434 research outputs found
11D supergravity at
We compute certain spinorial cohomology groups controlling possible
supersymmetric deformations of eleven-dimensional supergravity up to order
in the Planck length. At and the spinorial
cohomology groups are trivial and therefore the theory cannot be deformed
supersymmetrically. At the corresponding spinorial cohomology
group is generated by a nontrivial element. On an eleven-dimensional manifold
such that , this element corresponds to a supersymmetric
deformation of the theory, which can only be redefined away at the cost of
shifting the quantization condition of the four-form field strength.Comment: 10 pages, 1 figure. v2: references adde
Partial Supersymmetry Breaking and N=2 U(N_c) Gauge Model with Hypermultiplets in Harmonic Superspace
We provide a manifestly N=2 supersymmetric formulation of the N=2 U(N_c)
gauge model constructed in terms of N=1 superfields in hep-th/0409060. The
model is composed of N=2 vector multiplets in harmonic superspace and can be
viewed as the N=2 U(N_c) Yang-Mills effective action equipped with the electric
and magnetic Fayet-Iliopoulos terms. We generalize this gauge model to an N=2
U(N_c) QCD model by introducing N=2 hypermultiplets in harmonic superspace
which include both the fundamental representation of U(N_c) and the adjoint
representation of U(N_c). The effect of the magnetic Fayet-Iliopoulos term is
to shift the auxiliary field by an imaginary constant. Examining vacua of the
model, we show that N=2 supersymmetry is spontaneously broken down to N=1.Comment: 26 pages; typos fixed; version to appear in Nucl.Phys.B; eqn.(2.4)
and typos correcte
Supergravity for Effective Theories
Higher-derivative operators are central elements of any effective field
theory. In supersymmetric theories, these operators include terms with
derivatives in the K\"ahler potential. We develop a toolkit for coupling such
supersymmetric effective field theories to supergravity. We explain how to
write the action for minimal supergravity coupled to chiral superfields with
arbitrary numbers of derivatives and curvature couplings. We discuss two
examples in detail, showing how the component actions agree with the
expectations from the linearized description in terms of a Ferrara-Zumino
multiplet. In a companion paper, we apply the formalism to the effective theory
of inflation.Comment: 26 page
Mass predictions based on a supersymmetric SU(5) fixed point
I examine the possibility that the third generation fermion masses are
determined by an exact fixed point of the minimal supersymmetric SU(5) model.
When one-loop supersymmetric thresholds are included, this unified fixed point
successfully predicts the top quark mass, 175 +(-) 2 GeV, as well as the weak
mixing angle. The bottom quark mass prediction is sensitive to the
supersymmetric thresholds; it approaches the measured value for mu <0 and very
large unified gaugino mass. The experimental measurement of the tau lepton mass
determines tan(beta), and the strong gauge coupling and fine structure constant
fix the unification scale and the unified gauge coupling.Comment: 40 pages, 9 figures, 9 tables, Revtex
Gauge theory in deformed N=(1,1) superspace
We review the non-anticommutative Q-deformations of N=(1,1) supersymmetric
theories in four-dimensional Euclidean harmonic superspace. These deformations
preserve chirality and harmonic Grassmann analyticity. The associated field
theories arise as a low-energy limit of string theory in specific backgrounds
and generalize the Moyal-deformed supersymmetric field theories. A
characteristic feature of the Q-deformed theories is the half-breaking of
supersymmetry in the chiral sector of the Euclidean superspace. Our main focus
is on the chiral singlet Q-deformation, which is distinguished by preserving
the SO(4) Spin(4) ``Lorentz'' symmetry and the SU(2) R-symmetry. We present the
superfield and component structures of the deformed N=(1,0) supersymmetric
gauge theory as well as of hypermultiplets coupled to a gauge superfield:
invariant actions, deformed transformation rules, and so on. We discuss quantum
aspects of these models and prove their renormalizability in the abelian case.
For the charged hypermultiplet in an abelian gauge superfield background we
construct the deformed holomorphic effective action.Comment: 1+60 pages, typos corrected, references adde
The Endogenous Th17 Response in NO<inf>2</inf>-Promoted Allergic Airway Disease Is Dispensable for Airway Hyperresponsiveness and Distinct from Th17 Adoptive Transfer
Severe, glucocorticoid-resistant asthma comprises 5-7% of patients with asthma. IL-17 is a biomarker of severe asthma, and the adoptive transfer of Th17 cells in mice is sufficient to induce glucocorticoid-resistant allergic airway disease. Nitrogen dioxide (NO2) is an environmental toxin that correlates with asthma severity, exacerbation, and risk of adverse outcomes. Mice that are allergically sensitized to the antigen ovalbumin by exposure to NO2 exhibit a mixed Th2/Th17 adaptive immune response and eosinophil and neutrophil recruitment to the airway following antigen challenge, a phenotype reminiscent of severe clinical asthma. Because IL-1 receptor (IL-1R) signaling is critical in the generation of the Th17 response in vivo, we hypothesized that the IL-1R/Th17 axis contributes to pulmonary inflammation and airway hyperresponsiveness (AHR) in NO2-promoted allergic airway disease and manifests in glucocorticoid-resistant cytokine production. IL-17A neutralization at the time of antigen challenge or genetic deficiency in IL-1R resulted in decreased neutrophil recruitment to the airway following antigen challenge but did not protect against the development of AHR. Instead, IL-1R-/- mice developed exacerbated AHR compared to WT mice. Lung cells from NO2-allergically inflamed mice that were treated in vitro with dexamethasone (Dex) during antigen restimulation exhibited reduced Th17 cytokine production, whereas Th17 cytokine production by lung cells from recipient mice of in vitro Th17-polarized OTII T-cells was resistant to Dex. These results demonstrate that the IL-1R/Th17 axis does not contribute to AHR development in NO2-promoted allergic airway disease, that Th17 adoptive transfer does not necessarily reflect an endogenously-generated Th17 response, and that functions of Th17 responses are contingent on the experimental conditions in which they are generated. © 2013 Martin et al
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