23,103 research outputs found

### A Comment on Fundamental Strings in M(atrix) Theory

We present a solution of M(atrix) theory describing type IIA fundamental
string. Our construction is based on the central charge of the longitudinal
membrane (= fundamental string), the BPS saturation condition and the relation
between M(atrix) theory and supersymmetric Yang-Mills theory. The fundamental
string corresponds to a photon in supersymmetric Yang-Mills theory.Comment: 11 pages + 2 uuencoded eps figures, LaTeX, errors corrected and
arguments generalize

### String junctions on backgrounds with a positively charged orientifold plane

By means of the heterotic/type IIB duality, we study properties of junctions
on backgrounds with a positively charged orientifold seven-plane and D-branes,
which are expected to give seven dimensional Sp(r) gauge theories. We give a
modified BPS condition for the junctions and show that it reproduces the
adjoint representation of the Sp(r) group.Comment: 16 pages + 3 eps figures, LaTeX, a reference adde

### A nonstandard construction of direct limit group actions

Manevitz and Weinberger proved that the existence of faithful $K$-Lipschitz
$\mathbb{Z}/n\mathbb{Z}$-actions implies the existence of faithful
$K$-Lipschitz $\mathbb{Q}/\mathbb{Z}$-actions. The
$\mathbb{Q}/\mathbb{Z}$-actions were constructed from suitable actions of a
sufficiently large hyperfinite cyclic group
${}^{\ast}\mathbb{Z}/\gamma{}^{\ast}\mathbb{Z}$ in the sense of nonstandard
analysis. In this paper, we modify their construction, and prove that the
existence of $\varepsilon$-faithful $K$-Lipschitz $G_{\lambda}$-actions implies
the existence of $\varepsilon$-faithful $K$-Lipschitz $\varinjlim
G_{\lambda}$-actions. In a similar way, we generalise Manevitz and Weinberger's
result to injective direct limits of torsion groups

### Branes in type 0/type II duality

We derive relations between type 0 and type II D-brane configurations under
the T-duality suggested by Bergman and Gaberdiel and confirm that the massless
fields on D-branes are identical to those on the dual D-brane configurations.
Furthermore, we discuss dualities of type 0 and type II NS5-branes and find
that the dual of an unwrapped type 0 NS5-brane is a Kaluza-Klein monopole with
non-supersymmetric blow up modes.Comment: 11 pages, 2 figures, explanations added, typos correcte

### Supercurrents on Asymmetric Orbifolds

We study $E_8 \times E_8$-heterotic string on asymmetric orbifolds associated
with semi-simple simply-laced Lie algebras. Using the fact that $E_6$-model
allows different twists, we present a new N=1 space-time supersymmetric model
whose supercurrent appears from twisted sectors but not untwisted sector.Comment: 7 pages, Latex, KOBE-TH-93-0

### On String Junctions in Supersymmetric Gauge Theories

We study junctions consisting of confining strings in N=1 supersymmetric
large N gauge theories by means of the gauge/gravity correspondence. We realize
these junctions as D-brane configurations in infrared geometries of the
Klebanov-Strassler (KS) and the Maldacena-Nunez (MN) solutions. After
discussing kinematics associated with the balance of tensions, we compute the
energies of baryon vertices numerically. In the KS background, baryon vertices
give negative contributions to the energies. The results for the MN background
strongly suggest that the energies of baryon vertices exactly vanish, as in the
case of supersymmetric (p,q)-string junctions. We find that brane
configurations in the MN background have a property similar to the holomorphy
of the M-theory realization of (p,q)-string junctions. With the help of this
property, we analytically prove the vanishing of the energies of baryon
vertices in the MN background.Comment: 33 pages, 16 figures, LaTeX2e; references added, typos correcte

### D-particle creation on an orientifold plane

We study the propagations of gravitational wave and D-particle on D6-brane
and orientifold 6-plane backgrounds in the M-theory framework. In the case of
orientifold plane, D-particle number is not conserved and gravitational wave
can convert into D-particle. For the simplest case, we calculate its amplitude
numerically.Comment: 10 pages + 3 eps figures, LaTeX, errors corrected and reference adde

- âŠ