A Two-Form Formulation of the Vector-Tensor Multiplet in Central Charge Superspace

A two-form formulation for the N=2 vector-tensor multiplet is constructed using superfield methods in central charge superspace. The N=2 non-Abelian standard supergauge multiplet in central charge superspace is also discussed, as is with the associated Chern-Simons form. We give the constraints, solve the Bianchi identities and present the action for a theory of the vector-tensor multiplet coupled to the non-Abelian supergauge multiplet via the Chern-Simons form.Comment: 16 pages, LaTeX2e with AMS-LaTe

A Study of Two-/One-form Superfields

We study two supersymmetric toy models of a k-form superfield, k=2,1 separately. By ``solving'' Jacobi identities, we show that each model is completely solvable at off-shell level, possesses a severely constrained kinematics, and gives a rigid representation of the supersymmetry algebra. This study of the toy models is motivated by our reanalysis on supersymmetry algebras in gauge theories where we discuss internal symmetry generators carrying spacetime/spinor indices.Comment: 1+35 pages, No figur

Vector-Tensor multiplet in N=2 superspace with central charge

We use the four-dimensional N=2 central charge superspace to give a geometrical construction of the Abelian vector-tensor multiplet consisting, under N=1 supersymmetry, of one vector and one linear multiplet. We derive the component field supersymmetry and central charge transformations, and show that there is a super-Lagrangian, the higher components of which are all total derivatives, allowing us to construct superfield and component actions.Comment: LaTeX2e with AMS-LaTeX, 12 page

Demokratie auf dem Rückzug? Zur Konfrontation zwischen amerikanischem Präsidenten und Kongress über einen Truppenabzug aus dem Irak

Im US-Präsidentschaftswahlkampf 2008 ist der Irakkrieg eines der wichtigsten Themen. Die Amerikaner sind allmählich kriegsmüde und die Mehrheit befürwortet einen Truppenrückzug aus dem Irak. Das brachten bereits der Ausgang der Kongresswahlen im Jahr 2006 sowie regelmäßige Meinungsumfragen zum Ausdruck. Es ist nun anzunehmen, dass in der ältesten Demokratie der Welt Volkes Wille direkten Einfluss auf die Politik haben müsste. Doch dies ist nur bedingt der Fall. Besonders Präsident George W. Bush hat wiederholt klargestellt, dass die Stimmung in der Bevölkerung für ihn in der Irakfrage nicht maßgebend sei. Für ihn zähle vielmehr, wie die Generäle vor Ort die aktuelle Sicherheitslage und die Fortschritte einschätzen. Dagegen versucht der seit Ende 2006 von Demokraten dominierte Kongress immer wieder, Rückzugspläne mit festen Fristen zu etablieren. Bislang ist sein Erfolg jedoch bescheiden. Vor allem die fehlende Unterstützung der Republikaner im Kongress und die Blockadepolitik des Präsidenten waren dafür verantwortlich. Hinter der Konfrontation steht eine tiefergehende Auseinandersetzung über die Kompetenzverteilung zwischen Präsident und Kongress bei Kriegsentscheidungen, die in der US-Verfassung in einer Grauzone bleibt. Stephanie Sohnius verknüpft vor diesem verfassungsrechtlichen Hintergrund die Aufarbeitung der aktuell wichtigsten USaußenpolitischen Debatte mit der Frage, ob sich die Demokratie in den USA in der Ära des „Krieges gegen den Terrorismus“ (weiterhin) auf dem Rückzug befindet

Will the Real 4D, N=1 SG Limit of Superstring/M-Theory Please Stand Up?

At the component-level we study the `beta-function-favored constraint' (bffc) formalism, suggested in 1988 as the most natural formulation for supergravity derived from more fundamental theories. We begin with the suggestion that \bffc supergravity be identified with new minimal supergravity together with an additional chiral compensator multiplet. After $U_{\rm A}(1)$symmetry breaking, the non-propagating axion 2-form of new minimal supergravity becomes the propagating axion 2-form required by string theory. The final form of the theory is seen to uniquely allow four simultaneous features: (i) local supersymmetry, (ii) implementation of the Green-Schwarz mechanism, (iii) a supersymmetry-breaking order parameter chiral superfield, and (iv) a dilaton superpotential.Comment: Minor changes with notational improvements in eqs.(3.6), (3.9) and (3.10), a note added with ref.[22]. 12 pages, late

Symplectic Geometry of Supersymmetry and Nonlinear Sigma Model

Recently it has been argued, that Poincar\'{e} supersymmetric field theories admit an underlying loop space hamiltonian (symplectic) structure. Here shall establish this at the level of a general $N=1$ supermultiplet. In particular, we advocate the use of a superloop space and explain the necessity of using nonconventional auxiliary fields. As an example we consider the nonlinear $\sigma$-model. Due to the quartic fermionic term, we conclude that the use of superloop space variables is necessary for the action to have a hamiltonian loop space interpretation.Comment: 9 pages, UU-ITP 30/9

N=4 Super-Yang-Mills Equations In Harmonic Superspace

We analyze the superfield equations of the 4-dimensional N=4 SYM-theory using light-cone gauge conditions and the harmonic-superspace approach. The harmonic superfield equations of motion are drastically simplified in this gauge, in particular, the basic harmonic-superfield matrices and the corresponding harmonic analytic gauge connections become nilpotent on-shell.Comment: To be published in Proceedings of the conference "Supersymmetry and quantum field theory" dedicated to the memory of prof. D.V. Volkov, Kharkov, July 25-31, 2000; minor corrections include

Towards the complete N=2 superfield Born-Infeld action with partially broken N=4 supersymmetry

We propose a systematic way of constructing $N=2, d=4$ superfield Born-Infeld action with a second nonlinearly realized N=2 supersymmetry. The latter, together with the manifest N=2 supersymmetry, form a central-charge extended $N=4, d=4$ supersymmetry. We embed the Goldstone-Maxwell N=2 multiplet into an infinite-dimensional off-shell supermultiplet of this N=4 supersymmetry and impose an infinite set of covariant constraints which eliminate all extra N=2 superfields through the Goldstone-Maxwell one. The Born-Infeld superfield Lagrangian density is one of these composite superfields. The constraints can be solved by iterations to any order in the fields. We present the sought N=2 Born-Infeld action up to the 10th order. It encompasses the action found earlier by Kuzenko and Theisen to the 8th order from a self-duality requirement. This is a strong indication that the complete N=2 Born-Infeld action with partially broken N=4 supersymmetry is also self-dual.Comment: 12 pages, LaTeX, typos corrected, version to appear in Phys. Rev.

Superform formulation for vector-tensor multiplets in conformal supergravity

The recent papers arXiv:1110.0971 and arXiv:1201.5431 have provided a superfield description for vector-tensor multiplets and their Chern-Simons couplings in 4D N = 2 conformal supergravity. Here we develop a superform formulation for these theories. Furthermore an alternative means of gauging the central charge is given, making use of a deformed vector multiplet, which may be thought of as a variant vector-tensor multiplet. Its Chern-Simons couplings to additional vector multiplets are also constructed. This multiplet together with its Chern-Simons couplings are new results not considered by de Wit et al. in hep-th/9710212.Comment: 28 pages. V2: Typos corrected and references updated; V3: References updated and typo correcte

N=2 Rigid Supersymmetry with Gauged Central Charge

We develop a general setting for N=2 rigid supersymmetric field theories with gauged central charge in harmonic superspace. We consider those N=2 multiplets which have a finite number of off-shell components and exist off shell owing to a non-trivial central charge. This class includes, in particular, the hypermultiplet with central charge and various versions of the vector-tensor multiplet. For such theories we present a manifestly supersymmetric universal action. Chern-Simons couplings to an external N=2 super Yang-Mills multiplet are given, in harmonic superspace, for both the linear and nonlinear vector-tensor multiplets with gauged central charge. We show how to deduce the linear version of the vector-tensor multiplet from six dimensions.Comment: 46 pages, latex, no figure