-based particle hydrogels. These particle hydrogels are sequentially loaded into a syringe to form a pattern and, once injected, they maintain the pattern. The applicability of this hydrogel in a wound healing skin model, a subcutaneous implant model, as well as a stroke brain model is examined and distinct patterning in all models tested is shown. This injectable and spatially patterned hydrogel can be used to create physical or biochemical gradients. Further, this design can better match the scaffold properties within the physical location of the tissue (e.g., wound border vs wound center). This allows for better design features within the material that promote repair and regeneration
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
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
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
Role of covalency in the ground state properties of perovskite ruthenates: A first principle study using local spin density approximations
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
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.
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
We investigate the Ward identities of the \W_{\infty} symmetry in the
super-Liouville theory coupled to the super-conformal matter of central charge
. The theory is classified into two chiralities.
For the positive chirality, all gravitationally dressed scaling operators are
generated from the 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, , where the equations for even and odd 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 and . 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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