2,002 research outputs found

    A Superfield for Every Dash-Chromotopology

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    The recent classification scheme of so-called adinkraic off-shell supermultiplets of N-extended worldline supersymmetry without central charges finds a combinatorial explosion. Completing our earlier efforts, we now complete the constructive proof that all of these trillions or more of supermultiplets have a superfield representation. While different as superfields and supermultiplets, these are still super-differentially related to a much more modest number of minimal supermultiplets, which we construct herein.Comment: 13 pages, integrated illustration

    Effective Symmetries of the Minimal Supermultiplet of N = 8 Extended Worldline Supersymmetry

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    A minimal representation of the N = 8 extended worldline supersymmetry, known as the `ultra-multiplet', is closely related to a family of supermultiplets with the same, E(8) chromotopology. We catalogue their effective symmetries and find a Spin(4) x Z(2) subgroup common to them all, which explains the particular basis used in the original construction. We specify a constrained superfield representation of the supermultiplets in the ultra-multiplet family, and show that such a superfield representation in fact exists for all adinkraic supermultiplets. We also exhibit the correspondences between these supermultiplets, their Adinkras and the E(8) root lattice bases. Finally, we construct quadratic Lagrangians that provide the standard kinetic terms and afford a mixing of an even number of such supermultiplets controlled by a coupling to an external 2-form of fluxes.Comment: 13 Figure

    Z7Z_7 Orbifold Models in M-Theory

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    Among T7/ΓT^7/\Gamma orbifold compactifications of MM-theory, we examine models containing the particle physics Standard Model in four-dimensional spacetimes, which appear as fixed subspaces of the ten-dimensional spacetimes at each end of the interval, I1≃S1/Z2I^1\simeq S^1/Z_2, spanning the 11th11^\text{th} dimension. Using the Z7Z_7 projection to break the E8E_8 gauge symmetry in each of the four-planes and a limiting relation to corresponding heterotic string compactifications, we discuss the restrictions on the possible resulting gauge field and matter spectra. In particular, some of the states are non-local: they connect two four-dimensional Worlds across the 11th11^\text{th} dimension. We illustrate our programmable calculations of the matter field spectrum, including the anomalous U(1) factor which satisfies a universal Green-Schwarz relation, discuss a Dynkin diagram technique to showcase a model with SU(3)×SU(2)×U(1)5SU(3)\times SU(2)\times U(1)^5 gauge symmetry, and discuss generalizations to higher order orbifolds.Comment: 23 pages, 2 figures, 4 tables; LaTeX 3 time

    Early Dark Energy Cosmologies

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    We propose a novel parameterization of the dark energy density. It is particularly well suited to describe a non-negligible contribution of dark energy at early times and contains only three parameters, which are all physically meaningful: the fractional dark energy density today, the equation of state today and the fractional dark energy density at early times. As we parameterize Omega_d(a) directly instead of the equation of state, we can give analytic expressions for the Hubble parameter, the conformal horizon today and at last scattering, the sound horizon at last scattering, the acoustic scale as well as the luminosity distance. For an equation of state today w_0 < -1, our model crosses the cosmological constant boundary. We perform numerical studies to constrain the parameters of our model by using Cosmic Microwave Background, Large Scale Structure and Supernovae Ia data. At 95% confidence, we find that the fractional dark energy density at early times Omega_early < 0.06. This bound tightens considerably to Omega_early < 0.04 when the latest Boomerang data is included. We find that both the gold sample of Riess et. al. and the SNLS data by Astier et. al. when combined with CMB and LSS data mildly prefer w_0 < -1, but are well compatible with a cosmological constant.Comment: 6 pages, 3 figures; references added, matches published versio

    Codes and Supersymmetry in One Dimension

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    Adinkras are diagrams that describe many useful supermultiplets in D=1 dimensions. We show that the topology of the Adinkra is uniquely determined by a doubly even code. Conversely, every doubly even code produces a possible topology of an Adinkra. A computation of doubly even codes results in an enumeration of these Adinkra topologies up to N=28, and for minimal supermultiplets, up to N=32.Comment: 48 pages, a new version that combines arXiv:0811.3410 and parts of arXiv:0806.0050, for submission for publicatio

    Solving the Einstein-Podolsky-Rosen puzzle: the origin of non-locality in Aspect-type experiments

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    So far no mechanism is known, which could connect the two measurements in an Aspect-type experiment. Here, we suggest such a mechanism, based on the phase of a photon's field during propagation. We show that two polarization measurements are correlated, even if no signal passes from one point of measurement to the other. The non-local connection of a photon pair is the result of its origin at a common source, where the two fields acquire a well defined phase difference. Therefore, it is not actually a non-local effect in any conventional sense. We expect that the model and the detailed analysis it allows will have a major impact on quantum cryptography and quantum computation.Comment: 5 pages 1 figure. Added an analysis of quantum steering. The result is that under certain conditions the experimental result at B can be predicted if the polarization angle and the result at A are known. The paper has been accepted for publication in Frontiers of Physics. arXiv admin note: substantial text overlap with arXiv:1108.435

    On Graph-Theoretic Identifications of Adinkras, Supersymmetry Representations and Superfields

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    In this paper we discuss off-shell representations of N-extended supersymmetry in one dimension, ie, N-extended supersymmetric quantum mechanics, and following earlier work on the subject codify them in terms of certain graphs, called Adinkras. This framework provides a method of generating all Adinkras with the same topology, and so also all the corresponding irreducible supersymmetric multiplets. We develop some graph theoretic techniques to understand these diagrams in terms of a relatively small amount of information, namely, at what heights various vertices of the graph should be "hung". We then show how Adinkras that are the graphs of N-dimensional cubes can be obtained as the Adinkra for superfields satisfying constraints that involve superderivatives. This dramatically widens the range of supermultiplets that can be described using the superspace formalism and organizes them. Other topologies for Adinkras are possible, and we show that it is reasonable that these are also the result of constraining superfields using superderivatives. The family of Adinkras with an N-cubical topology, and so also the sequence of corresponding irreducible supersymmetric multiplets, are arranged in a cyclical sequence called the main sequence. We produce the N=1 and N=2 main sequences in detail, and indicate some aspects of the situation for higher N.Comment: LaTeX, 58 pages, 52 illustrations in color; minor typos correcte
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