744 research outputs found

    Geometrical Interpretation of BRST Symmetry in Topological Yang-Mills-Higgs Theory

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    We study topological Yang-Mills-Higgs theories in two and three dimensions and topological Yang-Mills theory in four dimensions in a unified framework of superconnections. In this framework, we first show that a classical action of topological Yang-Mills type can provide all three classical actions of these theories via appropriate projections. Then we obtain the BRST and anti-BRST transformation rules encompassing these three topological theories from an extended definition of curvature and a geometrical requirement of Bianchi identity. This is an extension of Perry and Teo's work in the topological Yang-Mills case. Finally, comparing this result with our previous treatment in which we used the ``modified horizontality condition", we provide a meaning of Bianchi identity from the BRST symmetry viewpoint and thus interpret the BRST symmetry in a geometrical setting.Comment: 16 pages, LaTeX fil

    Axions in gravity with torsion

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    We study a scenario allowing a solution of the strong charge parity problem via the Peccei-Quinn mechanism, implemented in gravity with torsion. In this framework there appears a torsion-related pseudoscalar field known as Kalb-Ramond axion. We compare it with the so-called Barbero-Immirzi axion recently proposed in the literature also in the context of the gravity with torsion. We show that they are equivalent from the viewpoint of the effective theory. The phenomenology of these torsion-descended axions is completely determined by the Planck scale without any additional model parameters. These axions are very light and very weakly interacting with ordinary matter. We briefly comment on their astrophysical and cosmological implications in view of the recent BICEP2 and Planck data.Comment: 7 pages, no figures, comments and references added, published versio

    On Spinors Transformations

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    We begin showing that for even dimensional vector spaces VV all automorphisms of their Clifford algebras are inner. So all orthogonal transformations of VV are restrictions to VV of inner automorphisms of the algebra. Thus under orthogonal transformations PP and TT - space and time reversal - all algebra elements, including vectors vv and spinors φ\varphi, transform as vxvx1v \to x v x^{-1} and φxφx1\varphi \to x \varphi x^{-1} for some algebra element xx. We show that while under combined PTPT spinor φxφx1\varphi \to x \varphi x^{-1} remain in its spinor space, under PP or TT separately φ\varphi goes to a 'different' spinor space and may have opposite chirality. We conclude with a preliminary characterization of inner automorphisms with respect to their property to change, or not, spinor spaces.Comment: Minor changes to propositions 1 and

    Quantum Mechanics in Non-Inertial Frames with a Multi-Temporal Quantization Scheme: II) Non-Relativistic Particles

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    The non-relativistic version of the multi-temporal quantization scheme of relativistic particles in a family of non-inertial frames (see hep-th/0502194) is defined. At the classical level the description of a family of non-rigid non-inertial frames, containing the standard rigidly linear accelereted and rotating ones, is given in the framework of parametrized Galilei theories. Then the multi-temporal quantization, in which the gauge variables, describing the non-inertial effects, are not quantized but considered as c-number generalized times, is applied to non relativistic particles. It is shown that with a suitable ordering there is unitary evolution in all times and that, after the separation of center of mass, it is still possible to identify the inertial bound states. The few existing results of quantization in rigid non-inertial frames are recovered as special cases

    On the Einstein-Weyl and conformal self-duality equations

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    The equations governing anti-self-dual and Einstein-Weyl conformal geometries can be regarded as `master dispersionless systems' in four and three dimensions respectively. Their integrability by twistor methods has been established by Penrose and Hitchin. In this note we present, in specially adapted coordinate systems, explicit forms of the corresponding equations and their Lax pairs. In particular, we demonstrate that any Lorentzian Einstein-Weyl structure is locally given by a solution to the Manakov-Santini system, and we find a system of two coupled third-order scalar PDEs for a general anti-self-dual conformal structure in neutral signature.This is the accepted manuscript. The final version is available at http://scitation.aip.org/content/aip/journal/jmp/56/8/10.1063/1.4927251

    The relation between the model of a crystal with defects and Plebanski's theory of gravity

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    In the present investigation we show that there exists a close analogy of geometry of spacetime in GR with a structure of defects in a crystal. We present the relation between the Kleinert's model of a crystal with defects and Plebanski's theory of gravity. We have considered the translational defects - dislocations, and the rotational defects - disclinations - in the 3- and 4-dimensional crystals. The 4-dimensional crystalline defects present the Riemann-Cartan spacetime which has an additional geometric property - "torsion" - connected with dislocations. The world crystal is a model for the gravitation which has a new type of gauge symmetry: the Einstein's gravitation has a zero torsion as a special gauge, while a zero connection is another equivalent gauge with nonzero torsion which corresponds to the Einstein's theory of "teleparallelism". Any intermediate choice of the gauge with nonzero connection A^{IJ}_\mu is also allowed. In the present investigation we show that in the Plebanski formulation the phase of gravity with torsion is equivalent to the ordinary or topological gravity, and we can exclude a torsion as a separate dynamical variable.Comment: 13 pages, 2 figure

    Uniform materials and the multiplicative decomposition of the deformation gradient in finite elasto-plasticity

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    In this work we analyze the relation between the multiplicative decomposition F=FeFp\mathbf F=\mathbf F^{e}\mathbf F^{p} of the deformation gradient as a product of the elastic and plastic factors and the theory of uniform materials. We prove that postulating such a decomposition is equivalent to having a uniform material model with two configurations - total ϕ\phi and the inelastic ϕ1\phi_{1}. We introduce strain tensors characterizing different types of evolutions of the material and discuss the form of the internal energy and that of the dissipative potential. The evolution equations are obtained for the configurations (ϕ,ϕ1)(\phi,\phi_{1}) and the material metric g\mathbf g. Finally the dissipative inequality for the materials of this type is presented.It is shown that the conditions of positivity of the internal dissipation terms related to the processes of plastic and metric evolution provide the anisotropic yield criteria

    A torsional completion of gravity for Dirac matter fields and its applications to neutrino oscillations

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    In this paper, we consider the torsional completion of gravitation for an underlying background filled with Dirac fields, applying it to the problem of neutrino oscillations: we discuss the effects of the induced torsional interactions as corrections to the neutrino oscillation mechanism.Comment: 4 page

    Polar Actions on Berger Spheres

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    The object of this article is to study a torus action on a so-called Berger sphere. We also make some comments on polar actions on naturally reductive homogeneous spaces. Finally, we prove a rigidity-type theorem for Riemannian manifolds carrying a polar action with a fix point

    Torsional Monopoles and Torqued Geometries in Gravity and Condensed Matter

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    Torsional degrees of freedom play an important role in modern gravity theories as well as in condensed matter systems where they can be modeled by defects in solids. Here we isolate a class of torsion models that support torsion configurations with a localized, conserved charge that adopts integer values. The charge is topological in nature and the torsional configurations can be thought of as torsional `monopole' solutions. We explore some of the properties of these configurations in gravity models with non-vanishing curvature, and discuss the possible existence of such monopoles in condensed matter systems. To conclude, we show how the monopoles can be thought of as a natural generalization of the Cartan spiral staircase.Comment: 4+epsilon, 1 figur
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