1,193 research outputs found
Rigid N=2 superconformal hypermultiplets
We discuss superconformally invariant systems of hypermultiplets coupled to
gauge fields associated with target-space isometries.Comment: Invited talk given at the International Seminar "Supersymmetries and
Quantum Symmetries", July 1997, Dubna. Latex, 9 p
Fermions and Supersymmetry Breaking in the Interval
We study fermions, such as gravitinos and gauginos in supersymmetric
theories, propagating in a five-dimensional bulk where the fifth dimensional
component is assumed to be an interval. We show that the most general boundary
condition at each endpoint of the interval is encoded in a single complex
parameter representing a point in the Riemann sphere. Upon introducing a
boundary mass term, the variational principle uniquely determines the boundary
conditions and the bulk equations of motion. We show the mass spectrum becomes
independent from the Scherk-Schwarz parameter for a suitable choice of one of
the two boundary conditions. Furthermore, for any value of the Scherk-Schwarz
parameter, a zero-mode is present in the mass spectrum and supersymmetry is
recovered if the two complex parameters are tuned.Comment: 10 pages. v2: Paragraph on off-shell globally supersymmetric
Lagrangian added. Version published in PL
N=2 Super-Born-Infeld from Partially Broken N=3 Supersymmetry in d=4
We employ the non-linear realization techniques to relate the N=1 chiral, and
the N=2 vector multiplets to the Goldstone spin 1/2 superfield arising from
partial supersymmetry breaking of N=2 and N=3 respectively. In both cases, we
obtain a family of non-linear transformation laws realizing an extra
supersymmetry. In the N=2 case, we find an invariant action which is the low
energy limit of the supersymmetric Born-Infeld theory expected to describe a
D3-brane in six dimensions.Comment: 15 pages, no figures, RevTeX4, new comments and references added,
some equations corrected, discussion at end of sec. 3 change
Superheavy Supersymmetry from Scalar Mass--A Parameter Fixed Points
In supersymmetric models, the well-known tension between naturalness and
experimental constraints is relieved if the squarks and sleptons of the first
two generations are superheavy, with masses of order 10 TeV, and all other
superpartners are light, with masses of order 1 TeV. We show that even if all
scalar masses and trilinear A parameters are of order 10 TeV at some high
scale, a mass-squared hierarchy of order 400 may be generated dynamically
through renormalization group evolution. The required high energy relations are
consistent with grand unification, or, alternatively, may be realized in
moduli-dominated supersymmetry-breaking scenarios.Comment: 12 pages, 3 figure
Unifying N=5 and N=6
We write the Lagrangian of the general N=5 three-dimensional superconformal
Chern-Simons theory, based on a basic Lie superalgebra, in terms of our
recently introduced N=5 three-algebras. These include N=6 and N=8
three-algebras as special cases. When we impose an antisymmetry condition on
the triple product, the supersymmetry automatically enhances, and the N=5
Lagrangian reduces to that of the well known N=6 theory, including the ABJM and
ABJ models.Comment: 19 pages. v2: Published version. Minor typos corrected, references
adde
The influence of shield gases on the surface condition of laser treated concrete
This work aims to elucidate the effects of using O2, Ar and He shield gasses during the treatment of the ordinary Portland cement (OPC) surface of concrete with a high power diode laser (HPDL). The findings showed a marked difference existed in the surface condition of the concrete after HPDL treatment depending on the shield gas used. The use of O2 as the shield gas was seen to result in glazes with far fewer microcracks and porosities than those generated with either Ar or He shield gases. Such differences were found to be due to the smaller O2 gas molecules dissolving molecularly into the open structure of the HPDL generated glaze on the OPC surface of concrete and react with the glass network to increase the fluidity of the melt. This in turn was also seen to affect the cooling rate and therefore the tendency to generate microcracks
Oblique DLCQ M-theory and Multiple M2-branes
We propose an oblique DLCQ as a limit to realize a theory of multiple
M2-branes in M(atrix)-theory context. The limit is a combination of an infinite
boosting of a space-like circle and a tuned tilting of the circle direction. We
obtain a series of supergravity solutions describing various dual
configurations including multiple M2-branes. For an infinite boosting along a
circle wrapped obliquely around a rectangular torus, Seiberg's DLCQ limit
distorts the torus modulus. In the context of supergravity, we show explicitly
how this torus modulus of -theory is realized as the
vacuum modulus of dual IIB-theory.Comment: v3: 25pages, extended version, References adde
Supersymmetric branes with (almost) arbitrary tensions
We present a supersymmetric version of the two-brane Randall-Sundrum
scenario, with arbitrary brane tensions T_1 and T_2, subject to the bound
|T_{1,2}| \leq \sqrt{-6\Lambda_5}, where \Lambda_5 < 0 is the bulk cosmological
constant. Dimensional reduction gives N=1, D=4 supergravity, with cosmological
constant \Lambda_4 in the range \half\Lambda_5 \leq \Lambda_4 \leq 0. The case
with \Lambda_4 = 0 requires T_1 = -T_2 = \sqrt{-6\Lambda_5}. This work unifies
and generalizes previous approaches to the supersymmetric Randall-Sundrum
scenario. It also shows that the Randall-Sundrum fine-tuning is not a
consequence of supersymmetry.Comment: 19pp; Published versio
The BLG Theory in Light-Cone Superspace
The light-cone superspace version of the d=3, N=8 superconformal theory of
Bagger, Lambert and Gustavsson (BLG) is obtained as a solution to constraints
imposed by OSp(2,2|8) superalgebra. The Hamiltonian of the theory is shown to
be a quadratic form of the dynamical supersymmetry transformation.Comment: 45 pages, v2: reference added, minor typos corrected, published
versio
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