503 research outputs found
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 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 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
-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 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
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
Self-Dual Supergravity Theories in 2+2 Dimensions
Starting from the new minimal multiplet of supergravity in dimensions,
we construct two types of self-dual supergravity theories. One of them involves
a self-duality condition on the Riemann curvature and implies the equations of
motion following from the Hilbert-Einstein type supergravity action. The other
one involves a self-duality condition on a {\it torsionful} Riemann curvature
with the torsion given by the field-strength of an antisymmetric tensor field,
and implies the equations of motion that follow from an -type action.Comment: 11 pages (TEX), UG-4/92 and CTP TAMU-46/9
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