324 research outputs found
Four-Dimensional N=2(4) Superstring Backgrounds and The Real Heavens
We study N=2(4) superstring backgrounds which are four-dimensional
non-\Kahlerian with non-trivial dilaton and torsion fields. In particular we
consider the case that the backgrounds possess at least one isometry and
are characterized by the continual Toda equation and the Laplace equation. We
obtain a string background associated with a non-trivial solution of the
continual Toda equation, which is mapped, under the T-duality transformation,
to the hyper-\Kahler Taub-NUT instanton background. It is shown that the
integrable property of the non-\Kahlerian spaces have the direct origin in the
real heavens: real, self-dual, euclidean, Einstein spaces. The Laplace equation
and the continual Toda equation imposed on quasi-\Kahler geometry for
consistent string propagation are related to the self-duality conditions of the
real heavens with ``translational'' and ``rotational''Killing symmetry
respectively.Comment: 21 pages, plain te
Non-commutative M-branes from Open Pure Spinor Supermembrane
Open supermembrane with a constant three-form flux in the pure spinor
formalism is examined. The BRST symmetry of the open supermembrane action leads
to non-commutative (NC) M-branes. In addition to the NC M5-brane with a
self-dual two-form flux, we find a NC M9-brane with an electric flux and a NC
M9-brane with a magnetic flux. The former reduces in the critical electric flux
limit to an M2-brane on the M9-brane, while the latter reduces in the strong
magnetic flux limit to infinitely many Kaluza-Klein monopoles dissolved into
the M9-brane. These NC M-branes are shown to preserve a half of 32
supersymmetries.Comment: 17 pages, published versio
A Covariant Approach to Noncommutative M5-branes
We briefly review how to discuss noncommutative (NC) M5-branes and
intersecting NC M5-branes from kappa-invariance of an open supermembrane action
with constant three-form fluxes. The kappa-invariance gives rise to possible
Dirichlet brane configurations. We shortly summarize a construction of
projection operators for NC M5-branes and some intersecting configurations of
NC M5-branes. A strong flux limit of them is also discussed.Comment: 4 pages, 1 figure, LaTeX, A contribution to Nishinomiya-Yukawa
Memorial Symposium on Theoretical Physics ``Noncommutative Geometry and
Quantum Spacetime in Physics'' (Nov. 11-15, 2006, Japan). To appear in
Progress of Theoretical Physics Supplemen
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