Noncommutative Quantum Hall Effect and Aharonov-Bohm Effect

We study a system of electrons moving on a noncommutative plane in the presence of an external magnetic field which is perpendicular to this plane. For generality we assume that the coordinates and the momenta are both noncommutative. We make a transformation from the noncommutative coordinates to a set of commuting coordinates and then we write the Hamiltonian for this system. The energy spectrum and the expectation value of the current can then be calculated and the Hall conductivity can be extracted. We use the same method to calculate the phase shift for the Aharonov-Bohm effect. Precession measurements could allow strong upper limits to be imposed on the noncommutativity coordinate and momentum parameters $\Theta$ and $\Xi$.Comment: 9 pages, RevTeX4, references added, small changes in the tex

The ⋆\star-value Equation and Wigner Distributions in Noncommutative Heisenberg algebras

We consider the quantum mechanical equivalence of the Seiberg-Witten map in the context of the Weyl-Wigner-Groenewold-Moyal phase-space formalism in order to construct a quantum mechanics over noncommutative Heisenberg algebras. The formalism is then applied to the exactly soluble Landau and harmonic oscillator problems in the 2-dimensional noncommutative phase-space plane, in order to derive their correct energy spectra and corresponding Wigner distributions. We compare our results with others that have previously appeared in the literature.Comment: 19 page

Aspects of finite electrodynamics in D=3 dimensions

We study the impact of a minimal length on physical observables for a three-dimensional axionic electrodynamics. Our calculation is done within the framework of the gauge-invariant, but path-dependent, variables formalism which is alternative to the Wilson loop approach. Our result shows that the interaction energy contains a regularised Bessel function and a linear confining potential. This calculation involves no theta expansion at all. Once again, the present analysis displays the key role played by the new quantum of length.Comment: 12 pages, 2 figures; reference list updated and extended; new aknowlegments; removed line after eq.(1) erroneously inserte

UV divergence-free QFT on noncommutative plane

We formulate Noncommutative Qauntum Field Theory in terms of fields defined as mean value over coherent states of the noncommutative plane. No *-product is needed in this formulation and noncommutativity is carried by a modified Fourier transform of fields. As a result the theory is UV finite and the cutoff is provided by the noncommutative parameter theta.Comment: 6 pages, Latex, no figures. Accepted for publication in J.Phys.A. New references adde

Minimal Scales from an Extended Hilbert Space

We consider an extension of the conventional quantum Heisenberg algebra, assuming that coordinates as well as momenta fulfil nontrivial commutation relations. As a consequence, a minimal length and a minimal mass scale are implemented. Our commutators do not depend on positions and momenta and we provide an extension of the coordinate coherent state approach to Noncommutative Geometry. We explore, as toy model, the corresponding quantum field theory in a (2+1)-dimensional spacetime. Then we investigate the more realistic case of a (3+1)-dimensional spacetime, foliated into noncommutative planes. As a result, we obtain propagators, which are finite in the ultraviolet as well as the infrared regime.Comment: 16 pages, version which matches that published on CQ

Noncommutative Inspired Reissner-Nordstr\"om Black Holes in Large Extra Dimensions

Recently, a new noncommutative geometry inspired solution of the coupled Einstein-Maxwell field equations including black holes in 4-dimension is found. In this paper, we generalize some aspects of this model to the Reissner-Nordstr\"om (RN) like geometries with large extra dimensions. We discuss Hawking radiation process based on noncommutative inspired solutions. In this framework, existence of black hole remnant and possibility of its detection in LHC are investigated.Comment: 24 pages, 12 figures, revised version to appear in Commun. Theor. Phy

Tunneling of massive and charged particles from noncommutative Reissner-Nordstr\"{o}m black hole

Massive charged and uncharged particles tunneling from commutative Reissner-Nordstrom black hole horizon has been studied with details in literature. Here, by adopting the coherent state picture of spacetime noncommutativity, we study tunneling of massive and charged particles from a noncommutative inspired Reissner-Nordstrom black hole horizon. We show that Hawking radiation in this case is not purely thermal and there are correlations between emitted modes. These correlations may provide a solution to the information loss problem. We also study thermodynamics of noncommutative horizon in this setup.Comment: 10 pages, 2 figure

Noncommutative Inspired Black Holes in Extra Dimensions

In a recent string theory motivated paper, Nicolini, Smailagic and Spallucci (NSS) presented an interesting model for a noncommutative inspired, Schwarzschild-like black hole solution in 4-dimensions. The essential effect of having noncommutative co-ordinates in this approach is to smear out matter distributions on a scale associated with the turn-on of noncommutativity which was taken to be near the 4-d Planck mass. In particular, NSS took this smearing to be essentially Gaussian. This energy scale is sufficiently large that in 4-d such effects may remain invisible indefinitely. Extra dimensional models which attempt to address the gauge hierarchy problem, however, allow for the possibility that the effective fundamental scale may not be far from $\sim$ 1 TeV, an energy regime that will soon be probed by experiments at both the LHC and ILC. In this paper we generalize the NSS model to the case where flat, toroidally compactified extra dimensions are accessible at the Terascale and examine the resulting modifications in black hole properties due to the existence of noncommutativity. We show that while many of the noncommutativity-induced black hole features found in 4-d by NSS persist, in some cases there can be significant modifications due the presence of extra dimensions. We also demonstrate that the essential features of this approach are not particularly sensitive to the Gaussian nature of the smearing employed by NSS.Comment: 30 pages, 12 figures; slight text modifications and references adde

Individual and group based parenting programmes for improving psychosocial outcomes for teenage parents and their children.

BACKGROUND: Parenting programmes are a potentially important means of supporting teenage parents and improving outcomes for their children, and parenting support is a priority across most Western countries. This review updates the previous version published in 2001. OBJECTIVES: To examine the effectiveness of parenting programmes in improving psychosocial outcomes for teenage parents and developmental outcomes in their children. SEARCH STRATEGY: We searched to find new studies for this updated review in January 2008 and May 2010 in CENTRAL, MEDLINE, EMBASE, ASSIA, CINAHL, DARE, ERIC, PsycINFO, Sociological Abstracts and Social Science Citation Index. The National Research Register (NRR) was last searched in May 2005 and UK Clinical Research Network Portfolio Database in May 2010. SELECTION CRITERIA: Randomised controlled trials assessing short-term parenting interventions aimed specifically at teenage parents and a control group (no-treatment, waiting list or treatment-as-usual). DATA COLLECTION AND ANALYSIS: We assessed the risk of bias in each study. We standardised the treatment effect for each outcome in each study by dividing the mean difference in post-intervention scores between the intervention and control groups by the pooled standard deviation. MAIN RESULTS: We included eight studies with 513 participants, providing a total of 47 comparisons of outcome between intervention and control conditions. Nineteen comparisons were statistically significant, all favouring the intervention group. We conducted nine meta-analyses using data from four studies in total (each meta-analysis included data from two studies). Four meta-analyses showed statistically significant findings favouring the intervention group for the following outcomes: parent responsiveness to the child post-intervention (SMD -0.91, 95% CI -1.52 to -0.30, P = 0.04); infant responsiveness to mother at follow-up (SMD -0.65, 95% CI -1.25 to -0.06, P = 0.03); and an overall measure of parent-child interactions post-intervention (SMD -0.71, 95% CI -1.31 to -0.11, P = 0.02), and at follow-up (SMD -0.90, 95% CI -1.51 to -0.30, P = 0.004). The results of the remaining five meta-analyses were inconclusive. AUTHORS' CONCLUSIONS: Variation in the measures used, the included populations and interventions, and the risk of bias within the included studies limit the conclusions that can be reached. The findings provide some evidence to suggest that parenting programmes may be effective in improving a number of aspects of parent-child interaction both in the short- and long-term, but further research is now needed

Mini-Cog for the diagnosis of Alzheimer's disease dementia and other dementias within a secondary care setting

© 2014 The Cochrane Collaboration. This is the protocol for a review and there is no abstract. The objectives are as follows: To determine the diagnostic accuracy of the Mini-Cog for detecting Alzheimer's disease dementia and related dementias in a secondary care setting. To investigate the heterogeneity of test accuracy in the included studies and potential sources of heterogeneity. These potential sources of heterogeneity will include the baseline prevalence of dementia in study samples, thresholds used to determine positive test results, the type of dementia (Alzheimer's disease dementia or all causes of dementia), and aspects of study design related to study quality. We will also identify gaps in the evidence where further research is required