1,215 research outputs found

    Neutral modes edge state dynamics through quantum point contacts

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    Dynamics of neutral modes for fractional quantum Hall states is investigated for a quantum point contact geometry in the weak-backscattering regime. The effective field theory introduced by Fradkin-Lopez for edge states in the Jain sequence is generalized to the case of propagating neutral modes. The dominant tunnelling processes are identified also in the presence of non-universal phenomena induced by interactions. The crossover regime in the backscattering current between tunnelling of single-quasiparticles and of agglomerates of p-quasiparticles is analysed. We demonstrate that higher order cumulants of the backscattering current fluctuations are a unique resource to study quantitatively the competition between different carrier charges. We find that propagating neutral modes are a necessary ingredient in order to explain this crossover phenomena.Comment: 28 pages, 5 figure

    Composite Fermion Wavefunctions Derived by Conformal Field Theory

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    The Jain theory of hierarchical Hall states is reconsidered in the light of recent analyses that have found exact relations between projected Jain wavefunctions and conformal field theory correlators. We show that the underlying conformal theory is precisely given by the W-infinity minimal models introduced earlier. This theory involves a reduction of the multicomponent Abelian theory that is similar to the projection to the lowest Landau level in the Jain approach. The projection yields quasihole excitations obeying non-Abelian fractional statistics. The analysis closely parallels the bosonic conformal theory description of the Pfaffian and Read-Rezayi states.Comment: 4 pages, 1 figur

    On parity functions in conformal field theories

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    We examine general aspects of parity functions arising in rational conformal field theories, as a result of Galois theoretic properties of modular transformations. We focus more specifically on parity functions associated with affine Lie algebras, for which we give two efficient formulas. We investigate the consequences of these for the modular invariance problem.Comment: 18 pages, no figure, LaTeX2

    Dietary Supplement, Containing the Dry Extract of Curcumin, Emblica and Cassia, Counteracts Intestinal Inflammation and Enteric Dysmotility Associated with Obesity

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    Intestinal epithelial barrier (IEB) impairment and enteric inflammation are involved in the onset of obesity and gut-related dysmotility. Dietary supplementation with natural plant extracts represents a useful strategy for the management of body weight gain and systemic inflammation associated with obesity. Here, we evaluate the efficacy of a food supplement containing the dry extract of Curcumin, Emblica and Cassia in counteracting enteric inflammation and motor abnormalities in a mouse model of obesity, induced by a high-fat diet (HFD). Male C57BL/6 mice, fed with standard diet (SD) or HFD, were treated with a natural mixture (Curcumin, Emblica and Cassia). After 8 weeks, body weight, BMI, liver and spleen weight, along with metabolic parameters and colonic motor activity were evaluated. Additionally, plasma LBP, fecal calprotectin, colonic levels of MPO and IL-1ÎČ, as well as the expression of occludin, TLR-4, MYD88 and NF-ÎșB were investigated. Plant-based food supplement administration (1) counteracted the increase in body weight, BMI and metabolic parameters, along with a reduction in spleen and liver weight; (2) showed strengthening effects on the IEB integrity; and (3) reduced enteric inflammation and oxidative stress, as well as ameliorated the colonic contractile dysfunctions. Natural mixture administration reduced intestinal inflammation and counteracted the intestinal motor dysfunction associated with obesity

    Field Theory Entropy, the HH-theorem and the Renormalization Group

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    We consider entropy and relative entropy in Field theory and establish relevant monotonicity properties with respect to the couplings. The relative entropy in a field theory with a hierarchy of renormalization group fixed points ranks the fixed points, the lowest relative entropy being assigned to the highest multicritical point. We argue that as a consequence of a generalized HH theorem Wilsonian RG flows induce an increase in entropy and propose the relative entropy as the natural quantity which increases from one fixed point to another in more than two dimensions.Comment: 25 pages, plain TeX (macros included), 6 ps figures. Addition in title. Entropy of cutoff Gaussian model modified in section 4 to avoid a divergence. Therefore, last figure modified. Other minor changes to improve readability. Version to appear in Phys. Rev.

    Lattice realizations of unitary minimal modular invariant partition functions

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    The conformal spectra of the critical dilute A-D-E lattice models are studied numerically. The results strongly indicate that, in branches 1 and 2, these models provide realizations of the complete A-D-E classification of unitary minimal modular invariant partition functions given by Cappelli, Itzykson and Zuber. In branches 3 and 4 the results indicate that the modular invariant partition functions factorize. Similar factorization results are also obtained for two-colour lattice models.Comment: 18 pages, Latex, with minor corrections and clarification

    Adapting to the digital age: a narrative approach

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    The article adopts a narrative inquiry approach to foreground informal learning and exposes a collection of stories from tutors about how they adapted comfortably to the digital age. We were concerned that despite substantial evidence that bringing about changes in pedagogic practices can be difficult, there is a gap in convincing approaches to help in this respect. In this context, this project takes a “bottom-up” approach and synthesises several life-stories into a single persuasive narrative to support the process of adapting to digital change. The project foregrounds the small, every-day motivating moments, cultural features and environmental factors in people's diverse lives which may have contributed to their positive dispositions towards change in relation to technology enhanced learning. We expect that such narrative approaches could serve to support colleagues in other institutions to warm up to ever-changing technological advances

    Fermionic representations for characters of M(3,t), M(4,5), M(5,6) and M(6,7) minimal models and related Rogers-Ramanujan type and dilogarithm identities

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    Characters and linear combinations of characters that admit a fermionic sum representation as well as a factorized form are considered for some minimal Virasoro models. As a consequence, various Rogers-Ramanujan type identities are obtained. Dilogarithm identities producing corresponding effective central charges and secondary effective central charges are derived. Several ways of constructing more general fermionic representations are discussed.Comment: 14 pages, LaTex; minor correction
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