529 research outputs found

    Symmetries of noncommutative scalar field theory

    Full text link
    We investigate symmetries of the scalar field theory with harmonic term on the Moyal space with euclidean scalar product and general symplectic form. The classical action is invariant under the orthogonal group if this group acts also on the symplectic structure. We find that the invariance under the orthogonal group can be restored also at the quantum level by restricting the symplectic structures to a particular orbit.Comment: 12 pages, revised versio

    Connes distance by examples: Homothetic spectral metric spaces

    Full text link
    We study metric properties stemming from the Connes spectral distance on three types of non compact noncommutative spaces which have received attention recently from various viewpoints in the physics literature. These are the noncommutative Moyal plane, a family of harmonic Moyal spectral triples for which the Dirac operator squares to the harmonic oscillator Hamiltonian and a family of spectral triples with Dirac operator related to the Landau operator. We show that these triples are homothetic spectral metric spaces, having an infinite number of distinct pathwise connected components. The homothetic factors linking the distances are related to determinants of effective Clifford metrics. We obtain as a by product new examples of explicit spectral distance formulas. The results are discussed.Comment: 23 pages. Misprints corrected, references updated, one remark added at the end of the section 3. To appear in Review in Mathematical Physic

    Anyonic Excitations in Fast Rotating Bose Gases Revisited

    Full text link
    The role of anyonic excitations in fast rotating harmonically trapped Bose gases in a fractional Quantum Hall state is examined. Standard Chern-Simons anyons as well as "non standard" anyons obtained from a statistical interaction having Maxwell-Chern-Simons dynamics and suitable non minimal coupling to matter are considered. Their respective ability to stabilize attractive Bose gases under fast rotation in the thermodynamical limit is studied. Stability can be obtained for standard anyons while for non standard anyons, stability requires that the range of the corresponding statistical interaction does not exceed the typical wavelenght of the atoms.Comment: 5 pages. Improved version to be published in Phys. Rev. A, including a physical discussion on relevant interactions and scattering regime together with implication on the nature of statistical interactio

    On Auxiliary Fields in BF Theories

    Full text link
    We discuss the structure of auxiliary fields for non-Abelian BF theories in arbitrary dimensions. By modifying the classical BRST operator, we build the on-shell invariant complete quantum action. Therefore, we introduce the auxiliary fields which close the BRST algebra and lead to the invariant extension of the classical action.Comment: 7 pages, minor changes, typos in equations corrected and acknowledgements adde

    MerTK mediates immune homeostasis: effects upon dendritic cell function and Type 1 diabetes

    Get PDF
    The receptor tyrosine kinase Mer (MerTK) is expressed by dendritic cells (DC) in mice. The heretofore undefined role of MerTK in DC was investigated in two major studies. First, the role of MerTK in the inhibition of DC activation by apoptotic cells was investigated. It was found that apoptotic cells inhibited DC activation by bacterial lipopolysaccharide or CD40 crosslinking via MerTK. Inhibition of DC was characterized by blockade of IL-12p70 secretion, co-stimulatory molecule expression and stimulation of CD4+ and CD8+ T cells. The MerTK ligand growth arrest specific factor-6 (Gas6) was expressed on the surface of apoptotic cells, and Gas6 was essential for the inhibitory effects of apoptotic cells upon DC. Non-obese diabetic (NOD) mice, lacking MerTK expression (NOD.MerTKKD/KD), demonstrated aberrant expansion of type 1 CD4+ and CD8+ T cell effectors in response to apoptotic cell death in vivo. Furthermore, NOD.MerTKKD/KD mice expressing a diabetogenic T cell receptor transgene, developed diabetes at an accelerated rate and a greater frequency than mice expressing MerTK. These findings support a role for MerTK in peripheral immune homeostasis. Secondly, the impact of MerTK-deficiency in NOD mice was investigated. NOD.MerTKKD/KD mice were protected from diabetes onset and protection was due to lack of self-specific type 1 CD4+ and CD8+ T cell effectors. Thymic selection was enhanced in NOD.MerTKKD/KD mice resulting in deletion of pathogenic, autoreactive T cells. The change in thymic selection efficiency was mediated by bone marrow-derived cells and was likely due to dysregulation of thymic DC. These data indicate that MerTK mediates immunoregulation of DC in both the periphery and the thymus

    Using mixed data in the inverse scattering problem

    Full text link
    Consider the fixed-\ell inverse scattering problem. We show that the zeros of the regular solution of the Schr\"odinger equation, rn(E)r_{n}(E), which are monotonic functions of the energy, determine a unique potential when the domain of the energy is such that the rn(E)r_{n}(E) range from zero to infinity. This suggests that the use of the mixed data of phase-shifts {δ(0,k),kk0}{δ(,k0),0}\{\delta(\ell_0,k), k \geq k_0 \} \cup \{\delta(\ell,k_0), \ell \geq \ell_0 \}, for which the zeros of the regular solution are monotonic in both domains, and range from zero to infinity, offers the possibility of determining the potential in a unique way.Comment: 9 pages, 2 figures. Talk given at the Conference of Inverse Quantum Scattering Theory, Hungary, August 200

    Chimeric protein and nano-construct for tissue-retained enzyme to locally suppress inflammation

    Get PDF
    There is considerable need for new retention strategies of immunomodulatory biologics for localized suppression of inflammation. We developed a chimeric protein as a well as a self-assembled nano-construct incorporating novel approaches for both retention and suppression to induce potent, confined metabolic programming. Immunosuppressive indoleamine 2,3 dioxygenase (IDO), which depletes tryptophan through the kynurenine pathway, was fused to Galectin 3 (Gal3), which binds extracellular glycans and provides tissue anchoring. Using a luciferase-Gal3 fusion reporter, tissue retention was prolonged to ~6 d whereas native luciferase is not retained and undetectable by 24 h. IDO-Gal3 injected subcutaneously controlled local LPS-challenged tissue inflammation. Furthermore, subgingival injection suppressed periodontal disease (PD) in a polymicrobial challenged mouse model. Multiplex analysis of gingival tissue revealed decreased inflammatory (IL-1β, IL-12p70, KC, IP10, MCP1, MIP2) and increased anti-inflammatory (IL-10, TGFβ3) proteins, indicating a shift toward homeostasis. Animals treated with IDO-Gal3 also showed significant decrease in bone loss commonly associated with PD, as determined by µCT analysis

    Vortex in Maxwell-Chern-Simons models coupled to external backgrounds

    Full text link
    We consider Maxwell-Chern-Simons models involving different non-minimal coupling terms to a non relativistic massive scalar and further coupled to an external uniform background charge. We study how these models can be constrained to support static radially symmetric vortex configurations saturating the lower bound for the energy. Models involving Zeeman-type coupling support such vortices provided the potential has a "symmetry breaking" form and a relation between parameters holds. In models where minimal coupling is supplemented by magnetic and electric field dependant coupling terms, non trivial vortex configurations minimizing the energy occur only when a non linear potential is introduced. The corresponding vortices are studied numericallyComment: LaTeX file, 2 figure

    Examples of derivation-based differential calculi related to noncommutative gauge theories

    Full text link
    Some derivation-based differential calculi which have been used to construct models of noncommutative gauge theories are presented and commented. Some comparisons between them are made.Comment: 22 pages, conference given at the "International Workshop in honour of Michel Dubois-Violette, Differential Geometry, Noncommutative Geometry, Homology and Fundamental Interactions". To appear in a special issue of International Journal of Geometric Methods in Modern Physic
    corecore