181 research outputs found

    Becoming The Boss: Discretion And Postsuccession Success In Family Firms

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    Family firms can enjoy substantial longevity. Ironically, however, they are often imperiled by the very process that is essential to this longevity. Using the concept of managerial discretion as a starting point, we use a human agency lens to introduce the construct of successor discretion as a factor that affects the family business succession process. While important in general, successor discretion is positioned as a particularly relevant factor for productively managing organizational renewal in family businesses. This study represents a foundation for future empirical research investigating the role of agency in entrepreneurial action in the family business context, which consequently can contribute to the larger research literature on succession and change

    Variable-Speed-of-Light Cosmology from Brane World Scenario

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    We argue that the four-dimensional universe on the TeV brane of the Randall-Sundrum scenario takes the bimetric structure of Clayton and Moffat, with gravitons traveling faster than photons instead, while the radion varies with time. We show that such brane world bimetric model can thereby solve the flatness and the cosmological constant problems, provided the speed of a graviton decreases to the present day value rapidly enough. The resolution of other cosmological problems such as the horizon problem and the monopole problem requires supplementation by inflation, which may be achieved by the radion field provided the radion potential satisfies the slow-roll approximation.Comment: 18 pages, LaTeX, revised version to appear in Phys. Rev.

    Large-scale magnetic fields from inflation in dilaton electromagnetism

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    The generation of large-scale magnetic fields is studied in dilaton electromagnetism in inflationary cosmology, taking into account the dilaton's evolution throughout inflation and reheating until it is stabilized with possible entropy production. It is shown that large-scale magnetic fields with observationally interesting strength at the present time could be generated if the conformal invariance of the Maxwell theory is broken through the coupling between the dilaton and electromagnetic fields in such a way that the resultant quantum fluctuations in the magnetic field has a nearly scale-invariant spectrum. If this condition is met, the amplitude of the generated magnetic field could be sufficiently large even in the case huge amount of entropy is produced with the dilution factor 1024\sim 10^{24} as the dilaton decays.Comment: 28 pages, 5 figures, the version accepted for publication in Phys. Rev. D; some references are adde

    What Can WMAP Tell Us About The Very Early Universe? New Physics as an Explanation of Suppressed Large Scale Power and Running Spectral Index

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    The Wilkinson Microwave Anisotropy Probe microwave background data may be giving us clues about new physics at the transition from a ``stringy'' epoch of the universe to the standard Friedmann Robertson Walker description. Deviations on large angular scales of the data, as compared to theoretical expectations, as well as running of the spectral index of density perturbations, can be explained by new physics whose scale is set by the height of an inflationary potential. As examples of possible signatures for this new physics, we study the cosmic microwave background spectrum for two string inspired models: 1) modifications to the Friedmann equations and 2) velocity dependent potentials. The suppression of low ``l'' modes in the microwave background data arises due to the new physics. In addition, the spectral index is red (n<1) on small scales and blue (n>1) on large scales, in agreement with data.Comment: 18 pages, 2 figures, submitted for publication in Physical Review D, references added in this versio

    The Ekpyrotic Universe: Colliding Branes and the Origin of the Hot Big Bang

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    We propose a cosmological scenario in which the hot big bang universe is produced by the collision of a brane in the bulk space with a bounding orbifold plane, beginning from an otherwise cold, vacuous, static universe. The model addresses the cosmological horizon, flatness and monopole problems and generates a nearly scale-invariant spectrum of density perturbations without invoking superluminal expansion (inflation). The scenario relies, instead, on physical phenomena that arise naturally in theories based on extra dimensions and branes. As an example, we present our scenario predominantly within the context of heterotic M-theory. A prediction that distinguishes this scenario from standard inflationary cosmology is a strongly blue gravitational wave spectrum, which has consequences for microwave background polarization experiments and gravitational wave detectors.Comment: 67 pages, 4 figures. v2,v3: minor corrections, references adde

    A Corporate Social Entrepreneurship Approach to Market-Based Poverty Reduction

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    In this article, we aim to conceptualize a market-based approach to poverty reduction from a corporate social entrepreneurship (CSE) perspective. Specifically, we describe some market-based initiatives at the base of the economic pyramid and relate them to the social entrepreneurship literature. We refer to the entrepreneurial activities of multinational corporations that create social value as CSE. We then conceptualize CSE according to the corporate entrepreneurship and social entrepreneurship domains and shed light on how corporations can implement CSE. Finally, by reviewing relevant literature, we propose some of the factors that can stimulate CSE in organizations and some of the benefits companies can gain by implementing CSE

    Pyrotechnic Universe

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    One of the central points of the ekpyrotic cosmological scenario based on Horava-Witten theory is that we live on a negative tension brane. However, the tension of the visible brane is positive in the usual HW phenomenology with stronger coupling on the hidden brane, both for standard and non-standard embedding. To make ekpyrotic scenario realistic one must solve the problem of the negative cosmological constant on the visible brane and fine-tune the bulk brane potential with an accuracy of 105010^{-50}. In terms of a canonically normalized scalar field ϕ\phi describing the position of the brane, this potential must take a very unusual form V(ϕ)e5000ϕMpV(\phi)\sim e^{-{5000 \phi\over M_p}}. We describe the problems which appear when one attempts to obtain this potential in string theory. The mechanism for the generation of density perturbations in this scenario is not brane-specific; it is a particular limiting case of the mechanism of tachyonic preheating. Unlike inflation, this mechanism exponentially amplifies not only quantum fluctuations, but also initial inhomogeneities. As a result, to solve the homogeneity problem in this scenario, one would need the branes to be parallel to each other with an accuracy better than 106010^{-60} on a scale 103010^{30} times greater than the distance between the branes. Thus, at present, inflation remains the only robust mechanism that produces density perturbations with a flat spectrum and simultaneously solves all major cosmological problems.Comment: 35 pages, 2 figs. The issue of the brane tension is clarified and a new Appendix explaining constraints on the parameters is adde

    Search for flavour-changing neutral currents in processes with one top quark and a photon using 81 fb⁻¹ of pp collisions at \sqrts = 13 TeV with the ATLAS experiment

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    A search for flavour-changing neutral current (FCNC) events via the coupling of a top quark, a photon, and an up or charm quark is presented using 81 fb−1 of proton–proton collision data taken at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC. Events with a photon, an electron or muon, a b-tagged jet, and missing transverse momentum are selected. A neural network based on kinematic variables differentiates between events from signal and background processes. The data are consistent with the background-only hypothesis, and limits are set on the strength of the tqγ coupling in an effective field theory. These are also interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tuγ coupling of 36 fb (78 fb) and on the branching ratio for t→γu of 2.8×10−5 (6.1×10−5). In addition, they are interpreted as 95% CL upper limits on the cross section for FCNC tγ production via a left-handed (right-handed) tcγ coupling of 40 fb (33 fb) and on the branching ratio for t→γc of 22×10−5 (18×10−5). © 2019 The Author(s

    Search for single vector-like B quark production and decay via B → bH(b¯b) in pp collisions at √s = 13 TeV with the ATLAS detector

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    A search is presented for single production of a vector-like B quark decaying into a Standard Model b-quark and a Standard Model Higgs boson, which decays into a b¯b pair. The search is carried out in 139 fb−1 of √s = 13 TeV proton-proton collision data collected by the ATLAS detector at the LHC between 2015 and 2018. No significant deviation from the Standard Model background prediction is observed, and mass-dependent exclusion limits at the 95% confidence level are set on the resonance production cross-section in several theoretical scenarios determined by the couplings cW, cZ and cH between the B quark and the Standard Model W, Z and Higgs bosons, respectively. For a vector-like B occurring as an isospin singlet, the search excludes values of cW greater than 0.45 for a B resonance mass (mB) between 1.0 and 1.2 TeV. For 1.2 TeV < mB < 2.0 TeV, cW values larger than 0.50–0.65 are excluded. If the B occurs as part of a (B, Y) doublet, the smallest excluded cZ coupling values range between 0.3 and 0.5 across the investigated resonance mass range 1.0 TeV < mB < 2.0 TeV

    Search for heavy resonances decaying into a Z or W boson and a Higgs boson in final states with leptons and b-jets in 139 fb−1 of pp collisions at s√ = 13 TeV with the ATLAS detector

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    This article presents a search for new resonances decaying into a Z or W boson and a 125 GeV Higgs boson h, and it targets the νν¯¯¯bb¯¯, ℓ+ℓ−bb¯¯, or ℓ±νbb¯¯ final states, where ℓ = e or μ, in proton-proton collisions at s√ = 13 TeV. The data used correspond to a total integrated luminosity of 139 fb−1 collected by the ATLAS detector during Run 2 of the LHC at CERN. The search is conducted by examining the reconstructed invariant or transverse mass distributions of Zh or Wh candidates for evidence of a localised excess in the mass range from 220 GeV to 5 TeV. No significant excess is observed and 95% confidence-level upper limits between 1.3 pb and 0.3 fb are placed on the production cross section times branching fraction of neutral and charged spin-1 resonances and CP-odd scalar bosons. These limits are converted into constraints on the parameter space of the Heavy Vector Triplet model and the two-Higgs-doublet model
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