679 research outputs found
The Q-Sort Method: Assessing Reliability And Construct Validity Of Questionnaire Items At A Pre-Testing Stage
This paper describes the Q-sort, which is a method of assessing reliability and construct validity of questionnaire items at a pre-testing stage. The method uses Cohen\u27s Kappa and Moore and Benbasat\u27s Hit Ratio in assessing the questionnaire
Free tensor multiplets and strings in spontaneously broken six-dimensional (2,0) theory
We first review the representations of the six-dimensional (2,0) superalgebra
on a free tensor multiplet and on a free string. We then construct a
supersymmetric Lagrangian describing a free tensor multiplet. (It also includes
a decoupled anti self-dual part of the three-form field strength.) This field
theory is then rewritten in variables appropriate for analyzing a situation
where the R-symmetry is spontaneously broken by the vacuum expectation values
of the scalar moduli fields. Finally, we construct a supersymmetric and
kappa-symmetric action for a free string.Comment: 15 pages, LaTe
Dyons in N=4 Supersymmetric Theories and Three-Pronged Strings
We construct and explore BPS states that preserve 1/4 of supersymmetry in N=4
Yang-Mills theories. Such states are also realized as three-pronged strings
ending on D3-branes. We correct the electric part of the BPS equation and
relate its solutions to the unbroken abelian gauge group generators. Generic
1/4-BPS solitons are not spherically symmetric, but consist of two or more
dyonic components held apart by a delicate balance between static
electromagnetic force and scalar Higgs force. The instability previously found
in three-pronged string configurations is due to excessive repulsion by one of
these static forces. We also present an alternate construction of these 1/4-BPS
states from quantum excitations around a magnetic monopole, and build up the
supermultiplet for arbitrary (quantized) electric charge. The degeneracy and
the highest spin of the supermultiplet increase linearly with a relative
electric charge. We conclude with comments.Comment: 33 pages, two figures, LaTex, a footnote added, the figure caption of
Fig.2 expanded, one more referenc
Democratic Supersymmetry
We present generalisations of N-extended supersymmetry algebras in four
dimensions, using Lorentz covariance and invariance under permutation of the N
supercharges as selection criteria.Comment: 26 pages, latex fil
Stringy Derivation of Nahm Construction of Monopoles
We derive the Nahm construction of monopoles from exact tachyon condensation
on unstable D-branes. The Dirac operator used in the Nahm construction is
identified with the tachyon profile in our D-brane approach, and we provide
physical interpretation of the procedures Nahm gave. Crucial is the
introduction of infinite number of brane-antibranes from which arbitrary
D-brane can be constrcuted, exhibitting a unified view of various D-branes. We
explicitly show the equivalence of the D3-brane boundary state with the
monopole profile and the D1-brane boundary state with the Nahm data as
transverse scalars.Comment: 18 pages, 4 eps figures, JHEP style, comments about low energy limits
added, references adde
Monopoles and Instantons on Partially Compactified D-Branes
Motivated by the recent D-brane constructions of world-volume monopoles and
instantons, we study the supersymmetric SU(N) Yang-Mills theory on , spontaneously broken by a Wilson loop. In addition to the usual N-1
fundamental monopoles, the N-th BPS monopole appears from the Kaluza-Klein
sector. When all N monopoles are present, net magnetic charge vanishes and the
solution can be reinterpreted as a Wilson-loop instanton of unit Pontryagin
number. The instanton/multi-monopole moduli space is explicitly constructed,
and seen to be identical to a Coulomb phase moduli space of a U(1)^N gauge
theory in 2+1 dimensions related to Kronheimer's gauge theory of SU(N) type.
This extends the results by Intriligator and Seiberg to the finite couplings
that, in the infrared limit of Kronheimer's theory, the Coulomb phase
parameterizes a centered SU(N) instanton. We also elaborate on the case of
restored SU(N) symmetry.Comment: LaTex, 18pages, no figur
Quantum corrections to static solutions of Nahm equation and Sin-Gordon models via generalized zeta-function
One-dimensional Yang-Mills Equations are considered from a point of view of a
class of nonlinear Klein-Gordon-Fock models. The case of self-dual Nahm
equations and non-self-dual models are discussed. A quasiclassical quantization
of the models is performed by means of generalized zeta-function and its
representation in terms of a Green function diagonal for a heat equation with
the correspondent potential. It is used to evaluate the functional integral and
quantum corrections to mass in the quasiclassical approximation.
Quantum corrections to a few periodic (and kink) solutions of the Nahm as a
particular case of the Ginzburg-Landau (phi-in-quadro) and and Sin-Gordon
models are evaluated in arbitrary dimensions. The Green function diagonal for
heat equation with a finite-gap potential is constructed by universal
description via solutions of Hermit equation. An alternative approach based on
Baker-Akhiezer functions for KP equation is proposed . The generalized
zeta-function and its derivative at zero point as the quantum corrections to
mass is expressed in terms of elliptic integrals.Comment: Workshop Nonlinear Physics and Experiment; Gallipoli, 200
New hyper-Kaehler manifolds by fixing monopoles
The construction of new hyper-Kaehler manifolds by taking the infinite
monopole mass limit of certain Bogomol'nyi-Prasad-Sommerfield monopole moduli
spaces is considered. The one-parameter family of hyperkaehler manifolds due to
Dancer is shown to be an example of such manifolds. A new family of fixed
monopole spaces is constructed. They are the moduli spaces of four SU(4)
monopoles, in the infinite mass limit of two of the monopoles. These manifolds
are shown to be nonsingular when the fixed monopole positions are distinct.Comment: Version in Phys. Rev. D. 11 pp, RevTeX, 14 Postscript diagram
On Modular Invariance and 3D Gravitational Instantons
We study the modular transformation properties of Euclidean solutions of 3D
gravity whose asymptotic geometry has the topology of a torus. These solutions
represent saddle points of the grand canonical partition function with an
important example being the BTZ black hole, and their properties under modular
transformations are inherited from the boundary conformal field theory encoding
the asymptotic dynamics. Within the Chern Simons formulation, classical
solutions are characterised by specific holonomies describing the wrapping of
the gauge field around cycles of the torus. We find that provided these
holonomies transform in an appropriate manner, there exists an associated
modular invariant grand canonical partition function and that the spectrum of
saddle points naturally includes a thermal bath in as discussed by
Maldacena and Strominger. Indeed, certain modular transformations can naturally
be described within classical bulk dynamics as mapping between different
foliations with a "time" coordinate along different cycles of the asymptotic
torus.Comment: 14 pages, RevTeX, typos corrected, to appear in Phys. Rev.
Super-Ehlers in Any Dimension
We classify the enhanced helicity symmetry of the Ehlers group to extended
supergravity theories in any dimension. The vanishing character of the
pseudo-Riemannian cosets occurring in this analysis is explained in terms of
Poincar\'e duality. The latter resides in the nature of regularly embedded
quotient subgroups which are non-compact rank preserving.Comment: 1+55 pages; 15 Tables, 6 Figures; v2 : some clarifications added in
Sec. 1 and in App.
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