369 research outputs found
Gauge Five-brane Solutions of Co-dimension Two in Heterotic Supergravity
We continue to study the BPS gauge five-brane solutions of codimension two in
ten-dimensional heterotic supergravity. The geometry including the dilaton and
the NS-NS -field are sourced from the monopole chain in . We find that the geometry is asymptotically Ricci flat and the dilaton is
no longer imaginary valued. These properties are contrasted with the smeared
counterpart discussed in our previous paper. We perform the T-duality
transformations of the solution and find that it never results in a
non-geometric object.Comment: 24 pages, 4 figures, typos corrected, version published in JHE
World-volume Effective Actions of Exotic Five-branes
We construct world-volume effective actions of exotic -branes in type
IIA and IIB string theories. The effective actions are given in fully
space-time covariant forms with two Killing vectors associated with background
isometries. The effective theories are governed by the six-dimensional
tensor multiplet and vector multiplet,
respectively. Performing the S-duality transformation to the -brane
effective action in type IIB string theory, we also work out the world-volume
action of the -brane. We discuss some additional issues relevant to the
exotic five-branes in type I and heterotic string theories.Comment: 34 pages, 2 figures, typos corrected, figures replace
World-volume Effective Action of Exotic Five-brane in M-theory
We study the world-volume effective action of an exotic five-brane, known as
the M-theory 5-brane (M5-brane) in eleven dimensions. The
supermultiplet of the world-volume theory is the tensor
multiplet in six dimensions. The world-volume action contains three Killing
vectors associated with the
isometry. We find the effective T-duality rule for the
eleven-dimensional backgrounds that transforms the M5-brane effective action to
that of the M5-brane. We also show that our action provides the source
term for the M5-brane geometry in eleven-dimensional supergravityComment: 23 pages, comments and references added, version published in JHE
Scattering and inverse scattering for nonlinear quantum walks
We study large time behavior of quantum walks (QWs) with self-dependent
(nonlinear) coin. In particular, we show scattering and derive the reproducing
formula for inverse scattering in the weak nonlinear regime. The proof is based
on space-time estimate of (linear) QWs such as dispersive estimates and
Strichartz estimate. Such argument is standard in the study of nonlinear
Schr\"odinger equations and discrete nonlinear Schr\"odinger equations but it
seems to be the first time to be applied to QW.Comment: 18 pages, text overlap with arXiv:1711.0062
Hyper-K\"ahler with Torsion, T-duality, and Defect (p,q) Five-branes
We investigate a five-branes interpretation of hyper-K\"{a}hler geometry with
torsion (HKT). This geometry is obtained by conformal transformation of the
Taub-NUT space which represents a Kaluza-Klein five-brane. This HKT would
represent an NS5-brane on the Taub-NUT space. In order to explore the HKT
further, we compactify one transverse direction, and study the monodromy structure
associated with two-torus. Performing the conjugate transformation, we obtain a
new solution whose physical interpretation is a defect five-brane on
the ALG space. Throughout this analysis, we understand that the HKT represents
a coexistent state of two kinds of five-branes. This situation is different
from composite states such as five-branes or seven-branes in
type IIB theory. We also study the T-dualized system of the HKT. We again find
a new solution which also indicates another defect five-brane on the
ALG space.Comment: 21 pages, version published in JHE
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