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The solution to the one dimensional Schrodinger equation for the potential of type x 2 + αx −2, for positive values of the constant α is discussed using an operator method by factorizing the Hamiltonian.

The Lanczos potential for the Weyl tensor is derived from a quadratic curvature Lagrangian by making use of the exterior algebra of forms and the variational principles with constraints., Published version, typos fixed, 14 pages, 42 references

We linearize vacuum Einstein field equations with a cosmological constant around a curved background to elaborate on the reconstruction of the Abbott-Deser charges and incorporate a spin connection into the definition using the algebra of differential forms on a given curved background spacetime., Comment: Published version, 6 pages, formatted using EPL class files

The family of metrics corresponding to the plane-fronted gravitational waves with parallel propagation,commonly referred to as the family of pp-wave metrics, is studied in the context of various modi ed gravitational modelsin a self-contained and coherent manner by using a variant of the null coframe formulation of Newman and Penrose andthe exterior algebra of differential forms on pseudo-Riemannian manifolds.

© 2013 Japanese Society of Neuropathology. This is the peer reviewed version of the following article: Jelinek, A. G., Fuller, C., Baykal, A., Stogner-Underwood, K., Richard, H. and Arkun, K. (2014), Headaches and hemiparesis in an immunocompetent inmate. Neuropathology, 34: 314-317, which has been published in final form at doi: 10.1111/ neup.12084. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.

Impulsive, non-diverging, Petrov-Segre type N gravitational wave solutions to a general massive three-dimensional gravity in the de Sitter, anti-de Sitter and flat Minkowski backgrounds are constructed in a unified manner by using the exterior algebra of differential forms., Published version

A technique to linearize gravitational field equations is developed in which the perturbation metric coefficients are treated as second rank, symmetric, 1-form fields belonging to the Minkowski background spacetime by using the exterior algebra of differential forms., Comment: 17 pages, 56 references, typos fixed, published version

WOS: 000382366800003, A modified Einstein-Gauss-Bonnet gravity in four dimensions where the quadratic Gauss-Bonnet term is coupled to a scalar field is considered. The field equations of the model are obtained by variational methods by making use of the constrained first-order formalism covering both pseudo-Riemannian and non-Riemannian cases. In the pseudo-Riemannian case, the Lagrange multiplier forms, which impose the vanishing torsion constraint, are eliminated in favor of the remaining fields and the resulting metric field equations are expressed in terms of the double dual curvature 2-form. In the non-Riemannian case with torsion, the field equations are expressed in terms of the pseudo-Riemannian quantities by a perturbative scheme valid for a weak coupling constant. It is shown that, for both cases, the model admits a maximally symmetric de Sitter solution with non-trivial scalar field. Minimal coupling of a Dirac spinor to the Gauss-Bonnet modified gravity is also discussed briefly.

The definition of the Sparling-Thirring form is extended to the Brans-Dicke theory. By writing the Brans-Dicke field equations in a formally Maxwell-like form, a superpotential and a corresponding pseudo energy-momentum form are defined. The general energy expression provided by the superpotential in the Jordan frame is discussed in relation to the corresponding expression in the Einstein frame. In order to substantiate its formal definition, the generalized Sparling-Thirring form is used to calculate the energy for the spherically symmetric vacuum solution in the Brans-Dicke theory., Comment: Revtex 4.1, 20 pages

We calculate the bi-invariant metric of FIO(2), the inhomogeneous invariance quantum group of the fermion algebra. We find that this metric is identical to that of the bi-invariant metric of GL(2, R) ≃ ℝ+ × SU (1, 1). However, the quantum group manifold is restricted to a region of the GL(2, R) manifold.

The family of metrics corresponding to the plane-fronted gravitational waves with parallel propagation, commonly referred to as the family of pp-wave metrics, is studied in the context of various modified gravitational models in a self-contained and coherent manner by using a variant of the null coframe formulation of Newman and Penrose and the exterior algebra of differential forms on pseudo-Riemannian manifolds., Comment: References updated. Additions/corrections have been made. 70 pages

A system of field equations for an Einstein-Maxwell model with $RF^2$-type nonminimal coupling in a non-Riemannian space-time with a non-vanishing torsion is derived and the resulting field equations are expressed in terms of the Riemannian quantities based on a metric with a Lorentzian signature. The torsion is generated by the gradients of the electromagnetic field invariants. An electromagnetic constitutive tensor is introduced in the formulation of the field equations., 1+10 pages, minor corrections to the text, published version

WOS: 000334308800010, Quadratic curvature gravity equations are projected to a complex null coframe by using the algebra of exterior forms and expressed in terms of the spinor quantities defined originally by Newman and Penrose. As an application, a new family of impulsive gravitational wave solutions propagating in various Petrov type D backgrounds is introduced.

WOS: 000326051200002, A method of calculation for the constrained variational derivatives for gravitational actions in the pseudo-Riemannian case is proposed as a practical variant of the first-order formalism with constraints. The proposed method calculation is then used to derive the metric field equations for a generic f (R) model.

The quadratic curvature lagrangians having metric field equations with second order trace are constructed relative to an orthonormal coframe. In $n>4$ dimensions, pure quadratic curvature lagrangian having second order trace constructed contains three free parameters in the most general case. The fourth order field equations of some of these models, in arbitrary dimensions, are cast in a particular form using the Schouten tensor. As a consequence, the field equations for the New massive gravity theory are related to those of the Topologically massive gravity. In particular, the conditions under which the latter is "square root" of the former are presented., 24 pages, to appear in GRG

A conserved current for generic quadratic curvature gravitational models is defined, and it is shown that, at the linearized level, it corresponds to the Deser-Tekin charges. An explicit expression for the charge for new massive gravity in three dimensions is given. Some implications of the linearized equations are discussed., Comment: 7 pages

The authors present a case of a 56-year-old man with altered mental status. Magnetic resonance imaging (MRI) of the brain revealed non-enhancing abnormalities on T2 and FLAIR imaging in the brainstem, cerebellum, and cerebrum. Immunohistochemisty demonstrated precursor T-cell lymphoblastic lymphoma. After treatment with methotrexate, he improved clinically without focal sensorimotor deficits and with improving orientation. MRI showed almost complete resolution of brainstem and cerebral lesions. To the authors' knowledge, there are only five previous reports of primary central nervous system T-cell lymphoblastic lymphoma. Since treatable, it deserves consideration in patients with altered mental status and imaging abnormalities that include diffuse, non-enhancing changes with increased signal on T2-weighted images.

WOS: 000280854500020, Higher dimensional, static, cylindrically symmetric vacuum solutions with and without a cosmological constant in the Brans-Dicke theory are presented. We show that for a negative cosmological constant and for specific values of the parameters, a particular subclass of these solutions includes higher dimensional topological black hole-type solutions with a flat horizon topology. We briefly extend our discussion to stationary vacuum and Lambda-vacuum solutions. (C) 2010 American Institute of Physics. [doi:10.1063/1.3459939]

WOS: 000263011400003, We investigate cylindrically symmetric vacuum solutions with both null and non-null electromagnetic fields in the framework of the Brans-Dicke theory and compare these solutions with some of the well-known solutions of general relativity for special values of the parameters of the resulting field functions. We see that, unlike general relativity where the gravitational force of an infinite and charged line mass acting on a test particle is always repulsive, it can be attractive or repulsive for Brans-Dicke theory depending on the values of the parameters as well as the radial distance from the symmetry axis.

Proje çizelgelemesinde aktivite süreleri ek kaynaklar tahsis edilerek azaltılabilir.Zaman/Maliyet Ödünleşim Problemi toplam maliyet ve proje süresi arasındaki uzlaşmayıele alır. Problemin kesikli versiyonu mod diye tabir edilen, belirli sayıda zaman/maliyetçiftleri varsayar ve her aktivite için bir mod seçer.Bu tezde Kesikli Zaman/Maliyet Ödünleşim Problemini ele aldık. ÖncelikleZaman Sınırı Problemi, başka bir deyişle, proje bitirme süresi sınırına bağlı toplammaliyet enazlama problemi üzerinde çalıştık. Zaman Sınırı Problemini çözmek için,optimal doğrusal programlama gevşetmesine dayanan eniyileme ve yaklaşıklamaalgoritmaları önerdik. Sonra Tüm Verimli Çözümleri Üretme Problemini inceledik, veZaman Sınırı Probleminin ardışık çözümlerini kullanan bir yaklaşım önerdik.Büyük ölçekli problem örneklerindeki sonuçlarımız algoritmalarımızınmemnuniyet verici tutumunu göstermektedir.Anahtar Kelimeler: Proje Çizelgelemesi, Zaman/Maliyet Ödünleşimi, Dal-SınırYöntemi In project scheduling, the activity durations can often be reduced by dedicatingadditional resources. Time/Cost Trade-off Problem considers the compromise betweenthe total cost and project duration. The discrete version of the problem assumes a numberof time/cost pairs, so called modes, and selects a mode for each activity.In this thesis we consider the Discrete Time/Cost Trade-off Problem. We firststudy the Deadline Problem, i.e., the problem of minimizing total cost subject to adeadline on project duration. To solve the Deadline Problem, we propose severaloptimization and approximation algorithms that are based on optimal LinearProgramming Relaxation solutions. We then analyze the problem of generating allefficient solutions, and propose an approach that uses the successive solutions of theDeadline Problem.Our computational results on large-sized problem instances have revealed thesatisfactory behavior of our algorithms.Keywords: Project Scheduling, Time/Cost Trade-off, Branch and Bound 99

By using the algebra of exterior forms and the first order formalism with constraints, an alternative derivation of the field equations for the Minimal massive 3D gravity model is presented., 12 pages in IOP article format, improved presentation with minor corrections, an appendix added

In this study, heart sounds of 10 normal subjects are recorded in three different respiratory states. These signals are analyzed and the changes of model parameters with respiration are studied. As a result, it is observed that the frequency of modes do not vary during respiration while the energy of modes significantly differ between inspiration and expiration. The results of the study are discussed with respect to proposed heart sound generation mechanisms.