19,038 research outputs found

    Oscillation-based methods for actuation and manipulation of nano-objects

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    This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in AIP Conference Proceedings 1882, 020056 (2017) and may be found at https://doi.org/10.1063/1.5001635.We discuss how oscillations can be used for fixation or manipulation of nano-objects or producing nano-drives. The underlying principles are scale-invariant and principally can be scaled down up to the molecular scale. The main underlying principle of fixation and actuation occurs to be symmetry breaking of an oscillating system. From this unifying standpoint, a series of actuation principles are discussed as dragging, ratchets, micro walking, friction-inertia actuators, oscillation tweezers, flagella motors for propulsion in liquids as well as some recently proposed actuation principles

    The full replica symmetry breaking in the Ising spin glass on random regular graph

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    In this paper, we extend the full replica symmetry breaking scheme to the Ising spin glass on a random regular graph. We propose a new martingale approach, that overcomes the limits of the Parisi-M\'ezard cavity method, providing a well-defined formulation of the full replica symmetry breaking problem in random regular graphs. Finally, we define the order parameters of the system and get a set of self-consistency equations for the order parameters and the free energy. We face up the problem only from a technical point of view: the physical meaning of this approach and the quantitative evaluation of the solution of the self-consistency equations will be discussed in next works.Comment: 23 page

    Gravity, Lorentz Violation, and the Standard Model

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    The role of the gravitational sector in the Lorentz- and CPT-violating Standard-Model Extension (SME) is studied. A framework is developed for addressing this topic in the context of Riemann-Cartan spacetimes, which include as limiting cases the usual Riemann and Minkowski geometries. The methodology is first illustrated in the context of the QED extension in a Riemann-Cartan background. The full SME in this background is then considered, and the leading-order terms in the SME action involving operators of mass dimension three and four are constructed. The incorporation of arbitrary Lorentz and CPT violation into general relativity and other theories of gravity based on Riemann-Cartan geometries is discussed. The dominant terms in the effective low-energy action for the gravitational sector are provided, thereby completing the formulation of the leading-order terms in the SME with gravity. Explicit Lorentz symmetry breaking is found to be incompatible with generic Riemann-Cartan geometries, but spontaneous Lorentz breaking evades this difficulty.Comment: 21 pages REVTeX, references added, accepted in Physical Review

    Automated mass spectrum generation for new physics

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    We describe an extension of the FeynRules package dedicated to the automatic generation of the mass spectrum associated with any Lagrangian-based quantum field theory. After introducing a simplified way to implement particle mixings, we present a new class of FeynRules functions allowing both for the analytical computation of all the model mass matrices and for the generation of a C++ package, dubbed ASperGe. This program can then be further employed for a numerical evaluation of the rotation matrices necessary to diagonalize the field basis. We illustrate these features in the context of the Two-Higgs-Doublet Model, the Minimal Left-Right Symmetric Standard Model and the Minimal Supersymmetric Standard Model.Comment: 11 pages, 1 table; version accepted by EPJ

    Scale Symmetry Breaking from the Dynamics of Maximal Rank Gauge Field Strengths

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    Scale invariant theories which contain maximal rank gauge field strengths (of DD indices in DD dimensions) are studied. The integration of the equations of motion of these gauge fields leads to the s.s.b. of scale invariance. The cases in study are: i) the spontaneous generation of r1r^{-1} potentials in particle mechanics in a theory that contains only r2r^{-2} potentials in the scale invariant phase, ii) mass generation in scalar field theories iii) generation of non trivial dilaton potentials in generally covariant theories, iv) spontaneous generation of confining behavior in gauge theories. The possible origin of these models is discussed.Comment: 14 pages, latex, no figures, references adde
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