Time and distance constraints on accelerating cosmological models

The absence of guidance from fundamental physics about the mechanism behind cosmic acceleration has given rise to a number of alternative cosmological scenarios. These are based either on modifications of general relativistic gravitation theory on large scales or on the existence of new fields in Nature. In this Letter we investigate the observational viability of some accelerating cosmological models in light of 32 age measurements of passively evolving galaxies as a function of redshift and recent estimates of the product of the cosmic microwave background acoustic scale and the baryonic acoustic oscillation peak scale. By using information-criteria model selection, we select the best-fit models and rank the alternative scenarios. We show that some of these models may provide a better fit to the data than does the current standard cosmological constant dominated (ΛCDM) model.     

Weighted oscillator strengths and lifetimes for the S XIV spectrum

The weighted oscillator strengths gf and the lifetimes for S XIV presented in this work have been calculated in a multiconfigurational Hartree–Fock relativistic approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure in order to improve the adjustment to experimental energy levels. This method produces gf values that are in better agreement with observed line intensities and lifetime values closer to the experimentally determined ones. In this work we presented all the experimentally known electric dipole S XIV spectral lines. Published in Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 3, pp. 473–476, 2009.     

<Emphasis Type="Italic">L</Emphasis><Superscript>2</Superscript>-approximating Pricing under Restricted Information

We consider the mean-variance hedging problem under partial information in the case where the flow of observable events does not contain the full information on the underlying asset price process. We introduce a certain type martingale equation and characterize the optimal strategy in terms of the solution of this equation. We give relations between this equation and backward stochastic differential equations for the value process of the problem. This work was supported by Georgian National Science Foundation grant STO07/3-172.     

Functional equations and martingales

Aequationes mathematicae - We consider functional equations&nbsp;(Cauchy’s, Abel’s and some other functional equations) and show that finding the general solution of these equations...     

Thermal Restructuring of Silica‐Grafted TiClx Species and Consequences for Epoxidation Catalysis

TiCl₄ grafted to dehydrated silica is an industrially applied catalyst for the epoxidation of propylene. As with many heterogeneous catalysts, the precise nature of the surface species is not yet fully known, prohibiting reliable structure–activity correlations. In this study, the speciation and restructuring of site‐isolated Ti^IV Lewis acid centers was carefully investigated by using a variety of techniques. The initially formed ?SiOTiCl₃ species were found to restructure upon heating through the transfer of Cl ligands to the silica surface, eventually leading to tripodal (?SiO)₃TiCl species. The superior activity and stability of such tripodal species is demonstrated for catalytic olefin epoxidation under continuous flow conditions.     

Oscillator strengths and lifetimes for the P XII

Semi-empirical weighted oscillator strengths (gf) and lifetimes presented in this work for all experimentally known electric dipole P XII spectral lines and energy levels were computed within a multiconfiguration Hartree-Fock relativistic approach. In this calculation, the electrostatic parameters were optimized by a leastsquares procedure in order to improve the adjustment to experimental energy levels. The method produces lifetime and gf values that are in agreement with intensity observations used for the interpretation of spectrograms of solar and laboratory plasmas.     

A Legendre spectral element method on a large spatial domain to solve the predator–prey system modeling interacting populations

A Legendre spectral element method is developed for solving a one-dimensional predator–prey system on a large spatial domain. The predator–prey system is numerically solved where the prey population growth is described by a cubic polynomial and the predator’s functional response is Holling type I. The discretization error generated from this method is compared with the error obtained from the Legendre pseudospectral and finite element methods. The Legendre spectral element method is also presented where the predator response is Holling type II and the initial data are discontinuous.     

A spectral element method for solving the Pennes bioheat transfer equation by using triangular and quadrilateral elements

A spectral element method is developed for the numerical solution of the Pennes bioheat transfer equation which models the thermal behavior of the living tissue. For the one and two dimensional cases, the implementation of this method is completely explained. In the two dimensional case, both triangular and quadrilateral elements are investigated. Through test problems, the discretization error generated from this method is reported. In the triangular elements, the error is obtained when quadrature points coincide and do not coincide with nodal points. This method is employed to solve the equation in order to obtain the temperature of the skin layers, healthy tissue, and tissue that contains the tumor.