title:
Effect of Surface Finish of Substrate on Mechanical Reliability of
  in-48SN Solder Joints in Moems Package

abstract:
  Interfacial reactions and shear properties of the In-48Sn (in wt.%) ball grid
array (BGA) solder joints after bonding were investigated with four different
surface finishes of the substrate over an underlying Cu pad: electroplated
Ni/Au (hereafter E-NG), electroless Ni/immersion Au (hereafter ENIG), immersion
Ag (hereafter I-Ag) and organic solderability preservative (hereafter OSP).
During bonding, continuous AuIn2, Ni3(Sn,In)4 and Cu6(Sn,In)5 intermetallic
compound (IMC) layers were formed at the solder/E-NG, solder/ENIG and
solder/OSP interface, respectively. The interfacial reactions between the
solder and I-Ag substrate during bonding resulted in the formation of
Cu6(Sn,In)5 and Cu(Sn,In)2 IMCs with a minor Ag element. The In-48Sn/I-Ag
solder joint showed the best shear properties among the four solder joints
after bonding, whereas the solder/ENIG solder joint exhibited the weakest
mechanical integrity.


title:
Quasiparticles at the verge of localization near the Mott
  metal-insulator transition in a two-dimensional material

abstract:
  The dynamics of charge carriers close to the Mott transition is explored
theoretically and experimentally in the quasi two-dimensional organic
charge-transfer salt $\kappa$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Br$_x$Cl$_{1-x}$, with
varying Br content. The frequency dependence of the conductivity deviates
significantly from simple Drude model behavior: there is a strong
redistribution of spectral weight as the Mott transition is approached and with
temperature. The effective mass of the quasiparticles increases considerably
when coming close to the insulating phase. A dynamical mean-field-theory
treatment of the relevant Hubbard model gives a good quantitative description
of the experimental data.


title:
Non Linear Techniques for Increasing Harvesting Energy from
  Piezoelectric and Electromagnetic Micro-Power-Generators

abstract:
  Non-linear techniques are used to optimize the harvested energy from
piezoelectric and electromagnetic generators. This paper introduces an
analytical study for the voltage amplification obtained from these techniques.
The analytical study is experimentally validated using a macro model of
piezoelectric generator. Moreover, the integration influences on these
techniques is studied. Through all the obtained results, a suitable structure
for autonomous microsystems is proposed.


title:
Optimization of Piezoelectric Electrical Generators Powered by Random
  Vibrations

abstract:
  This paper compares the performances of a vibrationpowered electrical
generators using PZT piezoelectric ceramic associated to two different power
conditioning circuits. A new approach of the piezoelectric power conversion
based on a nonlinear voltage processing is presented and implemented with a
particular power conditioning circuit topology. Theoretical predictions and
experimental results show that the nonlinear processing technique may increase
the power harvested by a factor up to 4 compared to the Standard optimization
technique. Properties of this new technique are analyzed in particular in the
case of broadband, random vibrations, and compared to those of the Standard
interface.


title: Spatially Resolved Spitzer-IRS Spectroscopy of the Central Region of M82

abstract:
  We present high spatial resolution (~ 35 parsec) 5-38 um spectra of the
central region of M82, taken with the Spitzer Infrared Spectrograph. From these
spectra we determined the fluxes and equivalent widths of key diagnostic
features, such as the [NeII]12.8um, [NeIII]15.5um, and H_2 S(1)17.03um lines,
and the broad mid-IR polycyclic aromatic hydrocarbon (PAH) emission features in
six representative regions and analysed the spatial distribution of these lines
and their ratios across the central region. We find a good correlation of the
dust extinction with the CO 1-0 emission. The PAH emission follows closely the
ionization structure along the galactic disk. The observed variations of the
diagnostic PAH ratios across M82 can be explained by extinction effects, within
systematic uncertainties. The 16-18um PAH complex is very prominent, and its
equivalent width is enhanced outwards from the galactic plane. We interpret
this as a consequence of the variation of the UV radiation field. The EWs of
the 11.3um PAH feature and the H_2 S(1) line correlate closely, and we conclude
that shocks in the outflow regions have no measurable influence on the H_2
emission. The [NeIII]/[NeII] ratio is on average low at ~0.18, and shows little
variations across the plane, indicating that the dominant stellar population is
evolved (5 - 6 Myr) and well distributed. There is a slight increase of the
ratio with distance from the galactic plane of M82 which we attribute to a
decrease in gas density. Our observations indicate that the star formation rate
has decreased significantly in the last 5 Myr. The quantities of dust and
molecular gas in the central area of the galaxy argue against starvation and
for negative feedback processes, observable through the strong extra-planar
outflows.


title: Power Processing Circuits for Mems Inertial Energy Scavengers

abstract:
  Inertial energy scavengers are self-contained devices which generate power
from ambient motion, by electrically damping the internal motion of a suspended
proof mass. There are significant challenges in converting the power generated
from such devices to useable form, particularly in micro-engineered variants.
This paper presents approaches to this power conversion requirement, with
emphasis on the cases of electromagnetic and electrostatic transduction.


title: Motion-Based Generators for Industrial Applications

abstract:
  Scaling down of electronic systems has generated a large interest in the
research on miniature energy sources. In this paper a closer look is given to
the use of vibration based scavengers in industrial environments, where waste
energy is abundantly available as engine related vibrations or large amplitude
motions. The modeling of mechanical generators resulted in the design and
realization of two prototypes, based on electromagnetic and electrostatic
conversion of energy. Although the prototypes are not yet optimized against
size and efficiency, a power of 0.3 mW has been generated in a 5 Hz motion with
a 0.5 meter amplitude.


title:
Design and Fabrication of a Micro Electrostatic Vibration-to-Electricity
  Energy Converter

abstract:
  This paper presents a micro electrostatic vibration-toelectricity energy
converter. For the 3.3 V supply voltage and 1cm2 chip area constraints, optimal
design parameters were found from theoretical calculation and Simulink
simulation. In the current design, the output power is 200 $\mu$W/cm2 for the
optimal load of 8 M\Omega. The device was fabricated in a silicon-on-insulator
(SOI) wafer. Mechanical and electrical measurements were conducted. Residual
particles caused shortage of the variable capacitor and the output power could
not be measured. Device design and fabrication processes are being refined.


title:
Macro and Micro Scale Electromagnetic Kinetic Energy Harvesting
  Generators

abstract:
  This paper is concerned with generators that harvest electrical energy from
the kinetic energy present in the sensor nodes environment. These generators
have the potential to replace or augment battery power which has a limited
lifetime and requires periodic replacement which limits the placement and
application of the sensor node.


title: Impact of Thermal Behavior on Offset in a High-Q Gyroscope

abstract:
  In this paper, CFD approach is used to simulate the thermal behavior in a
sensitive high-Q gyroscope. The electromagnetically driving wires, in which AC
current flows, are treated as Joule heat sources in the model. We found that
the differences of temperature, pressure and velocity along the driving
direction and transversely across the proof masses increased as the gap height
between the proof mass and top glass became smaller. Local pressure gradient is
expected to possibly enhance the impact of any imperfect led by MEMS processes
or designs on the offset of our tuning fork type gyroscope, which has been
experimentally verified. A device with 200um gap gives a two-third offset down
compared with that of its counterpart with 50um gap.


title: Scaling Effects for Electromagnetic Vibrational Power Generators

abstract:
  This paper investigates how the power generated by electromagnetic based
vibrational power generators scales with the dimension of the generator. The
effects of scaling on the magnetic fields, the coil parameters and the
electromagnetic damping are presented. An analysis is presented for both
wire-wound coil technology and micro-fabricated coils.


title:
A Generic Surface Micromachining Module for Mems Hermetic Packaging at
  Temperatures Below 200 degrees C

abstract:
  This paper presents the different processing steps of a new generic surface
micromachining module for MEMS hermetic packaging at temperatures around 180
degrees C based on nickel plating and photoresist sacrificial layers. The
advantages of thin film caps are the reduced thickness and area consumption and
the promise of being a low-cost batch process. Moreover, sealing happens by a
reflow technique, giving the freedom of choosing the pressure and atmosphere
inside the cavity. Sacrificial etch holes are situated above the device
allowing shorter release times compared to the state-of-the-art. With the
so-called over-plating process, small etch holes can be created in the membrane
without the need of expensive lithography tools. The etch holes in the membrane
have been shown to be sufficiently small to block the sealing material to pass
through, but still large enough to enable an efficient release.


title:
A Ku-Band Novel Micromachined Bandpass Filter with Two Transmission
  Zeros

abstract:
  This paper presents a micromachined bandpass filter with miniature size that
has relatively outstanding performance. A silicon-based eight-order microstrip
bandpass filter is fabricated and measured. A novel design method of the
interdigital filter that can create two transmission zeros is described. The
location of the transmission zeros can be shifted arbitrarily in the stopband.
By adjusting the zero location properly, the filter provides much better skirt
rejection and lower insertion loss than a conventional microstrip interdigital
filter. To reduce the chip size, through-silicon-substrate-via-hole is used.
Good experimental results are obtained.


title: The Design and Fabrication of Platform Device for Dna Amplification

abstract:
  Thermalcycler were extensively used machine for amplify DNA sample. One of
the major problems in the working time was that it spent most of time for
cooling and heating. In order to improve the efficient, this study presented a
novel method for amplify DNA sample. For this concept, the DNA sample in the
silicon chamber which was pushed by a beam through three temperature regions
around a center and then the DNA segments could be amplified rapidly after 30
cycles. The polymerase chain reaction platform was composed of thin-film
heaters, copper plates, DC powers, and temperature controllers. The
photolithography and bulk etching technologies were utilized to construct the
thin-film heater and DNA reaction chambers. Finally, 1 pound gL 100bp DNA
segment of E. coli K12 was amplified successfully within 36 minutes on this PCR
platform.


title:
Design and Modeling of a Mems-Based Valveless Pump Driven by an
  Electromagnetic Force

abstract:
  A novel valveless micro impedance pump is proposed and analyzed in this
study.


title:
Electrostatic Actuators Operating in Liquid Environment : Suppression of
  Pull-in Instability and Dynamic Response

abstract:
  This paper presents results about fabrication and operation of electrostatic
actuators in liquids with various permittivities. In the static mode, we
provide experimental and theoretical demonstration that the pull-in effect can
be shifted beyond one third of the initial gap and even be eliminated when
electrostatic actuators are operated in liquids. This should benefit to
applications in microfluidics requiring either binary state actuation (e.g.
pumps, valves) or continuous displacements over the whole gap (e.g.
microtweezers). In dynamic mode, actuators like micro-cantilevers present a
great interest for Atomic Force Microscopy (AFM) in liquids. As this
application requires a good understanding of the cantilever resonance frequency
and Q-factor, an analytical modeling in liquid environment has been
established. The theoretically derived curves are validated by experimental
results using a nitride encapsulated cantilever with integrated electrostatic
actuation. Electrode potential screening and undesirable electrochemistry in
dielectric liquids are counteracted using AC-voltages. Both experimental and
theoretical results should prove useful in micro-cantilever design for AFM in
liquids.


title: Spots, plages, and flares on lambda Andromedae and II Pegasi

abstract:
  We present the results of a contemporaneous photometric and spectroscopic
monitoring of lambda And and II Peg aimed at investigating the behavior of
surface inhomogeneities in the atmospheres of these active stars which have
nearly the same temperature but different gravity. The light curves and the
modulation of the surface temperature, as recovered from LDRs, are used to map
the photospheric spots, while the H-alpha emission has been used as an
indicator of chromospheric inhomogeneities. The spot temperatures and sizes
were derived from a spot model applied to the contemporaneous light and
temperature curves. We find larger and cooler spots on II Peg (T_sp ~ 3600 K)
compared to lambda And (T_sp ~ 3900 K); this could be the result of both the
different gravity and the higher activity level of the former. Moreover, we
find a clear anti-correlation between the H-alpha emission and the photospheric
diagnostics. We have also detected a modulation of the intensity of the HeI D_3
line with the star rotation. A rough reconstruction of the 3D structure of
their atmospheres has been also performed by applying a spot/plage model to the
light and temperature curves and to the H-alpha flux modulation. A close
spatial association of photospheric and chromospheric active regions has been
found in both stars. Larger and cooler spots have been found on II Peg, the
system with the active component of higher gravity and higher activity level.
The area ratio of plages to spots seems to decrease when the spots get bigger.
Moreover, with the present and literature data, a correlation between the
temperature difference Delta_T = T_ph - T_sp and the surface gravity has been
also suggested. In addition, a strong flare affecting the H-alpha, the HeI D_3,
and the cores of NaI D_1,2 lines has been observed on II Peg.


title:
Au-SN Flip-Chip Solder Bump for Microelectronic and Optoelectronic
  Applications

abstract:
  As an alternative to the time-consuming solder pre-forms and pastes currently
used, a co-electroplating method of eutectic Au-Sn alloy was used in this
study. Using a co-electroplating process, it was possible to plate the Au-Sn
solder directly onto a wafer at or near the eutectic composition from a single
solution. Two distinct phases, Au5Sn and AuSn, were deposited at a composition
of 30at.%Sn. The Au-Sn flip-chip joints were formed at 300 and 400 degrees
without using any flux. In the case where the samples were reflowed at 300
degrees, only an (Au,Ni)3Sn2 IMC layer formed at the interface between the
Au-Sn solder and Ni UBM. On the other hand, two IMC layers, (Au,Ni)3Sn2 and
(Au,Ni)3Sn, were found at the interfaces of the samples reflowed at 400
degrees. As the reflow time increased, the thickness of the (Au,Ni)3Sn2 and
(Au,Ni)3Sn IMC layers formed at the interface increased and the eutectic
lamellae in the bulk solder coarsened.


title:
Contactless Thermal Characterization Method of PCB-s Using an IR Sensor
  Array

abstract:
  In this paper the feasibility study of an IR sensor card is presented. The
methodology and the results of a quasi real-time thermal characterization tool
and method for the temperature mapping of circuits and boards based on sensing
the infrared radiation is introduced. With the proposed method the IR
radiation-distribution of boards from the close proximity of the sensor card is
monitored in quasi real-time. The proposed method is enabling in situ IR
measurement among operating cards of a system e.g. in a rack.


title:
Miniaturized Fluorescence Excitation Platform with Optical Fiber for
  Bio-Detection Chips

abstract:
  This paper presents a new research study on the platform fabrication of
fluorescence bio-detection chip with an optical fiber transmission. Anisotropic
wet etching on (100) silicon wafers to fabrication V-groove for optical fiber
alignment and micro-mirror were included. Combing with anodic bonding technique
to adhere glass, silicon structure and optical fiber for a fluorescence
excitation platform was completed. In this study, the etching solution 40% KOH
was used to study the parameters effect. The results show that working
temperature is the main parameter to significantly effect the etch rate. The
anisotropic etching resulted 54.7 degrees reflective mirrors and its
reflectivity for optical beam were also examined. The surface roughness of the
micro-mirror is Ra 4.1 nm measured using AFM, it provides excellent optical
reflection. The incident light and beam profiles were also examined for further
study. This study can show this micro-platform adaptable for fluorescence
bio-detection.


title: Characterization of Flexible RF Microcoil Dedicated to Surface Mri

abstract:
  In Magnetic Resonance Imaging (MRI), to achieve sufficient Signal to Noise
Ratio (SNR), the electrical performance of the RF coil is critical. We
developed a device (microcoil) based on the original concept of monolithic
resonator. This paper presents the used fabrication process based on
micromoulding. The dielectric substrates are flexible thin films of polymer,
which allow the microcoil to be form fitted to none-plane surface. Electrical
characterizations of the RF coils are first performed and results are compared
to the attempted values. Proton MRI of a saline phantom using a flexible RF
coil of 15 mm in diameter is performed. When the coil is conformed to the
phantom surface, a SNR gain up to 2 is achieved as compared to identical but
planar RF coil. Finally, the flexible coil is used in vivo to perform MRI with
high spatial resolution on a mouse using a small animal dedicated scanner
operating at in a 2.35 T.


title:
Integration of Micro-Electro-Mechanical Deformable Mirrors in Doped
  Fiber Amplifiers

abstract:
  We present a simple technique to produce active Q-switching in various types
of fiber amplifiers by active integration of an electrostatic actuated
deformable metallic micro-mirror. The optical MEMS (MOEMS) device acts as one
of the laser cavity reflectors and, at the same time, as switching/ modulator
element. We aim to obtain laser systems emitting short, high-power pulses and
having variable repetition rate. The electro-mechanical behavior of membrane
(bridge-type) was simulated by using electrostatic and modal 3D finite element
analysis (FEA). The results of the simulations fit well with the experimental
mechanical, electrical and thermal measurements of the components. In order to
decrease the sensitiveness to fiber-mirror alignment we are developing novel
optical devices based on stressed-metal cantilever-type geometry that allow
deflections up to 50 $\mu$m with increased reflectivity discrimination during
actuation.


title: The Atiyah conjecture and Artinian rings

abstract:
  Let G be a group such that its finite subgroups have bounded order, let d
denote the lowest common multiple of the orders of the finite subgroups of G,
and let K be a subfield of C that is closed under complex conjugation. Let U(G)
denote the algebra of unbounded operators affiliated to the group von Neumann
algebra N(G), and let D(KG,U(G)) denote the division closure of KG in U(G);
thus D(KG,U(G)) is the smallest subring of U(G) containing KG that is closed
under taking inverses. Suppose n is a positive integer, and \alpha \in
\Mat_n(KG). Then \alpha induces a bounded linear map \alpha: l^2(G)^n \to
\l^2(G)^n, and \ker\alpha has a well-defined von Neumann dimension \dim_{N(G)}
(\ker\alpha). This is a nonnegative real number, and one version of the Atiyah
conjecture states that d \dim_{N(G)}(\ker\alpha) \in Z. Assuming this
conjecture, we shall prove that if G has no nontrivial finite normal subgroup,
then D(KG,U(G)) is a d \times d matrix ring over a skew field. We shall also
consider the case when G has a nontrivial finite normal subgroup, and other
subrings of U(G) that contain KG.


title:
Micro-Ball Lens Array Fabrication in Photoresist Using Ptfe Hydrophobic
  Effect

abstract:
  This paper presents a simple method to fabricate micro-ball lens and its
array. The key technology is to use the hydrophobic characteristics of
polyterafluoroethylene (PTFE) substrate. High contact angle between melted
photoresist pattern and PTFE can generate micro-ball lens and its array. PTFE
thin film was spun onto a silicon wafer and dried in oven. Photoresist AZ4620
was used to pattern micro-columns with different diameters 60, 70 and 80
$\mu$m. A thermal reflow process then was applied to melt these micro-column
patterns resulted in micro-ball lens array. The achieved micro-ball lens array
with diameter 98 $\mu$m was fabricated using 80 $\mu$m in diameter patterns.
This method provides a simple fabrication process and low material cost.


title:
Reduced-Order Modelling of the Bending of an Array of Torsional
  Micromirrors

abstract:
  Reduced-Order Modelling of the Bending of an Array of An array of
micromirrors for beam steering optical switching has been designed in a thick
polysilicon technology. A novel semi-analytical method to calculate the static
characteristics of the micromirrors by taking into account the flexural
deformation of the structure is presented. The results are compared with 3D
coupled-field FEM simulation.


title:
Model of Electrostatic Actuated Deformable Mirror Using Strongly Coupled
  Electro-Mechanical Finite Element

abstract:
  The aim of this paper is to deal with multi-physics simulation of
micro-electro-mechanical systems (MEMS) based on an advanced numerical
methodology. MEMS are very small devices in which electric as well as
mechanical and fluid phenomena appear and interact. Because of their
microscopic scale, strong coupling effects arise between the different physical
fields, and some forces, which were negligible at macroscopic scale, have to be
taken into account. In order to accurately design such micro-electro-mechanical
systems, it is of primary importance to be able to handle the strong coupling
between the electric and the mechanical fields. In this paper, the finite
element method (FEM) is used to model the strong coupled electro-mechanical
interactions and to perform static and transient analyses taking into account
large mesh displacements. These analyses will be used to study the behaviour of
electrostatically actuated micro-mirrors.


title:
New Internal Stress Driven on-Chip Micromachines for Extracting
  Mechanical Properties of Thin Films

abstract:
  A new concept of micromachines has been developed for measuring the
mechanical properties of thin metallic films. The actuator is a beam undergoing
large internal stresses built up during the deposition process. Al thin films
are deposited partly on the actuator beam and on the substrate. By etching the
structure, the actuator contracts and pulls the Al film. Full stress strain
curves can be generated by designing a set of micromachines with various
actuator lengths. In the present study, the displacements have been measured by
scanning electronic microscopy. The stress is derived from simple continuum
mechanics relationships. The tensile properties of Al films of various
thicknesses have been tested. A marked increase of the strength with decreasing
film thickness is observed.


title: Process Issues for a Multi-Layer Microelectrofluidic Platform

abstract:
  We report on the development of some process capabilities for a
polymer-based, multi-layer microelectrofluidic platform, namely: the hot
embossing process, metallization on polymer and polymer bonding. Hot embossing
experiments were conducted to look at the effects of load applied, embossing
temperature and embossing time on the fidelity of line arrays representing
micro channels. The results revealed that the embossing temperature is a more
sensitive parameter than the others due to its large effect on the polymer
material's viscoelastic properties. Dynamic mechanical analysis (DMA) on
polymethyl methacrylate (PMMA) revealed a steep glass transition over a 20 oC
range, with the material losing more than 95 % of its storage modulus. The data
explained the hot embossing results which showed large change in the embossed
channel dimensions when the temperature is within the glass transition range.
It was demonstrated that the micro-printing of silver epoxy is a possible
low-cost technique in the mass production of disposable lab chips. An
interconnecting network of electrical traces was fabricated in the form of a
four-layer PMMA-based device. A four PMMA layer device with interconnecting
microfluidic channels was also fabricated and tested.


title: Fabrication of Switches on Polymer-Based by Hot Embossing

abstract:
  In MEMS technology, most of the devices are fabricated on glass or silicon
substrate. However, this research presents a novel manufacture method that is
derived from conventional hot embossing technology to fabricate the
electrostatic switches on polymer material. The procedures of fabrication
involve the metal deposition, photolithography, electroplating, hot embossing
and hot embed techniques. The fundamental concept of the hot embed technology
is that the temperature should be increased above Tg of polymer, and the
polymer becomes plastic and viscous and could be molded. According to the
fundamental concept, the metal layer on the silicon/glass substrate could be
embedded into polymer material during the hot embossing process. Afterward, the
metal layer is bonded together with the polymer after removing the substrate in
the de-embossing step. Finally, the electrostatic switch is fabricated on
polymethylmethacrylate(PMMA) material to demonstrate the novel method.


title:
A New Model of Fringing Capacitance and its Application to the Control
  of Parallel-Plate Electrostatic Micro Actuators

abstract:
  Fringing field has to be taken into account in the formulation of
electrostatic parallel-plate actuators when the gap separating the electrodes
is comparable to the geometrical dimensions of the moving plate. Even in this
case, the existing formulations often result in complicated mathematical models
from which it is difficult to determine the deflection of the moving plate for
given voltages and therefore to predict the necessary applied voltages for
actuation control. This work presents a new method for the modeling of fringing
field, in which the effect of fringing field is modeled as a serial capacitor.
Numerical simulation demonstrates the suitability of this formulation. Based on
this model, a robust control scheme is constructed using the theory of
input-to-state stabilization (ISS) and back-stepping state feedback design. The
stability and the performance of the system using this control scheme are
demonstrated through both stability analysis and numerical simulation.


title:
Numerical evaluation of Chandrasekhar's H-function, its first and second
  differential coefficients, its pole and moments from the new form for plane
  parallel scattering atmosphere in radiative transfer

abstract:
  In this paper, the new forms obtained for Chandrasekhar's H- function in
Radiative Transfer by one of the authors both for non-conservative and
conservative cases for isotropic scattering in a semi-infinite plane parallel
atmosphere are used to obtain exclusively new forms for the first and second
derivatives of H-function . The numerics for evaluation of zero of dispersion
function, for evaluation of H-function and its derivatives and its zeroth, the
first and second moments are outlined. Those are used to get ready and accurate
extensive tables of H-function and its derivatives, pole and moments for
different albedo for scattering by iteration and Simpson's one third rule . The
schemes for interpolation of H-function for any arbitrary value of the
direction parameter for a given albedo are also outlined. Good agreement has
been observed in checks with the available results within one unit of ninth
decimal


title: Numerical Investigation of Glassy Dynamics in Low Density Systems

abstract:
  Vitrification in colloidal systems typically occurs at high densities driven
by sharply varying, short-ranged interactions. The possibility of glassy
behavior arising from smoothly varying, long-ranged particle interactions has
received relatively little attention. Here we investigate the behavior of
screened charged particles, and explicitly demonstrate that these systems
exhibit glassy properties in the regime of low temperature and low density.
Properties close to this low density (Wigner) glass transition share many
features with their hard-sphere counterparts, but differ in quantitative
aspects that may be accounted for via microscopic theoretical considerations.


title: Bounds for Compression in Streaming Models

abstract:
  Compression algorithms and streaming algorithms are both powerful tools for
dealing with massive data sets, but many of the best compression algorithms --
e.g., those based on the Burrows-Wheeler Transform -- at first seem
incompatible with streaming. In this paper we consider several popular
streaming models and ask in which, if any, we can compress as well as we can
with the BWT. We first prove a nearly tight tradeoff between memory and
redundancy for the Standard, Multipass and W-Streams models, demonstrating a
bound that is achievable with the BWT but unachievable in those models. We then
show we can compute the related Schindler Transform in the StreamSort model and
the BWT in the Read-Write model and, thus, achieve that bound.


title:
Elastic s-wave scattering phase shifts and |Vub| from lattice
  calculations of form factors for exclusive semileptonic decays

abstract:
  Omnes dispersion relations make a connection between form factors for
exclusive semileptonic decays and phase shifts in the corresponding elastic
scattering channels. We describe two applications. In the first, we use lattice
form factor calculations to learn about phase shifts in elastic s-wave
isospin-1/2 channels for K pi, B pi, D pi and D K scattering. The aim of the
second application is to make the determination of the CKM matrix element
magnitude |Vub| from exclusive semileptonic B to pi decays competitive with
that from inclusive decays. Here we use many subtractions in an Omnes
dispersion relation to motivate a simple fitting function, allowing data to
constrain the q^2 shape of the differential decay rate and theory, primarily
lattice results, to provide normalisation via form factor values.


title: Efficient path sampling on multiple reaction channels

abstract:
  Due to the time scale problem, rare events are not accessible by straight
forward molecular dynamics. The presence of multiple reaction channels
complicates the problem even further. The feasibility of the standard free
energy based methods relies strongly on the success in finding a proper
reaction coordinate. This can be very difficult task in high-dimensional
complex systems and even more if several distinct reaction channels exist.
Moreover, even if a proper reaction coordinate can be found, ergodic sampling
will be a challenge. In this article, we discuss the recent advancements of
path sampling methods to tackle this problem. We argue why the path sampling
methods, via the transition interface sampling technique, is less sensitive to
the choice of reaction coordinate. Moreover, we review a new algorithm,
parallel path swapping, that can dramatically improve the ergodic sampling of
trajectories for the multiple reaction channel systems.


title:
The DRIFT Directional Dark Matter Detector and First Studies of the
  Head-Tail Effect

abstract:
  Measurement of the direction of the elastic nuclear recoil track and
ionization charge distribution along it, gives unique possibility for
unambiguous detection of the dark matter WIMP particle. Within current
radiation detection technologies only Time Projection Chambers filled with low
pressure gas are capable of such measurement. Due to the character of the
electronic and nuclear stopping powers of low energy nuclear recoils in the
gas, an asymmetric ionization charge distribution along their tracks may be
expected. Preliminary study of this effect, called Head-Tail, has been carried
out here using the SRIM simulation program for Carbon and Sulfur in 40 Torr
carbon disulfide, as relevant to the DRIFT detector. Investigations were
focused on ion tracks projected onto the axis of the initial direction of
motion in the energy range between 10 and 400 keV. Results indicate the likely
existence of an asymmetry influenced by two competing effects: the nature of
the stopping power and range straggling. The former tends to result in the Tail
being greater than the Head and the latter the reverse. It has been found that
for projected tracks the mean position of the ionization charge flows from
'head' to 'tail' with the magnitude depending on the ion type and its energy.


title: Estimation of the Hurst parameter from discrete noisy data

abstract:
  We estimate the Hurst parameter $H$ of a fractional Brownian motion from
discrete noisy data observed along a high frequency sampling scheme. The
presence of systematic experimental noise makes recovery of $H$ more difficult
since relevant information is mostly contained in the high frequencies of the
signal. We quantify the difficulty of the statistical problem in a min-max
sense: we prove that the rate $n^{-1/(4H+2)}$ is optimal for estimating $H$ and
propose rate optimal estimators based on adaptive estimation of quadratic
functionals.


title:
The ELODIE survey for northern extra-solar planets IV. HD196885, a close
  binary star with a 3.7-year planet

abstract:
  Aims:We aim to significantly increase the number of detected extra-solar
planets in a magnitude-limited sample to improve our knowledge of their orbital
element distributions and thus obtain better constraints for planet-formation
models.
  Methods: Radial-velocity data were taken at Haute-Provence Observatory (OHP,
France) with the ELODIE echelle spectrograph.
  Results: We report the presence of a planet orbiting HD 196885 A, with an
orbital period of 1349 days. This star was previously suggested to host a 386
-day planet, but we cannot confirm its existence. We also detect the presence
of a stellar companion, HD 196885 B, and give some constraints on its orbit.


title: On the nature of the fast moving star S2 in the Galactic Center

abstract:
  We analyze the properties of the star S2 orbiting the supermassive black hole
at the center of the Galaxy. A high quality SINFONI H and K band spectrum
obtained from coadding 23.5 hours of observation between 2004 and 2007 reveals
that S2 is an early B dwarf (B0-2.5V). Using model atmospheres, we constrain
its stellar and wind properties. We show that S2 is a genuine massive star, and
not the core of a stripped giant star as sometimes speculated to resolve the
problem of star formation so close to the supermassive black hole. We give an
upper limit on its mass loss rate, and show that it is He enriched, possibly
because of the presence of a magnetic field.


title: Random Bistochastic Matrices

abstract:
  Ensembles of random stochastic and bistochastic matrices are investigated.
While all columns of a random stochastic matrix can be chosen independently,
the rows and columns of a bistochastic matrix have to be correlated. We
evaluate the probability measure induced into the Birkhoff polytope of
bistochastic matrices by applying the Sinkhorn algorithm to a given ensemble of
random stochastic matrices. For matrices of order N=2 we derive explicit
formulae for the probability distributions induced by random stochastic
matrices with columns distributed according to the Dirichlet distribution. For
arbitrary $N$ we construct an initial ensemble of stochastic matrices which
allows one to generate random bistochastic matrices according to a distribution
locally flat at the center of the Birkhoff polytope. The value of the
probability density at this point enables us to obtain an estimation of the
volume of the Birkhoff polytope, consistent with recent asymptotic results.

categories: nlin.SI cond-mat.stat-mech math-ph math.MP


title: Constraints on Large-Scale Magnetic Fields from the Auger Results

abstract:
  A recent article from the Pierre Auger Collaboration links the direction of
charged cosmic rays to possible extragalactic sites of emission. The
correlation of the direction of such particles with the direction of the
emitter allows constraining the value of large-scale magnetic fields B.
Assuming for B a coherence length in the range between 1 Mpc and 10 Mpc, we
find values of B between 0.3 and 0.9 nG.


title: Straight Quantum Waveguide with Robin Boundary Conditions

abstract:
  We investigate spectral properties of a quantum particle confined to an
infinite straight planar strip by imposing Robin boundary conditions with
variable coupling. Assuming that the coupling function tends to a constant at
infinity, we localize the essential spectrum and derive a sufficient condition
which guarantees the existence of bound states. Further properties of the
associated eigenvalues and eigenfunctions are studied numerically by the
mode-matching technique.


title: Example of a possible interpretation of Tsallis entropy

abstract:
  We demonstrate and discuss the process of gaining information and show an
example in which some specific way of gaining information about an object
results in the Tsallis form of entropy rather than in the Shannon one.


title: Ferromagnetism in QCD phase diagram

abstract:
  A possibility and properties of spontaneous magnetization in quark matter are
investigated. Magnetic susceptibility is evaluated within Fermi liquid theory,
taking into account of the screening effect of gluons. Spin wave in the
polarized quark matter, as the Nambu-Goldstone mode, is formulated by way of
the coherent-state path integral.


title: Boundary proximity of SLE

abstract:
  This paper examines how close the chordal $\SLE_\kappa$ curve gets to the
real line asymptotically far away from its starting point. In particular, when
$\kappa\in(0,4)$, it is shown that if $\beta>\beta_\kappa:=1/(8/\kappa-2)$,
then the intersection of the $\SLE_\kappa$ curve with the graph of the function
$y=x/(\log x)^{\beta}$, $x>e$, is a.s. bounded, while it is a.s. unbounded if
$\beta=\beta_\kappa$. The critical $\SLE_4$ curve a.s. intersects the graph of
$y=x^{-(\log\log x)^\alpha}$, $x>e^e$, in an unbounded set if $\alpha\le 1$,
but not if $\alpha>1$. Under a very mild regularity assumption on the function
$y(x)$, we give a necessary and sufficient integrability condition for the
intersection of the $\SLE_\kappa$ path with the graph of $y$ to be unbounded.
We also prove that the Hausdorff dimension of the intersection set of the
$\SLE_{\kappa}$ curve and real axis is $2-8/\kappa$ when $4<\kappa<8$.


title: Three dimensional vortices in Abelian Gauge Theories

abstract:
  In this paper we consider an Abelian Gauge Theory in R^4 equipped with the
Minkowski metric. This theory leads to a system of equations, the
Klein-Gordon-Maxwell equations, which provide models for the interaction
between the electromagnetic field and matter. A three dimensional vortex is a
finite energy solution of these equations in which the magnetic field looks
like the field created by a finite solenoid. Under suitable assumptions, we
prove the existence of vortex-solutions.


title: An Approach to SU_q(2)p Gauge Theory

abstract:
  In the usual approach to q-deformed gauge theories, the gauge fields are
required to be non-local or non-commutative one's. If we introduce, however, an
extended product, which we call `` $\star$-product\rq\rq, among the generators
of a q-deformed Lie group, the deformed group can be reduced to a ordinary Lie
group under the $\star$-product. According to this line of approach, we try to
construct a $[SU_q(2)\times U(1)]_\star$, a $SU(2)\times U(1)$ analogue under
the $\star$-product, gauge theory. In this gauge theory with the
$\star$-product, the U(1) symmetry is naturally incorporated into the SU(2)
symmetry. We also study the symmetry breaking by the Higgs mechanism associated
with $J=1/2$ and J=1 representations of $SU_q(2)$ algebra, and show that the
mixing angle between the SU(2) and U(1) gauge fields is determined uniquely in
a tree level.


title: On orbits of antichains of positive roots

abstract:
  For any finite poset P, there is a natural operator $X$ acting on the
antichains of P. We discuss conjectural properties of this operator for some
graded posets associated with irreducible root systems. In particular, if
$\Delta^+$ is the set of positive roots and $\Pi$ is the set of simple roots in
$\Delta^+$, then we consider the cases $P=\Delta^+$ and $\Delta^+\setminus
\Pi$. For the root system of type $A_n$, we consider an $X$-invariant
integer-valued function on the set of antichains of $\Delta^+$ and establish
some properties of it.


title: The renormalization of non commutative \phi_4^{\star 4}

abstract:
  We present an overview of the different renormalization proofs of the non
commutative $\phi_4^{\star 4}$ model. This paper is a contribution to the
MemPhys project.


title:
Feynman amplitudes in renormalizable non-commutative quantum field
  theory

abstract:
  We consider here the Feynman amplitudes of renormalizable non-commutative
quantum field theory models. Different representations (the parametric and the
Mellin one) are presented. The latter further allows the proof of meromorphy of
a amplitude in the space-time dimension.


title: Solitary waves in Abelian Gauge Theories

abstract:
  Abelian gauge theories consist of a class of field equations which provide a
model for the interaction between matter and electromagnetic fields. In this
paper we analyze the existence of solitary waves for these theories. We assume
that the lower order term W is positive and we prove the existence of solitary
waves if the coupling between matter and electromagnetic field is small. We
point out that the positiveness assumption on W implies that the energy is
positive: this fact makes these theories more suitable to model physical
phenomena.


title:
Self-similarity symmetry and fractal distributions in iterative dynamics
  of dissipative mappings

abstract:
  We consider transformations of deterministic and random signals governed by
simple dynamical mappings. It is shown that the resulting signal can be a
random process described in terms of fractal distributions and fractal domain
integrals. In typical cases a steady state satisfies a dilatation equation,
relating an unknown function $f(x)$ to $f(\kappa x)$ (for example,
${f(x)=g(x)f(\kappa x)}$). We discuss simple linear models as well as nonlinear
systems with chaotic behavior including dissipative circuits with delayed
feedback.


title: The Physics of the Intergalactic Medium

abstract:
  Intergalactic space is filled with a pervasive medium of ionized gas, the
Intergalactic Medium (IGM). A residual neutral fraction is detected in the
spectra of Quasi-Stellar Objects at both low and high redshifts, revealing a
highly fluctuating medium with temperatures characteristic of photoionized gas.
The statistics of the fluctuations are well-reproduced by numerical
gravity-hydrodynamics simulations within the context of standard cosmological
structure formation scenarios. As such, the study of the IGM offers an
opportunity to probe the nature of the primordial density fluctuations on
scales unavailable to other methods. The simulations also suggest the IGM is
the dominant reservoir of baryons produced by the Big Bang, and so the
principal source of the matter from which galaxies formed. The detection of
metal systems within the IGM shows that it was enriched by evolved stars early
in its history, demonstrating an intimate connection between galaxy formation
and the IGM. The author presents a comprehensive review of the current
understanding of the structure and physical properties of the IGM and its
relation to galaxies, concluding with comments on prospects for furthering the
study of the IGM using future ground-based facilities and space-based
experiments.


title:
J/\psi suppression at forward rapidity as a potential probe for QGP
  formation in colour screening scenario

abstract:
  In order to study the properties of $J/\psi$ (1S) in the deconfining medium,
we extend our previous formalism [Phys. Lett. B {\bf 656}, 45 (2007)] on
$J/\psi$ suppression at mid-rapidity using the colour screening framework. Our
formalism is more general as the complete rapidity, transverse momentum and
centrality dependence including $J/\psi$ suppression at forward as well as
mid-rapidity can be computed directly from it. Careful attention is paid to the
role of the medium's proper time in determining the locus of the screening
region where $J/\psi$ gets suppressed. Other important ingredients in the
calculation are bag model equation of state for QGP, the longitudinal expansion
of the QGP fluid obeying Bjorken's boost invariant scaling law and
non-sequential/sequential melting of $\chi_c$ (1P) as well as $\psi^{'}$ (2S)
higher resonances. Upon comparison with the recent data of PHENIX collaboration
on $J/\psi$ suppression at forward and mid-rapidity regions, we find that our
model shows a reasonable agreement with the data without incorporating any
sequential decay mechanism of higher charmonia states. Furthermore, we observe
a larger suppression at forward rapidity in our model which is again well
supported by the PHENIX data and also gives a hint that a scenario based on
directly produced $J/\psi$'s is preferable.


title: Stability of multi-field cosmological solutions

abstract:
  We explore the stability properties of multi-field solutions of assisted
inflation type, where several fields collectively evolve to the same
configuration. In the case of noninteracting fields, we show that the condition
for such solutions to be stable is less restrictive than that required for
tracking in quintessence models. Our results, which do not rely on the
slow-roll approximation, further indicate that to linear order in homogeneous
perturbations the fields are in fact unaware of each other's existence. We end
by generalizing our results to some cases of interacting fields and to other
background solutions and dynamics, including the high-energy braneworld.


title: Higgs Boson Decays into Single Photon plus Unparticle

abstract:
  The decay of the standard model Higgs boson into a single photon and a vector
unparticle through a one-loop process is studied. For an intermediate mass
Higgs boson, this single photon plus unparticle mode can have a branching ratio
comparable with the two-photon discovery mode. The emitted photon has a
continuous energy spectrum encoding the nature of the recoil unparticle. It can
be measured in precision studies of the Higgs boson after its discovery.


title: Partial list of bipartite Bell inequalities with four binary settings

abstract:
  We give a partial list of 26 tight Bell inequalities for the case where Alice
and Bob choose among four two-outcome measurements. All tight Bell inequalities
with less settings are reviewed as well. For each inequality we compute
numerically the maximal quantum violation, the resistance to noise and the
minimal detection efficiency required for closing the detection loophole.
Surprisingly, most of these inequalities are outperformed by the CHSH
inequality.


title:
On Schr\"odinger operators with multisingular inverse-square anisotropic
  potentials

abstract:
  We study positivity, localization of binding and essential self-adjointness
properties of a class of Schroedinger operators with many anisotropic inverse
square singularities, including the case of multiple dipole potentials.


title: Grain - A Java Analysis Framework for Total Data Readout

abstract:
  Grain is a data analysis framework developed to be used with the novel Total
Data Readout data acquisition system. In Total Data Readout all the electronics
channels are read out asynchronously in singles mode and each data item is
timestamped. Event building and analysis has to be done entirely in the
software post-processing the data stream. A flexible and efficient event parser
and the accompanying software framework have been written entirely in Java. The
design and implementation of the software are discussed along with experiences
gained in running real-life experiments.


title: Exponential sums: questions by Denef, Sperber, and Igusa

abstract:
  We prove the remaining part of the conjecture by Denef and Sperber [Denef, J.
and Sperber, S., \textit{Exponential sums mod $p^n$ and {N}ewton polyhedra},
Bull. Belg. Math. Soc., {\bf{suppl.}} (2001) 55-63] on nondegenerate local
exponential sums modulo $p^m$. We generalize Igusa's conjecture of the
introduction of [Igusa, J., \textit{Lectures on forms of higher degree}, Lect.
math. phys., Springer-Verlag, {\bf{59}} (1978)] from the homogeneous to the
quasi-homogeneous case and prove the nondegenerate case as well as the modulo
$p$ case. We generalize some results by Katz of [Katz, N. M., \textit{Estimates
for "singular" exponential sums}, Internat. Math. Res. Notices (1999) no. 16,
875-899] on finite field exponential sums to the quasi-homogeneous case.


title:
Anisotropic flow in Pb+Pb collisions at LHC from the quark gluon string
  model with parton rearrangement

abstract:
  We present predictions for the pseudorapidity dependence of the azimuthal
anisotropy parameters v_1 and v_2 of baryons and inclusive charged hadrons in
Pb+Pb collisions at a LHC energy of sqrt(s) = 5.5 TeV applying a microscopic
transport model, namely the quark gluon string model (QGSM) which has been
recently extended for parton rearrangement and fusion processes. Pb+Pb
collisions with impact parameters b = 2.3 fm and b = 8 fm have been simulated
in order to investigate additionally the difference between central and
semiperipheral configurations. In contrast to v_1(eta) at RHIC, the directed
flow of charged hadrons shows a small normal flow alignment. The elliptic flow
v_2(eta) turns out to be rather similar in shape for RHIC and LHC conditions,
the magnitude however increases about 10-20 % at the LHC, leading to the
conclusion that the hydrodynamical limit will be reached.


title:
The high density equation of state: constraints from accelerators and
  astrophysics

abstract:
  The nuclear equation of state (EoS) at high densities and/or extreme isospin
is one of the longstanding problems of nuclear physics. In the last years
substantial progress has been made to constrain the EoS both, from the
astrophysical side and from accelerator based experiments. Heavy ion
experiments support a soft EoS at moderate densities while the possible
existence of high mass neutron star observations favors a stiff EoS. Ab initio
calculations for the nuclear many-body problem make predictions for the density
and isospin dependence of the EoS far away from the saturation point. Both, the
constraints from astrophysics and accelerator based experiments are shown to be
in agreement with the predictions from many-body theory.


title: Betti numbers of hypergraphs

abstract:
  In this paper we study some algebraic properties of hypergraphs, in particula
their Betti numbers. We define some different types of complete hypergraphs,
which to the best of our knowledge, are not previously considered in the
literature. Also, in a natural way, we define a product on hypergraphs, which
in a sense is dual to the join operation on simplicial complexes. For such
product, we give a general formula for the Betti numbers, which specializes
neatly in case of linear resolutions.


title:
Van der Waals interaction and spontaneous decay of an excited atom in a
  superlens-type geometry

abstract:
  Within the framework of macroscopic quantum electrodynamics, the resonant van
der Waals potential experienced by an excited two-level atom near a planar
magneto-electric two-layer system consisting of a slab of left-handed material
and a perfect mirror is studied. It is shown that disregarding of material
absorption leads to unphysical results, with divergent values for the potential
away from the surface. Under appropriate conditions, the setup is found to
feature a barrier near the surface which can be employed to levitate particles
or used as a trapping or cooling mechanism. Finally, the problem of spontaneous
decay [J. K\"{a}stel and M. Fleischhauer, Phys. Rev. A \textbf{68}, 011804(R)
(2005)] is revisited. Disregarding of absorption is shown to drastically
falsify the dependence on the atomic position of the decay rate.


title:
Local Density of States in Mesoscopic Samples from Scanning Gate
  Microscopy

abstract:
  We study the relationship between the local density of states (LDOS) and the
conductance variation $\Delta G$ in scanning-gate-microscopy experiments on
mesoscopic structures as a charged tip scans above the sample surface. We
present an analytical model showing that in the linear-response regime the
conductance shift $\Delta G$ is proportional to the Hilbert transform of the
LDOS and hence a generalized Kramers-Kronig relation holds between LDOS and
$\Delta G$. We analyze the physical conditions for the validity of this
relationship both for one-dimensional and two-dimensional systems when several
channels contribute to the transport. We focus on realistic Aharonov-Bohm rings
including a random distribution of impurities and analyze the LDOS-$\Delta G$
correspondence by means of exact numerical simulations, when localized states
or semi-classical orbits characterize the wavefunction of the system.


title:
Intrinsic characterization for Lipschitz asymptotically hyperbolic
  metrics

abstract:
  Conformally compact asymptotically hyperbolic metrics have been intensively
studied. The goal of this note is to understand what intrinsic conditions on a
complete Riemannian manifold (M,g) will ensure that g is asymptotically
hyperbolic in this sense. We use the geodesic compactification by asymptotic
geodesic rays to compactify M and appropriate curvature decay conditions to
study the regularity of the conformal compactification. We also present an
interesting example that shows our conclusion is nearly optimal for our
assumptions.


title:
On the range of validity of the fluctuation theorem for stochastic
  Markovian dynamics

abstract:
  We consider the fluctuations of generalized currents in stochastic Markovian
dynamics. The large deviations of current fluctuations are shown to obey a
Gallavotti-Cohen (GC) type symmetry in systems with a finite state space.
However, this symmetry is not guaranteed to hold in systems with an infinite
state space. A simple example of such a case is the Zero-Range Process (ZRP).
Here we discuss in more detail the already reported breakdown of the GC
symmetry in the context of the ZRP with open boundaries and we give a physical
interpretation of the phases that appear. Furthermore, the earlier analytical
results for the single-site case are extended to cover multiple-site systems.
We also use our exact results to test an efficient numerical algorithm of
Giardina, Kurchan and Peliti, which was developed to measure the current large
deviation function directly. We find that this method breaks down in some
phases which we associate with the gapless spectrum of an effective
Hamiltonian.


title:
PopStar: A new grid of Evolutionary Synthesis Models in the Virtual
  Observatory

abstract:
  We present a new set of theoretical evolutionary synthesis models, PopStar.
This grid of Single Stellar Populations covers a wide range in both, age and
metallicity. The models use the most recent evolutionary tracks together with
the use of new NLTE atmosphere models for the hot stars (O, B, WR, post-AGB
stars, planetary nebulae) that dominate the stellar cluster's ionizing spectra.
The results of the models in VO format can be used through VOSpec.


title:
A note on non-linear electrodynamics, regular black holes and the
  entropy function

abstract:
  We examine four dimensional magnetically charged extremal black holes in
certain non-linear U(1) gauge theories coupled to two derivative gravity. For a
given coupling, one can tune the magnetic charge (or vice versa) so that the
curvature singularity at the centre of the space-time is cancelled. Since these
solutions have a horizon but no singularity, they have been called regular
black holes. Contrary to recent claims in the literature, we find that the
entropy function formalism reproduces the near horizon geometry and gives the
correct entropy for these objects.


title: An Inflationary Fixed Point Operator in XQuery

abstract:
  We introduce a controlled form of recursion in XQuery, inflationary fixed
points, familiar in the context of relational databases. This imposes
restrictions on the expressible types of recursion, but we show that
inflationary fixed points nevertheless are sufficiently versatile to capture a
wide range of interesting use cases, including the semantics of Regular XPath
and its core transitive closure construct.
  While the optimization of general user-defined recursive functions in XQuery
appears elusive, we will describe how inflationary fixed points can be
efficiently evaluated, provided that the recursive XQuery expressions exhibit a
distributivity property. We show how distributivity can be assessed both,
syntactically and algebraically, and provide experimental evidence that XQuery
processors can substantially benefit during inflationary fixed point
evaluation.


title: Solving the flavour problem with hierarchical fermion wave functions

abstract:
  We investigate the flavour structure of generic extensions of the SM where
quark and lepton mass hierarchies and the suppression of flavour-changing
transitions originate only by the normalization constants of the fermion
kinetic terms. We show that in such scenarios the contributions to quark FCNC
transitions from dimension-six effective operators are sufficiently suppressed
without (or with modest) fine tuning in the effective scale of new physics. The
most serious challenge to this type of scenarios appears in the lepton sector,
thanks to the stringent bounds on LFV. The phenomenological consequences of
this scenarios in view of improved experimental data on quark and lepton FCNC
transitions, and its differences with respect to the Minimal Flavour Violation
hypothesis are also discussed.


title:
Storage and retrieval of nonclassical photon pairs and conditional
  single photons generated by parametric down-conversion process

abstract:
  Storage and retrieval of parametric down-conversion (PDC) photons are
demonstrated with electromagnetically induced transparency (EIT). Extreme
frequency filtering is performed for THz order of broadband PDC light and the
frequency bandwidth of the light is reduced to MHz order. Storage and retrieval
procedures are carried out for the frequency filtered PDC photons. Since the
filtered bandwidth [full width at half-maximum (FWHM) = 9 MHz] is within the
EIT window (FWHM = 12.6 MHz), the flux of the PDC light is successfully stored
and retrieved. The nonclassicality of the retrieved light is confirmed by using
photon counting method, where the classical inequality which is only satisfied
for classical light fields is introduced. Since the PDC photons can be utilized
for producing the single photon state conditionally, storage and retrieval
procedures are also performed for the conditional single photons.
Anti-correlation parameter used for checking the property of single photon
state shows the value less than 1, which means the retrieved light is in a
non-classical region.


title:
Strain-assisted spin manipulating and the discerption of strain-induced
  spin splitting

abstract:
  We show that the efficiency of manipulating electron spin in semiconductor
quantum wells can be enhanced by tuning the strain strength. The effect
combining intrinsic and strain-induced spin splitting varies for different
systems, which provides an alternative route to understand the experimental
phenomena brought in by the strain. The types of spin splittings caused by
strain are suggested to be distinguished by the measurement of the
electron-dipole-spin-resonance intensity through changing the direction of the
$ac$ electric field in the $x$-$y$ plane of the quantum well and tuning the
strain strengths.


title: On scale symmetry breaking and confinement in D=3 models

abstract:
  Within the framework of the gauge-invariant, but path-dependent, variables
formalism, we study the connection between scale symmetry breaking and
confinement in three-dimensional gluodynamics. We explicitly show that the
static potential profile contains a linear potential, leading to the
confinement of static charges. Also, we establish a new type of equivalence
among different three-dimensional effective theories.


title: Generalized test ideals, sharp F-purity, and sharp test elements

abstract:
  Consider a pair $(R, \ba^t)$ where $R$ is a ring of positive characteristic,
$\ba$ is an ideal such that $a \cap $R^{\circ} \neq \emptyset$, and $t > 0$ is
a real number. In this situation we have the ideal $\tau_R(\ba^t)$, the
generalized test ideal associated to $(R, a^t)$ as defined by Hara and Yoshida.
We show that $\tau_R(a^t) \cap R^{\circ}$ is made up of appropriately defined
generalized test elements which we call \emph{sharp test elements}. We also
define a variant of $F$-purity for pairs, \emph{sharp $F$-purity}, which
interacts well with sharp test elements and agrees with previously defined
notions of $F$-purity in many common situations. We show that if $(R, \ba^t)$
is sharply F-pure, then $\tau_R(\ba^t)$ is a radical ideal. Furthermore, by
following an argument of Vassilev, we show that if $R$ is a quotient of an
$F$-finite regular local ring and $(R, \ba^t)$ is sharply $F$-pure, then
$R/{\tau_R(\ba^t)}$ itself is $F$-pure. We conclude by showing that sharp
$F$-purity can be used to define the $F$-pure threshold. As an application we
show that the $F$-pure threshold must be a rational number under certain
hypotheses.


title:
Polarized Emission Lines from Single InGaN/GaN Quantum Dots: Role of the
  Valence-band Structure of Wurtzite Group-III Nitrides

abstract:
  We present a study of the polarization properties of emission lines from
single InGaN/GaN quantum dots (QDs). The QDs, formed by spinodal decomposition
within ultra-thin InGaN quantum wells, are investigated using single-QD
cathodoluminescence (CL). The emission lines exhibit a systematic linear
polarization in the orthogonal crystal directions [1 1 -2 0] and [-1 1 0 0]--a
symmetry that is non-native to hexagonal crystals.
  Eight-band k.p calculations reveal a mechanism that can explain the observed
polarizations: The character of the hole(s) in an excitonic complex determines
the polarization direction of the respective emission if the QD is slightly
elongated. Transitions involving A-band holes are polarized parallel to the
elongation; transitions involving B-type holes are polarized in the orthogonal
direction. The energetic separation of both hole states is smaller than 10 meV.
The mechanism leading to the linear polarizations is not restricted to InGaN
QDs, but should occur in other wurtzite-nitride QDs and in materials with
similar valence band structure.


title: The role of bulk energy in nuclear multifragmentation

abstract:
  Because of thermal expansion and residual interactions, hot nuclear fragments
produced in multifragmentation reactions may have lower nucleon density than
the equilibrium density of cold nuclei. In terms of liquid-drop model this
effect can be taken into account by reducing the bulk energy of fragments. We
study the influence of this change on fragment yields and isotope distributions
within the framework of the statistical multifragmentation model. Similarities
and differences with previously discussed modifications of symmetry and surface
energies of nuclei are analyzed.


title: Solution of the Pompeiu problem (I)

abstract: This paper has been withdrawn by the author due to some errors.


title:
Replica-symmetry breaking: discrete and continuous schemes in the
  Sherrington-Kirkpatrick model

abstract:
  We study hierarchies of replica-symmetry-breaking solutions of the
Sherrington-Kirkpatrick model. Stationarity equations for order parameters of
solutions with an arbitrary number of hierarchies are set and the limit to
infinite number of hierarchical levels is discussed. In particular, we
demonstrate how the continuous replica-symmetry breaking scheme of Parisi
emerges and how the limit to infinite-many hierarchies leads to equations for
the order-parameter function of the continuous solution. The general analysis
is accompanied by an explicit asymptotic solution near the de Almeida-Thouless
instability line in the nonzero magnetic field.


title: Global Attractor in Competitive Lotka-Volterra Systems

abstract:
  For autonomous Lotka-Volterra systems of differential equations modelling the
dynamics of n competing species, new criteria are established for the existence
of a single point global attractor. Under the conditions of these criteria,
some of the species will survive and stabilise at a steady state whereas the
others, if any, will die out.


title: Converging to Gosper's Algorithm

abstract:
  Given two polynomials, we find a convergence property of the GCD of the
rising factorial and the falling factorial. Based on this property, we present
a unified approach to computing the universal denominators as given by Gosper's
algorithm and Abramov's algorithm for finding rational solutions to linear
difference equations with polynomial coefficients.


title:
Enumeration of some classes of words avoiding two generalized patterns
  of length three

abstract:
  The method we have applied in "A. Bernini, L. Ferrari, R. Pinzani,
Enumerating permutations avoiding three Babson-Steingrimsson patterns, Ann.
Comb. 9 (2005), 137--162" to count pattern avoiding permutations is adapted to
words. As an application, we enumerate several classes of words simultaneously
avoiding two generalized patterns of length 3.


title: Inverse Conjecture for the Gowers norm is false

abstract:
  Let $p$ be a fixed prime number, and $N$ be a large integer. The 'Inverse
Conjecture for the Gowers norm' states that if the "$d$-th Gowers norm" of a
function $f:\F_p^N \to \F_p$ is non-negligible, that is larger than a constant
independent of $N$, then $f$ can be non-trivially approximated by a degree
$d-1$ polynomial. The conjecture is known to hold for $d=2,3$ and for any prime
$p$. In this paper we show the conjecture to be false for $p=2$ and for $d =
4$, by presenting an explicit function whose 4-th Gowers norm is
non-negligible, but whose correlation any polynomial of degree 3 is
exponentially small.
  Essentially the same result (with different correlation bounds) was
independently obtained by Green and Tao \cite{gt07}. Their analysis uses a
modification of a Ramsey-type argument of Alon and Beigel \cite{ab} to show
inapproximability of certain functions by low-degree polynomials. We observe
that a combination of our results with the argument of Alon and Beigel implies
the inverse conjecture to be false for any prime $p$, for $d = p^2$.


title:
Moduli Stabilisation versus Chirality for MSSM like Type IIB
  Orientifolds

abstract:
  We investigate the general question of implementing a chiral MSSM like
D-brane sector in Type IIB orientifold models with complete moduli
stabilisation via F-terms induced by fluxes and space-time instantons,
respectively gaugino condensates. The prototype examples are the KKLT and the
so-called large volume compactifications. We show that the ansatz of first
stabilising all moduli via F-terms and then introducing the Standard Model
module is misleading, as a chiral sector notoriously influences the structure
of non-perturbative effects and induces a D-term potential. Focusing for
concreteness on the large volume scenario, we work out the geometry of the
swiss-cheese type Calabi-Yau manifold P_[1,3,3,3,5][15]_(3,75) and analyse
whether controllable and phenomenologically acceptable Kaehler moduli
stabilisation can occur by the combination of F- and D-terms.


title:
A class of inequalities inducing new separability criteria for bipartite
  quantum systems

abstract:
  Inspired by the realignment or computable cross norm criterion, we present a
new result about the characterization of quantum entanglement. Precisely, an
interesting class of inequalities satisfied by all separable states of a
bipartite quantum system is derived. These inequalities induce new separability
criteria that generalize the realignment criterion.


title:
Exact valence bond entanglement entropy and probability distribution in
  the XXX spin chain and the Potts model

abstract:
  By relating the ground state of Temperley-Lieb hamiltonians to partition
functions of 2D statistical mechanics systems on a half plane, and using a
boundary Coulomb gas formalism, we obtain in closed form the valence bond
entanglement entropy as well as the valence bond probability distribution in
these ground states. We find in particular that for the XXX spin chain, the
number N_c of valence bonds connecting a subsystem of size L to the outside
goes, in the thermodynamic limit, as <N_c> = (4/pi^2) ln L, disproving a recent
conjecture that this should be related with the von Neumann entropy, and thus
equal to 1/(3 ln 2) ln L. Our results generalize to the Q-state Potts model.


title:
Unified description of inelastic propensity rules for electron transport
  through nanoscale junctions

abstract:
  We present a method to analyze the results of first-principles based
calculations of electronic currents including inelastic electron-phonon
effects. This method allows us to determine the electronic and vibrational
symmeties in play, and hence to obtain the so-called propensity rules for the
studied systems. We show that only a few scattering states -- namely those
belonging to the most transmitting eigenchannels -- need to be considered for a
complete description of the electron transport. We apply the method on
first-principles calculations of four different systems and obtain the
propensity rules in each case.


title:
Pinning and Binding Energies for Vortices in Neutron Stars: Comments on
  Recent Results

abstract:
  We investigate when the energy that pins a superfluid vortex to the lattice
of nuclei in the inner crust of neutron stars can be approximated by the energy
that binds the vortex to a single nucleus. Indeed, although the pinning energy
is the quantity relevant to the theory of pulsar glitches, so far full quantum
calculations have been possible only for the binding energy. Physically, the
presence of nearby nuclei can be neglected if the lattice is dilute, namely
with nuclei sufficiently distant from each other. We find that the dilute limit
is reached only for quite large Wigner-Seitz cells, with radii > 55 fm; these
are found only in the outermost low-density regions of the inner crust. We
conclude that present quantum calculations do not correspond to the pinning
energies in almost the entire inner crust and thus their results are not
predictive for the theory of glitches.


title: Maximally entangled fermions

abstract:
  Fermions play an essential role in many areas of quantum physics and it is
desirable to understand the nature of entanglement within systems that consists
of fermions. Whereas the issue of separability for bipartite fermions has
extensively been studied in the present literature, this paper is concerned
with maximally entangled fermions. A complete characterization of maximally
entangled quasifree (gaussian) fermion states is given in terms of the
covariance matrix. This result can be seen as a step towards distillation
protocols for maximally entangled fermions.


title:
Inhibition of thermohaline mixing by a magnetic field in Ap star
  descendants: Implications for the Galactic evolution of 3He

abstract:
  To reconcile the measurements of 3He/H in Galactic HII regions with high
values of 3He in a couple of planetary nebulae, we propose that thermohaline
mixing is inhibited by a fossil magnetic field in red giant stars that are
descendants of Ap stars. We examine the effect of a magnetic field on the
salt-finger instability, using a local analysis. We obtain a threshold for the
magnetic field of 10^4 - 10^5 Gauss, above which it inhibits thermohaline
mixing in red giant stars located at or above the bump. Fields of that order
are expected in the descendants of the Ap stars, taking into account the
contraction of their core. We conclude that in a large fraction of the
descendants of Ap stars thermohaline mixing does not occur. As a consequence
these objects must produce 3He as predicted by the standard theory of stellar
evolution and as observed in the planetary nebulae NGC3242 and J320. The
relative number of such stars with respect to non-magnetic objects that undergo
thermohaline mixing is consistent with the statistical constraint coming from
observations of the carbon isotopic ratio in red giant stars. It also satisfies
the Galactic requirements for the evolution of the 3He abundance.


title: Hadron structure at low Q^2

abstract:
  This review deals with the structure of hadrons, strongly interacting
many-body systems consisting of quarks and gluons. These systems have a size of
about 1 fm, which shows up in scattering experiments at low momentum transfers
$Q$ in the GeV region. At this scale the running coupling constant of Quantum
Chromodynamics (QCD), the established theory of the strong interactions,
becomes divergent. It is therefore highly intriguing to explore this theory in
the realm of its strong interaction regime. However, the quarks and gluons can
not be resolved at the GeV scale but have to be studied through their
manifestations in the bound many-body systems, for instance pions, nucleons and
their resonances. The review starts with a short overview of QCD at low
momentum transfer and a summary of the theoretical apparatus describing the
interaction of hadrons with electrons and photons. In the following sections we
present the experimental results for the most significant observables studied
with the electromagnetic probe: form factors, polarizabilities, excitation
spectra, and sum rules. These experimental findings are compared and
interpreted with various theoretical approaches to QCD, such as
phenomenological models with quarks and pions, dispersion relations as a means
to connect observables from different experiments, and, directly based on the
QCD lagrangian, chiral perturbation theory and lattice gauge theory.


title:
Three flavor Nambu-Jona Lasinio model with Polyakov loop and competition
  with nuclear matter

abstract:
  We study the phase diagram of the three flavor Polyakov-Nambu-Jona Lasinio
(PNJL) model and in particular the interplay between chiral symmetry
restoration and deconfinement crossover. We compute chiral condensates, quark
densities and the Polyakov loop at several values of temperature and chemical
potential. Moreover we investigate on the role of the Polyakov loop dynamics in
the transition from nuclear matter to quark matter.


title:
A prototype large-angle photon veto detector for the P326 experiment at
  CERN

abstract:
  The P326 experiment at the CERN SPS has been proposed with the purpose of
measuring the branching ratio for the decay K^+ \to \pi^+ \nu \bar{\nu} to
within 10%. The photon veto system must provide a rejection factor of 10^8 for
\pi^0 decays. We have explored two designs for the large-angle veto detectors,
one based on scintillating tiles and the other using scintillating fibers. We
have constructed a prototype module based on the fiber solution and evaluated
its performance using low-energy electron beams from the Frascati Beam-Test
Facility. For comparison, we have also tested a tile prototype constructed for
the CKM experiment, as well as lead-glass modules from the OPAL electromagnetic
barrel calorimeter. We present results on the linearity, energy resolution, and
time resolution obtained with the fiber prototype, and compare the detection
efficiency for electrons obtained with all three instruments.


title: Improved Poincare inequalities with weights

abstract:
  In this paper we prove that if $\Omega\in\mathbb{R}^n$ is a bounded John
domain, the following weighted Poincare-type inequality holds: $$ \inf_{a\in
\mathbb{R}}\| (f(x)-a) w_1(x) \|_{L^q(\Omega)} \le C \|\nabla f(x) d(x)^\alpha
w_2(x) \|_{L^p(\Omega)} $$ where $f$ is a locally Lipschitz function on
$\Omega$, $d(x)$ denotes the distance of $x$ to the boundary of $\Omega$, the
weights $w_1, w_2$ satisfy certain cube conditions, and $\alpha \in [0,1]$
depends on $p,q$ and $n$. This result generalizes previously known weighted
inequalities, which can also be obtained with our approach.


title:
On the Non-degeneracy of Kendall's and Spearman's Correlation
  Coefficients

abstract:
  Hoeffding proved that Kendall's and Spearman's nonparametric measures of
correlation between two continuous random variables X and Y are each
asymptotically normal with an asymptotic variance of the form sigma^2/n --
provided the non-degeneracy condition sigma^2>0 holds, where sigma^2 is a
certain (always nonnegative) expression which is determined by the joint
distribution (say mu) of X and Y. Sufficient conditions for sigma^2>0 in terms
of the support set (say S) of mu are given, the same for both correlation
statistics. One of them is that there exist a rectangle with all its vertices
in S, sides parallel to the X and Y axes, and an interior point also in S.
Another sufficient condition is that the Lebesgue measure of S be nonzero.


title:
Uniform approximation for the overlap caustic of a quantum state with
  its translations

abstract:
  The semiclassical Wigner function for a Bohr-quantized energy eigenstate is
known to have a caustic along the corresponding classical closed phase space
curve in the case of a single degree of freedom. Its Fourier transform, the
semiclassical chord function, also has a caustic along the conjugate curve
defined as the locus of diameters, i.e. the maximal chords of the original
curve. If the latter is convex, so is its conjugate, resulting in a simple fold
caustic. The uniform approximation through this caustic, that is here derived,
describes the transition undergone by the overlap of the state with its
translation, from an oscillatory regime for small chords, to evanescent
overlaps, rising to a maximum near the caustic. The diameter-caustic for the
Wigner function is also treated.


title:
Thread-wire surfaces: Near-wire minimizers and topological finiteness
  (superseded)

abstract:
  (NOTE: per referee comments, this article has been split; it is now
superseded by "Existence of thread-wire minimizers" and "Near-wire thread-wire
minimizers"; please see http://www.bkstephens.net.) Alt's thread problem asks
for least-area surfaces bounding a fixed "wire" curve and a movable "thread"
curve of length L. We conjecture that if the wire has finitely many maxima of
curvature, then its Alt minimizers have finitely many surface components. We
show that this conjecture reduces to controlling near-wire minimizers, and thus
begin a three paper series to understand them. In this paper we show they
arise, show that they are embedded, and show that they have a nice
parametrization in wire exponential coordinates. In doing so we prove tools of
independent interest: a weighted isoperimetric inequality, a nonconvex
enclosure theorem, and a classification of how Alt minimizers intersect planes.
The last item reduces to a question about harmonic functions in the spirit of
Rado's lemma.


title:
On the a priori estimates for the Euler, the Navier-Stokes and the
  quasi-geostrophic equations

abstract:
  We prove new \emph{a priori} estimates for the 3D Euler, the 3D Navier-Stokes
and the 2D quasi-geostrophic equations by the method of similarity transforms.


title: The Ising model and planar N=4 Yang-Mills

abstract:
  The scattering-matrix for planar Yang-Mills with N=4 supersymmetry relies on
the assumption that integrability holds to all orders in perturbation theory.
In this note we define a map from the spectral variables x^{\pm},
parameterizing the long-range magnon momenta, to couplings in a two-dimensional
Ising model. Under this map integrability of planar N=4 Yang-Mills becomes
equivalent to the Yang-Baxter equation for the two-dimensional Ising model, and
the long-range variables x^{\pm} translate into the entries of the Ising
transfer matrices. We explore the Ising correlation length which equals the
inverse magnon momentum in the small momentum limit. The critical regime is
thus reached for vanishing magnon momentum. We also discuss the meaning of the
Kramers-Wannier duality transformation on the gauge theory, together with that
of the Ising model critical points.


title:
On the generation of the coefficient field of a newform by a single
  Hecke eigenvalue

abstract:
  Let f be a non-CM newform of weight k > 1.
  Let L be a subfield of the coefficient field of f.
  We completely settle the question of the density of the set of primes p such
that the p-th coefficient of f generates the field L. This density is
determined by the inner twists of f. As a particular case, we obtain that in
the absence of non-trivial inner twists, the density is 1 for L equal to the
whole coefficient field. We also present some new data on reducibility of Hecke
polynomials, which suggest questions for further investigation.


title: Ultra-cold dipolar gases

abstract:
  We present a concise review of the physics of ultra-cold dipolar gases, based
mainly on the theoretical developments in our own group. First, we discuss
shortly weakly interacting ultra-cold trapped dipolar gases. Dipolar
Bose-Einstein condensates exhibit non-standard instabilities and the physics of
both Bose and Fermi dipolar gases depends on the trap geometry. We focus then
the second part of the paper on strongly correlated dipolar gases and discuss
ultra-cold dipolar gases in optical lattices. Such gases exhibit a spectacular
richness of quantum phases and metastable states, which may perhaps be used as
quantum memories. We comment shortly on the possibility of superchemistry
aiming at the creation of dipolar heteronuclear molecules in lattices. Finally,
we turn to ultra-cold dipolar gases in artificial magnetic fields, and consider
rotating dipolar gases, that provide in our opinion the best option towards the
realization of the fractional quantum Hall effect and quantum Wigner crystals.


title:
Expansion schemes for gravitational clustering: computing two-point and
  three-point functions

abstract:
  We describe various expansion schemes that can be used to study gravitational
clustering. Obtained from the equations of motion or their path-integral
formulation, they provide several perturbative expansions that are organized in
different fashion or involve different partial resummations. We focus on the
two-point and three-point correlation functions, but these methods also apply
to all higher-order correlation and response functions. We present the general
formalism, which holds for the gravitational dynamics as well as for similar
models, such as the Zeldovich dynamics, that obey similar hydrodynamical
equations of motion with a quadratic nonlinearity. We give our explicit
analytical results up to one-loop order for the simpler Zeldovich dynamics. For
the gravitational dynamics, we compare our one-loop numerical results with
numerical simulations. We check that the standard perturbation theory is
recovered from the path integral by expanding over Feynman's diagrams. However,
the latter expansion is organized in a different fashion and it contains some
UV divergences that cancel out as we sum all diagrams of a given order.
Resummation schemes modify the scaling of tree and one-loop diagrams, which
exhibit the same scaling over the linear power spectrum (contrary to the
standard expansion). However, they do not significantly improve over standard
perturbation theory for the bispectrum, unless one uses accurate two-point
functions (e.g. a fit to the nonlinear power spectrum from simulations).
Extending the range of validity to smaller scales, to reach the range described
by phenomenological models, seems to require at least two-loop diagrams.


title:
New connection formulae for some q-orthogonal polynomials in q-Askey
  scheme

abstract:
  New nonlinear connection formulae of the q-orthogonal polynomials, such
continuous q-Laguerre, continuous big q-Hermite, q-Meixner-Pollaczek and
q-Gegenbauer polynomials, in terms of their respective classical analogues are
obtained using a special realization of the q-exponential function as infinite
multiplicative series of ordinary exponential function.


title: Results of an analysis of SDSS galaxies in the VO

abstract:
  We present here the VO access to the results of an analysis of the spectra of
Sloan Digital Sky Survey (SDSS) galaxies performed with the STARLIGHT code by
Cid Fernandes et al. (2005). The results include for each galaxy the original
SDSS spectrum, the best-fit synthetic spectrum, the star formation history, the
pure emission line spectrum corrected from underlying stellar population (in
SDSS emission line galaxies) and the intensity of several emission/absorption
lines. The database will be accessible from the PGos3 at the end of summer
2007.


title:
Self-consistent coupled-channel approach to $D$ and $\bar D$ in hot
  dense matter

abstract:
  A self-consistent coupled-channel approach is used to study the properties of
$D$ and $\bar D$ mesons in hot dense matter. The starting point is a broken
SU(4) s-wave Tomozawa-Weinberg $DN$ ($\bar DN$) interaction supplemented by an
attractive isoscalar-scalar term. The Pauli blocking effects, baryon mean-field
bindings, and $\pi$ and open-charm meson self-energies are incorporated in
dense matter at finite temperature. In the $DN$ sector, the dynamically
generated $\tilde\Lambda_c$ and $\tilde\Sigma_c$ resonances remain close to
their free space position while acquiring a remarkable width because of the
thermal smearing of Pauli blocking. Therefore, the $D$ meson spectral density
shows a single pronounced quasiparticle peak close to the free mass, that
broadens with increasing density, and a low energy tail associated to smeared
$\tilde\Lambda_c N^{-1}$, $\tilde\Sigma_c N^{-1}$ configurations. In the $\bar
DN$ case, the low-density approximation to the repulsive $\bar D$ self-energy
is found unreliable already at subsaturation densities. From this study we
speculate the possible existence of $D$-mesic nuclei. We also discuss the
consequences for $J/\Psi$ suppression at FAIR.


title:
The $C^{\a}$ regularity of a class of non-homogeneous ultraparabolic
  equations

abstract:
  We obtain the $C^{\a}$ regularity for weak solutions of a class of
non-homogeneous ultraparabolic equation, with measurable coefficients. The
result generalizes our recent $C^{\a}$ regularity results of homogeneous
ultraparabolic equation.


title: Morphological annotation of Korean with Directly Maintainable Resources

abstract:
  This article describes an exclusively resource-based method of morphological
annotation of written Korean text. Korean is an agglutinative language. Our
annotator is designed to process text before the operation of a syntactic
parser. In its present state, it annotates one-stem words only. The output is a
graph of morphemes annotated with accurate linguistic information. The
granularity of the tagset is 3 to 5 times higher than usual tagsets. A
comparison with a reference annotated corpus showed that it achieves 89% recall
without any corpus training. The language resources used by the system are
lexicons of stems, transducers of suffixes and transducers of generation of
allomorphs. All can be easily updated, which allows users to control the
evolution of the performances of the system. It has been claimed that
morphological annotation of Korean text could only be performed by a
morphological analysis module accessing a lexicon of morphemes. We show that it
can also be performed directly with a lexicon of words and without applying
morphological rules at annotation time, which speeds up annotation to 1,210
word/s. The lexicon of words is obtained from the maintainable language
resources through a fully automated compilation process.


title: A knitting algorithm for calculating Green functions in quantum systems

abstract:
  We propose a fast and versatile algorithm to calculate local and transport
properties such as conductance, shot noise, local density of state or local
currents in mesoscopic quantum systems. Within the non equilibrium Green
function formalism, we generalize the recursive Green function technique to
tackle multiterminal devices with arbitrary geometries. We apply our method to
analyze two recent experiments: an electronic Mach-Zehnder interferometer in a
2D gas and a Hall bar made of graphene nanoribbons in quantum Hall regime. In
the latter case, we find that the Landau edge state pinned to the Dirac point
gets diluted upon increasing carrier density.


title:
Developing and Deploying Advanced Algorithms to Novel Supercomputing
  Hardware

abstract:
  The objective of our research is to demonstrate the practical usage and
orders of magnitude speedup of real-world applications by using alternative
technologies to support high performance computing. Currently, the main barrier
to the widespread adoption of this technology is the lack of development tools
and case studies that typically impede non-specialists that might otherwise
develop applications that could leverage these technologies. By partnering with
the Innovative Systems Laboratory at the National Center for Supercomputing, we
have obtained access to several novel technologies, including several
Field-Programmable Gate Array (FPGA) systems, NVidia Graphics Processing Units
(GPUs), and the STI Cell BE platform. Our goal is to not only demonstrate the
capabilities of these systems, but to also serve as guides for others to follow
in our path. To date, we have explored the efficacy of the SRC-6 MAP-C and
MAP-E and SGI RASC Athena and RC100 reconfigurable computing platforms in
supporting a two-point correlation function which is used in a number of
different scientific domains. In a brute force test, the FPGA based
single-processor system has achieved an almost two orders of magnitude speedup
over a single-processor CPU system. We are now developing implementations of
this algorithm on other platforms, including one using a GPU. Given the
considerable efforts of the cosmology community in optimizing these classes of
algorithms, we are currently working to implement an optimized version of the
basic family of correlation functions by using tree-based data structures.
Finally, we are also exploring other algorithms, such as instance-based
classifiers, power spectrum estimators, and higher-order correlation functions
that are also commonly used in a wide range of scientific disciplines.


title:
Anomalous Hall effect in a two dimensional electron gas with magnetic
  impurities

abstract:
  Magnetic impurities play an important role in many spintronics-related
materials. Motivated by this fact, we study the anomalous Hall effect in the
presence of magnetic impurities, focusing on two-dimensional electron systems
with Rashba spin-orbit coupling. We find a highly nonlinear dependence on the
impurity polarization, including possible sign changes. At small impurity
magnetizations, this is a consequence of the remarkable result that the linear
term is independent of the spin-orbit coupling strength. Near saturation of the
impurity spins, the anomalous Hall conductivity can be resonantly enhanced, due
to interference between potential and magnetic scattering.


title: Nodal domains on graphs - How to count them and why?

abstract:
  The purpose of the present manuscript is to collect known results and present
some new ones relating to nodal domains on graphs, with special emphasize on
nodal counts. Several methods for counting nodal domains will be presented, and
their relevance as a tool in spectral analysis will be discussed.


title: Vacuum Bubble in an Inhomogeneous Cosmology

abstract:
  We study the propagation of bubbles of new vacuum in a radially inhomogeneous
Lemaitre-Tolman-Bondi background that includes a cosmological constant. This
exemplifies the classical evolution of a tunneling bubble through a metastable
state with curvature inhomogeneities, and will be relevant in the context of
the Landscape. We demand that the matter profile in the LTB background satisfy
the weak energy condition. For sample profiles that satisfy this restriction,
we find that the evolution of the bubble (in terms of the physically relevant
coordinates intrinsic to the shell) is largely unaffected by the prsence of
local inhomogeneities. Our setup should also be a useful toy model for
capturing the effects of ambient inhomogeneities on an inflating region.


title:
Realistic simulations of gravitational lensing by galaxy clusters:
  extracting arc parameters from mock DUNE images

abstract:
  We present a newly developed code that allows simulations of optical
observations of galaxy fields with a variety of instruments. The code
incorporates gravitational lensing effects and is targetted at simulating
lensing by galaxy clusters. Our goal is to create the tools required for
comparing theoretical expectations with observations to obtain a better
understanding of how observational noise affects lensing applications such as
mass estimates, studies on the internal properties of galaxy clusters and arc
statistics. Starting from a set of input parameters, characterizing both the
instruments and the observational conditions, the simulator provides a virtual
observation of a patch of the sky. It includes several sources of noise such as
photon-noise, sky background, seeing, and instrumental noise. Ray-tracing
through simulated mass distributions accounts for gravitational lensing. Source
morphologies are realistically simulated based on shapelet decompositions of
galaxy images retrieved from the GOODS-ACS archive. According to their
morphological class, spectral-energy-distributions are assigned to the source
galaxies in order to reproduce observations of each galaxy in arbitrary
photometric bands. We illustrate our techniques showing virtual observations of
a galaxy-cluster core as it would be observed with the space telescope DUNE,
which was recently proposed to ESA within its "Cosmic vision" programme.
(Abridged)


title:
Translating OWL and Semantic Web Rules into Prolog: Moving Toward
  Description Logic Programs

abstract:
  To appear in Theory and Practice of Logic Programming (TPLP), 2008.
  We are researching the interaction between the rule and the ontology layers
of the Semantic Web, by comparing two options: 1) using OWL and its rule
extension SWRL to develop an integrated ontology/rule language, and 2) layering
rules on top of an ontology with RuleML and OWL. Toward this end, we are
developing the SWORIER system, which enables efficient automated reasoning on
ontologies and rules, by translating all of them into Prolog and adding a set
of general rules that properly capture the semantics of OWL. We have also
enabled the user to make dynamic changes on the fly, at run time. This work
addresses several of the concerns expressed in previous work, such as negation,
complementary classes, disjunctive heads, and cardinality, and it discusses
alternative approaches for dealing with inconsistencies in the knowledge base.
In addition, for efficiency, we implemented techniques called
extensionalization, avoiding reanalysis, and code minimization.


title: On Ramanujan Cubic Polynomials

abstract:
  A polynomial x^3+px^2+qx+r with the condition pr^(1/3)+ 3r^(2/3)+q=0 we call
a Ramanujan cubic polynomial (RCP). We study different interest properties of
RCP, in particular, an important role of a parameter pq/r. We prove some new
beautiful identities containing sums of 6 cubic radicals of values of
trigonometrical functions as well.


title: A growth model for RNA secondary structures

abstract:
  A hierarchical model for the growth of planar arch structures for RNA
secondary structures is presented, and shown to be equivalent to a tree-growth
model. Both models can be solved analytically, giving access to scaling
functions for large molecules, and corrections to scaling, checked by numerical
simulations of up to 6500 bases. The equivalence of both models should be
helpful in understanding more general tree-growth processes.


title: Dipolar interaction in ultra-cold atomic gases

abstract:
  Ultra-cold atomic systems provide a new setting where to investigate the role
of long-range interactions. In this paper we will review the basics features of
those physical systems, in particular focusing on the case of Chromium atoms.
  On the experimental side, we report on the observation of dipolar effects in
the expansion dynamics of a Chromium Bose-Einstein condensate. By using a
Feshbach resonance, the scattering length characterising the contact
interaction can be strongly reduced, thus increasing the relative effect of the
dipole-dipole interaction. Such experiments make Chromium atoms the strongest
candidates at present for the achievement of the strong dipolar regime.
  On the theoretical side, we investigate the behaviour of ultra-cold dipolar
systems in the presence of a periodic potential. We discuss how to realise this
situation experimentally and we characterise the system in terms of its quantum
phases and metastable states, discussing in detail the differences with respect
to the case of zero-range interactions.


title: On beta-function of tube of light cone

abstract:
  We construct $B$-function of the Hermitian symmetric space
$\OO(n,2)/\OO(n)\times \OO(2)$ or equivalently of the tube $(Re z_0)^2> (Re
z_1)^2+...+ (Re z_n)^2$ in $C^{n+1}