Quantum Geometry Phenomenology: Angle and Semiclassical States

The phenomenology for the deep spatial geometry of loop quantum gravity is discussed. In the context of a simple model of an atom of space, it is shown how purely combinatorial structures can affect observations. The angle operator is used to develop a model of angular corrections to local, continuum flat-space 3-geometries. The physical effects involve neither breaking of local Lorentz invariance nor Planck scale suppression, but rather reply on only the combinatorics of SU(2) recouping theory. Bhabha scattering is discussed as an example of how the effects might be observationally accessible.Comment: 5 pages, slightly extended version of the contribution to the Loops'11 conference proceeding

Regulation of network industries in the European Union and in Central and Eastern Europe

Cost-based pricing has dominated the regulatory regime of network industries - and first of all, the regulation of the infocommunications sector - in the European Union since the early 1990s. When privatization of network industries began in Central and Eastern Europe (CEE), one of the main stumbling blocks on the road toward privately owned telecomm companies and postal services, energy producers and distributors, and other network industries was the lack of efficient and up-to-date industry regulations. From the mid-1990s, accessing countries that later became members of the EU, and other CEE countries that are still waiting for admission swiftly adopted the regulatory framework of the European Union. The EU has been striving for market opening and liberalization in these industries; it abolished industry regulation in several segments of the market of network industries. Now it applies so-called cost-based pricing in areas where regulation is still in place. CEE countries now use the same type of regulation as the advanced member states of the EU. But the regulatory capacity of most CEE countries is still far behind of their West European counterparts. Experts of network industries advocate, and telecommunications, energy and other market regulators in various parts of the world practice, cost-based pricing for inter-firm network access services. Cost-based pricing is carried out under the assumption that the regulator has perfect information regarding the costs of producing the services. We show in this paper that - under fairly general conditions - cost-based pricing creates incentives for regulated firms not to improve their efficiency. We also show that cost-based pricing results in smaller consumer welfare than incentive regulation that takes into account the existence of information asymmetry between the regulator and the firm. A model of interconnection with adverse selection and moral hazard is presented. --network industries,regulation,incentive contracts

The three-dimensional carrier-envelope-phase map of focused few-cycle pulsed Gaussian beams

We derive an analytical expression that describes the complete three-dimensional carrier-envelope phase (CEP) distribution of in the focal volume of ultrashort pulsed Gaussian beams focused by spherical mirrors or lenses. The focal CEP map depends on the so-called factor $g$ specifying the frequency-dependence of the beam width of the source few-cycle pulse, on its chirp and on the small chromatic aberration introduced by a lens without appreciably distorting or broadening the few-cycle pulse. We show how to tailor the CEP map of mirror-focused and lens-focused few-cycle pulses in order to produce negligible transversal and axial CEP variations in specific regions of the focal volume for phase-sensitive interactions of light with matter taking place in a volume or on a surface. We propose a quasi-achromatic doublet lens that can implement in practice these tailored CEP distributions.Comment: 9 pages, 6 figure

The Electrostatic Ion Beam Trap : a mass spectrometer of infinite mass range

We study the ions dynamics inside an Electrostatic Ion Beam Trap (EIBT) and show that the stability of the trapping is ruled by a Hill's equation. This unexpectedly demonstrates that an EIBT, in the reference frame of the ions works very similar to a quadrupole trap. The parallelism between these two kinds of traps is illustrated by comparing experimental and theoretical stability diagrams of the EIBT. The main difference with quadrupole traps is that the stability depends only on the ratio of the acceleration and trapping electrostatic potentials, not on the mass nor the charge of the ions. All kinds of ions can be trapped simultaneously and since parametric resonances are proportional to the square root of the charge/mass ratio the EIBT can be used as a mass spectrometer of infinite mass range

Spin-triplet paired phases inside ferromagnet induced by Hund's rule coupling and electronic correlations: Application to UGe2\mathrm{UGe}_2

We discuss a mechanism of real-space spin-triplet pairing, alternative to that due to quantum paramagnon excitations, and demonstrate its applicability to $\mathrm{UGe_2}$. Both the Hund's rule ferromagnetic exchange and inter-electronic correlations contribute to the same extent to the equal-spin pairing, particularly in the regime in which the weak-coupling solution does not provide any. The theoretical results, obtained within the orbitally-degenerate Anderson lattice model, match excellently the observed phase diagram for $\mathrm{UGe_2}$ with the coexistent ferromagnetic (FM1) and superconducting ($A_1$-type) phase. Additionally, weak $A_2$- and $A$-type paired phases appear in very narrow regions near the metamaganetic (FM2 $\rightarrow$ FM1) and FM1 $\rightarrow$ paramagnetic first-order phase-transition borders, respectively. The values of magnetic moments in the FM2 and FM1 states are also reproduced correctly in a semiquantitative manner. The Hund's metal regime is also singled out as appearing near FM1-FM2 boundary

A sock for foot-drop: A preliminary study on two chronic stroke patients

Background: Foot-drop is a common motor impairment of chronic stroke patients, which may be addressed with an ankle foot orthosis. Although there is reasonable evidence of effectiveness for ankle foot orthoses, user compliance is sometimes poor. This study investigated a new alternative to the ankle foot orthosis, the dorsiflex sock. Case description and methods: The dorsiflex sock was evaluated using an A-B single case experimental design. Two community-dwelling, chronic stroke patients with foot-drop participated in this study. Measures were selected to span the International Classification of Function, Disability and Health domains and user views on the dorsiflex sock were also collected. Findings and outcomes: The dorsiflex sock was not effective in improving participants’ walking symmetry, speed or energy expenditure. Participant 1 showed improvement in the distance he could walk in 6 min when using the dorsiflex sock, but this was in keeping with a general improvement trend over the course of this study. However, both participants viewed the dorsiflex sock positively and reported a positive effect on their walking. Conclusion: Despite positive user perceptions, the study found no clear evidence that dorsiflex sock is effective in improving foot-drop. Clinical relevance Although the dorsiflex sock offers an attractive alternative to an ankle foot orthosis, the case studies found no clear evidence of its efficacy. Clinicians should view this device with caution until further research becomes availabl

Management accounting change in the Portuguese telecommunications industry

This paper sought to study the reasons that explain why has a telecommunications operator (called Marconi) changed its traditional management accounting systems (MAS) and replaced it with activity-based costing (ABC). The paper relied on qualitative data collected through a longitudinal and in-depth case study in the telecommunications sector. The investigation was informed by new institutional sociology (NIS) insights. The study evidenced that Marconi adopted ABC in order to fulfil its constituencies’ expectations of efficiency created with the reorganisation of the Portuguese telecommunications sector and the introduction of competition in the market. Furthermore, the paper contests the managerial emphasis that ABC has been subject to and claims that social accounting theories, such as institutionalism, should be adopted by management accounting researchers in order to achieve a deeper understanding of the ‘ABC phenomenon’

On the Universality of the Entropy-Area Relation

We present an argument that, for a large class of possible dynamics, a canonical quantization of gravity will satisfy the Bekenstein-Hawking entropy-area relation. This result holds for temperatures low compared to the Planck temperature and for boundaries with areas large compared to Planck area. We also relate our description, in terms of a grand canonical ensemble, to previous geometric entropy calculations using area ensembles.Comment: 6 page