1/R multidimensional gravity with form-fields: stabilization of extra dimensions, cosmic acceleration and domain walls

We study multidimensional gravitational models with scalar curvature nonlinearity of the type 1/R and with form-fields (fluxes) as a matter source. It is assumed that the higher dimensional space-time undergoes Freund-Rubin-like spontaneous compactification to a warped product manifold. It is shown that for certain parameter regions the model allows for a freezing stabilization of the internal space near the positive minimum of the effective potential which plays the role of the positive cosmological constant. This cosmological constant provides the observable late-time accelerating expansion of the Universe if parameters of the model is fine tuned. Additionally, the effective potential has the saddle point. It results in domain walls in the Universe. We show that these domain walls do not undergo inflation.Comment: 10 pages, revtex, 5 eps figures, footnotes and references adde

The Compactification Problems of Additional Dimensions in Multidimensional Cosmological Theories

Multidimensionality of our Universe is one of the most intriguing assumption in modern physics. It follows naturally from theories unifying different fundamental interactions with gravity, e.g. M/string theory. The idea has received a great deal of renewed attention over the last few years. However, it also brings a row of additional questions. According to observations the internal space should be static or nearly static at least from the time of primordial nucleosynthesis, otherwise the fundamental physical constants would vary. This means that at the present evolutionary stage of the Universe there are two possibilities: slow variation or compactification of internal space scale parameters. In many recent studies the problem of extra dimensions stabilization was studied for so-called ADD. Under these approaches a massive scalar fields (gravitons or radions) of external space-time can be presented as conformal excitations. In above mentioned works it was assumed that multidimensional action to be linear with respect to curvature. Although as follows from string theory, the gravity action needs to be extended to nonlinear one. In order to investigate effects of nonlinearity, in this Thesis a multidimensional Lagrangian will be studied, having the form L = f(R), where f(R) is an arbitrary smooth function of the scalar curvature.Comment: 126 pages, 33 figures; the PhD thesis for physical and mathematical scienc

On the problem of inflation in nonlinear multidimensional cosmological models

We consider a multidimensional cosmological model with nonlinear quadratic $R^2$ and quartic $R^4$ actions. As a matter source, we include a monopole form field, D-dimensional bare cosmological constant and tensions of branes located in fixed points. In the spirit of the Universal Extra Dimensions models, the Standard Model fields are not localized on branes but can move in the bulk. We define conditions which ensure the stable compactification of the internal space in zero minimum of the effective potentials. Such effective potentials may have rather complicated form with a number of local minima, maxima and saddle points. Then, we investigate inflation in these models. It is shown that $R^2$ and $R^4$ models can have up to 10 and 22 e-foldings, respectively. These values are not sufficient to solve the homogeneity and isotropy problem but big enough to explain the recent CMB data. Additionally, $R^4$ model can provide conditions for eternal topological inflation. However, the main drawback of the given inflationary models consists in a value of spectral index $n_s$ which is less than observable now $n_s\approx 1$. For example, in the case of $R^4$ model we find $n_s \approx 0.61$.Comment: 18 pages, RevTex4, References are correcte

LOW-FLUENCE LASER INDUCED FRAGMENTATION AND DESORPTION OF 3,4,9,10?PERYLENETETRACARBOXYLIC DIANHYDRIDE (PTCDA) THIN FILM

Laser-induced fragmentation and desorption of fragments of PTCDA films vacuum-deposited on GaAs(100) substrate has been studied by time-of-flight (TOF) mass spectroscopy. The main effect caused by pulsed laser light irradiation (pulse duration: 10 ns, photon energy: 2.34 eV and laser fluence ranging from 0.5 to 7 mJ/cm2) is PTCDA molecular fragmentation and desorption of the fragments formed, whereas no desorption of intact PTCDA molecule was detected. Fragments formed are perylene core C20H8, its half C10H4, carbon dioxide, carbon monoxide and atomic oxygen. All desorbing fragments have essentially different kinetic energy. The mechanism of photoinduced molecular fragmentation and desorption is discussed. 

Bouncing inflation in nonlinear R2+R4R^2+R^4 gravitational model

We study a gravitational model with curvature-squared $R^2$ and curvature-quartic $R^4$ nonlinearities. The effective scalar degree of freedom $\phi$ (scalaron) has a multi-valued potential $U(\phi)$ consisting of a number of branches. These branches are fitted with each other in the branching and monotonic points. In the case of four-dimensional space-time, we show that the monotonic points are penetrable for scalaron while in the vicinity of the branching points scalaron has the bouncing behavior and cannot cross these points. Moreover, there are branching points where scalaron bounces an infinite number of times with decreasing amplitude and the Universe asymptotically approaches the de Sitter stage. Such accelerating behavior we call bouncing inflation. For this accelerating expansion there is no need for original potential $U(\phi)$ to have a minimum or to check the slow-roll conditions. A necessary condition for such inflation is the existence of the branching points. This is a new type of inflation. We show that bouncing inflation takes place both in the Einstein and Brans-Dicke frames.Comment: RevTex 13 pages, 13 figures, a few comments and references adde

УДОВЛЕТВОРЕННОСТЬ БРАКОМ И СУПРУЖЕСКОЕ ВЗАИМОДЕЙСТВИЕ У ПРЕДСТАВИТЕЛЕЙ РАЗНЫХ ЭТНИЧЕСКИХ ГРУПП

Цель. Статья посвящена изучению социально-психологических особенностей удовлетворенности браком у представителей разных этнических групп. Методы исследования: экспресс-методика «Удовлетворённость браком» (В.В. Столин, Т.Л. Романова, Г.П. Бутенко), методика «Особенности общения в семье» (Ю.Е. Алёшина, Л.Я. Гозман, Е.М. Дубовская), методика «Распределение ролей в семье» (Ю.Е. Алёшина, Л.Я. Гозман, Е.М. Дубовская), «Пятифакторный личностный опросник» (Р. МакКрае, П. Коста). Результаты. В статье представлены результаты эмпирического исследования социально-психологических особенностей удовлетворённости браком у представителей разных этнических групп. Выявлены достоверные различия в удовлетворённости браком, супружеском взаимодействии, индивидуально-психологических особенностях у респондентов различных национальностей. Описаны корреляционные связи между удовлетворённостью браком и особенностями межличностного общения супругов, распределением ролей, индивидуально-психологическими свойствами у осетин и азербайджанцев. Область применения результатов. Результаты исследования могут быть использованы в практике семейного консультирования, а также для разработки психокоррекционных программ для представителей данных этнических групп

Seasonal and Regional Clean Drinking Water Map for Kazakhstan

The scarcity of drinking water is becoming a more urgent problem in the world each day. This problem is even more crucial for Kazakhstan due to its geographic location since the major sources of drinking water today are underground water and lakes, which will be close to their limits in the future, if they remain to be the primary origins of fresh water [1]. However, the progress in technologies of water harvesting enables us today to harvest drinking water from the use of renewable and unintegrated sources of water. The main aim of this work is to determine the most economically viable technologies for obtaining drinking water in Kazakhstan, on a regional and seasonal basis and with minimal environmental impact

Important Aspects of Polygraph Examinations of Islamic Faith People

In this article the author gives recommendations for running polygraph examinations of Islamic faith representatives during the Muslim fasting period of Ramadan based on his own practical experience and interactions with Muslim psychologists, and also analyzes examples of incorrect formulations of relevant questions on the subject of Islamic terrorism / extremism in the course of screening examinations

The formation of meta-stable sodium sulphate heptahydrate during drying as studied by NMR

Salt weathering is a major cause of deterioration of porous building materials. Of the salts responsible, especially sodium sulfate is seen as very damaging. However many questions arise concerning which sodium sulfate phase will crystallize out during salt weathering. In this study we focused on the crystallization during isothermal drying of a sample saturated with a sodium sulfate solution. As the material is drying moisture will leave and hence the salt concentration will rise until the maximum solubility is reached. From that point on crystals will be formed. Using NMR we have measured quasi simultaneously both the moisture and Na profiles during drying. These experiments have been performed at various temperatures and concentrations. In our NMR experiments we observe the formation of a metastable phase of sodium sulfate, the heptahydrate crystals

The formation of meta-stable sodium sulphate heptahydrate during drying as studied by NMR

Salt weathering is a major cause of deterioration of porous building materials. Of the salts responsible, especially sodium sulfate is seen as very damaging. However many questions arise concerning which sodium sulfate phase will crystallize out during salt weathering. In this study we focused on the crystallization during isothermal drying of a sample saturated with a sodium sulfate solution. As the material is drying moisture will leave and hence the salt concentration will rise until the maximum solubility is reached. From that point on crystals will be formed. Using NMR we have measured quasi simultaneously both the moisture and Na profiles during drying. These experiments have been performed at various temperatures and concentrations. In our NMR experiments we observe the formation of a metastable phase of sodium sulfate, the heptahydrate crystals