117 research outputs found
Three-dimensional N=4 supersymmetry in harmonic N=3 superspace
We consider the map of three-dimensional N=4 superfields to N=3 harmonic
superspace. The left and right representations of the N=4 superconformal group
are constructed on N=3 analytic superfields. These representations are
convenient for the description of N=4 superconformal couplings of the Abelian
gauge superfields with hypermultiplets. We analyze the N=4 invariance in the
non-Abelian N=3 Yang-Mills theory.Comment: Latex file, 22 pages; v2 two references adde
Constrained superpotentials in harmonic gauge theories with 8 supercharges
We consider D-dimensional supersymmetric gauge theories with 8 supercharges
(D<6,) in the framework of harmonic superspaces. The effective
Abelian low-energy action for D=5 contains the free and Chern-Simons terms.
Effective superfield actions for D<4 can be written in terms of
the superpotentials satisfying the superfield constraints and (6-D)-dimensional
Laplace equations. The role of alternative harmonic structures is discussed.Comment: LATEX file, 9 pages, version published in Teor. Mat. Fi
Quantum N=3, d=3 Chern-Simons Matter Theories in Harmonic Superspace
We develop the background field method for studying classical and quantum
aspects of N=3, d=3 Chern-Simons and matter theories in N=3 harmonic
superspace. As one of the immediate consequences, we prove a nonrenormalization
theorem implying the ultra-violet finiteness of the corresponding supergraph
perturbation theory. We also derive the general hypermultiplet and gauge
superfield propagators in a Chern-Simons background. The leading supergraphs
with two and four external lines are evaluated. In contrast to the
non-supersymmetric theory, the leading quantum correction to the massive
charged hypermultiplet proves to be the super Yang-Mills action rather than the
Chern-Simons one. The hypermultiplet mass is induced by a constant triplet of
central charges in the N=3, d=3 Poincare superalgebra.Comment: 1+37 pages, 3 figures; v2: a reference added, to appear in JHE
Unifying the PST and the auxiliary tensor field formulations of 4D self-duality
We unify the Lorentz- and O(2) duality-covariant approach to 4D self-dual
theories by Pasti, Sorokin and Tonin (PST) with the formulation involving an
auxiliary tensor field. We present the basic features of the new hybrid
approach, including symmetries of the relevant generalized PST action. Its
salient peculiarity is the unique form of the realization of the PST gauge
symmetries. The corresponding transformations do not affect the auxiliary
tensor field, which guarantees the self-duality of the nonlinear actions in
which the O(2) invariant interactions are constructed out of the tensor field.Comment: 0 + 12 pages, typos corrected; published versio
Chern-Simons theory in the SO(5)/U(2) harmonic superspace
We consider the superspace of D=3, N=5 supersymmetry using SO(5)/U(2)
harmonic coordinates. Three analytic N=5 gauge superfields depend on three
vector and six harmonic bosonic coordinates and also on six Grassmann
coordinates. Decomposition of these superfields in Grassmann and harmonic
coordinates yields infinite-dimensional supermultiplets including a
three-dimensional gauge Chern-Simons field and auxiliary bosonic and fermionic
fields carrying SO(5) vector indices. The superfield action of this theory is
invariant with respect to D=3, N=6 conformal supersymmetry realized on N=5
superfields.Comment: Latex file, 17 pages, v2 with minor changes, v3 journal versio
Superspace Formulation in a Three-Algebra Approach to D=3, N=4,5 Superconformal Chern-Simons Matter Theories
We present a superspace formulation of the D=3, N=4,5 superconformal
Chern-Simons Matter theories, with matter supermultiplets valued in a
symplectic 3-algebra. We first construct an N=1 superconformal action, and then
generalize a method used by Gaitto and Witten to enhance the supersymmetry from
N=1 to N=5. By decomposing the N=5 supermultiplets and the symplectic 3-algebra
properly and proposing a new super-potential term, we construct the N=4
superconformal Chern-Simons matter theories in terms of two sets of generators
of a (quaternion) symplectic 3-algebra. The N=4 theories can also be derived by
requiring that the supersymmetry transformations are closed on-shell. The
relationship between the 3-algebras, Lie superalgebras, Lie algebras and
embedding tensors (proposed in [E. A. Bergshoeff, O. Hohm, D. Roest, H.
Samtleben, and E. Sezgin, J. High Energy Phys. 09 (2008) 101.]) is also
clarified. The general N=4,5 superconformal Chern-Simons matter theories in
terms of ordinary Lie algebras can be rederived in our 3-algebra approach. All
known N=4,5 superconformal Chern-Simons matter theories can be recovered in the
present superspace formulation for super-Lie-algebra realization of symplectic
3-algebras.Comment: 37 pages, minor changes, published in PR
Reality in Noncommutative Gravity
We study the problem of reality in the geometric formalism of the 4D
noncommutative gravity using the known deformation of the diffeomorphism group
induced by the twist operator with the constant deformation parameters
\vt^{mn}. It is shown that real covariant derivatives can be constructed via
-anticommutators of the real connection with the corresponding fields.
The minimal noncommutative generalization of the real Riemann tensor contains
only \vt^{mn}-corrections of the even degrees in comparison with the
undeformed tensor. The gauge field describes a gravitational field on
the flat background. All geometric objects are constructed as the perturbation
series using -polynomial decomposition in terms of . We consider
the nonminimal tensor and scalar functions of of the odd degrees in
\vt^{mn} and remark that these pure noncommutative objects can be used in the
noncommutative gravity.Comment: Latex file, 14 pages, corrected version to be publised in CQ
ABJM models in N=3 harmonic superspace
We construct the classical action of the Aharony-Bergman-Jafferis-Maldacena
(ABJM) model in the N=3, d=3 harmonic superspace. In such a formulation three
out of six supersymmetries are realized off shell while the other three mix the
superfields and close on shell. The superfield action involves two
hypermultiplet superfields in the bifundamental representation of the gauge
group and two Chern-Simons gauge superfields corresponding to the left and
right gauge groups. The N=3 superconformal invariance allows only for a minimal
gauge interaction of the hypermultiplets. Amazingly, the correct sextic scalar
potential of ABJM emerges after the elimination of auxiliary fields. Besides
the original U(N)xU(N) ABJM model, we also construct N=3 superfield
formulations of some generalizations. For the SU(2)xSU(2) case we give a simple
superfield proof of its enhanced N=8 supersymmetry and SO(8) R-symmetry.Comment: 1+35 pages, minor changes, a reference added, published versio
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