Quantum Complexity of Parametric Integration

We study parametric integration of functions from the class C^r([0,1]^{d_1+d_2}) to C([0,1]^{d_1}) in the quantum model of computation. We analyze the convergence rate of parametric integration in this model and show that it is always faster than the optimal deterministic rate and in some cases faster than the rate of optimal randomized classical algorithms.Comment: Paper submitted to the Journal of Complexity, 28 page

Concept for sleeve induction motor with 1-msec mechanical time constant

Conductive sleeve induction motor having a 1-msec mechanical time constant is used with solid-state devices to control all-electric servo power systems. The servomotor rotor inertia is small compared to the maximum force rating of the servo motion, permitting high no-load acceleration

Potential and availability of market research data for empirical social and economic research

The potential of market research data for secondary analyses lays mainly in the fields of consumer behaviour, consumption patterns and media usage. Their availability for empirical social and economic research depends on the professional rules as well as on the readiness of the market research agencies and their clients to make them available. Many market research projects are focused on specific target groups. This focuses their potential for secondary analyses on representative insights regarding these groups as well as on basic and methodological research. In most cases it is necessary that public availability of market research data is agreed contractually with the client of the research project. For a number of market research projects access to the official statistical data is important for methodological reasons. Therefore private research agencies should have the same privileged access to them as academic research institutions. As long as this access has not been established it is unlikely that their readiness to make market research data publicly available will increase.

Relativistic Lagrangian displacement field and tensor perturbations

We investigate the purely spatial Lagrangian coordinate transformation from the Lagrangian to the basic Eulerian frame. We demonstrate three techniques for extracting the relativistic displacement field from a given solution in the Lagrangian frame. These techniques are (a) from defining a local set of Eulerian coordinates embedded into the Lagrangian frame; (b) from performing a specific gauge transformation; and (c) from a fully non-perturbative approach based on the ADM split. The latter approach shows that this decomposition is not tied to a specific perturbative formulation for the solution of the Einstein equations. Rather, it can be defined at the level of the non-perturbative coordinate change from the Lagrangian to the Eulerian description. Studying such different techniques is useful because it allows us to compare and develop further the various approximation techniques available in the Lagrangian formulation. We find that one has to solve the gravitational wave equation in the relativistic analysis, otherwise the corresponding Newtonian limit will necessarily contain spurious non-propagating tensor artefacts at second order in the Eulerian frame. We also derive the magnetic part of the Weyl tensor in the Lagrangian frame, and find that it is not only excited by gravitational waves but also by tensor perturbations which are induced through the non-linear frame-dragging. We apply our findings to calculate for the first time the relativistic displacement field, up to second order, for a $\Lambda$CDM Universe in the presence of a local primordial non-Gaussian component. Finally, we also comment on recent claims about whether mass conservation in the Lagrangian frame is violated.Comment: 19 pages, two figures, improved discussion, matches published versio

Renormalization and ultraviolet sensitivity of gauge vertices in universal extra dimensions

When computing radiative corrections in models with compactified extra dimen- sions, one has to sum over the entire tower of Kaluza-Klein excitations inside the loops. The loop corrections generate a difference between the coupling strength of a zero-mode gauge boson and the coupling strength of its Kaluza-Klein excitation, although both originate from the same higher-dimensional gauge interaction. Furthermore, this dis- crepancy will in general depend on the cutoff scale and assumptions about the UV completion of the extra-dimensional theory. In this article, these effects are studied in detail within the context of the minimal universal extra dimension model (MUED). The broad features of the cutoff scale dependence can be captured through the so- lution of the functional flow equation in five-dimensional space. However, an explicit diagrammatic calculation reveals some modifications due to the compactification of the extra dimension. Nevertheless, when imposing a physical renormalization condition, one finds that the UV sensitivity of the effective Kaluza-Klein gauge-boson vertex is relatively small and not very important for most phenomenological purposes. Similar conclusions should hold in a larger class of extra-dimensional models besides MUED.Comment: 20 pages, 5 figure

Multiscale approach to inhomogeneous cosmologies

The backreaction of inhomogeneities on the global expansion history of the Universe suggests a possible link of the formation of structures to the recent accelerated expansion. In this paper, the origin of this conjecture is illustrated and a model without Dark Energy that allows for a more explicit investigation of this link is discussed. Additionally to this conceptually interesting feature, the model leads to a LCDM-like distance-redshift relation that is consistent with SN data.Comment: 5 pages, 4 figures, contributed talk at the Workshop: New Directions in Modern Cosmology, Leiden, The Netherlands, 27.9.-1.10. (2010

QCD corrections to massive color-octet vector boson pair production

This paper describes the calculation of the next-to-leading order (NLO) QCD corrections to massive color-octet vector boson pair production at hadron colliders. As a concrete framework, a two-site coloron model with an internal parity is chosen, which can be regarded as an effective low-energy approximation of Kaluza-Klein gluon physics in universal extra dimensions. The renormalization procedure involves several subtleties, which are discussed in detail. The impact of the NLO corrections is relatively modest, amounting to a reduction of 11-14% in the total cross-section, but they significantly reduce the scale dependence of the LO result

Multiscale cosmology and structure-emerging Dark Energy: A plausibility analysis

Cosmological backreaction suggests a link between structure formation and the expansion history of the Universe. In order to quantitatively examine this connection, we dynamically investigate a volume partition of the Universe into over-- and underdense regions. This allows us to trace structure formation using the volume fraction of the overdense regions \lambda_{\CM} as its characterizing parameter. Employing results from cosmological perturbation theory and extrapolating the leading mode into the nonlinear regime, we construct a three--parameter model for the effective cosmic expansion history, involving \lambda_{\CM_{0}}, the matter density \Omega_{m}^{\CD_{0}}, and the Hubble rate H_{\CD_{0}} of today's Universe. Taking standard values for \Omega_{m}^{\CD_{0}} and H_{\CD_{0}} as well as a reasonable value for \lambda_{\CM_{0}}, that we derive from $N$--body simulations, we determine the corresponding amounts of backreaction and spatial curvature. We find that the obtained values that are sufficient to generate today's structure also lead to a $\Lambda$CDM--like behavior of the scale factor, parametrized by the same parameters \Omega_{m}^{\CD_{0}} and H_{\CD_{0}}, but without a cosmological constant. However, the temporal behavior of \lambda_{\CM} does not faithfully reproduce the structure formation history. Surprisingly, however, the model matches with structure formation with the assumption of a low matter content, \Omega_{m}^{\CD_{0}}\approx3\%, a result that hints to a different interpretation of part of the backreaction effect as kinematical Dark Matter. (truncated)Comment: 25 pages, 10 figures, includes calculation of luminosity distances, matches published version in Phys. Rev.