39 research outputs found
Two-Field Born-Infeld with Diverse Dualities
We elaborate on how to build, in a systematic fashion, two-field Abelian
extensions of the Born-Infeld Lagrangian. These models realize the non-trivial
duality groups that are allowed in this case, namely U(2), SU(2) and U(1)xU(1).
For each class, we also construct an explicit example. They all involve an
overall square root and reduce to the Born-Infeld model if the two fields are
identified, but differ in quartic and higher interactions. The U(1)xU(1) and
SU(2) examples recover some recent results obtained with different techniques,
and we show that the U(1)xU(1) model admits an N=1 supersymmetric completion.
The U(2) example includes some unusual terms that are not analytic at the
origin of field space.Comment: 30 pages. Final version with reference added, typo corrected and
comment added in the Conclusions. To appear in a special Nucl. Phys. B issue
dedicated to the memory of Raymond Stor
Doubly Self-Dual Actions in Various Dimensions
The self-duality of the N=1 supersymmetric Born--Infeld action implies a
double self-duality of the tensor multiplet square-root action when the scalar
and the antisymmetric tensor are interchanged via Poincare' duality. We show
how this phenomenon extends to D space-time dimensions for non-linear actions
involving pairs of forms of rank p and D-p-2. As a byproduct, we construct a
new two-field generalization of the Born-Infeld action whose equations of
motion are invariant under a U(1) duality. In these systems, the introduction
of Green-Schwarz terms results in explicit non-linear mass-like terms for dual
massive pairs.Comment: 17 pages, LaTeX. References added, duality group of eq. (4.16)
changed to SU(2). Final version to appear in JHE
Attractors and first order formalism in five dimensions revisited
The attractor mechanism in five dimensional Einstein-Maxwell Chern-Simons
theory is studied. The expression of the five dimensional rotating black object
potential depending on Taub-NUT, electric and magnetic charges as well as on
all the scalar and gauge fields, is investigated. The first order formalism in
d=5 is constructed and analyzed. We derive a general expression defining the
fake superpotential which is valid for all charge configurations. An explicit
expression for the fake superpotential is constructed, for all very special
geometries, in the case of vanishing Taub-NUT charge. We carry out an analogous
construction in the very special geometries corresponding to and
models, for the most general charge configurations. The attractor flows and
horizon values of all fields are given.Comment: 33 pages, PACS numbers: 04.65.+e, 04.50.Gh, 04.70.Bw, 04.70.Dy,
keywords: five dimensional supergravity, black objects, entropy, attractor
flows, first order formalism, fake superpotential. Several typos corrected;
one reference added; section 6 (conclusions) expande
Supermembrane in D=5: component action
Based on the connection between partial breaking of global supersymmetry,
coset approach, which realized the given pattern of supersymmetry breaking, and
the Nambu-Goto actions for the extended objects, we have constructed on-shell
component action for N=1, D=5 supermembrane and its dual cousins. We
demonstrate that the proper choice of the components and the use of the
covariant (with respect to broken supersymmetry) derivatives drastically
simplify the action: it can be represented as a sum of four terms each having
an explicit geometric meaning.Comment: 14 pages, PACS: 11.30.Pb, 12.60.J
Generalized Born--Infeld Actions and Projective Cubic Curves
We investigate supersymmetric Born-Infeld Lagrangians with a
second non-linearly realized supersymmetry. The resulting non-linear structure
is more complex than the square root present in the standard Born-Infeld
action, and nonetheless the quadratic constraints determining these models can
be solved exactly in all cases containing three vector multiplets. The
corresponding models are classified by cubic holomorphic prepotentials. Their
symmetry structures are associated to projective cubic varieties.Comment: 17 pages, LaTeX, 1 eps figure. Comments added and misprints
corrected. Final version to appear in Fortschritte der Physik - Progress of
Physic
Noncommutative Coulombic Monopole
We have constructed the appropriate Hamiltonian of the noncommutative
coulombic monopole (i.e. the noncommutative hydrogen atom with a monopole). The
energy levels of this system have been calculated, discussed and compared with
the noncommutative hydrogen atom ones. The main emphasis is put on the ground
state. In addition, the Stark effect for the noncommutative coulombic monopole
has been studied.Comment: 5 pages, PACS numbers: 03.65.-w, 14.80.Hv, 02.40.Gh, 32.60.+
stu Black Holes Unveiled
The general solutions of the radial attractor flow equations for extremal
black holes, both for non-BPS with non-vanishing central charge Z and for Z=0,
are obtained for the so-called stu model, the minimal rank-3 N=2 symmetric
supergravity in d=4 space-time dimensions. Comparisons with previous results,
as well as the fake supergravity (first order) formalism and an analysis of the
BPS bound all along the non-BPS attractor flows and of the marginal stability
of corresponding D-brane configurations, are given.Comment: 1+40 pages; v2: various typos fixed; v3: improved version, with the
BPS bound for ADM mass obtained for all non-BPS configurations, both with
non-vanishing and vanishing central charg