Quintessential Quartic Quasi-topological Quartet

We construct the quartic version of generalized quasi-topological gravity, which was recently constructed to cubic order in arXiv: 1703.01631. This class of theories includes Lovelock gravity and a known form of quartic quasi-topological gravity as special cases and possess a number of remarkable properties: (i) In vacuum, or in the presence of suitable matter, there is a single independent field equation which is a total derivative. (ii) At the linearized level, the equations of motion on a maximally symmetric background are second order, coinciding with the linearized Einstein equations up to a redefinition of Newton's constant. Therefore, these theories propagate only the massless, transverse graviton on a maximally symmetric background. (iii) While the Lovelock and quasi-topological terms are trivial in four dimensions, there exist four new generalized quasi-topological terms (the quartet) that are nontrivial, leading to interesting higher curvature theories in $d \geq 4$ dimensions that appear well suited for holographic study. We construct four dimensional black hole solutions to the theory and study their properties. A study of black brane solutions in arbitrary dimensions reveals that these solutions are modified from the `universal' properties these solutions have. This result may lead to interesting consequences for the dual CFTs.Comment: 46 pages, 1 figure. Discussion of black branes added to section

Attractor Solutions in f(T) Cosmology

In this paper, we explore the cosmological implications of interacting dark energy model in a torsion based gravity namely $f(T)$. Assuming dark energy interacts with dark matter and radiation components, we examine the stability of this model by choosing different forms of interaction terms. We consider three different forms of dark energy: cosmological constant, quintessence and phantom energy. We then obtain several attractor solutions for each dark energy model interacting with other components. This model successfully explains the coincidence problem via the interacting dark energy scenario.Comment: 10 pages, 23 figures, version accepted for publication in European Physical Journal C (2012

Numerical study of resistivity of model disordered three-dimensional metals

We calculate the zero-temperature resistivity of model 3-dimensional disordered metals described by tight-binding Hamiltonians. Two different mechanisms of disorder are considered: diagonal and off-diagonal. The non-equilibrium Green function formalism provides a Landauer-type formula for the conductance of arbitrary mesoscopic systems. We use this formula to calculate the resistance of finite-size disordered samples of different lengths. The resistance averaged over disorder configurations is linear in sample length and resistivity is found from the coefficient of proportionality. Two structures are considered: (1) a simple cubic lattice with one s-orbital per site, (2) a simple cubic lattice with two d-orbitals. For small values of the disorder strength, our results agree with those obtained from the Boltzmann equation. Large off-diagonal disorder causes the resistivity to saturate, whereas increasing diagonal disorder causes the resistivity to increase faster than the Boltzmann result. The crossover toward localization starts when the Boltzmann mean free path relative to the lattice constant has a value between 0.5 and 2.0 and is strongly model dependent.Comment: 4 pages, 5 figure

Kadar Pengenapan dan Kepekatan Beberapa Logam Berat pada Permukaan Sedimen di Hutan Paya Bakau Bebar, Pahang

Sampel permukaan yang dikutip dari 3 transet (54 stesen pensampelan) di hutan paya bakau Bebar telah diukur kadar pemendapan, ciri-ciri sedimen dan kepekatan beberapa logam. Dalam kajian ini, kadar sedimentasi diukur dengan menggunakan kaedah penunjuk tiruan mendatar di mana purata pemendapan sebanyak 0.52 cm.thn·' telah diperoleh. Min saiz partikel sedimen permukaan didapati beljulat di antara dari pasir halus (5.151/» hingga kelodak halus (6.911/». Min saiz partikel menunjukkan hubungan signifikan (P<0.05) terhadap perubahan musim dengan penurunan nilainya ketika musim monsun. Bagi logam Cr, Cu, Pb dan Zn didapati menunjukkan perubahan mengikut jarak dengan purata kepekatan yang rendah di kawasan muara dan tinggi secara relatif di kawasan yang lebih jauh dari muara

Investigating the antecedents to the adoption of SCRM technologies by start-up companies

Despite their fairly recent emergence, start-up companies now play an important role in the economic development of countries around the globe. These companies have fewer tangible assets and capital, and therefore, the efficient delivery of services and products is a key business priority for them. Customer relationship management (CRM) technologies, which are designed to facilitate customer engagement during the design, development and delivery of services and products may play a significant role in the success or failure of start-up companies. Developments in new communication technologies have transformed traditional CRM into electronic CRM (eCRM), mobile CRM (mCRM); and more recently, social CRM (SCRM). However, there remains very little understanding of the factors affecting SCRM adoption in start-up businesses. The relative newness of SCRM technologies, coupled with the swiftly evolving nature of start-up companies: which has made them difficult cases to study – has limited the amount of research undertaken in this area. This paper aims to close this gap by proposing a framework that depicts the factors affecting start-up companies’ intention to adopt SCRM applications, and explores the relative importance of these factors. Inspired by an extended Technological, Organisational and Environmental (TOE) framework, this paper investigates effects of technological characteristics (TC), organisational characteristics (OC), environmental characteristics (EC) and managerial characteristics (MC) on start-up companies’ intentions to adopt SCRM applications. The results outlined in this research indicate that the observability, compatibility and trialability of SCRM solutions positively affect SCRM adoption in start-up businesses. Moreover, the availability of internal financial resources has a similarly positive effect. When considering environmental characteristics, it was found that support from venture capitalists, crowd funding support, governmental support, business angels support and external pressure all positively affect the intention to adopt SCRM applications within start-up businesses

Pengaruh Return On Equity dan Dividend Payout Ratio terhadap Price Book Value

Penelitian ini dilakukan pada Perusahaan BUMN. Tujuan penelitian ini yaitu untuk mengetahui besarnya pengaruh return on equity dan dividend payout ratio secara parsial dan simultan terhadap price book value. Return on equity adalah salah satu profitabilitas yang digunakan untuk mengukur kemampuan Perusahaan untuk menghasilkan laba sesuai dengan ekuitasnya. Selanjutnya dividend payout ratio adalah persentase dari laba yang didistribusikan sebagai dividen. Teori ini merupakan aturan dividen yang dibayarkan kepada investor. Teori selanjutnya PBV yang digunakan untuk membandingkan nilai harga saham dengan nilai buku. Objek dari penelitian ini yaitu 13 Perusahaan dan projek ini dilakukan dengan menggunakan purposive sampling untuk mengumpulkan data. Teknik analisis yang digunakan dalam penelitian ini adalah analisis regresi berganda dengan menggunakan SPSS 23 dimana sebelumnya data telah diuji dengan menggunakan uji asumsi klasik. Kesimpulannya return on equity dan dividend payout ratio secara bersama-sama berpengaruh terhadap price book value dengan nilai R Square yaitu 16,1%. return on equity sendiri berpengaruh terhadap price book value, tetapi dividend payout ratio tidak berpengaruh terhadap price book value

Evolution of Primordial Black Holes in Loop Quantum Gravity

In this work, we study the evolution of Primordial Black Holes within the context of Loop Quantum Gravity. First we calculate the scale factor and energy density of the universe for different cosmic era and then taking these as inputs we study evolution of primordial black holes. From our estimation it is found that accretion of radiation does not affect evolution of primordial black holes in loop quantum gravity even though a larger number of primordial black holes may form in early universe in comparison with Einstein's or scalar-tensor theories.Comment: 8 pages, 1 figur

Statefinder Parameter for Varying G in Three Fluid System

In this work, we have considered variable G in flat FRW universe filled with the mixture of dark energy, dark matter and radiation. If there is no interaction between the three fluids, the deceleration parameter and statefinder parameters have been calculated in terms of dimensionless density parameters which can be fixed by observational data. Also the interaction between three fluids has been analyzed due to constant $G$. The statefinder parameters also calculated in two cases: pressure is constant and pressure is variable.Comment: 5 pages, Accepted for publication in "Astrophysics and Space Science

Power-law entropy-corrected HDE and NADE in Brans-Dicke cosmology

Considering the power-law corrections to the black hole entropy, which appear in dealing with the entanglement of quantum fields inside and outside the horizon, the holographic energy density is modified accordingly. In this paper we study the power-law entropy-corrected holographic dark energy in the framework of Brans-Dicke theory. We investigate the cosmological implications of this model in detail. We also perform the study for the new agegraphic dark energy model and calculate some relevant cosmological parameters and their evolution. {As a result we find that this model can provide the present cosmic acceleration and even the equation of state parameter of this model can cross the phantom line $w_D=-1$ provided the model parameters are chosen suitably}.Comment: 14 pages, 2 figure, accepted by IJT