Coherent control of the cooperative branching ratio for nuclear x-ray pumping

Coherent control of nuclear pumping in a three level system driven by x-ray light is investigated. In single nuclei, the pumping performance is determined by the branching ratio of the excited state populated by the x-ray pulse. Our results are based on the observation that in ensembles of nuclei, cooperative excitation and decay leads to a greatly modified nuclear dynamics, which we characterize by a time-dependent cooperative branching ratio. We discuss prospects of steering the x-ray pumping by coherently controlling the cooperative decay. First, we study an ideal case with purely superradiant decay and perfect control of the cooperative emission. A numerical analysis of x-ray pumping in nuclear forward scattering with coherent control of the cooperative decay via externally applied magnetic fields is presented. Next, we provide an extended survey of nuclei suitable for our scheme, and propose proof-of-principle implementations already possible with typical M\"ossbauer nuclear systems such as $^{57}\mathrm{Fe}$. Finally, we discuss the application of such control techniques to the population or depletion of long-lived nuclear states.Comment: 11 pages, 8 figures; updated to the published versio

Observations of Stellar Objects at a Shell Boundary in the Star-Forming Complex in the Galaxy IC1613

The single region of ongoing star formation in the galaxy IC 1613 has been observed in order to reveal the nature of compact emission-line objects at the edges of two shells in the complex, identified earlier in H-alpha line images. The continuum images show these compact objects to be stars. Detailed spectroscopic observations of these stars and the surrounding nebulae were carried out with an integral field spectrograph MPFS mounted on the 6m telescope of the Special Astrophysical Observatory. The resulting stellar spectra were used to determine the spectral types and luminosity classes of the objects. An Of star we identified is the only object of this spectral type in IC 1613. The results of optical observations of the multi-shell complex are compared to 21cm radio observations. The shells harboring the stars at their boundaries constitute the most active part of the star-forming region. There is evidence that shocks have played an important role in the formation of the shells.Comment: 10 pages, 5 PS and 1 color JPEG figur

Detection of an intergalactic meteor particle with the 6-m telescope

On July 28, 2006 the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences recorded the spectrum of a faint meteor. We confidently identify the lines of FeI and MgI, OI, NI and molecular-nitrogen N_2 bands. The entry velocity of the meteor body into the Earth's atmosphere estimated from radial velocity is equal to 300 km/s. The body was several tens of a millimeter in size, like chondrules in carbon chondrites. The radiant of the meteor trajectory coincides with the sky position of the apex of the motion of the Solar system toward the centroid of the Local Group of galaxies. Observations of faint sporadic meteors with FAVOR TV CCD camera confirmed the radiant at a higher than 96% confidence level. We conclude that this meteor particle is likely to be of extragalactic origin. The following important questions remain open: (1) How metal-rich dust particles came to be in the extragalactic space? (2) Why are the sizes of extragalactic particles larger by two orders of magnitude (and their masses greater by six orders of magnitude) than common interstellar dust grains in our Galaxy? (3) If extragalactic dust surrounds galaxies in the form of dust (or gas-and-dust) aureoles, can such formations now be observed using other observational techniques (IR observations aboard Spitzer satellite, etc.)? (4) If inhomogeneous extragalactic dust medium with the parameters mentioned above actually exists, does it show up in the form of irregularities on the cosmic microwave background (WMAP etc.)?Comment: 9 pages, 6 EPS figure

Main results on nuclear physics obtained at IPHENP NSC KIPT during 2002-2004 years

The main experimental results on nuclear physics obtained at Institute of High Energy Physics & Nuclear Physics National Science Center “Kharkov Institute of Physics and Technology” during 2002-2004 years are presented.Представлено основні результати експериментальних досліджень по ядерній фізиці, отримані в ІФВЕЯФ ННЦ ХФТІ протягом 2002-2004 рр.Представлены основные результаты экспериментальных исследований по ядерной физике, полученные в ИФВЭЯФ ННЦ ХФТИ в течение 2002-2004 г

Modulational instability of bright solitary waves in incoherently coupled nonlinear Schr\"odinger equations

We present a detailed analysis of the modulational instability (MI) of ground-state bright solitary solutions of two incoherently coupled nonlinear Schr\"odinger equations. Varying the relative strength of cross-phase and self-phase effects we show existence and origin of four branches of MI of the two-wave solitary solutions. We give a physical interpretation of our results in terms of the group velocity dispersion (GVD) induced polarization dynamics of spatial solitary waves. In particular, we show that in media with normal GVD spatial symmetry breaking changes to polarization symmetry breaking when the relative strength of the cross-phase modulation exceeds a certain threshold value. The analytical and numerical stability analyses are fully supported by an extensive series of numerical simulations of the full model.Comment: Physical Review E, July, 199

Влияние российского фондового рынка на экономический рост

The article considers the impact of the stock market on the economic growth. The aim of the study is to determine the degree of impact of the Russian stock market on gross domestic product, as well as to analyze the significance of various financial instruments in this process. The study suggests three hypotheses: 1) the dynamics of changes in the stock market as a whole has an impact on GDP growth; 2) the growth of the stock market has a positive impact on the change in GDP; 3) the stock market affects the GDP growth more, than that of corporate bonds. To test these hypotheses, the work employs methods of economic and mathematical modeling and building a vector autoregressive (VAR) model. The authors used the data from the International Monetary Fund (IMF), Moscow Exchange (MOEX) and Finam Investment Holding for the period from January 2000 to July 2019. As a result, they proved that not only traditional macroeconomic and production factors affect the country’s GDP growth, but also the positive dynamics of the stock market. The paper revealed that the impact of the growth of stock indices and corporate bonds on the change in gross domestic product would be different. At the same time, a different degree of impact of the stock market on gross domestic product over time. The authors concluded that ensuring the growth of stock indices is a condition to achieve stable growth in Russia’s GDP. Most of all, the GDP growth depends on the growth of the largest liquid companies trading in the Russian stock market.Авторы исследуют влияние фондового рынка на экономический рост. Цель исследования — определить степень влияния российского фондового рынка на валовой внутренний продукт, а также проанализировать значимость в этом процессе различных финансовых инструментов. Выдвинуты три гипотезы: 1) динамика изменения состояния фондового рынка в целом оказывает влияние на рост ВВП; 2) рост рынка акций положительно влияет на изменение ВВП; 3) на рост ВВП в большей степени влияет рынок акций, чем корпоративных облигаций. Для проверки данных гипотез использованы методы экономико-математического моделирования, построения модели векторной авторегрессии (VAR). Использованы данные Международного валютного фонда (IMF), Московской биржи (MOEX) и инвестиционного холдинга Финам за период с января 2000 по июль 2019 г. В результате исследования доказано, что на рост валового внутреннего продукта страны оказывают влияние не только традиционные макроэкономические и производственные факторы, но и положительная динамика фондового рынка. Установлено, что степень влияния роста индексов акций и корпоративных облигаций на изменение валового внутреннего продукта будет различной. При этом отмечена различная степень влияния фондового рынка на валовой внутренний продукт с течением времени. Сделан вывод, что обеспечение роста фондовых индексов является одним из условий достижения стабильного роста ВВП России. В наибольшей степени рост ВВП зависит от роста наиболее крупных ликвидных компаний, торгующих на российском фондовом рынке