Alex B . Gaina

The article concerns the biography and scientifuc did of the former President of the first Democratic Moldavian Parliament "Sfatul Tarii" , Ion Inculeț, which was a Private Dotzent at the Sankt Petersburg Imperial University till 1917, while since 1918 elected as an ordinary Member of the Romanian Academy.
The scientific did concern Physics.

The author is considering 2 possible scenarios of Black Holes evaporation. First one coincide with well known S. Hawking’s (1974,1975) scenarios, according to which actually Black Holes (created after the Big Bang, perhaps) with should evaporate, while another, which would take into account the occurency of Mass particles Bound states ([1]), especially Bose mass particles, of which the Higgs boson is of special interest. The second scenarios suppose a concurrence between the Hawking process and Bose mass particles exponentially fast accumulation with a rate of Black Hole’s mass evolution. When the time is going to ∞ the mass of a Black Hole is going to 0. The time of diminishing by a half of the initial mass of a Black Hole is such, that it corresponds to ~ 54700 sec=15.19 hours for a Black Hole of mass nearly 1 mln tones in weight. This would occur due to generation of a Higgs boson (s=o) with mass m_Higgs=1Tev. If the Higgs boson mass is 125Gev, the time of diminishing by a half o...

Analysis of the processes of spontaneous and induced creation and accumulation of charged bosons in quasi-bound superradiative levels in a Kerr-Newman black-hole field demonstrates that boson instability can result exclusively from rotation of the hole. In particular, the Reissner-Nordstrom configuration will be stable. If the hole is rotating and charged, the instability may strengthen its charge. 12 references.

We consider the effect of relativistic corrections and rotation of the central body on the structure of the energy spectrum of a particle with spin in the Schwarzchild and Kerr fields. A splitting of levels is obtained, which corresponds to the classical shift of the perihelion of the orbit and precession of the plane of the gravitational spin-orbit interaction and several nonlinear spin effects are calculated.

In the weakly relativistic limit, an expression is obtained for the damping of quasistationary energy levels in Schwarzschild and Kerr fields due to capture by a collapsar. The strength of the damping in the Schwarzschild field decreases strongly with increasing angular momentum of the particle. If the conditionω < mΩH is satisfied in the case of a rotating black hole, the damping can be replaced by excitation. A particle production process (Hawking process) is considered that leads to the accumulation of particles on quasistationary levels near the black hole. Dynamical equilibrium can be established in the system between the processes of production and capture of particles by the black hole.

The influence of relativistic gravitational effects and rotation of the central body on the structure of the quasidiscrete spectrum of a spinless particle in the field of a Schwarzschild amd Kerr black hole is examined, up to G^4 terms in the Schwarzschild field and G^5 terms for the Kerr field. The quasiclassical approach is examined also, which gives the exact value for the perihelion shift, prdicted by the classical theory of General Relativity. The same is valid as well for the orbits plane precession in the Kerr field with week rotation. The s-bound state needs a special treatment.

The Klein-Gordon and Dirac equation are solved in Kerr gravitational background in the long wavelength limit. The transmission (tunneling) probabilities are obtained analytically using a procedure used previously by A.Starobinskii, G. Gibbons, L. Ford, for scalar particles and W. Unruh for Dirac particles (See also the review by D. Page). The absorption cross section and spectral powers are calculated for both scalar and Dirac particles in Kerr background. The particularities of the radiation are discussed.

The finite motion of mass, electrically charged scalar and spin particles in the Kerr-Newman fields is considered. The particles motion is nonstationary, due to singularity of the metric and the presence of an events horizon. A criterion for the existence of the quasibound states is found, which are described by a hydrogen like nonrelativistic spectrum in the null approximation [1], [2]. The probabilities of the disintegration and the timelifes of the levels are calculated. The possibility of the occurence of s- bound states (l=m=0) is demonstrated. The Postnewtonian and electromagnetic relativistic effects lead to fine and hyperfine structures of the spectrum. The gravitational spin-orbit interaction lead to the removing of the electronic levels degeneration by the orbital momentum quantum number and by the total momentum quantum numbers. The interaction of the orbit and of the spin of the particle with the "quasimagnetic components" of the gravitational field, related wi...

The quantum mechanics of the scattering and absorption of mass, electrically charged particles in the Reissner-Nordstrom central fields is considered, with the taking in account of the boundary conditions at the events horizon. The obtained results shown, that the differential scattering cross section for small angles has Rutherfordian character, independently of the energy of particles and the parameters of the central body, except for the case, when the gravitational attraction is compensated by the electric repulsion. When long wavelength particles scatter by a small and weekly charged black hole ("Gravitational radius"/" particles wavelength" ~Z"alpha"<>1), differences from the Rutherfordian cross section appear in terms ~ 1/("scattering angle"^3). In the same case the consideration of the absorption leads to week diffraction phenomena. For back scattering ("scattering angle"->"pi") a maximum of intensity shoul...

A reveiw of the Odessa Astronomical Almanac (Odesskii Astronomicheskii Kalendari, Astroprint, Odessa, 2006, 255 pp. ) is given for the constant part ( V.G. Karetnikov, V.V. Mihalchuk, A.A. Bazey, S.M. Andrievskii, I.L. Andronov, M.Yu. Volyanskaia, G.A. Garbuzov, N.I. Koshkin, V.A. Pozigun and M.I. Ryabov- astronomers from the Odessa Astronomical Observatory) and the papers published in the 2006 issue ( B.A.

The broadcast represents an interview to Journalist Orest Melnic (National TV of Moldova) , concerning the theory of the Solar Eclipses in general, the Eclipse from 11 august 1999 in particular and the circumstances of the Eclipse for the Republic of Moldova. Some recommendations for amateur astronomers are givien.

The main problems of Astrophysics and Cosmology in Technical High School are presented as a development of knowledges obtained by students during learning of Electroweek theory, Quantum Chromodynamics, GUT Theory, Quantification of Gravitation, the elementrary ideas on Strings. The space for these topics is very limited in the curriculum for the Physics of the High Schools , but the rapid

The curve of the temperature (http://www.astro.websib.ru/Rasnoe/pismo/Gaina/Gaina_3/her.htm), Few photographs of the Total eclipse of the Sun from 29 march 2006 made in Chisinau (The Republic of Moldova)(47 Deg.03 Min. N.L., 28 Deg. 46 Min. E.L.)(http://www.astro.websib.ru/Rasnoe/pismo/Gaina/Gaina_3/zat.htm) are presented. A miscellaneous photo of the comet Halle -Bopp made by FED-5B (No. 101962, manufactured in 1979)is presented also. For translation of the texts from

A report of the eclipse of the Sun from 01 August 2008 is given with photographs from Germany (House of Optics), Romania (Timisoara, Sighetu Marmatiei, Calarasi near Iasi), a report from Chisinau (The Repblic of Moldova) as well as a discussion of the circumstances and the observations.

The article is devoted to milestones of life and scientific activity of the eminent astronomer Nikolay Nikolaevich Donitch (Nicolae N. Donici) (1874-1956), a graduate from the Odessa (Novorossiski) university. He was a wellknown expert in the field of reseacrh of objects of Solar system. A person highly cultured, which built the first in Bessarabia (actually a part of the Republic of Moldova) observatory. He was borne in Kishinev (Chisinau) in a nobles family of notable Moldavian landersmen. N.D. graduated from the Richelieu lyceym in Odessa and afterwards, in 1897, graduated from the Odessa (Novorossiysky) University. A.K. Kononovich (1850-1910)headed the chair of astronomy and the Observatory at that time - a foremost authority in the field of astrophysics and stellar astronomy. Many of his disciples became eminent scientists of their time. N. Donitch was among them. N.D. worked till 1918 at Pulkovo Observatory and became a master in the field of studying of such phenomena as sola...

In the single-particle approximation of the Dirac equation, a study is made of the finite motion of electrons in the field of small black holes (M ≪10^17 g) under the assumption that the black hole has rotation (a ≪ M) and charge much less than the critical value (Z<<137). In this case, the motion of the particle is nonrelativistic, and the energy spectrum is hydrogen-like. The influence of rotation of the hole on the binding energy of the particle is small and unimportant for determining the damping of the levels due to capture by the hole. In contrast to a scalar particle, the damping of the electron states is not replaced by excitation for ω << mjΩH + eVH. The gravitational spin-orbit interaction has a strong influence on the damping. The probability of capture of an electron with spin anti-parallel to the orbital angular momentum is much greater than the probability of capture for a particle with spin parallel to it. In the Schwarzschild field, the damping of the S state of an electron is eight times less than the damping of the ground state of a scalar particle.

The differential cross section for backward scattering (  θ ->π) of spinless particles with nonzero rest mass on the background of a Schwarzschild geometry is calculated by quantum-mechanical methods. It is shown that a glory exists if the gravitational radius exceeds the particle wavelength.

This paper describes a history of friendship and collaboration between the astronomers N. Donitch and A.A. Baikov. Information on other astronomers L.V. Okulitch and E.A. Von der Pahlen, and meteorologists V.H. Dubinskii and Nina Gouma, can also be found. Details on the expeditions aimed at observing the total solar eclipses on 30 August 1905 (organized by the Imperial Academy of Sciences in Sankt-Petersburg) and 19 June 1936 (organized by the Romanian Royal Cultural foundation) are given. The main part represents the first English translation of the paper by Baikov, published earlier in Russian and Romanian, with a new preface, annotations, and comments.

A short outline of the history of astronomy, astronomical navigation, geodesy and map-drawing in Moldova since the Middle Ages till the World War I is presented. The contribution of Rudjer Boskovic to the determination of geographical coordinates of Galati and Iasi and the triangulation of Montenegro in 1879-1880 by Russian military geodesists has been discussed as well.

The bound orbits of test particles with nonzero rest massnear the center of a strong Schwarzschild gravitational field are described quantum mechanically. The energy spectrum and damping of the corresponding quasi levels are calculated on the basis of a generalized Relativistic Klein- Gordon equation. Comparison of the minimal damping time with the orbital period shows that the circular orbit nearest the center , which is stable in the sense of classical mechanics , is also stable in the sense of quantum mechanics for massive compact objects of stellar origin and all known elementary particles , nuclei, and atoms. For mini black holes with masses M≤10^5-6 Mpl^2/m, where m is the mass of the test body, this orbit is unstable with respect to tunneling decay.

The differential cross section for backward scattering (6-n) of spinless particles with nonzero rest mass on the background of a Schwarzschild geometry is calculated by quantum-mechanical methods. It is shown that a glory exists if the gravitational radius exceeds the particle wavelength.

We demonstrate the possibility that a boson condensate is formed in the field of microscopic black hole with a gravitational radius of the order of the Compton wavelength as a result of boson instability and dropping of the angular momentum of a black hole to quantum levels.The equations of boson instability are integrated for the case of microscopic mM<<Mpl^2 and rapidly rotating ( a~GM/c^2, mM≥Mpl^2) Black Holes. The properties of the envelope ( shell) are investigated.

A unified approach to the description of scattering processes and resonance states for the Klein-Gordon equation in the field of a black hole is developed on the basis of Jost's method. Some general definitions and properties of the S matrix, amplitudes, and differential and total absorption and scattering cross sections are obtained for the axisymmetric Kerr-Newman configuration. Concrete results (scattering and absorption cross sections and the characteristics of resonance levels of massive particles) are obtained for the long-wave case.

The absorption and scattering partial coefficients as well as absorption amplitudes and differential cross sections for mass fermions of spin 1/2 by a Kerr and weakly charged Kerr- Newman black holes are obtained in an analytical form, after performing the solutions of the radial Chandrasekhar- Dirac equation.

The purpose of this article is to review and classify a great number of articles in the area of scattering of particles and fields by Black Holes. In a case of mass fields the calculation of scattering matrix allows to calculate also the energies spectrum and time life of bound states for mass fields. A second purpose is to give a calculation of quantum mechanical scattering in a short wavelength approximation for mass fields based on perturbations method. 2 various perturbation schemes can be developed, which give a slightly different results. The actual one is giving a result which agree exactly with calculations in the massless limit and with the calculations in a classic limit. A comparison of this cross section has been made with gravitational selfaction one, which would contribute at the same magnitude. The electromagnetic self-action has been taken into account when the particles and the Black Holes carries electric or magnetic charges. The absorption cross section has been written explicitly for a case of magnetic monopoles scattered by a magnetically charged Black hole. A misprint in a previous paper has been corrected.

The history of Killing and Killing-Tensors has been given shortly. They allow separating not only Hamilton-Jacobi equation for test particles on a given space-time, but also equations for quantum fields: spin wave equations, neutrino, Klein-Gordon, Dirac, and Maxwell. Their existence for Kerr Space-time, which is fundamental for the observed Black Holes in Astrophysics, represents a significant connection between theory of motion (Mechanics and Quantum Mechanics), Mathematical relativity, and Astrophysics. Consequences for quantum field's theories of spins 0 and 1/2 in Plebanski-Demianski and Plebanski geometries resulting from the existence of non-trivial Killing and Killing-Yano tensors are examined. Chemical potential and conditions of particles creation near Black Hole horizon are obtained.

Being a true disciple of Niels Bohr, Wheeler first of all learned the idea of quantizing the atomic energy levels of his great teacher. So he asked himself a question. It is well known that an electron and a proton form a hydrogen atom, two hydrogen atoms form a hydrogen molecule, and if we do not have hydrogen, and so-called Positronium, that is, a system consisting of an electron and a positron, an electron antiparticle predicted by Paul Dirac (and underlying concepts of "holes" in solids)-would be stable such a system? By the way, such an atom can have two states depending on the orientation of the spin: parapositronium (spins are antiparallel-then this system is more stable) and orthopositronium (the spins are parallel; then this system is less stable, its binding energy is higher and, therefore, some time after the radiation photon, it can go to parapositronium, that is, a spin flip occurs) [1,2].Soviet scientists [5,6] were interested in this problem since 1949, but obviously they do not cite J.A. Wheeler as the author of the idea, preferring E. Hylleras and A.Ore [3,4] which are late by 1 year at least. How will elementary objects that are different in their physical essence bind to "atoms"? Physicists are interested not only in the binding of an electron and a proton to a hydrogen atom, but, also in the binding of an electron and a hole to an exciton, and then, just as two hydrogen atoms create a hydrogen molecule, the binding of two excitons to a biexciton or, in a more chemical language, an exciton molecule. Who would have thought that in 1946 Wheeler could foresee the existence of exciton molecules in semiconductors? This area of science is developed after 1946, a lot of scientific schools throughout the world in connection with the most direct technological interest. Both in Russia, in the former Soviet republics and in the West, the problem of excitons and biexcitons (for example, biexcitons were predicted independently by Moldovan physicist Svyatoslav Moskalenko in 1958 [7] and by American Murray Lampert from Princeton University in the same year [8]), boson condensate were of wide interest (see, for detail [9])