The degenerate gravitino scenario

In this work, we explore the "degenerate gravitino" scenario where the mass difference between the gravitino and the lightest MSSM particle is much smaller than the gravitino mass itself. In this case, the energy released in the decay of the next to lightest sypersymmetric particle (NLSP) is reduced. Consequently the cosmological and astrophysical constraints on the gravitino abundance, and hence on the reheating temperature, become softer than in the usual case. On the other hand, such small mass splittings generically imply a much longer lifetime for the NLSP. We find that, in the constrained MSSM (CMSSM), for neutralino LSP or NLSP, reheating temperatures compatible with thermal leptogenesis are reached for small splittings of order 10^{-2} GeV. While for stau NLSP, temperatures of 4x10^9 GeV can be obtained even for splittings of order of tens of GeVs. This "degenerate gravitino" scenario offers a possible way out to the gravitino problem for thermal leptogenesis in supersymmetric theories.Comment: 27 pages, 10 figures and 1 table. Minor typos and references fixed. Matches published version in JCAP

ЗАДОВОЛЕННЯ АКТУАЛЬНИХ ПОТРЕБ ЯК ФАКТОР ПСИХОЛОГІЧНОЇ АДАПТАЦІЇ ДО СТРЕСУ В СТУДЕНТІВ-ПСИХОЛОГІВ У ПЕРІОД СЕСІЇ

Background.  Intensi?cation of education provokes neurotic and psychosomatic disorders as well as destructive behaviour among young people. Currently there has been a growing interest in the factors of effective adaptation to the contemporary education system. Objective. This study is aimed to research the problem of students’ adaptation to stress during the examination period.Method.  The  needs  that  facilitate  stress  tension  during  the  examination  period were de?ned by ranking them by 70 students of Psychology (aged from 18 to 21 years old). The PSM-25 (L. Lemyre, R. Tessier, L. Fillion) was used for diagnostic somatic, behaviour and emotional effect of stress. The Beck Depression Inventory (A.T. Beck) was used for measuring the level of depression. Results. The correlations between the actual needs satisfaction and the stress level, as well as between the stress and depression level in students of Psychology during the examination period were found. Conclusions. The psychodiagnostic tools were used to study the level of satisfaction and types of actual needs. Most of research participants appeared to be adapted to mental stress during the examination period. Satisfaction of social and safety needs turned out to be the most signi?cant factor that in?uences the students’ adaptation to mental stress. Mental stress during the examination period correlates with level of depression.Изложены  результаты  исследования  уровня  стресса  у  студентов-психологов во время сессии. Исследована связь удовлетворения актуальных потребностей с уровнем нервно-психического напряжения у студентов-психологов во время сессии. Установлено, что удовлетворение социальных потребностей и потребности в безопасности способствует лучшей адаптации к экзаменационным стрессам.Розглянуто  проблему  адаптації  студентів  до  стресу  в  період  сесії. Представлено результати дослідження рівня стресу у студентів психологічних спеціальностей під час сесії. Установлено зв’язок між задоволенням актуальних потреб та рівнем нервово-психічного напруження у студентів-психологів у період сесії. Визначено, що задоволення потреби в безпеці та соціальних потреб – найпродуктивніші механізми зниження рівня стресу. Доведено вплив екзаменаційного стресу на виникнення депресії у студентів-психологів

Використання нейронних мереж в задачах експлуатації і ремонту рухомого складу електротранспорту

Deep neural networks have achieved great success in controlled learning problems, and MIL as a typical poorly controlled learning method is effective for many applications in computer vision, biometrics, natural language processing, etc. In this article, we review several neural networks with multiple instances ( MINN), which neural networks seek to solve MIL problems. MINNs perform MILs in the end, which take bags with different numbers of instances as input and directly output the tags of the bags. All parameters in MINN can be optimized by back propagation. In addition to revising old MINNs, we offer a new type of MINN for exploring bag representations, which differs from existing MINNs that focus on the evaluation of an instance label. In addition, recent tricks developed in deep learning have been studied in MINN; we find that deep supervision is effective for a better understanding of bag views. In experiments, the proposed MINNs achieve the most advanced or competitive performance on several MIL tests. Moreover, for testing and learning it is very fast, for example, it takes only 0.0.0 03 s to predict the bag and a few seconds to learn on the MIL datasets on a moderate processor. Initially, several instances (MILs) were proposed to predict bounce activity [1]. Now it is widely applied to many domains and is an important problem in computer training. Many multimedia data have a multiplier (MI) structure; For example, a text article contains several paragraphs, the image can be divided into several local areas, and gene expression data contains several genes. MIL is useful for processing and understanding MI data. Studying multiple instances is a type of weak controlled learning (WSL). Each sample is executed in the form of labeled data, which consist of a wide variety of instances associated with the functions of input. The purpose of MIL in the dual task is to prepare a classifier for prediction of test packet labels, based on the assumption that there is a positive packet and contains at least one positive instance, while the data is negative if it consists only of negative instances.Нейронні мережі і багаторазові навчання (MIL) є привабливими темами в дослідницьких областях, пов’язаних зі штучним інтелектом. Глибокі нейронні мережі домоглися великих успіхів в контрольованих проблемах навчання, а MIL як типовий слабо контрольований метод навчання є ефективний для багатьох додатків в області комп’ютерного зору, біометрії і т. д

Black hole solutions with dilatonic hair in higher curvature gravity

A new numerical integration method for examining a black hole structure was realized. Black hole solutions with dilatonic hair of 4D low energy effective SuperString Theory action with Gauss-Bonnet quadratic curvature contribution were studied, using this method, inside and outside the event horizon. Thermodynamical properties of this solution were also studied.Comment: 10 pages, 6 figures, RevTeX, figures in LaTeX or PostScript are avaible upon request via e-mail address: [email protected], Submitted to Phys.Rev.

Do stringy corrections stabilize coloured black holes?

We consider hairy black hole solutions of Einstein-Yang-Mills-Dilaton theory, coupled to a Gauss-Bonnet curvature term, and we study their stability under small, spacetime-dependent perturbations. We demonstrate that the stringy corrections do not remove the sphaleronic instabilities of the coloured black holes with the number of unstable modes being equal to the number of nodes of the background gauge function. In the gravitational sector, and in the limit of an infinitely large horizon, the coloured black holes are also found to be unstable. Similar behaviour is exhibited by the magnetically charged black holes while the bulk of the neutral black holes are proven to be stable under small, gauge-dependent perturbations. Finally, the electrically charged black holes are found to be characterized only by the existence of a gravitational sector of perturbations. As in the case of neutral black holes, we demonstrate that for the bulk of electrically charged black holes no unstable modes arise in this sector.Comment: 17 pages, Revtex, comments and a reference added, version to appear in Physical Review

Self-similarity and singularity formation in a coupled system of Yang-Mills-dilaton evolution equations

We study both analytically and numerically a coupled system of spherically symmetric SU(2) Yang-Mills-dilaton equation in 3+1 Minkowski space-time. It has been found that the system admits a hidden scale invariance which becomes transparent if a special ansatz for the dilaton field is used. This choice corresponds to transition to a frame rotated in the $\ln r-t$ plane at a definite angle. We find an infinite countable family of self-similar solutions which can be parametrized by the $N$ - the number of zeros of the relevant Yang-Mills function. According to the performed linear perturbation analysis, the lowest solution with N=0 only occurred to be stable. The Cauchy problem has been solved numerically for a wide range of smooth finite energy initial data. It has been found that if the initial data exceed some threshold, the resulting solutions in a compact region shrinking to the origin, attain the lowest N=0 stable self-similar profile, which can pretend to be a global stable attractor in the Cauchy problem. The solutions live a finite time in a self-similar regime and then the unbounded growth of the second derivative of the YM function at the origin indicates a singularity formation, which is in agreement with the general expectations for the supercritical systems.Comment: 10 pages, 5 figure

On the n=4 Supersymmetry for the FRW Model

In this work we have constructed the n=4 extended local conformal time supersymmetry for the Friedmann-Robertson-Walker (FRW) cosmological models. This is based on the superfield construction of the action, which is invariant under wordline local n=4 supersymmetry with $SU(2)_{local} \otimes SU(2)_{global}$ internal symmetry. It is shown that the supersymmetric action has the form of the localized (or superconformal) version of the action for n=4 supersymmetric quantum mechanics. This superfield procedure provides a well defined scheme for including supermatter.Comment: 8 pages. Accepted for publication in Phys. Rev

Sequences of globally regular and black hole solutions in SU(4) Einstein-Yang-Mills theory

SU(4) Einstein-Yang-Mills theory possesses sequences of static spherically symmetric globally regular and black hole solutions. Considering solutions with a purely magnetic gauge field, based on the 4-dimensional embedding of $su(2)$ in $su(4)$, these solutions are labelled by the node numbers $(n_1,n_2,n_3)$ of the three gauge field functions $u_1$, $u_2$ and $u_3$. We classify the various types of solutions in sequences and determine their limiting solutions. The limiting solutions of the sequences of neutral solutions carry charge, and the limiting solutions of the sequences of charged solutions carry higher charge. For sequences of black hole solutions with node structure $(n,j,n)$ and $(n,n,n)$, several distinct branches of solutions exist up to critical values of the horizon radius. We determine the critical behaviour for these sequences of solutions. We also consider SU(4) Einstein-Yang-Mills-dilaton theory and show that these sequences of solutions are analogous in most respects to the corresponding SU(4) Einstein-Yang-Mills sequences of solutions.Comment: 40 pages, 5 tables, 19 Postscript figures, use revtex.st