Non-linear Realisation of the N=2, D=6 Supergravity

We have applied the method of dualisation to construct the coset realisation of the bosonic sector of the N=2, D=6 supergravity which is coupled to a tensor multiplet. The bosonic field equations are regained through the Cartan-Maurer equation which the Cartan form satisfies. The first-order formulation of the theory is also obtained as a twisted self-duality condition within the non-linear coset construction.Comment: 11 page

On the Symmetric Space Sigma-Model Kinematics

The solvable Lie algebra parametrization of the symmetric spaces is discussed. Based on the solvable Lie algebra gauge two equivalent formulations of the symmetric space sigma model are studied. Their correspondence is established by inspecting the normalization conditions and deriving the field transformation laws.Comment: 17 page

On the Asserted Clash between the Freud and the Bianchi Identities

Through a constructive method it is shown that the claim advanced in recent times about a clash that should occur between the Freud and the Bianchi identities in Einstein's general theory of relativity is based on a faulty argument.Comment: 4 pages, plain Te

Mathematical formulation of instability of a subsea suspendent pipeline

Lateral vibration of underwater suspended pipeline was investigated for the case of pipeline oscillation due to vortex shedding. Firstly, tension force was defined at the connection legs on sea bottom. To define the dynamical equation the analogy of the Mathieu equation was applied, meanwhile Ince-Strutt diagram was used for its solution. As a numerical example we used the behavior of pipeline in a project between Turkey and North Cyprus in the East Mediterranean Sea. Good agreement was found between the theoretical results and experimental data of Danish Hydraulic Institute (DHI

Exponential Metric Fields

The Laser Interferometer Space Antenna (LISA) mission will use advanced technologies to achieve its science goals: the direct detection of gravitational waves, the observation of signals from compact (small and dense) stars as they spiral into black holes, the study of the role of massive black holes in galaxy evolution, the search for gravitational wave emission from the early Universe. The gravitational red-shift, the advance of the perihelion of Mercury, deflection of light and the time delay of radar signals are the classical tests in the first order of General Relativity (GR). However, LISA can possibly test Einstein's theories in the second order and perhaps, it will show some particular feature of non-linearity of gravitational interaction. In the present work we are seeking a method to construct theoretical templates that limit in the first order the tensorial structure of some metric fields, thus the non-linear terms are given by exponential functions of gravitational strength. The Newtonian limit obtained here, in the first order, is equivalent to GR.Comment: Accepted for publication in Astrophysics and Space Science, 17 page

Gravity on a parallelizable manifold. Exact solutions

The wave type field equation \square \vt^a=\la \vt^a, where \vt^a is a coframe field on a space-time, was recently proposed to describe the gravity field. This equation has a unique static, spherical-symmetric, asymptotically-flat solution, which leads to the viable Yilmaz-Rosen metric. We show that the wave type field equation is satisfied by the pseudo-conformal frame if the conformal factor is determined by a scalar 3D-harmonic function. This function can be related to the Newtonian potential of classical gravity. So we obtain a direct relation between the non-relativistic gravity and the relativistic model: every classical exact solution leads to a solution of the field equation. With this result we obtain a wide class of exact, static metrics. We show that the theory of Yilmaz relates to the pseudo-conformal sector of our construction. We derive also a unique cosmological (time dependent) solution of the described type.Comment: Latex, 17 page

Equality of averaged and quenched large deviations for random walks in random environments in dimensions four and higher

We consider large deviations for nearest-neighbor random walk in a uniformly elliptic i.i.d. environment. It is easy to see that the quenched and the averaged rate functions are not identically equal. When the dimension is at least four and Sznitman's transience condition (T) is satisfied, we prove that these rate functions are finite and equal on a closed set whose interior contains every nonzero velocity at which the rate functions vanish.Comment: 17 pages. Minor revision. In particular, note the change in the title of the paper. To appear in Probability Theory and Related Fields

Spinodal Instabilities in Nuclear Matter in a Stochastic Relativistic Mean-Field Approach

Spinodal instabilities and early growth of baryon density fluctuations in symmetric nuclear matter are investigated in the basis of stochastic extension of relativistic mean-field approach in the semi-classical approximation. Calculations are compared with the results of non-relativistic calculations based on Skyrme-type effective interactions under similar conditions. A qualitative difference appears in the unstable response of the system: the system exhibits most unstable behavior at higher baryon densities around $\rho_{b}=0.4 ~\rho_{0}$ in the relativistic approach while most unstable behavior occurs at lower baryon densities around $\rho_{b}=0.2 ~\rho_{0}$ in the non-relativistic calculationsComment: 18 pages, 7 figure

An exploration of individual personality types in software development

Previous research - using conventional psychometric questionnaires - has highlighted the importance of aligning compatible personality types in software development teams. However, there does not exist a dedicated, robust questionnaire instrument for revealing the pertinent personality types for software development practitioners. This study analyzes the validity and reliability of a 70-item (context dependent) personality-profiling questionnaire particularly developed to assess personality types of software practitioners. A systematic process of validation, using an iterative approach to questionnaire development, was employed. The questions were developed both with a qualitative analysis of interview data, and based on the opinions of expert reviewers who revised the items through a set of examination. To investigate how stable the questions and reproducible the results, we measured test-retest reliability of the instrument, yielding satisfactory results. The present study provided evidence for the construct validity of the instrument. Ultimately, an initial comparison of the results delivered by the instrument demonstrated positive correlations with the findings acquired with well- known personality assessment instrument, i.e. the big five personality questionnaire