An Entrepreneurial Theory of Formal Organizations. Part I - Patterns of Formal Organizations

Theory of formal organizations with ordering of relevant dat

An introduction to quantum gravity

After an overview of the physical motivations for studying quantum gravity, we reprint THE FORMAL STRUCTURE OF QUANTUM GRAVITY, i.e. the 1978 Cargese Lectures by Professor B.S. DeWitt, with kind permission of Springer. The reader is therefore introduced, in a pedagogical way, to the functional integral quantization of gravitation and Yang-Mills theory. It is hoped that such a paper will remain useful for all lecturers or Ph.D. students who face the task of introducing (resp. learning) some basic concepts in quantum gravity in a relatively short time. In the second part, we outline selected topics such as the braneworld picture with the same covariant formalism of the first part, and spectral asymptotics of Euclidean quantum gravity with diffeomorphism-invariant boundary conditions. The latter might have implications for singularity avoidance in quantum cosmology.Comment: 68 pages, Latex file. Sections from 2 to 17 are published thanks to kind permission of Springe

How cold is cold dark matter? Small scales constraints from the flux power spectrum of the high-redshift Lyman-alpha forest

We present constraints on the mass of warm dark matter (WDM) particles derived from the Lyman-alpha flux power spectrum of 55 high- resolution HIRES spectra at 2.0 < z < 6.4. From the HIRES spectra, we obtain a lower limit of mwdm > 1.2 keV 2 sigma if the WDM consists of early decoupled thermal relics and mwdm > 5.6 keV (2 sigma) for sterile neutrinos. Adding the Sloan Digital Sky Survey Lyman-alpha flux power spectrum, we get mwdm > 4 keV and mwdm > 28 keV (2 sigma) for thermal relics and sterile neutrinos. These results improve previous constraints by a factor two.Comment: Some issues clarified (especially resolution related). Conclusions unchanged. Accepted version by PR

State education as high-yield investment: human capital theory in European policy discourse

Human Capital Theory has been an increasingly important phenomenon in economic thought over the last 50 years. The central role it affords to education has become even more marked in recent years as the concept of the ‘knowledge economy’ has become a global concern. In this paper, the prevalence of Human Capital Theory within European educational policy discourse is explored. The paper examines a selection of policy documents from a number of disparate European national contexts and considers the extent to which the ideas of Human Capital Theory can be seen to be influential. In the second part of the paper, the implications of Human Capital Theory for education are considered, with a particular focus on the possible ramifications at a time of economic austerity. The paper argues that Human Capital Theory risks offering a diminished view of the person, a diminished view of education, but that with its sole focus on economic goals leaves room for educationists and others to argue for the educational, social, and moral values it ignores, and for the conception of the good life and good society it fails to mention

Detection of Pulsed X-ray Emission from XMM-Newton Observations of PSR J0538+2817

We report on the XMM-Newton observations of the 143 ms pulsar PSR J0538+2817. We present evidence for the first detections of pulsed X-rays from the source at a frequency which is consistent with the predicted radio frequency. The pulse profile is broad and asymmetric, with a pulse fraction of 18 +/- 3%. We find that the spectrum of the source is well-fit with a blackbody with T^{infty} = (2.12^{+0.04}_{-0.03}) x 10^6 K and N_{H} = 2.5 x 10^21 cm^{-2}. The radius determined from the model fit of 1.68 +/- 0.05 km suggests that the emission is from a heated polar cap. A fit to the spectrum with an atmospheric model reduces the inferred temperature and hence increases the radius of the emitting region, however the pulsar distance determined from the fit is then smaller than the dispersion distance.Comment: 24 pages, 6 figures, 3 tables, accepted for publication in ApJ. Error in radius calculation corrected, discussion and conclusions remain unchange

Quantum Gravity Corrections for Schwarzschild Black Holes

We consider the Matrix theory proposal describing eleven-dimensional Schwarzschild black holes. We argue that the Newtonian potential between two black holes receives a genuine long range quantum gravity correction, which is finite and can be computed from the supergravity point of view. The result agrees with Matrix theory up to a numerical factor which we have not computed.Comment: 14 pages, Tex, no figure

A Simplest Swimmer at Low Reynolds Number: Three Linked Spheres

We propose a very simple one-dimensional swimmer consisting of three spheres that are linked by rigid rods whose lengths can change between two values. With a periodic motion in a non-reciprocal fashion, which breaks the time-reversal symmetry as well as the translational symmetry, we show that the model device can swim at low Reynolds number. This model system could be used in constructing molecular-size machines

Chemical abundances of damped Lyman alpha systems in the XQ-100 survey

The XQ-100 survey has provided high signal-noise spectra of 100 redshift 3-4.5 quasars with the X-Shooter spectrograph. The metal abundances for 13 elements in the 41 damped Lyman alpha systems (DLAs) identified in the XQ-100 sample are presented, and an investigation into abundances of a variety of DLA classes is conducted. The XQ-100 DLA sample contains five DLAs within 5000 km/s of their host quasar (proximate DLAs; PDLAs) as well as three sightlines which contain two DLAs within 10,000 km/s of each other along the same line-of-sight (multiple DLAs; MDLAs). Combined with previous observations in the literature, we demonstrate that PDLAs with logN(HI)<21.0 show lower [S/H] and [Fe/H] (relative to intervening systems with similar redshift and N(HI)), whilst higher [S/H] and [Si/H] are seen in PDLAs with logN(HI)>21.0. These abundance discrepancies are independent of their line-of-sight velocity separation from the host quasar, and the velocity width of the metal lines (v90). Contrary to previous studies, MDLAs show no difference in [alpha/Fe] relative to single DLAs matched in metallicity and redshift. In addition, we present follow-up UVES data of J0034+1639, a sightline containing three DLAs, including a metal-poor DLA with [Fe/H]=-2.82 (the third lowest [Fe/H] in DLAs identified to date) at z=4.25. Lastly we study the dust-corrected [Zn/Fe], emphasizing that near-IR coverage of X-Shooter provides unprecedented access to MgII, CaII and TiII lines (at redshifts 3-4) to provide additional evidence for subsolar [Zn/Fe] ratio in DLAs.Comment: Accepted to MNRAS. 19 pages plus Appendix material (102 pages total

Time-Varying Priority Queuing Models for Human Dynamics

Queuing models provide insight into the temporal inhomogeneity of human dynamics, characterized by the broad distribution of waiting times of individuals performing tasks. We study the queuing model of an agent trying to execute a task of interest, the priority of which may vary with time due to the agent's "state of mind." However, its execution is disrupted by other tasks of random priorities. By considering the priority of the task of interest either decreasing or increasing algebraically in time, we analytically obtain and numerically confirm the bimodal and unimodal waiting time distributions with power-law decaying tails, respectively. These results are also compared to the updating time distribution of papers in the arXiv.org and the processing time distribution of papers in Physical Review journals. Our analysis helps to understand human task execution in a more realistic scenario.Comment: 8 pages, 6 figure