388 research outputs found

    Exact metric around a wiggly cosmic string

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    The exact metric around a wiggly cosmic string is found by modifying the energy momentum-tensor of a straight infinitely thin cosmic string to include an electric current along the symmetry axis.Comment: 5 page

    Anomaly/Transport in an Ideal Weyl gas

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    We study some of the transport processes which are specific to an ideal gas of relativistic Weyl fermions and relate the corresponding transport coefficients to various anomaly coefficients of the system. We propose that these transport processes can be thought of as arising from the continuous injection of chiral states and their subsequent adiabatic flow driven by vorticity. This in turn leads to an elegant expression relating the anomaly induced transport coefficients to the anomaly polynomial of the Ideal Weyl gas.Comment: 35 pages, JHEP forma

    Fractional Super Lie Algebras and Groups

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    n^{th} root of a Lie algebra and its dual (that is fractional supergroup) based on the permutation group SnS_n invariant forms are formulated in the Hopf algebra formalism. Detailed discussion of S3S_3-graided sl(2)sl(2) algebras is done.Comment: 13 pages, detailed discussion of S3S_3-graided sl(2)sl(2) is adde

    Membranes in the two-Higgs standard model

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    We present some non-topological static wall solutions in two-Higgs extensions of the standard model. They are classically stable in a large region of parameter space, compatible with perturbative unitarity and with present phenomenological bounds.Comment: 7 pages, latex, 3 figures available upon reques

    Cosmic Strings Lens Phenomenology: Model of Poisson Energy Distribution

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    We present a novel approach for investigating lens phenomenology of cosmic strings in order to elaborate detection strategies in galaxy deep field images. To account for the complexity of the projected energy distribution of string networks we assume their lens effects to be similar to those of a straight string carrying a {\em random} lineic energy distribution. In such a model we show that, unlike the case of uniform strings, critical phenomena naturally appear. We explore the properties of the critical lines and caustics. In particular, assuming that the energy coherence length along the string is much smaller than the observation scale, we succeeded in computing the total length of critical lines per unit string length and found it to be 4/3E(3/4)4/\sqrt{3} {\bf E}(3/4). The length of the associated caustic lines can also be computed to be 16/(Ï€3)E(3/4)16/(\pi \sqrt{3}) {\bf E}(3/4). The picture we obtain here for the phenomenology of cosmic string detection is clearly at variance with common lore.Comment: 10 pages, 5 figures. Minor correction

    Chiral Heat Wave and mixing of Magnetic, Vortical and Heat waves in chiral media

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    We show that a hot rotating fluid of relativistic chiral fermions possesses a new gapless collective mode associated with coherent propagation of energy density and chiral density waves along the axis of rotation. This mode, which we call the Chiral Heat Wave, emerges due to a mixed gauge-gravitational anomaly. At finite density the Chiral Heat Wave couples to the Chiral Vortical Wave while in the presence of an external magnetic field it mixes with the Chiral Magnetic Wave. The coupling of the Chiral Magnetic and Chiral Vortical Waves is also demonstrated. We find that the coupled waves - which are coherent fluctuations of the vector, axial and energy currents - have generally different velocities compared to the velocities of the individual waves.Comment: 33 pages, 6 figures; v2: minor changes, published versio

    Evolution Equation for Generalized Parton Distributions

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    The extension of the method [arXiv:hep-ph/0503109] for solving the leading order evolution equation for Generalized Parton Distributions (GPDs) is presented. We obtain the solution of the evolution equation both for the flavor nonsinglet quark GPD and singlet quark and gluon GPDs. The properties of the solution and, in particular, the asymptotic form of GPDs in the small x and \xi region are discussed.Comment: REVTeX4, 34 pages, 3 figure

    Cosmological Measures without Volume Weighting

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    Many cosmologists (myself included) have advocated volume weighting for the cosmological measure problem, weighting spatial hypersurfaces by their volume. However, this often leads to the Boltzmann brain problem, that almost all observations would be by momentary Boltzmann brains that arise very briefly as quantum fluctuations in the late universe when it has expanded to a huge size, so that our observations (too ordered for Boltzmann brains) would be highly atypical and unlikely. Here it is suggested that volume weighting may be a mistake. Volume averaging is advocated as an alternative. One consequence may be a loss of the argument that eternal inflation gives a nonzero probability that our universe now has infinite volume.Comment: 15 pages, LaTeX, added references for constant-H hypersurfaces and also an idea for minimal-flux hypersurface

    Dynamics of Gravitating Magnetic Monopoles

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    According to previous work on magnetic monopoles, static regular solutions are nonexistent if the vacuum expectation value of the Higgs field η\eta is larger than a critical value ηcr\eta_{{\rm cr}}, which is of the order of the Planck mass. In order to understand the properties of monopoles for η>ηcr\eta>\eta_{{\rm cr}}, we investigate their dynamics numerically. If η\eta is large enough (≫ηcr\gg\eta_{{\rm cr}}), a monopole expands exponentially and a wormhole structure appears around it, regardless of coupling constants and initial configuration. If η\eta is around ηcr\eta_{{\rm cr}}, there are three types of solutions, depending on coupling constants and initial configuration: a monopole either expands as stated above, collapses into a black hole, or comes to take a stable configuration.Comment: 11 pages, revtex, postscript figures; results for various initial conditions are added; to appear in Phys. Rev.

    The no-boundary measure in string theory: Applications to moduli stabilization, flux compactification, and cosmic landscape

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    We investigate the no-boundary measure in the context of moduli stabilization. To this end, we first show that for exponential potentials, there are no classical histories once the slope exceeds a critical value. We also investigate the probability distributions given by the no-boundary wave function near maxima of the potential. These results are then applied to a simple model that compactifies 6D to 4D (HBSV model) with fluxes. We find that the no-boundary wave function effectively stabilizes the moduli of the model. Moreover, we find the a priori probability for the cosmological constant in this model. We find that a negative value is preferred, and a vanishing cosmological constant is not distinguished by the probability measure. We also discuss the application to the cosmic landscape. Our preliminary arguments indicate that the probability of obtaining anti de Sitter space is vastly greater than for de Sitter.Comment: 27 pages, 8 figure
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