5,842 research outputs found
Reionization constraints on primordial magnetic fields
We study the impact of the extra density fluctuations induced by primordial
magnetic fields on the reionization history in the redshift range: . We perform a comprehensive MCMC physical analysis allowing the variation
of parameters related to primordial magnetic fields (strength, , and
power-spectrum index ), reionization, and
CDM cosmological model. We find that magnetic field strengths in the
range: nG (for nearly scale-free power spectra) can
significantly alter the reionization history in the above redshift range and
can relieve the tension between the WMAP and quasar absorption spectra data.
Our analysis puts upper-limits on the magnetic field strength nG (95 % c.l.) for , respectively. These represent the strongest magnetic field constraints
among those available from other cosmological observables.Comment: Accepted for publication in MNRAS; 9 pages, 6 figure
One-loop renormalisation of N=1/2 supersymmetric gauge theory with a superpotential
We construct a superpotential for the general N=1/2 supersymmetric gauge
theory coupled to chiral matter in the fundamental and adjoint representations,
and investigate the one-loop renormalisability of the theories.Comment: 67 pages, including 17 figures. Plain TeX. Uses Harvmac and epsf.
Combined and condensed version of hep-th/0607194 and hep-th/0607195 with some
added material including in particular a generalisation of the Lunin-Rey
classification of potentially divergent operator
Contour spectrograms for POGO analysis
Contour spectrograms for POGO analysis in Saturn S-2 and S-4b stage
Supersymmetric Sum Rules for Electromagnetic Multipoles
We derive model independent, non-perturbative supersymmetric sum rules for
the magnetic and electric multipole moments of any theory with N=1
supersymmetry. We find that in any irreducible N=1 supermultiplet the diagonal
matrix elements of the l-multipole moments are completely fixed in terms of
their off-diagonal matrix elements and the diagonal (l-1)-multipole moments.Comment: 10 pages, plain Te
On the construction of variant supergravities in D=11, D=10
We construct with a geometric procedure the supersymmetry transformation laws
and Lagrangian for all the ``variant'' D=11 and D=10 Type IIA supergravities.
We identify into our classification the D=11 and D=10 Type IIA ``variant''
theories first introduced by Hull performing T-duality transformation on both
spacelike and timelike circles. We find in addition a set of D=10 Type IIA
``variant'' supergravities that can not be obtained trivially from eleven
dimensions compactifying on a circle.Comment: 21 pages, Late
On Central Charges and Hamiltonians for 0-brane dynamics
We consider general properties of central charges of zero branes and
associated duality invariants, in view of their double role, on the bulk and on
the world volume (quantum-mechanical) theory. A detailed study of the BPS
condition for the mass spectrum arising from toroidal compactifications is
given for 1/2, 1/4 and 1/8 BPS states in any dimensions. As a byproduct, we
retreive the U-duality invariant conditions on the charge (zero mode) spectrum
and the orbit classification of BPS states preserving different fractions of
supersymmetry. The BPS condition for 0-branes in theories with 16
supersymmetries in any dimension is also discussed.Comment: 23 pages, latex fil
Branes, central charges and U-duality invariant BPS conditions
In extended supergravity theories there are -brane solutions preserving
different numbers of supersymmetries, depending on the charges, the spacetime
dimension and the number of original supersymmetries (8, 16 or 32). We find
U-duality invariant conditions on the quantized charges which specify the
number of supersymmetries preserved with a particular charge configuration.
These conditions relate U-duality invariants to the picture of intersecting
branes. The analysis is carried out for all extended supergravities with 16 or
32 supersymmetries in various dimensions.Comment: 15 pages, no figures, typos correcte
D=6, N=2, F(4)-Supergravity with supersymmetric de Sitter Background
We show that there exists a supersymmetric de Sitter background for the D=6,
N=2, F(4) supergravity preserving the compact R-symmetry and gauging with
respect to the conventional Anti de Sitter version of the theory. We construct
the gauged matter coupled F(4) de Sitter supergravity explicitly and show that
it contains ghosts in the vector sector.Comment: 19 pages, Late
On the Stability of Non-Supersymmetric Quantum Attractors in String Theory
We study four dimensional non-supersymmetric attractors in type IIA string
theory in the presence of sub-leading corrections to the prepotential. For a
given Calabi-Yau manifold, the D0-D4 system admits an attractor point in the
moduli space which is uniquely specified by the black hole charges. The
perturbative corrections to the prepotential do not change the number of
massless directions in the black hole effective potential. We further study
non-supersymmetric D0-D6 black holes in the presence of sub-leading
corrections. In this case the space of attractor points define a hypersurface
in the moduli space.Comment: References Added, Typos Corrected, Appendix A.2 Reordere
N=2 Supergravity and N=2 Super Yang-Mills Theory on General Scalar Manifolds: Symplectic Covariance, Gaugings and the Momentum Map
The general form of N=2 supergravity coupled to an arbitrary number of vector
multiplets and hypermultiplets, with a generic gauging of the scalar manifold
isometries is given. This extends the results already available in the
literature in that we use a coordinate independent and manifestly symplectic
covariant formalism which allows to cover theories difficult to formulate
within superspace or tensor calculus approach. We provide the complete
lagrangian and supersymmetry variations with all fermionic terms, and the form
of the scalar potential for arbitrary quaternionic manifolds and special
geometry, not necessarily in special coordinates. Lagrangians for rigid
theories are also written in this general setting and the connection with local
theories elucidated. The derivation of these results using geometrical
techniques is briefly summarized.Comment: LaTeX, 80 pages, extended version of hep-th/960300
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