Non-Abelian statistics in the interference noise of the Moore-Read quantum Hall state

We propose noise oscillation measurements in a double point contact, accessible with current technology, to seek for a signature of the non-abelian nature of the \nu=5/2 quantum Hall state. Calculating the voltage and temperature dependence of the current and noise oscillations, we predict the non-abelian nature to materialize through a multiplicity of the possible outcomes: two qualitatively different frequency dependences of the nonzero interference noise. Comparison between our predictions for the Moore-Read state with experiments on \nu=5/2 will serve as a much needed test for the nature of the \nu=5/2 quantum Hall state.Comment: 4 pages, 4 figures v2: typo's corrected, discussions clarified, references adde

Self-tuning of the cosmological constant

Here, I discuss the cosmological constant (CC) problems, in particular paying attention to the vanishing cosmological constant. There are three cosmological constant problems in particle physics. Hawking's idea of calculating the probability amplitude for our Universe is peaked at CC = 0 which I try to obtain after the initial inflationary period using a self-tuning model. I review what has been discussed on the Hawking type calculation, and present a (probably) correct way to calculate the amplitude, and show that the Kim-Kyae-Lee self-tuning model allows a finite range of parameters for the CC = 0 to have a singularly large probability, approached from the AdS side.Comment: 12 pages with 8 figure

To steal or not to steal: Firm attributes, legal environment, and valuation

Newly released data on corporate governance and disclosure practices reveal wide within-country variation, with the variation increasing as legal environment gets less investor friendly. This paper examines why firms practice high-quality governance when law does not require it; firm attributes that are related to the quality of governance; how the attributes interact with legal environment; and the relation between firm valuation and corporate governance. A simple model, in which a controlling shareholder trades off private benefits of diversion against costs that vary across countries and time, identifies three relevant firm attributes: investment opportunities, external financing, and ownership structure. Using firm-level governance and transparency data on 859 firms in 27 countries, we find that firms with greater growth opportunities, greater needs for external financing, and more concentrated cash flow rights practice higher-quality governance and disclose more. Moreover, firms that score higher in governance and transparency rankings are valued higher in the stock market. Equally important, all these relations are stronger in countries that are less investor friendly, demonstrating that firms do adapt to poor legal environments to establish efficient governance practices.http://deepblue.lib.umich.edu/bitstream/2027.42/39939/3/wp554.pd

Surplus Angle and Sign-flipped Coulomb Force in Projectable Horava-Lifshitz Gravity

We obtain the static spherically symmetric vacuum solutions of Horava-Lifshitz gravity theory, imposing the detailed balance condition only in the UV limit. We find the solutions in two different coordinate systems, the Painlev\'e-Gullstrand coordinates and the Poincare coordinates, to examine the consequences of imposing the projectability condition. The solutions in two coordinate systems are distinct due to the non-relativistic nature of the HL gravity. In the Painleve-Gullstrand coordinates complying with the projectability condition, the solution involves an additional integration constant which yields surplus angle and implies attractive Coulomb force between same charges.Comment: 13 page

Review of economic evidence in the prevention and early detection of colorectal cancer.

This paper aims to systematically review the cost-effectiveness evidence, and to provide a critical appraisal of the methods used in the model-based economic evaluation of CRC screening and subsequent surveillance. A search strategy was developed to capture relevant evidence published 1999-November 2012. Databases searched were MEDLINE, EMBASE, National Health Service Economic Evaluation (NHS EED), EconLit, and HTA. Full economic evaluations that considered costs and health outcomes of relevant intervention were included. Sixty-eight studies which used either cohort simulation or individual-level simulation were included. Follow-up strategies were mostly embedded in the screening model. Approximately 195 comparisons were made across different modalities; however, strategies modelled were often simplified due to insufficient evidence and comparators chosen insufficiently reflected current practice/recommendations. Studies used up-to-date evidence on the diagnostic test performance combined with outdated information on CRC treatments. Quality of life relating to follow-up surveillance is rare. Quality of life relating to CRC disease states was largely taken from a single study. Some studies omitted to say how identified adenomas or CRC were managed. Besides deterministic sensitivity analysis, probabilistic sensitivity analysis (PSA) was undertaken in some studies, but the distributions used for PSA were rarely reported or justified. The cost-effectiveness of follow-up strategies among people with confirmed adenomas are warranted in aiding evidence-informed decision making in response to the rapidly evolving technologies and rising expectations

Brane gravity, massless bulk scalar and self-tuning of the cosmological constant

We show that a self-tuning mechanism of the cosmological constant could work in 5D non-compact space-time with a $Z_2$ symmetry in the presence of a massless scalar field. The standard model matter fields live only on the 4D brane. The change of vacuum energy on the brane (brane cosmological constant) by, for instance, electroweak and QCD phase transitions, just gives rise to dynamical shifts of the profiles of the background metric and the scalar field in the extra dimension, keeping 4D space-time flat without any fine-tuning. To avoid naked singularities in the bulk, the brane cosmological constant should be negative. We introduce an additional brane-localized 4D Einstein-Hilbert term so as to provide the observed 4D gravity with the non-compact extra dimension. With a general form of brane-localized gravity term allowed by the symmetries, the low energy Einstein gravity is successfully reproduced on the brane at long distances. We show this phenomenon explicitly for the case of vanishing bulk cosmological constant.Comment: 1+15 pages, no figure, Version to appear in PR

Second order quantum corrections to the classical reflection factor of the sinh-Gordon model

The sinh-Gordon model on a half-line with integrable boundary conditions is considered in low order perturbation theory developed in affine Toda field theory. The quantum corrections to the classical reflection factor of the model are studied up to the second order in the difference of the two boundary parameters and to one loop order in the bulk coupling. It is noticed that the general form of the second order quantum corrections are consistent with Ghoshal's formula.Comment: 24 pages and 1 figure. LaTex2

Non-volatile bistability effect based on electrically controlled phase transition in scaled magnetic semiconductor nanostructures

We explore the bistability effect in a dimensionally scaled semiconductor nanostruncture consisting of a diluted magnetic semiconductor quantum dot (QD) and a reservoir of itinerant holes separated by a barrier. The bistability stems from the magnetic phase transition in the QD mediated by the changes in the hole population. Our calculation shows that when properly designed, the thermodynamic equilibrium of the scaled structure can be achieved at two different configurations; i.e., the one with the QD in a ferromagnetic state with a sufficient number of holes and the other with the depopulated QD in a paramagnetic state. Subsequently, the parameter window suitable for this bistability formation is discussed along with the the conditions for the maximum robustness/non-volatility. To examine the issue of scaling, an estimation of the bistabiity lifetime is made by considering the thermal fluctuation in the QD hole population via the spontaneous transitions. A numerical evaluation is carried out for a typical carrier-mediated magnetic semiconductor (e.g., GaMnAs) as well as for a hypothetical case of high Curie temperature for potential room temperature operation.Comment: 9 pages, 7 figure

First order quantum corrections to the classical reflection factor of the sinh-Gordon model

The sinh-Gordon model is restricted to a half-line by boundary conditions maintaining integrability. A perturbative calculation of the reflection factor is given to one loop order in the bulk coupling and to first order in the difference of the two parameters introduced at the boundary, providing a further verification of Ghoshal's formula. The calculation is consistent with a conjecture for the general dependence of the reflection factor on the boundary parameters and the bulk coupling.Comment: 16 pages, 1 figur

Non-Classical Response from Quench-Cooled Solid Helium Confined in Porous Gold

We have investigated the non-classical response of solid 4He confined in porous gold set to torsional oscillation. When solid helium is grown rapidly, nearly 7% of the solid helium appears to be decoupled from the oscillation below about 200 mK. Dissipation appears at temperatures where the decoupling shows maximum variation. In contrast, the decoupling is substantially reduced in slowly grown solid helium. The dynamic response of solid helium was also studied by imposing a sudden increase in the amplitude of oscillation. Extended relaxation in the resonant period shift, suggesting the emergence of the pinning of low energy excitations, was observed below the onset temperature of the non-classical response. The motion of a dislocation or a glassy solid is restricted in the entangled narrow pores and is not likely responsible for the period shift and long relaxation