Two dimensional general covariance from three dimensions

A 3d generally covariant field theory having some unusual properties is described. The theory has a degenerate 3-metric which effectively makes it a 2d field theory in disguise. For 2-manifolds without boundary, it has an infinite number of conserved charges that are associated with graphs in two dimensions and the Poisson algebra of the charges is closed. For 2-manifolds with boundary there are additional observables that have a Kac-Moody Poisson algebra. It is further shown that the theory is classically integrable and the general solution of the equations of motion is given. The quantum theory is described using Dirac quantization, and it is shown that there are quantum states associated with graphs in two dimensions.Comment: 10 pages (Latex), Alberta-Thy-19-9

General covariance, and supersymmetry without supersymmetry

An unusual four-dimensional generally covariant and supersymmetric SU(2) gauge theory is described. The theory has propagating degrees of freedom, and is invariant under a local (left-handed) chiral supersymmetry, which is half the supersymmetry of supergravity. The Hamiltonian 3+1 decomposition of the theory reveals the remarkable feature that the local supersymmetry is a consequence of Yang-Mills symmetry, in a manner reminiscent of how general coordinate invariance in Chern-Simons theory is a consequence of Yang-Mills symmetry. It is possible to write down an infinite number of conserved currents, which strongly suggests that the theory is classically integrable. A possible scheme for non-perturbative quantization is outlined. This utilizes ideas that have been developed and applied recently to the problem of quantizing gravity.Comment: 17 pages, RevTeX, two minor errors correcte

Frekuensi Pertemuan Dewan Komisaris dan Komite Audit terhadap Manajemen Laba dengan Pendekatan Non-Discreationary Accruals

This research aim to obtain empirical evidence about the practice of earnings management in use of corporate governance mechanism which consists of the frequency of board and audit committees meeting. This study uses measurements of earnings management with the non-discreationary accruals (NDA) approach introduced by Jones. The population of this study is sub-sectors companies in the construction and building in 2010-2016. The sampling technique uses a purposive method. The method of data analysis uses multiple regression analysis, the classical assumption test previously and followed by hypothesis testing. The results of this research indicate that the frequency of board meetings does not significantly influence on the earnings management, while the frequency of audit committee meetings has a negative effect on the earnings management

Solutions in Self-Dual Gravity Constructed Via Chiral Equations

The chiral model for self-dual gravity given by Husain in the context of the chiral equations approach is discussed. A Lie algebra corresponding to a finite dimensional subgroup of the group of symplectic diffeomorphisms is found, and then use for expanding the Lie algebra valued connections associated with the chiral model. The self-dual metric can be explicitly given in terms of harmonic maps and in terms of a basis of this subalgebra.Comment: Plain Latex, 13 Pages, major revisions of style in the above proof, several Comments added. Version to appear in Physical Review

Cervical cancer in women diagnosed at the National Health Laboratory, Sudan: A call for screening

Background: Cancer of the cervix is the second most prevalent cancer of women to date in the Sudan, in a concerted review of the records of the hospital-based cancer registry of the Radiation & Isotope Centre of Khartoum (RICK). However, in spite of a wealth of data, this is the first study to date describing the histopathologic prevalence of cervical cancer in the Sudan.Objectives: To identify the percentage and clinicopathological pattern of cervical cancer cases diagnosed at Histopathology Department, National Health Laboratory (NHL) in Khartoum, Sudan.Material and Methods: This is a cross-sectional, descriptive study  conducted at the NHL. All cases with histopathological diagnosis of cervical neoplasm in the period from 2004-2009 were reviewed. Patients’ clinical data were obtained from clinical records. Exclusion criteria included inadequate clinical information and unavailability of both Hematoxylin and Eosin stained (H&E) sections and formalin-fixed paraffin-embedded (FFPE) blocks. The WHO classification of cancer of the cervix (2003) was used to describe disease type. SPSS data analysis was applied.Results: A total of 287 cases were reviewed and 195 cases were included in the study. The mean of cervical cancer cases diagnosed per year at NHL is 7.9%. The commonest age group affected was patients grouped between 41- 60 years (52%) followed by 61-80 years (26.3%). Histologically, 95.9% of the cases were carcinomas. Squamous cell carcinomas were 90.9%, Adenocarcinomas 4.8%, and other epithelial tumours were 4.3%. Of the Squamous carcinomas, 98.8% were invasive and 1.2% intraepithelial (cervical intraepithelial neoplasia). The majority of case presentations were that of a protruding cervical mass. We noticed the commonest symptom being bleeding per vagina.Conclusion: To determine the incidence of cervical cancer in the Sudan a national populationbased registry is necessary. The mean age of patients presenting with cervical cancer to NHL is 53.25 years. This is in keeping with the natural history of the human papilloma virus (HPV). The late presentation of patients with aggressive disease necessitates health  education and cervical cancer screening as well as strict guidelines for medical record keeping in line with good medical practices, enabling good data collection for the newly established population-based cancer registry.Keywords: HPV, invasive squamous cell carcinoma

Background independent quantization and wave propagation

We apply a type of background independent "polymer" quantization to a free scalar field in a flat spacetime. Using semi-classical states, we find an effective wave equation that is both nonlinear and Lorentz invariance violating. We solve this equation perturbatively for several cases of physical interest, and show that polymer corrections to solutions of the Klein-Gordon equation depend on the amplitude of the field. This leads to an effective dispersion relation that depends on the amplitude, frequency and shape of the wave-packet, and is hence distinct from other modified dispersion relations found in the literature. We also demonstrate that polymer effects tend to accumulate with time for plane-symmetric waveforms. We conclude by discussing the possibility of measuring deviations from the Klein-Gordon equation in particle accelerators or astrophysical observations.Comment: 15 pages, minor revision to match PRD versio

Abelian BF-Theory and Spherically Symmetric Electromagnetism

Three different methods to quantize the spherically symmetric sector of electromagnetism are presented: First, it is shown that this sector is equivalent to Abelian BF-theory in four spacetime dimensions with suitable boundary conditions. This theory, in turn, is quantized by both a reduced phase space quantization and a spin network quantization. Finally, the outcome is compared with the results obtained in the recently proposed general quantum symmetry reduction scheme. In the magnetically uncharged sector, where all three approaches apply, they all lead to the same quantum theory.Comment: 21 pages, LaTeX2e, v2: minor corrections in some formulas and a new referenc

Quantum gravity and the Coulomb potential

We apply a singularity resolution technique utilized in loop quantum gravity to the polymer representation of quantum mechanics on R with the singular -1/|x| potential. On an equispaced lattice, the resulting eigenvalue problem is identical to a finite difference approximation of the Schrodinger equation. We find numerically that the antisymmetric sector has an energy spectrum that converges to the usual Coulomb spectrum as the lattice spacing is reduced. For the symmetric sector, in contrast, the effect of the lattice spacing is similar to that of a continuum self-adjointness boundary condition at x=0, and its effect on the ground state is significant even if the spacing is much below the Bohr radius. Boundary conditions at the singularity thus have a significant effect on the polymer quantization spectrum even after the singularity has been regularized.Comment: 10 pages, 5 figures. v2: Minor presentational changes. One data point added in Table

The Husain-Kuchar Model: Time Variables and Non-degenerate Metrics

We study the Husain-Kuchar model by introducing a new action principle similar to the self-dual action used in the Ashtekar variables approach to Quantum Gravity. This new action has several interesting features; among them, the presence of a scalar time variable that allows the definition of geometric observables without adding new degrees of freedom, the appearance of a natural non-degenerate four-metric and the possibility of coupling ordinary matter.Comment: LaTeX, 22 pages, accepted for publication in Phys. Rev.