36,227 research outputs found

    Redshift and lateshift from homogeneous and isotropic modified dispersion relations

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    Observables which would indicate a modified vacuum dispersion relations, possibly caused by quantum gravity effects, are a four momentum dependence of the cosmological redshift and the existence of a so called lateshift effect for massless or very light particles. Existence or non-existence of the later is currently analyzed on the basis of the available observational data from gamma ray bursts and compared to predictions of specific modified dispersion relation models. We consider the most general perturbation of the general relativistic dispersion relation of freely falling particles on homogeneous and isotropic spacetimes and derive the red- and lateshift to first order in the perturbation. Our result generalizes the existing formulae in the literature and we find that there exist modified dispersion relations causing both, one or none of the two effects to first order.Comment: 9 pages, refs added, extended outlook added, matches published versio

    Mechanisms of conflict and dispute resolution in Ancient Near Eastern Treaties

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    The paper focuses on the problems of a juridical classification and evaluation of Ancient Near Eastern treaties with regard to the question if there existed an Ancient Near Eastern International Law or not. Alternatively treaties and their content are looked at uncommitted as mechanisms of conflict and dispute resolution. Main aspects are preliminary and prophylactic conflict resolution in treaties and the procedural context and efficiency of treaties

    Radar orthogonality and radar length in Finsler and metric spacetime geometry

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    The radar experiment connects the geometry of spacetime with an observers measurement of spatial length. We investigate the radar experiment on Finsler spacetimes which leads to a general definition of radar orthogonality and radar length. The directions radar orthogonal to an observer form the spatial equal time surface an observer experiences and the radar length is the physical length the observer associates to spatial objects. We demonstrate these concepts on a forth order polynomial Finsler spacetime geometry which may emerge from area metric or pre-metric linear electrodynamics or in quantum gravity phenomenology. In an explicit generalisation of Minkowski spacetime geometry we derive the deviation from the euclidean spatial length measure in an observers rest frame explicitly.Comment: 18 pages, 7 figures, axes label in figures corrected, journal references adde

    Naïve Panentheism

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    Karl Pfeifer attempts to present a coherent view of panentheism that eschews Pickwickian senses of “in” and aligns itself with, and builds upon, familiar diagrammed portrayals of panentheism. The account is accordingly spatial-locative and moreover accepts the proposal of R.T. Mullins that absolute space and time be regarded as attributes of God. In addition, however, it argues that a substantive parthood relation between the world and God is required. Pfeifer’s preferred version of panpsychism, viz. panintentionalism, is thrown into the mix as an optional add-on. On this account, God is conceived of as a “spiritual field” whose nature can be made more intelligible by regarding “God” as having a mass-noun sense in some contexts. Pfeifer closes with the suggestion that we look to topology and mereology for further development of the position outlined in his paper

    Observers' measurements in premetric electrodynamics I: Time and radar length

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    The description of an observer's measurement in general relativity and the standard model of particle physics is closely related to the spacetime metric. In order to understand and interpret measurements, which test the metric structure of the spacetime, like the classical Michelson-Morley, Ives-Stilwell, Kennedy-Thorndike experiments or frequency comparison experiments in general, it is necessary to describe them in theories, which go beyond the Lorentzian metric structure. However, this requires a description of an observer's measurement without relying on a metric. We provide such a description of an observer's measurement of the fundamental quantities time and length derived from a premetric perturbation of Maxwell's electrodynamics and a discussion on how these measurements influence classical relativistic observables like time dilation and length contraction. Most importantly, we find that the modification of electrodynamics influences the measurements at two instances: the propagation of light is altered as well as the observer's proper time normalization. When interpreting the results of a specific experiment, both effects cannot be disentangled, in general, and have to be taken into account.Comment: 18 pages, updated to journal version, typos corrected, discussion extende

    Generating VaR scenarios with product beta distributions

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    We propose a Monte Carlo simulation method to generate stress tests by VaR scenarios under Solvency II for dependent risks on the basis of observed data. This is of particular interest for the construction of Internal Models and requirements on evaluation processes formulated in the Commission Delegated Regulation. The approach is based on former work on partition-ofunity copulas, however with a direct scenario estimation of the joint density by product beta distributions after a suitable transformation of the original data.Comment: 10 pages, 25 figures, 5 table

    Risk Aversion and Sorting into Public Sector Employment

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    This research note uses two German data sets – the large-scale German Socio-Economic Panel and unique data from own student questionnaires – to analyse the relationship between risk aversion and the choice for public sector employment. Main results are: (1) more risk averse individuals sort into public sector employment, (2) the impact of career specific and unemployment risk attitudes is larger than the impact of general risk attitudes, and (3) risk taking is rewarded with higher wages in the private but not in the public sector.public sector, risk aversion, sorting, wage differentials

    Incrementally Learned Mixture Models for GNSS Localization

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    GNSS localization is an important part of today's autonomous systems, although it suffers from non-Gaussian errors caused by non-line-of-sight effects. Recent methods are able to mitigate these effects by including the corresponding distributions in the sensor fusion algorithm. However, these approaches require prior knowledge about the sensor's distribution, which is often not available. We introduce a novel sensor fusion algorithm based on variational Bayesian inference, that is able to approximate the true distribution with a Gaussian mixture model and to learn its parametrization online. The proposed Incremental Variational Mixture algorithm automatically adapts the number of mixture components to the complexity of the measurement's error distribution. We compare the proposed algorithm against current state-of-the-art approaches using a collection of open access real world datasets and demonstrate its superior localization accuracy.Comment: 8 pages, 5 figures, published in proceedings of IEEE Intelligent Vehicles Symposium (IV) 201
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