8 research outputs found
The Gauging of Five-dimensional, N=2 Maxwell-Einstein Supergravity Theories coupled to Tensor Multiplets
We study the general gaugings of N=2 Maxwell-Einstein supergravity theories
(MESGT) in five dimensions, extending and generalizing previous work. The
global symmetries of these theories are of the form SU(2)_R X G, where SU(2)_R
is the R-symmetry group of the N=2 Poincare superalgebra and G is the group of
isometries of the scalar manifold that extend to symmetries of the full action.
We first gauge a subgroup K of G by turning some of the vector fields into
gauge fields of K while dualizing the remaining vector fields into tensor
fields transforming in a non-trivial representation of K. Surprisingly, we find
that the presence of tensor fields transforming non-trivially under the
Yang-Mills gauge group leads to the introduction of a potential which does not
admit an AdS ground state. Next we give the simultaneous gauging of the U(1)_R
subgroup of SU(2)_R and a subgroup K of G in the presence of K-charged tensor
multiplets. The potential introduced by the simultaneous gauging is the sum of
the potentials introduced by gauging K and U(1)_R separately. We present a list
of possible gauge groups K and the corresponding representations of tensor
fields. For the exceptional supergravity we find that one can gauge the SO^*(6)
subgroup of the isometry group E_{6(-26)} of the scalar manifold if one
dualizes 12 of the vector fields to tensor fields just as in the gauged N=8
supergravity.Comment: Latex file, 23 page
On the classification of OADP varieties
The main purpose of this paper is to show that OADP varieties stand at an
important crossroad of various main streets in different disciplines like
projective geometry, birational geometry and algebra. This is a good reason for
studying and classifying them. Main specific results are: (a) the
classification of all OADP surfaces (regardless to their smoothness); (b) the
classification of a relevant class of normal OADP varieties of any dimension,
which includes interesting examples like lagrangian grassmannians. Following
[PR], the equivalence of the classification in (b) with the one of
quadro-quadric Cremona transformations and of complex, unitary, cubic Jordan
algebras are explained.Comment: 13 pages. Dedicated to Fabrizio Catanese on the occasion of his 60th
birthday. To appear in a special issue of Science in China Series A:
Mathematic
Unified N=2 Maxwell-Einstein and Yang-Mills-Einstein Supergravity Theories in Four Dimensions
We study unified N=2 Maxwell-Einstein supergravity theories (MESGTs) and
unified Yang-Mills Einstein supergravity theories (YMESGTs) in four dimensions.
As their defining property, these theories admit the action of a global or
local symmetry group that is (i) simple, and (ii) acts irreducibly on all the
vector fields of the theory, including the ``graviphoton''. Restricting
ourselves to the theories that originate from five dimensions via dimensional
reduction, we find that the generic Jordan family of MESGTs with the scalar
manifolds [SU(1,1)/U(1)] X [SO(2,n)/SO(2)X SO(n)] are all unified in four
dimensions with the unifying global symmetry group SO(2,n). Of these theories
only one can be gauged so as to obtain a unified YMESGT with the gauge group
SO(2,1). Three of the four magical supergravity theories defined by simple
Euclidean Jordan algebras of degree 3 are unified MESGTs in four dimensions.
Two of these can furthermore be gauged so as to obtain 4D unified YMESGTs with
gauge groups SO(3,2) and SO(6,2), respectively. The generic non-Jordan family
and the theories whose scalar manifolds are homogeneous but not symmetric do
not lead to unified MESGTs in four dimensions. The three infinite families of
unified five-dimensional MESGTs defined by simple Lorentzian Jordan algebras,
whose scalar manifolds are non-homogeneous, do not lead directly to unified
MESGTs in four dimensions under dimensional reduction. However, since their
manifolds are non-homogeneous we are not able to completely rule out the
existence of symplectic sections in which these theories become unified in four
dimensions.Comment: 47 pages; latex fil
Unified Maxwell-Einstein and Yang-Mills-Einstein Supergravity Theories in Five Dimensions
Unified N=2 Maxwell-Einstein supergravity theories (MESGTs) are supergravity
theories in which all the vector fields, including the graviphoton, transform
in an irreducible representation of a simple global symmetry group of the
Lagrangian. As was established long time ago, in five dimensions there exist
only four unified Maxwell-Einstein supergravity theories whose target manifolds
are symmetric spaces. These theories are defined by the four simple Euclidean
Jordan algebras of degree three. In this paper, we show that, in addition to
these four unified MESGTs with symmetric target spaces, there exist three
infinite families of unified MESGTs as well as another exceptional one. These
novel unified MESGTs are defined by non-compact (Minkowskian) Jordan algebras,
and their target spaces are in general neither symmetric nor homogeneous. The
members of one of these three infinite families can be gauged in such a way as
to obtain an infinite family of unified N=2 Yang-Mills-Einstein supergravity
theories, in which all vector fields transform in the adjoint representation of
a simple gauge group of the type SU(N,1). The corresponding gaugings in the
other two infinite families lead to Yang-Mills-Einstein supergravity theories
coupled to tensor multiplets.Comment: Latex 2e, 28 pages. v2: reference added, footnote 14 enlarge
CARBON DIOXIDE ENRICHMENT ON GROWTH AND YIELD OF SWEET POTATOES (IPOMOEA BATATAS, cv GEORGIA JET)
This study was conducted to obtain field data on the growth and yield of sweet potaotes in elevated levels of carbon dioxide (C02 ) , Sweet potato plants were planted in open-top chambers as well as in open field plots. The plants were grown at ambient CO2 with and without chambers, ambient +75, +150, and +300 ppm (90 days). Enriched CO2 concentration increased the number of tubers and the percentage of dry matter of the tubers. The density, length and diameter of the tubers did not vary significantly in enriched CO2 levels. ----- Este estudio se llevrf a cabo con el objeto de obtener informacion sobre los ensayos relacionados con el desarrollo y la produccidn del camote con niveles altos de dioxido de carb6n' (C02 ) Los camotes fueron plantados en camaras sin techos, como tambien, se los cultivo' en parcelas de campo. Las plantas fueron cultivadas al ambiente C02, en camaras y fuera de elias, arnbiente +75, +150 y +300 ppm (noventa dias). Una concentraci6n mas fuerte de C02 incremento el numero de tuberculos, La densidad, ellargo y el diimetro de los tuberculos no vario significativamente en niveles altos de C02