239 research outputs found
N=1* in 5 dimensions: Dijkgraaf-Vafa meets Polchinski-Strassler
One of the powerful techniques to analyze the 5 dimensional Super Yang Mills
theory with a massive hypermultiplet (N=1*) is provided by the AdS/CFT
correspondence. It predicts that, for certain special values of the
hypermultiplet mass, this theory develops nonperturbative branches of the
moduli space as well as new light degrees of freedom.
We use the higher dimensional generalization of the matrix model/gauge theory
correspondence and recover all the prediction of the supergravity analysis. We
construct the map between the four dimensional holomorphic superpotential and
the five dimensional action and explicitly show that the superpotential is flat
along the nonperturbative branches. This is the first instance in which the
Dijkgraaf-Vafa method is used to analyze intrinsically higher dimensional
phenomena.Comment: 28 pages, Late
More on Penrose limits and non-local theories
We obtain the Penrose limit of six dimensional Non-Commutative Open String
(NCOS) theory and show that in the neighborhood of a particular null
geodesic it leads to an exactly solvable string theory (unlike their
counterparts in four or in other dimensions). We describe the phase structure
of this theory and discuss the Penrose limit in different phases including Open
D-string (OD1) theory. We compute the string spectrum and discuss their
relations with the states of various theories at different phases. We also
consider the case of general null geodesic for which the Penrose limit leads to
string theory in the time dependent pp-wave background and comment on the
renormalization group flow in the dual theory.Comment: latex, 22 pages, minor corrections, references added, published
versio
All-optical ion generation for ion trap loading
We have investigated the all-optical generation of ions by photo-ionisation
of atoms generated by pulsed laser ablation. A direct comparison between a
resistively heated oven source and pulsed laser ablation is reported. Pulsed
laser ablation with 10 ns Nd:YAG laser pulses is shown to produce large calcium
flux, corresponding to atomic beams produced with oven temperatures greater
than 650 K. For an equivalent atomic flux, pulsed laser ablation is shown to
produce a thermal load more than one order of magnitude smaller than the oven
source. The atomic beam distributions obey Maxwell-Boltzmann statistics with
most probable speeds corresponding to temperatures greater than 2200 K. Below a
threshold pulse fluence between 280 mJ/cm^2 and 330 mJ/cm^2, the atomic beam is
composed exclusively of ground state atoms. For higher fluences ions and
excited atoms are generated.Comment: 7 pages, 9 figure
Dilaton gravity approach to three dimensional Lifshitz black hole
The z=3 Lifshitz black hole is an exact black hole solution to the new
massive gravity in three dimensions. In order to understand this black hole
clearly, we perform a dimensional reduction to two dimensional dilaton gravity
by utilizing the circular symmetry. Considering the linear dilaton, we find the
same Lifshitz black hole in two dimensions. This implies that all thermodynamic
quantities of the z=3 Lifshitz black hole could be obtained from its
corresponding black hole in two dimensions. As a result, we derive the
temperature, mass, heat capacity, Bekesnstein-Hawking entropy, and free energy.Comment: 13 pages, 1 figure, version to appear in EPJ
Charge Deficiency, Charge Transport and Comparison of Dimensions
We study the relative index of two orthogonal infinite dimensional
projections which, in the finite dimensional case, is the difference in their
dimensions. We relate the relative index to the Fredholm index of appropriate
operators, discuss its basic properties, and obtain various formulas for it. We
apply the relative index to counting the change in the number of electrons
below the Fermi energy of certain quantum systems and interpret it as the
charge deficiency. We study the relation of the charge deficiency with the
notion of adiabatic charge transport that arises from the consideration of the
adiabatic curvature. It is shown that, under a certain covariance,
(homogeneity), condition the two are related. The relative index is related to
Bellissard's theory of the Integer Hall effect. For Landau Hamiltonians the
relative index is computed explicitly for all Landau levels.Comment: 23 pages, no figure
Open Strings in Exactly Solvable Model of Curved Spacetime and PP-Wave Limit
In this paper we study the superstring version of the exactly solvable string
model constructed by Russo and Tseytlin. This model represents superstring
theory in a curved spacetime and can be seen as a generalization of the Melvin
background. We investigate D-branes in this model as probes of the background
geometry by constructing the boundary states. We find that spacetime
singularities in the model become smooth at high energy from the viewpoint of
open string. We show that there always exist bulk (movable) D-branes by the
effect of electric flux. The model also includes Nappi-Witten model as the
Penrose limit and supersymmetry is enhanced in the limit. We examine this
phenomenon in the open string spectrum. We also find the similar enhancement of
supersymmetry can be occurred in several coset models.Comment: Latex, 32 pages, typos corrected, references added, to appear in
JHEP, eq.(2.22) correcte
Anomalous dimensions in gauge theories from rotating strings in
Semi-classical soliton solutions for superstrings in are
used to predict the dimension of gauge theory operators in SU(N) SYM
theory. We discuss the possible origin of scaling violations on the gauge
theory side.Comment: 12 pages, harvmac. References added. [JHEP06(2002) 038
SS Ari: a shallow-contact close binary system
Two CCD epochs of light minimum and a complete R light curve of SS Ari are
presented. The light curve obtained in 2007 was analyzed with the 2003 version
of the W-D code. It is shown that SS Ari is a shallow contact binary system
with a mass ratio and a degree of contact factor f=9.4(\pm0.8%). A
period investigation based on all available data shows that there may exist two
distinct solutions about the assumed third body. One, assuming eccentric orbit
of the third body and constant orbital period of the eclipsing pair results in
a massive third body with and P_3=87.00.278M_{\odot}$. Both of the cases
suggest the presence of an unseen third component in the system.Comment: 28 pages, 9 figures and 5 table
Superstrings on PP-Wave Backgrounds and Symmetric Orbifolds
We study the superstring theory on pp-wave background with NSNS-flux that is
realized as the Penrose limit of AdS_3 x S^3 x M^4, where M^4 is T^4 or
T^4/Z_2(~ K3). Quantizing this system in the covariant gauge, we explicitly
construct the space-time supersymmetry algebra and the complete set of DDF
operators. We analyse the spectrum of physical states by using the spectrally
flowed representations of current algebra. This spectrum is classified by the
``short string sectors'' and the ``long string sectors'' as in AdS_3 string
theory. The states of the latter propagate freely along the transverse plane of
pp-wave background, but the states of the former do not. We compare the short
string spectrum with the BPS and almost BPS states which have large R-charges
in the symmetric orbifold conformal theory, which is known as the candidate of
dual theory of superstrings on AdS_3 x S^3 x M^4. We show that every short
string states can be embedded successfully in the single particle Hilbert space
of symmetric orbifold conformal theory.Comment: Latex, 35 pages, minor change
Branes in AdS and pp-wave spacetimes
We find half supersymmetric AdS-embeddings in AdS_5 x S^5 corresponding to
all quarter BPS orthogonal intersections of D3-branes with Dp-branes. A
particular case is the Karch-Randall embedding AdS_4 x S^2. We explicitly prove
that these embeddings are supersymmetric by showing that the kappa symmetry
projections are compatible with half of the target space Killing spinors and
argue that all these cases lead to AdS/dCFT dualities involving a CFT with a
defect. We also find an asymptotically AdS_4 x S^2 embedding that corresponds
to a holographic RG-flow on the defect. We then consider the pp-wave limit of
the supersymmetric AdS-embeddings and show how it leads to half supersymmetric
D-brane embeddings in the pp-wave background. We systematically analyze D-brane
embeddings in the pp-wave background along with their supersymmetry. We
construct all supersymmetric D-branes wrapped along the light-cone using
operators in the dual gauge theory: the open string states are constructed
using defect fields. We also find supersymmetric D1 (monopoles) and D3 (giant
gravitons) branes that wrap only one of the light-cone directions. These
correspond to non-perturbative states in the dual gauge theory.Comment: 57 pages, 1 figure; corrections and addition
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