Redshift drift in axially symmetric quasi-spherical Szekeres models

Models of inhomogeneous universes constructed with exact solutions of Einstein's General Relativity have been proposed in the literature with the aim of reproducing the cosmological data without any need for a dark energy component. Besides large scale inhomogeneity models spherically symmetric around the observer, Swiss-cheese models have also been studied. Among them, Swiss-cheeses where the inhomogeneous patches are modeled by different particular Szekeres solutions have been used for reproducing the apparent dimming of the type Ia supernovae (SNIa). However, the problem of fitting such models to the SNIa data is completely degenerate and we need other constraints to fully characterize them. One of the tests which is known to be able to discriminate between different cosmological models is the redshift-drift. This drift has already been calculated by different authors for Lema\^itre-Tolman-Bondi (LTB) models. We compute it here for one particular axially symmetric quasi-spherical Szekeres (QSS) Swiss-cheese which has previously been shown to reproduce to a good accuracy the SNIa data, and we compare the results to the drift in the $\Lambda$CDM model and in some LTB models that can be found in the literature. We show that it is a good discriminator between them. Then, we discuss our model's remaining degrees of freedom and propose a recipe to fully constrain them.Comment: 15 pages, 7 figures, minor changes in title, text, figures and references; conclusions unchanged, this version matches the published versio

Selection Of A Filler For Tablets Manufactured With Direct Compression Method Containing Dry Ginger Extract

The preliminary studies of physico-chemical and pharmaco-technological properties of the dry extract of ginger have determined the need for introduction of different groups of excipients for developing a solid dosage form for the treatment of type II diabetes mellitus.Aim. To choose the rational filler in the composition of tablets with ginger obtained by direct compression.Materials and methods. The study object was the dry extract of ginger (DEG) (producer “Megaprom”, Dnepr,Ukraine) and modern excipients for the production of tablets by direct compression: GalenIQ 721 (BENEO-Palatinit Gmb), Flowlac 100 (Meggle Co.), Tablettose 80 (Meggle Co.), Farmaxx (Merck), Microcelac 100 (Meggle Co.), Vivapur 112 and 102 (JRS Pharm), Prosolv HD 90, Prosolv SMCC 50 (JRS Pharm) manufactured in Germany. Pharmaco-technological and physico-chemical properties of the samples were studied according to conventional methods of the State Pharmacopoeia of Ukraine.Results and discussion. According to the results of the crystallographic analysis, the ability to the moisture absorption, resistance to crushing, disintegration time, fluidity indicators, angle of repose and bulk volume the effect of modern excipients on physicochemical and pharmaco-technological properties of the dry extract of ginger has been studied.Conclusions. According to the results of microscopic analysis, it has been found, that the rational fillers are GalenIQ 721, Prosolv HD 90, Prosolv SMCC 50, Vivapur 102 and Vivapur 112, as they provide a uniform system and the necessary resistance to destruction. The study of the kinetics of the moisture absorption has shown that addition of the fillers significantly reduces the increase in moisture compared to the dry extract. The mixture with GalenIQ 721 has the lowest parameters of moisture absorption at a relative air humidity of 45 %, 75 % and 100 %. In accordance with the results of the pharmaco-technological studies, it has been found that addition of GalenIQ 721 leads to improved flowability, disintegration, settling qualities; it indicates the feasibility of its inclusion into the composition of the solid dosage form

The Fermi-Pasta-Ulam recurrence and related phenomena for 1D shallow-water waves in a finite basin

In this work, different regimes of the Fermi-Pasta-Ulam (FPU) recurrence are simulated numerically for fully nonlinear "one-dimensional" potential water waves in a finite-depth flume between two vertical walls. In such systems, the FPU recurrence is closely related to the dynamics of coherent structures approximately corresponding to solitons of the integrable Boussinesq system. A simplest periodic solution of the Boussinesq model, describing a single soliton between the walls, is presented in an analytical form in terms of the elliptic Jacobi functions. In the numerical experiments, it is observed that depending on a number of solitons in the flume and their parameters, the FPU recurrence can occur in a simple or complicated manner, or be practically absent. For comparison, the nonlinear dynamics of potential water waves over nonuniform beds is simulated, with initial states taken in the form of several pairs of colliding solitons. With a mild-slope bed profile, a typical phenomenon in the course of evolution is appearance of relatively high (rogue) waves, while for random, relatively short-correlated bed profiles it is either appearance of tall waves, or formation of sharp crests at moderate-height waves.Comment: revtex4, 10 pages, 33 figure

Exactly solvable model of wormhole supported by phantom energy

We have found a simple exact solution of spherically-symmetrical Einstein equations describing a wormhole for an inhomogeneous distribution of the phantom energy. The equation of state is linear but highly anisotropic: while the radial pressure is negative, the transversal one is positive. At infinity the spacetime is not asymptotically flat and possesses on each side of the bridge a regular cosmological Killing horizon with an infinite area, impenetrable for any particles. This horizon does not arise if the wormhole region is glued to the Schwarzschild region. In doing so, the wormhole can enclose an arbitrary amount of the phantom energy. The configuration under discussion has a limit in which the phantom energy turns into the string dust, the areal radius tends to the constant. In this limit, the strong gravitational mass defect is realized in that the gravitational active mass is finite and constant while the proper mass integrated over the total manifold is infinite.Comment: 6 pages. Two references added, typos corrected. Accepted for publication in Phys. Rev. D as Rapid Communicatio

SOLVING HYBRID FUZZY FRACTIONAL DIFFERENTIAL EQUATIONS BY IMPROVED EULER METHOD

In this paper we study numerical methods for hybrid fuzzy fractional differential equations and the iteration method is used to solve the hybrid fuzzy fractional differential equations with a fuzzy initial condition. We consider a differential equation of fractional order  and we compared the results with their exact solutions in order to demonstrate the validity and applicability of the method. We further give the definition of the Degree of Sub element hood of hybrid fuzzy fractional differential equations with examples.

SOLVING SECOND ORDER HYBRID FUZZY FRACTIONAL DIFFERENTIAL EQUATIONS BY RUNGE KUTTA 4TH ORDER METHOD

In this paper we study numerical methods for second order hybrid fuzzy fractional differential equations and the variational iteration method is used to solve the hybrid fuzzy fractional differential equations with a fuzzy initial condition. We consider a second differential equation of fractional order and we compared the results with their exact solutions in order to demonstrate the validity and applicability of the method. We further give the definition of the Degree of Sub element hood of hybrid fuzzy fractional differential equations with examples.   Keywords: hybrid fuzzy fractional differential equations, Degree of Sub Element Hoo

Slow flows of an relativistic perfect fluid in a static gravitational field

Relativistic hydrodynamics of an isentropic fluid in a gravitational field is considered as the particular example from the family of Lagrangian hydrodynamic-type systems which possess an infinite set of integrals of motion due to the symmetry of Lagrangian with respect to relabeling of fluid particle labels. Flows with fixed topology of the vorticity are investigated in quasi-static regime, when deviations of the space-time metric and the density of fluid from the corresponding equilibrium configuration are negligibly small. On the base of the variational principle for frozen-in vortex lines dynamics, the equation of motion for a thin relativistic vortex filament is derived in the local induction approximation.Comment: 4 pages, revtex, no figur