12 research outputs found
Dual versions of extended supergravities
Recently, using the model of N=2 supergravity -- vector multiplets
interaction with the scalar field geometry as an
example, we have shown that even when the scalar field geometry is fixed, one
can have a whole family of the Lagrangians, which differ by vector field
duality transformation. In this paper we carry out the construction of such
families for the case of N=3 and N=4 supergravities, the scalar field geometry
being and , correspondingly. Moreover, it turns out that these
families contain, as a partial case, the models describing the interaction of
arbitrary number of vector multiplets with our hidden sectors, admitting
spontaneous supersymmetry breaking without a cosmological term.Comment: 9 pages, plain LaTeX, no figure
Axion gauge symmetries and generalized Chern-Simons terms in N=1 supersymmetric theories
We compute the form of the Lagrangian of N=1 supersymmetric theories with
gauged axion symmetries. It turns out that there appear generalized
Chern-Simons terms that were not considered in previous superspace formulations
of general N=1 theories. Such gaugings appear in supergravities arising from
flux compactifications of superstrings, as well as from Scherk-Schwarz
generalized dimensional reduction in M-theory. We also present the dual
superspace formulation where axion chiral multiplets are dualized into linear
multiplets.Comment: References added and few misprints correcte
N=2 Super-Higgs, N=1 Poincare' Vacua and Quaternionic Geometry
In the context of N=2 supergravity we explain the occurrence of partial
super-Higgs with vanishing vacuum energy and moduli stabilization in a model
suggested by superstring compactifications on type IIB orientifolds with 3-form
fluxes.
The gauging of axion symmetries of the quaternionic manifold, together with
the use of degenerate symplectic sections for special geometry, are the
essential ingredients of the construction.Comment: 18 page
4-D gauged supergravity analysis of Type IIB vacua on
We analyze vacua of type IIB string theory on in
presence of three-form fluxes from a four dimensional supergravity viewpoint.
The quaternionic geometry of the moduli space together with the special
geometry of the NS and R-R dilatons and of the -complex structure moduli
play a crucial role in the analysis. The introduction of fluxes corresponds to
a particular gauging of N=2, D=4 supergravity. Our results agree with a recent
work of Tripathy and Trivedi. The present formulation shows the power of
supergravity in the study of effective theories with broken supersymmetry.Comment: AMS-LaTeX, 29 page
The minimal N=4 no-scale model from generalized dimensional reduction
We consider the generalized dimensional reduction of pure ungauged N=4, D=5
supergravity, where supersymmetry is spontaneously broken to N=2 or N=0 with
identically vanishing scalar potential. We explicitly construct the resulting
gauged D=4 theory coupled to a single vector multiplet, which provides the
minimal N=4 realization of a no-scale model. We discuss its relation with the
standard classification of N=4 gaugings, extensions to non-compact twists and
to higher dimensions, the N=2 theories obtained via consistent Z_2 orbifold
projections and prospects for further generalizations.Comment: 1+28 pages, no figures, JHEP3 LaTeX, published versio
N=4 Supergravity Lagrangian for Type IIB Orientifold on T^6/Z_2 in Presence of Fluxes and D3-Branes
We derive the Lagrangian and the transformation laws of N=4 gauged
supergravity coupled to matter multiplets whose sigma-model of the scalars is
SU(1,1)/U(1)x SO(6,6+n)/SO(6)xSO(6+n) and which corresponds to the effective
Lagrangian of the Type IIB string compactified on the T^6/Z_2 orientifold with
fluxes turned on and in presence of n D3-branes. The gauge group is T^12 x G
where G is the gauge group on the brane and T^12 is the gauge group on the bulk
corresponding to the gauged translations of the R-R scalars coming from the R-R
four--form. The N=4 bulk sector of this theory can be obtained as a truncation
of the Scherk-Schwarz spontaneously broken N=8 supergravity. Consequently the
full bulk spectrum satisfies quadratic and quartic mass sum rules, identical to
those encountered in Scherk-Schwarz reduction gauging a flat group. This theory
gives rise to a no scale supergravity extended with partial super-Higgs
mechanism.Comment: 49 pages, LaTex, 2 figures. Misprints corrected, more comments adde
Increasing the corrosion resistance of heat-resistant alloys for parts of power equipment
For the manufacture of parts and assemblies of the turbopump unit of details of power equipment, welded joints with corrosion resistant steels and heat-resistant alloys are used, requiring various modes heat treatment to achieve the required level of mechanical properties. In the manufacture of parts and assemblies of details of power equipment at the machine-building enterprises of Ukraine, it became necessary to replace semi-finished products. It is necessary to replace sheet products from high-alloy alloys ХН67МВТЮ and 06Х15Н6МВФБ with one alloy with a high complex of physical and mechanical characteristics. In the work, as a replacement for the applied heat-resistant alloys, Inconel 718 alloy welded to 316L steel. Samples of welded joints, processed according to the recommended mode, showed increased corrosion resistance.Для виготовлення деталей енергетичного обладнання застосовуються зварні з’єднання з корозійно-стійкими сталями та жароміцними сплавами, що потребують різних режимів термічної обробки для досягнення необхідного рівня механічних властивостей. При виготовленні деталей енергетичного обладнання на машинобудівних підприємствах України виникла потреба заміни напівфабрикатів. Необхідна заміна листового прокату з високолегованих сплавів ХН67МВТЮ та 06Х15Н6МВФБ на один сплав із високим комплексом фізико-механічних характеристик. У роботі в якості заміни жароміцних сплавів обраний сплав Inconel 718 у зварному з’єднанні зі сталлю 316L. Зразки зварних з’єднань, які оброблені за рекомендованим режимом, показали підвищену корозійну стійкість
Anomalies, Anomalous U(1)'s and generalized Chern-Simons terms
A detailed analysis of anomalous U(1)'s and their effective couplings is
performed both in field theory and string theory. It is motivated by the
possible relevance of such couplings in particle physics, as well as a
potential signal distinguishing string theory from other UV options. The most
general anomaly related effective action is analyzed and parameterized. It
contains Stuckelberg, axionic and Chern-Simons-like couplings. It is shown that
such couplings are generically non-trivial in orientifold string vacua and are
not in general fixed by anomalies. A similar analysis in quantum field theories
provides similar couplings. The trilinear gauge boson couplings are also
calculated and their phenomenological relevance is advocated. We do not find
qualitative differences between string and field theory in this sector.Comment: 52 pages, 2 eps figures, LaTeX, feynmf & youngtab packages (v2 -
Minor corrections, references added
N=3 Warped Compactifications
Orientifolds with three-form flux provide some of the simplest string
examples of warped compactification. In this paper we show that some models of
this type have the unusual feature of D=4, N=3 spacetime supersymmetry. We
discuss their construction and low energy physics. Although the local form of
the moduli space is fully determined by supersymmetry, to find its global form
requires a careful study of the BPS spectrum.Comment: 27 pages, v2: 32pp., RevTeX4, fixed factors, slightly improved
sections 3D and 4B, v3: added referenc
Holography of D-Brane Reconnection
Gukov, Martinec, Moore and Strominger found that the D1-D5-D5' system with
the D5-D5' angle at 45 degrees admits a deformation "rho" preserving
supersymmetry. Under this deformation, the D5-branes and D5'-branes reconnect
along a single special Lagrangian manifold. We construct the near-horizon limit
of this brane setup (for which no supergravity solution is currently known),
imposing the requisite symmetries perturbatively in the deformation rho.
Reducing to the three-dimensional effective gauged supergravity, we compute the
scalar potential and verify the presence of a deformation with the expected
properties. We compute the conformal dimensions as functions of rho. This
spectrum naturally organizes into N=3 supermultiplets, corresponding to the
3/16 preserved by the brane system. We give some remarks on the symmetric
orbifold CFT for Q_D5=Q_D5', outline the computation of rho-deformed
correlators in this theory, and probe computations in our rho-deformed
background.Comment: 33 pages, 5 figure