1,265 research outputs found
Superconformal spaces and implications for superstrings
We clarify some properties of projective superspace by using a manifestly
superconformal notation. In particular, we analyze the N=2 scalar multiplet in
detail, including its action, and the propagator and its super-Schwinger
parameters. The internal symmetry is taken to be noncompact (after Wick
rotation), allowing boundary conditions that preserve it off shell.
Generalization to N=4 suggests the coset superspace PSU(2,2|4)/OSp(4|4) for the
AdS/CFT superstring.Comment: 19 pages, no figures; v2: fixed sign, added note & reference; v3:
added note & references, version to appear in Physical Review
Supersymmetric sigma models and the 't Hooft instantons
Witten's linear sigma model for ADHM instantons possesses a natural
supersymmetry. We study generalizations of the infrared limit of the model that
are invariant under supersymmetry. In the case of four space-time
dimensions a background with a conformally flat metric and torsion is required.
The geometry is specified by a single real scalar function satisfying Laplace's
equation. It gives rise to 't Hooft instantons for the gauge group ,
instead of the general ADHM instantons for an gauge group in the case
.Comment: 11 pages, Latex fil
Manifest supersymmetry and the ADHM construction of instantons
We present the (0,4) superspace version of Witten's sigma model construction
for ADHM instantons. We use the harmonic superspace formalism, which exploits
the three complex structures common to both (0,4) supersymmetry and self-dual
Yang-Mills theory. A novel feature of the superspace formulation is the
manifest interplay between the ADHM construction and its twistor counterpart.Comment: minor changes in the text; also an Appendix on off-shell structure of
chiral fermion multiplets in (0,4) supersymmetry, and references adde
N=4, 3D Supersymmetric Quantum Mechanics in Non-Abelian Monopole Background
Using the harmonic superspace approach, we construct the three-dimensional
N=4 supersymmetric quantum mechanics of the supermultiplet (3,4,1) coupled to
an external SU(2) gauge field. The off-shell N=4 supersymmetry requires the
gauge field to be a static form of the 't Hooft ansatz for the 4D self-dual
SU(2) gauge fields, that is a particular solution of Bogomolny equations for
BPS monopoles. We present the explicit form of the corresponding superfield and
component actions, as well as of the quantum Hamiltonian and N=4 supercharges.
The latter can be used to describe a more general N=4 mechanics system, with an
arbitrary BPS monopole background and on-shell N=4 supersymmetry. The essential
feature of our construction is the use of semi-dynamical spin (4,4,0) multiplet
with the Wess-Zumino type action.Comment: 16 pages, reference added, published versio
Covariant Harmonic Supergraphity for N = 2 Super Yang--Mills Theories
We review the background field method for general N = 2 super Yang-Mills
theories formulated in the N = 2 harmonic superspace. The covariant harmonic
supergraph technique is then applied to rigorously prove the N=2
non-renormalization theorem as well as to compute the holomorphic low-energy
action for the N = 2 SU(2) pure super Yang-Mills theory and the leading
non-holomorphic low-energy correction for N = 4 SU(2) super Yang-Mills theory.Comment: 17 pages, LAMUPHYS LaTeX, no figures; based on talks given by I.
Buchbinder and S. Kuzenko at the International Seminar ``Supersymmetries and
Quantum Symmetries'', July 1997, Dubna; to be published in the proceeding
Harmonic space and quaternionic manifolds
We find a principle of harmonic analyticity underlying the quaternionic
(quaternion-K\"ahler) geometry and solve the differential constraints which
define this geometry. To this end the original -dimensional quaternionic
manifold is extended to a bi-harmonic space. The latter includes additional
harmonic coordinates associated with both the tangent local group and
an extra rigid group rotating the complex structures. Then the
constraints can be rewritten as integrability conditions for the existence of
an analytic subspace in the bi-harmonic space and solved in terms of two
unconstrained potentials on the analytic subspace. Geometrically, the
potentials have the meaning of vielbeins associated with the harmonic
coordinates. We also establish a one-to-one correspondence between the
quaternionic spaces and off-shell supersymmetric sigma-models coupled to
supergravity. The general sigma-model Lagrangian when written in
the harmonic superspace is composed of the quaternionic potentials. Coordinates
of the analytic subspace are identified with superfields describing
matter hypermultiplets and a compensating hypermultiplet of supergravity.
As an illustration we present the potentials for the symmetric quaternionic
spaces.Comment: 44 pages, LATEX, JHU-TIPAC-920023, ENSLAPP-L-405-92, MPI-Ph/92-8
Worldline Superfield Actions for N=2 Superparticles
We propose doubly supersymmetric actions in terms of n=2(D-2) worldline
superfields for N=2 superparticles in D=3,4 and Type IIA D=6 superspaces. These
actions are obtained by dimensional reduction of superfield actions for N=1
superparticles in D=4,6 and 10, respectively. We show that in all these models
geometrodynamical constraints on target superspace coordinates do not put the
theory on the mass shell, so the actions constructed consistently describe the
dynamics of the corresponding N=2 superparticles. We also find that in contrast
to the IIA D=6 superparticle a chiral IIB D=6 superparticle, which is not
obtainable by dimensional reduction from N=1, D=10, is described by superfield
constraints which produce dynamical equations. This implies that for the IIB
D=6 superparticle the doubly supersymmetric action does not exist in the
conventional form.Comment: Latex, 20 pp. Minor corrections, acknowledgements adde
Mass-Deformed BLG Theory in Light-Cone Superspace
Maximally supersymmetric mass deformation of the Bagger-Lambert-Gustavsson
(BLG) theory corresponds to a {non-central} extension of the d=3 N=8 Poincare
superalgebra (allowed in three dimensions). We obtain its light-cone superspace
formulation which has a novel feature of the dynamical supersymmetry generators
being {cubic} in the kinematical ones. The mass deformation picks a
quaternionic direction, which breaks the SO(8) R-symmetry down to SO(4)xSO(4).
The Hamiltonian of the theory is shown to be a quadratic form of the dynamical
supersymmetry transformations, to all orders in the mass parameter, M, and the
structure constants, f^{a b c d}.Comment: 23 page
Dissolution, Reactor, and Environmental Behavior of ZrO 2 -MgO Inert Fuel Matrix Neutronic Evaluation of MgO-ZrO2 Inert Fuels
In the second year of the “Dissolution, Reactor, and Environmental Behavior of ZrO2-MgO Inert Fuel Matrix” project initiated and directed by UNLV, the Ben-Gurion University (BGU) group research was focused on the development of practical PWR core nuclear design fully loaded with Reactor Grade (RG) Pu fuel incorporated in fertile free matrix. The design strategy was based on the basic feasibility study results performed at BGU in the Year 1 of the project
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