98 research outputs found

    Radiatively Induced Breaking of Conformal Symmetry in a Superpotential

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    Radiatively induced symmetry breaking is considered for a toy model with one scalar and one fermion field unified in a superfield. It is shown that the classical quartic self-interaction of the superfield possesses a quantum infrared singularity. Application of the Coleman-Weinberg mechanism for effective potential leads to the appearance of condensates and masses for both scalar and fermion components. That induces a spontaneous breaking of the initial classical symmetries: the supersymmetry and the conformal one. The energy scales for the scalar and fermion condensates appear to be of the same order, while the renormalization scale is many orders of magnitude higher. A possibility to relate the considered toy model to conformal symmetry breaking in the Standard Model is discussed.Comment: Improved final version with new references and misprints corrected, 9 pages , no figure

    New spherically symmetric monopole and regular solutions in Einstein-Born-Infeld theories

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    In this work a new asymptotically flat solution of the coupled Einstein-Born-Infeld equations for a static spherically symmetric space-time is obtained. When the intrinsic mass is zero the resulting spacetime is regular everywhere, in the sense given by B. Hoffmann and L. Infeld in 1937, and the Einstein-Born-Infeld theory leads to the identification of the gravitational with the electromagnetic mass. This means that the metric, the electromagnetic field and their derivatives have not discontinuities in all the manifold. In particular, there are not conical singularities at the origin, in contrast to well known monopole solution studied by B. Hoffmann in 1935. The lack of uniqueness of the action function in Non-Linear-Electrodynamics is discussed.Comment: Final version in journal. Amplied version with new results that previous talk in Protvino worksho

    The Newman-Janis Algorithm, Rotating Solutions and Einstein-Born-Infeld Black Holes

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    A new metric is obtained by applying a complex coordinate trans- formation to the static metric of the self-gravitating Born-Infeld monopole. The behaviour of the new metric is typical of a rotating charged source, but this source is not a spherically symmetric Born-Infeld monopole with rotation. We show that the structure of the energy-momentum tensor obtained with this new metric does not correspond to the typical structure of the energy momentum tensor of Einstein-Born-Infeld theory induced by a rotating spherically symmetric source. This also show, that the complex coordinate transformations have the interpretation given by Newman and Janis only in space-time solutions with linear sources

    Von Neumann's Quantization of General Relativity

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    Von Neumann's procedure is applied for quantization of General Relativity. We quantize the initial data of dynamical variables at the Planck epoch, where the Hubble parameter coincides with the Planck mass. These initial data are defined via the Fock simplex in the tangent Minkowskian space-time and the Dirac conformal interval. The Einstein cosmological principle is applied for the average of the spatial metric determinant logarithm over the spatial volume of the visible Universe. We derive the splitting of the general coordinate transformations into the diffeomorphisms (as the object of the second N\"other theorem) and the initial data transformations (as objects of the first N\"other theorem). Following von Neumann, we suppose that the vacuum state is a quantum ensemble. The vacuum state is degenerated with respect to quantum numbers of non-vacuum states with the distribution function that yields the Casimir effect in gravidynamics in analogy to the one in electrodynamics. The generation functional of the perturbation theory in gravidynamics is given as a solution of the quantum energy constraint. We discuss the region of applicability of gravidynamics and its possible predictions for explanation of the modern observational and experimental data.Comment: 14 pages, updated version with extended discussio

    Emanation Study of Gas Radon on the Ancient Cuexcomate Geyser in Puebla City, Mexico

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    Radon measurements were collected over a period of nine months in the area of the ancient Cuexcomate geyser, in Puebla City. For measuring radon, the passive method of nuclear tracks in solids was used, using polycarbonate CR-39 as radiation sensitive material. Radon concentrations varied in strong anti-correlation with the rainfall intensity. And are lower compared to other locations, in concordance with the stratigraphic composition, as travertine and deposits of volcanic origin, corresponding to the geyser chemical composition and the active environment in the north part of the Trans-Mexican Volcanic Belt with an andesitic and basalt composition

    Rotation and twist regular modes for trapped ghosts

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    A parameter-independent notion of stationary slow motion is formulated then applied to the case of stationary rotation of massless trapped ghosts. The excitations correspond to a rotation mode with angular momentum J0J\neq 0 and twist modes. It is found that the rotation mode, which has no parity, causes excess in the angular velocity of dragged distant coordinate frames in one sheet of the wormhole while in the other sheet the angular velocity of the ghosts is that of rotating stars: 2J/r32J/r^3. As to the twist modes, which all have parity, they cause excess in the angular velocity of one of the throat's poles with respect to the other.Comment: 11 pages, 3 figures; General Relativity and Gravitation - 201

    Electrified BPS Giants: BPS configurations on Giant Gravitons with Static Electric Field

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    We consider D3-brane action in the maximally supersymmetric type IIB plane-wave background. Upon fixing the light-cone gauge, we obtain the light-cone Hamiltonian which is manifestly supersymmetric. The 1/2 BPS solutions of this theory (solutions which preserve 16 supercharges) are either of the form of spherical three branes, the giant gravitons, or zero size point like branes. We then construct specific classes of 1/4 BPS solutions of this theory in which static electric field on the brane is turned on. These solutions are deformations about either of the two 1/2 BPS solutions. In particular, we study in some detail 1/4 BPS configurations with electric dipole on the three sphere giant, i.e. BIons on the giant gravitons, which we hence call BIGGons. We also study BPS configurations corresponding to turning on a background uniform constant electric field. As a result of this background electric field the three sphere giant is deformed to squashed sphere, while the zero size point like branes turn into circular or straight fundamental strings in the plane-wave background, with their tension equal to the background electric field.Comment: 32 pages, 1 eps figure; v2: Presentation of derivation of light-cone Hamiltonian improved, Refs adde

    Generalizations of Nonlinear and Supersymmetric Classical Electrodynamics

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    We first write down a very general description of nonlinear classical electrodynamics, making use of generalized constitutive equations and constitutive tensors. Our approach includes non-Lagrangian as well as Lagrangian theories, allows for electromagnetic fields in the widest possible variety of media (anisotropic, piroelectric, chiral and ferromagnetic), and accommodates the incorporation of nonlocal effects. We formulate electric-magnetic duality in terms of the constitutive tensors. We then propose a supersymmetric version of the general constitutive equations, in a superfield approach.Comment: 15 pages, based on the presentation by G. A. Goldin at QTS

    Irreducible holonomy algebras of Riemannian supermanifolds

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    Possible irreducible holonomy algebras \g\subset\osp(p,q|2m) of Riemannian supermanifolds under the assumption that \g is a direct sum of simple Lie superalgebras of classical type and possibly of a one-dimensional center are classified. This generalizes the classical result of Marcel Berger about the classification of irreducible holonomy algebras of pseudo-Riemannian manifolds.Comment: 27 pages, the final versio

    Seletividade e controle de grama-seda em aplicações sequenciais de herbicidas em cana-planta.

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    A grama-seda (Cynodon dactylon) infesta os canaviais, tem suas plantas perenizadas em curto espaço de tempo e consequentemente tornam-se tolerantes aos herbicidas. Para elucidar estratégias de controle objetivou-se avaliar aplicações sequenciais de herbicidas sobre a eficácia de controle da grama-seda e a seletividade sobre a cana-de-açúcar. O experimento de eficácia de controle foi conduzido em vasos de plástico (18 L) preenchidos com solo de textura arenosa e plantados com ramos de C. dactylon. As parcelas foram distribuídas em delineamento inteiramente casualizado e em sala de crescimento, regulada para atender as condições de verão do clima Cwa (Koppen). O experimento de seletividade foi conduzido em cana-planta com parcelas de 7,5 m x 25m e delineamento em blocos casualizados. Ambos os experimentos foram constituídos por 9 tratamentos em cinco repetições, sendo compostos pela aplicação de clomazone + sulfentrazone ou clomazone + indaziflam, cada um precedidos da ausência de herbicidas, imazapyr (aplicado 75 dias antes), clomazone ou indaziflam (aplicados 38 dias antes) e o tratamento testemunha. No experimento de eficácia avaliou-se a porcentagem de controle e a matéria seca das plantas aos 60 dias após a última aplicação e no experimento de seletividade a altura, estande, produtividade dos colmos e perfil isoenzimático da ?-esterase aos 315 dias após plantio da cultura. A aplicação de clomazone + sulfentrazone após 38 dias de pousio do clomazone diminuíram a matéria seca de Cynodon dactylon e não prejudicaram a altura, estande e produtividade dos colmos aos 315 dias após plantio
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