1,591 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
Supersymmetric Randall-Sundrum Scenario
We present the supersymmetric version of the minimal Randall-Sundrum model
with two opposite tension branes.Comment: Latex, 9 pages. Published versio
Spinor Algebras
We consider supersymmetry algebras in space-times with arbitrary signature
and minimal number of spinor generators. The interrelation between super
Poincar\'e and super conformal algebras is elucidated. Minimal super conformal
algebras are seen to have as bosonic part a classical semimisimple algebra
naturally associated to the spin group. This algebra, the Spin-algebra,
depends both on the dimension and on the signature of space time. We also
consider maximal super conformal algebras, which are classified by the
orthosymplectic algebras.Comment: References added, misprints corrected. Version to appear in the
Journal of Geometry and Physic
Identification of Limiting Case Between DBA and SBDBA (CL Break Area Sensitivity): A New Model for the Boron Injection System
Atucha-2 is a Siemens-designed PHWR reactor under construction in the Republic of
Argentina. Its geometrical complexity and (e.g., oblique Control Rods, Positive Void coefficient)
required a developed and validated complex three dimensional (3D) neutron kinetics (NK) coupled
thermal hydraulic (TH) model. Reactor shut-down is obtained by oblique CRs and, during
accidental conditions, by an emergency shut-down system (JDJ) injecting a highly concentrated
boron solution (boron clouds) in the moderator tank, the boron clouds reconstruction is obtained
using a CFD (CFX) code calculation. A complete LBLOCA calculation implies the application of
the RELAP5-3D© system code. Within the framework of the third Agreement âNA-SA â
University of Pisaâ a new RELAP5-3D control system for the boron injection system was developed
and implemented in the validated coupled RELAP5-3D/NESTLE model of the Atucha 2 NPP. The
aim of this activity is to find out the limiting case (maximum break area size) for the Peak Cladding
Temperature for LOCAs under fixed boundary conditions
Alleviating the non-ultralocality of coset sigma models through a generalized Faddeev-Reshetikhin procedure
The Faddeev-Reshetikhin procedure corresponds to a removal of the
non-ultralocality of the classical SU(2) principal chiral model. It is realized
by defining another field theory, which has the same Lax pair and equations of
motion but a different Poisson structure and Hamiltonian. Following earlier
work of M. Semenov-Tian-Shansky and A. Sevostyanov, we show how it is possible
to alleviate in a similar way the non-ultralocality of symmetric space sigma
models. The equivalence of the equations of motion holds only at the level of
the Pohlmeyer reduction of these models, which corresponds to symmetric space
sine-Gordon models. This work therefore shows indirectly that symmetric space
sine-Gordon models, defined by a gauged Wess-Zumino-Witten action with an
integrable potential, have a mild non-ultralocality. The first step needed to
construct an integrable discretization of these models is performed by
determining the discrete analogue of the Poisson algebra of their Lax matrices.Comment: 31 pages; v2: minor change
Supersymmetric Brane World Scenarios from Off-Shell Supergravity
Using N=2 off-shell supergravity in five dimensions, we supersymmetrize the
brane world scenario of Randall and Sundrum. We extend their construction to
include supersymmetric matter at the fixpoints.Comment: 15 pages, no figures, late
A special road to AdS vacua
We apply the techniques of special Kaehler geometry to investigate AdS_4
vacua of general N=2 gauged supergravities underlying flux compactifications of
type II theories. We formulate the scalar potential and its extremization
conditions in terms of a triplet of prepotentials P_x and their special Kaehler
covariant derivatives only, in a form that recalls the potential and the
attractor equations of N=2 black holes. We propose a system of first order
equations for the P_x which generalize the supersymmetry conditions and yield
non-supersymmetric vacua. Special geometry allows us to recast these equations
in algebraic form, and we find an infinite class of new N=0 and N=1 AdS_4
solutions, displaying a rich pattern of non-trivial charges associated with
NSNS and RR fluxes. Finally, by explicit evaluation of the entropy function on
the solutions, we derive a U-duality invariant expression for the cosmological
constant and the central charges of the dual CFT's.Comment: 41 pages; v2, v3: minor improvements, references added, published
versio
Optical response of a misaligned and suspended Fabry-Perot cavity
The response to a probe laser beam of a suspended, misaligned and detuned
optical cavity is examined. A five degree of freedom model of the fluctuations
of the longitudinal and transverse mirror coordinates is presented. Classical
and quantum mechanical effects of radiation pressure are studied with the help
of the optical stiffness coefficients and the signals provided by an FM
sideband technique and a quadrant detector, for generic values of the product
of the fluctuation frequency times the cavity round trip. A
simplified version is presented for the case of small misalignments. Mechanical
stability, mirror position entanglement and ponderomotive squeezing are
accommodated in this model. Numerical plots refer to cavities under test at the
so-called Pisa LF facility.Comment: 14 pages (4 figures) submitted to Phys. Rev.
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