ЛОГІКА ВПЛИВУ НЕМОНЕТАРНИХ ІНФОРМАЦІЙНИХ СИГНАЛІВ США НА НАДЛИШКОВУ ДОХІДНІСТЬ РИНКУ АКЦІЙ УКРАЇНИ

The research was conducted to assess the changes in the excess return of Ukrainian stock market (using the example of the representative stock index PFTS) on the informational content of such major non-monetary signals of the USA as “Consumer Price Index”, “Personal Spending”, “Unemployment Rate”, “Gross Domestic Product”, “Industrial Production”, “Consumer Confidence” and “Housing Starts” on the basis of daily data for 2000—2017 (number of observations — 4436). We used the toolkit of vector autoregressive modelling to determine the sources of Ukrainian stock index PFTS response to the US non-monetary information signals, which is based on the decomposition of changes in stock market excess return through the channels of economic transmission (“expected future dividends”, “real interest rate” and “risk premium”) and takes into account the unexpected values of the informational context of selected non-monetary signals. Target time series are stationary according to the KPSS and ADF criteria. The results show that four of the six selected non-monetary information signals of the USA do not have a significant effect on the response of endogenous variables of econometric model. The existence of significant direct influence of US non-monetary informational signals “Personal Spending” and “Consumer Confidence” on the response of the excess return of Ukrainian stock index PFTS has been established. It is substantiated that the actual and forecast state of the USA national economy is considered by the participants of the local stock markets, in particular in Ukraine, as one of the most important sources of macroeconomic information while making strategic and tactical investment decisions. Thus, the increasing importance of the component of “surprise” of such non-monetary information signals of the USA is considered as “positive” news for the domestic stock market by investors, which increases the excess return of the stock index PFTS.Проведено исследование по оценке изменений избыточной доходности украинского рынка акций (на примере репрезентативного фондового индекса PFTS) на информационное содержание немонетарных сигналов США на основе ежедневных данных за 2000—2017 гг. Использован инструментарий векторного авторегрессионного моделирования для определения источников реакции фондового индекса PFTS, основанный на декомпозиции изменений избыточной доходности рынка акций. Установлено наличие значительного прямого влияния немонетарных информационных сигналов США «Personal Spending» и «Consumer Confidence» на реакцию избыточной доходности фондового индекса PFTS. Таким образом, рост значения компоненты «неожиданность» по таким немонетарным информационным сигналам США рассматривается инвесторами как «позитивная» новость, которая увеличивает избыточную доходность фондового индекса PFTS.Проведено дослідження щодо оцінювання змін надлишкової доходності українського ринку акцій (на прикладі репрезентативного фондового індексу PFTS) на інформаційний зміст таких основних немонетарних сигналів США, як «Consumer Price Index», «Personal Spending», «Unemployment Rate», «Gross Domestic Product», «Industrial Production», «Consumer Confidence» та «Housing Starts» на основі щоденних даних за 2000—2017 рр. (кількість спостережень — 4 436). Використано інструментарій векторного авторегресійного моделювання для визначення джерел реакції українського фондового індексу PFTS на немонетарні інформаційні сигнали США, що ґрунтується на декомпозиції змін надлишкової дохідності ринку акцій через канали економічної трансмісії («очікувані майбутні дивіденди», «реальна відсоткова ставка» і «премія за ризик») та враховує неочікувані значення інформаційного контексту відібраних немонетарних сигналів. Цільові часові ряди є стаціонарними відповідно до критеріїв KPSS та ADF. Отримані результати свідчать, що чотири із шести відібраних немонетарних інформаційних сигналів США не мають суттєвого впливу на реакцію ендогенних змінних економетричної моделі. Установлено наявність значного прямого впливу немонетарних інформаційних сигналів США «Personal Spending» і «Consumer Confidence» на реакцію надлишкової дохідності українського фондового індексу PFTS. Обґрунтовано, що фактичний і прогнозний стани національної економіки США розглядається учасниками локальних ринків акцій, зокрема України, як одне з найважливіших джерел макроекономічної інформації при ухваленні стратегічних і тактичних інвестиційних рішень. Таким чином, зростання значення компоненти «несподіванки» за такими немонетарними інформаційними сигналами США розглядається інвесторами як «позитивна» новина для вітчизняного ринку акцій, яка збільшує надлишкову дохідність фондового індексу PFTS

Backscattering of Ultrasonic Waves as the Basis of the Method of Control of Structure and Physicо-Mechanical Properties of Cast Irons

Increasing the reliability of control of cast iron structure and its physical and mechanical characteristics is an important scientific and technical task of the machine-building industry. The paper studies the possibilities of controlling the structure of cast irons using structural noise created by ultrasonic scattering on graphite inclusions of different shapes. The subject of the present studies was such characteristics of structural noise as amplitude-temporal A(t) and as root mean square value of the amplitude of the ultrasonic waves backscattering field AN, compared with the data on ultrasonic velocity and strength or tensile strength of cast iron samples. As a result of the studies, a significant difference between the amplitude parameters of the AN structural noise obtained for samples with different shapes of graphite inclusions at 5 MHz was revealed for the first time. So, for example, for samples of gray cast iron (Russian: СЧ10, СЧ15, СЧ20, СЧ25), having predominantly plate-like form of graphite inclusions, the value of AN on 14–15 dB exceeds that measured in high-strength specimens of the cast iron with the prevailing form of spherical graphite inclusions ВЧ50 (Russian), etc. At the same time growth of longitudinal ultrasonic velocity amounted to 20–25 %. The method of rejection of gray cast iron from high-strength cast iron according to the data of amplitude parameters of structural noise AN at unilateral and local sounding of the object without using an additional reference signal reflected from its oppositional wall is suggested

Обратное рассеяние ультразвуковых волн как основа метода контроля структуры и физико-механических свойств чугунов

Increasing the reliability of control of cast iron structure and its physical and mechanical characteristics is an important scientific and technical task of the machine-building industry. The paper studies the possibilities of controlling the structure of cast irons using structural noise created by ultrasonic scattering on graphite inclusions of different shapes. The subject of the present studies was such characteristics of structural noise as amplitude-temporal A(t) and as root mean square value of the amplitude of the ultrasonic waves backscattering field AN, compared with the data on ultrasonic velocity and strength or tensile strength of cast iron samples. As a result of the studies, a significant difference between the amplitude parameters of the AN structural noise obtained for samples with different shapes of graphite inclusions at 5 MHz was revealed for the first time. So, for example, for samples of gray cast iron (Russian: СЧ10, СЧ15, СЧ20, СЧ25), having predominantly plate-like form of graphite inclusions, the value of AN on 14–15 dB exceeds that measured in high-strength specimens of the cast iron with the prevailing form of spherical graphite inclusions ВЧ50 (Russian), etc. At the same time growth of longitudinal ultrasonic velocity amounted to 20–25 %. The method of rejection of gray cast iron from high-strength cast iron according to the data of amplitude parameters of structural noise AN at unilateral and local sounding of the object without using an additional reference signal reflected from its oppositional wall is suggested.Повышение надёжности контроля структуры чугунов и их физико-механических характеристик является важной научно-технической задачей машиностроительной промышленности. В работе изучены возможности контроля структуры чугунов, используя структурный шум, создаваемый рассеянием ультразвуковых колебаний на графитовых включениях разной формы. Предметом настоящих исследований являлись такие характеристики структурного шума как амплитудновременные А(t) и среднеквадратичные амплитуды AN волн рассеяния, сопоставляемые с данными по скорости ультразвуковых колебаний, а также прочностью или временным сопротивлением на растяжение образцов чугунов. В результате исследований впервые выявлено существенное различие между амплитудными параметрами структурного шума AN, полученными для образцов с разной формой графитовых включений на частоте 5 МГц. Так, например, для образцов серого чугуна (СЧ10, СЧ15, СЧ20, СЧ25), имеющих преимущественно пластинчатую форму графитовых включений, величина AN на 14–15 дБ превышает ту, что измерена в высокопрочных чугунах с превалирующей формой включений графита шаровидной формы – ВЧ50. При этом, рост продольной скорости ультразвука с увеличением временного сопротивления составил ≈ 20–25 %. Предложен метод отбраковки серого чугуна от высокопрочного по данным амплитудных параметров структурного шума AN при одностороннем и локальном прозвучивании объекта без использования дополнительного опорного сигнала, отражённого от его оппозитной стенки

Y-system for Scattering Amplitudes

We compute N=4 Super Yang Mills planar amplitudes at strong coupling by considering minimal surfaces in AdS_5 space. The surfaces end on a null polygonal contour at the boundary of AdS. We show how to compute the area of the surfaces as a function of the conformal cross ratios characterizing the polygon at the boundary. We reduce the problem to a simple set of functional equations for the cross ratios as functions of the spectral parameter. These equations have the form of Thermodynamic Bethe Ansatz equations. The area is the free energy of the TBA system. We consider any number of gluons and in any kinematic configuration.Comment: 69 pages, 19 figures, v2: references added, minor addition

The low-energy limit of AdS(3)/CFT2 and its TBA

We investigate low-energy string excitations in AdS3 × S3 × T4. When the worldsheet is decompactified, the theory has gapless modes whose spectrum at low energies is determined by massless relativistic integrable S matrices of the type introduced by Al. B. Zamolodchikov. The S matrices are non-trivial only for excitations with identical worldsheet chirality, indicating that the low-energy theory is a CFT2. We construct a Thermodynamic Bethe Ansatz (TBA) for these excitations and show how the massless modes’ wrapping effects may be incorporated into the AdS3 spectral problem. Using the TBA and its associated Y-system, we determine the central charge of the low-energy CFT2 to be c = 6 from calculating the vacuum energy for antiperiodic fermions — with the vacuum energy being zero for periodic fermions in agreement with a supersymmetric theory — and find the energies of some excited states

Roadmap on Wilson loops in 3d Chern-Simons-matter theories

This is a compact review of recent results on supersymmetric Wilson loops in ABJ(M) and related theories. It aims to be a quick introduction to the state of the art in the field and a discussion of open problems. It is divided into short chapters devoted to different questions and techniques. Some new results, perspectives and speculations are also presented. We hope this might serve as a baseline for further studies of this topic

T-systems and Y-systems in integrable systems

The T and Y-systems are ubiquitous structures in classical and quantum integrable systems. They are difference equations having a variety of aspects related to commuting transfer matrices in solvable lattice models, q-characters of Kirillov-Reshetikhin modules of quantum affine algebras, cluster algebras with coefficients, periodicity conjectures of Zamolodchikov and others, dilogarithm identities in conformal field theory, difference analogue of L-operators in KP hierarchy, Stokes phenomena in 1d Schr\"odinger problem, AdS/CFT correspondence, Toda field equations on discrete space-time, Laplace sequence in discrete geometry, Fermionic character formulas and combinatorial completeness of Bethe ansatz, Q-system and ideal gas with exclusion statistics, analytic and thermodynamic Bethe ans\"atze, quantum transfer matrix method and so forth. This review article is a collection of short reviews on these topics which can be read more or less independently.Comment: 156 pages. Minor corrections including the last paragraph of sec.3.5, eqs.(4.1), (5.28), (9.37) and (13.54). The published version (JPA topical review) also needs these correction

Quantum Spectral Curve at Work: From Small Spin to Strong Coupling in N=4 SYM

We apply the recently proposed quantum spectral curve technique to the study of twist operators in planar N=4 SYM theory. We focus on the small spin expansion of anomalous dimensions in the sl(2) sector and compute its first two orders exactly for any value of the 't Hooft coupling. At leading order in the spin S we reproduced Basso's slope function. The next term of order S^2 structurally resembles the Beisert-Eden-Staudacher dressing phase and takes into account wrapping contributions. This expansion contains rich information about the spectrum of local operators at strong coupling. In particular, we found a new coefficient in the strong coupling expansion of the Konishi operator dimension and confirmed several previously known terms. We also obtained several new orders of the strong coupling expansion of the BFKL pomeron intercept. As a by-product we formulated a prescription for the correct analytical continuation in S which opens a way for deriving the BFKL regime of twist two anomalous dimensions from AdS/CFT integrability.Comment: 53 pages, references added; v3: due to a typo in the coefficients C_2 and D_2 on page 29 we corrected the rational part of the strong coupling predictions in equations (1.5-6), (6.22-24), (6.27-30) and in Table

Generalized cusp in AdS_4 x CP^3 and more one-loop results from semiclassical strings

We evaluate the exact one-loop partition function for fundamental strings whose world-surface ends on a cusp at the boundary of AdS_4 and has a "jump" in CP^3. This allows us to extract the stringy prediction for the ABJM generalized cusp anomalous dimension Gamma_{cusp}^{ABJM} (phi,theta) up to NLO in sigma-model perturbation theory. With a similar analysis, we present the exact partition functions for folded closed string solutions moving in the AdS_3 parts of AdS_4 x CP^3 and AdS_3 x S^3 x S^3 x S^1 backgrounds. Results are obtained applying to the string solutions relevant for the AdS_4/CFT_3 and AdS_3/CFT_2 correspondence the tools previously developed for their AdS_5 x S^5 counterparts.Comment: 48 pages, 2 figures, version 3, corrected misprints in formulas 2.12, B.86, C.33, added comment on verification of the light-like limi