5,330 research outputs found
The Operator Spectrum of the Six-dimensional (1,0) Theory
We study the large N operator spectrum of the (1,0) superconformal chiral
six-dimensional theory with E_8 global symmetry. This spectrum is dual to the
Kaluza-Klein spectrum of supergravity on AdS_7 X S^4/Z_2 with a ten-dimensional
E_8 theory at its singular locus. We identify those operators in short
multiplets of OSp(6,2|2), whose dimensions are exact for any N. We also discuss
more general issues concerning AdS/CFT duality on orbifold supergravity
backgrounds.Comment: 16pp, Late
Transfer Functions for Pairs of Wandering Subspaces
To a pair of subspaces wandering with respect to a row isometry we associate
a transfer function which in general is multi-Toeplitz and in interesting
special cases is multi-analytic. Then we describe in an expository way how
characteristic functions from operator theory as well as transfer functions
from noncommutative Markov chains fit into this scheme.Comment: In v2: A few typos corrected. Minor changes, in particular Theorem
1.2 improved, Corollary 1.4 added, Section 2 improved with additional
comments. To appear in the Proceedings of IWOTA 201
MOCVD-Fabricated TiO2 Thin Films: Influence of Growth Conditions on Fibroblast Cells Culture
TiO2 thin films with various morphologies were grown on Ti substrates by the LP-MOCVD technique (Low Pressure Chemical Vapour Deposition from Metal-Organic precursor), with titanium tetra-iso-propoxide as a precursor. All the films were prepared in the same conditions except the deposition time. They were characterized by X-ray diffraction, scanning electron microscopy, optical 15 interferometry, water contact angle measurements. MOCVD-fabricated TiO2 thin films are known to be adapted to cell culture for implant requirements. Human gingival fibroblasts were cultured on the various TiO2 deposits. Differences in cell viability (MTT tests) and cell spreading (qualitative assessment) were observed and related to film roughness, wettability and allotropic composition
Entanglement entropy of multipartite pure states
Consider a system consisting of -dimensional quantum particles and
arbitrary pure state of the whole system. Suppose we simultaneously
perform complete von Neumann measurements on each particle. One can ask: what
is the minimal possible value of the entropy of outcomes joint
probability distribution? We show that coincides with entanglement
entropy for bipartite states. We compute for two sample multipartite
states: the hexacode state () and determinant states (). The
generalization of determinant states to the case is considered.Comment: 7 pages, REVTeX, corrected some typo
Age and Mass for 920 LMC Clusters Derived from 100 Million Monte Carlo Simulations
We present new age and mass estimates for 920 stellar clusters in the Large
Magellanic Cloud (LMC) based on previously published broad-band photometry and
the stellar cluster analysis package, MASSCLEANage. Expressed in the generic
fitting formula, d^{2}N/dM dt ~ M^{\alpha} t^{\beta}, the distribution of
observed clusters is described by \alpha = -1.5 to -1.6 and \beta = -2.1 to
-2.2. For 288 of these clusters, ages have recently been determined based on
stellar photometric color-magnitude diagrams, allowing us to gauge the
confidence of our ages. The results look very promising, opening up the
possibility that this sample of 920 clusters, with reliable and consistent age,
mass and photometric measures, might be used to constrain important
characteristics about the stellar cluster population in the LMC. We also
investigate a traditional age determination method that uses a \chi^2
minimization routine to fit observed cluster colors to standard infinite mass
limit simple stellar population models. This reveals serious defects in the
derived cluster age distribution using this method. The traditional \chi^2
minimization method, due to the variation of U,B,V,R colors, will always
produce an overdensity of younger and older clusters, with an underdensity of
clusters in the log(age/yr)=[7.0,7.5] range. Finally, we present a unique
simulation aimed at illustrating and constraining the fading limit in observed
cluster distributions that includes the complex effects of stochastic
variations in the observed properties of stellar clusters.Comment: Accepted for publication in The Astrophysical Journal, 37 pages, 18
figure
Diffusive spreading and mixing of fluid monolayers
The use of ultra-thin, i.e., monolayer films plays an important role for the
emerging field of nano-fluidics. Since the dynamics of such films is governed
by the interplay between substrate-fluid and fluid-fluid interactions, the
transport of matter in nanoscale devices may be eventually efficiently
controlled by substrate engineering. For such films, the dynamics is expected
to be captured by two-dimensional lattice-gas models with interacting
particles. Using a lattice gas model and the non-linear diffusion equation
derived from the microscopic dynamics in the continuum limit, we study two
problems of relevance in the context of nano-fluidics. The first one is the
case in which along the spreading direction of a monolayer a mesoscopic-sized
obstacle is present, with a particular focus on the relaxation of the fluid
density profile upon encountering and passing the obstacle. The second one is
the mixing of two monolayers of different particle species which spread side by
side following the merger of two chemical lanes, here defined as domains of
high affinity for fluid adsorption surrounded by domains of low affinity for
fluid adsorption.Comment: 12 pages, 3 figure
Precursor films in wetting phenomena
The spontaneous spreading of non-volatile liquid droplets on solid substrates
poses a classic problem in the context of wetting phenomena. It is well known
that the spreading of a macroscopic droplet is in many cases accompanied by a
thin film of macroscopic lateral extent, the so-called precursor film, which
emanates from the three-phase contact line region and spreads ahead of the
latter with a much higher speed. Such films have been usually associated with
liquid-on-solid systems, but in the last decade similar films have been
reported to occur in solid-on-solid systems. While the situations in which the
thickness of such films is of mesoscopic size are rather well understood, an
intriguing and yet to be fully understood aspect is the spreading of
microscopic, i.e., molecularly thin films. Here we review the available
experimental observations of such films in various liquid-on-solid and
solid-on-solid systems, as well as the corresponding theoretical models and
studies aimed at understanding their formation and spreading dynamics. Recent
developments and perspectives for future research are discussed.Comment: 51 pages, 10 figures; small typos correcte
Polarization-squeezed light formation in a medium with electronic Kerr nonlinearity
We analyze the formation of polarization-squeezed light in a medium with
electronic Kerr nonlinearity. Quantum Stokes parameters are considered and the
spectra of their quantum fluctuations are investigated. It is established that
the frequency at which the suppression of quantum fluctuations is the greatest
can be controlled by adjusting the linear phase difference between pulses. We
shown that by varying the intensity or the nonlinear phase shift per photon for
one pulse, one can effectively control the suppression of quantum fluctuations
of the quantum Stokes parameters.Comment: final version, RevTeX, 10 pages, 5 eps figure
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