title: Accretion Disc Particle Accretion in Major Merger Simulations

abstract:
  A recent approach to simulating localized feedback from active galactic
nuclei by Power et al. (2011) uses an accretion disc particle to represent both
the black hole and its accretion disc. We have extrapolated and adapted this
approach to simulations of Milky Way-sized galaxy mergers containing black
holes and explored the impact of the various parameters in this model as well
as its resolution dependence. The two key parameters in the model are an
effective accretion radius, which determines the radius within which gas
particles are added to the accretion disc, and a viscous time-scale which
determines how long it takes for material in the accretion disc to accrete on
to the black hole itself. We find that there is a limited range of permitted
accretion radii and viscous time-scales, with unphysical results produced
outside this range. For permitted model parameters, the nuclear regions of
simulations with the same resolution follow similar evolutionary paths,
producing final black hole masses that are consistent within a factor of two.
When comparing the resolution dependence of the model, there is a trend towards
higher resolution producing slightly lower mass black holes, but values for the
two resolutions studied again agree within a factor of two. We also compare
these results to two other AGN feedback algorithms found in the literature.
While the evolution of the systems vary, most notably the intermediate total
black hole mass, the final black hole masses differ by less than a factor of
five amongst all of our models, and the remnants exhibit similar structural
parameters. The implication of this accretion model is that, unlike most
accretion algorithms, a decoupling of the accretion rate on to the black hole
and the local gas properties is permitted and obtained; this allows for black
hole growth even after feedback has prevented additional accretion events on to
the disc.


title: Dark Radiation Constraints on Mixed Axion/Neutralino Dark Matter

abstract:
  Recent analyses of WMAP9 data show that dark radiation-- parametrized by the
apparent number of additional neutrinos \Delta N_{eff} contributing to the
cosmic expansion-- is consistent with the Standard Model and bounded from above
by about \Delta N_{eff} ~< 0.5 at 95% CL. We consider the mixed
axion/neutralino cold dark matter scenario which arises in R-parity conserving
supersymmetric (SUSY) models wherein the strong CP problem is solved by
hadronic axions with a concommitant axion(a)/saxion(s)/axino(\ta)
supermultiplet. Our new results include improved calculations of thermal axion
and saxion production and include effects of saxion decay to axinos and axions.
We show that the above bound on \Delta N_{eff} is easily satisfied if saxions
are mainly thermally produced and m_{LSP} < m_{\ta} \lesssim m_s. However, if
the dominant mechanism of saxion production is through coherent oscillations,
the WMAP9 data provides a strong bound on saxion production followed by saxion
decays to axions. Furthermore we show that scenarios with mixed
neutralino/axion dark matter are highly constrained by combined WMAP9, BBN and
Xe-100 constraints. In particular, supersymmetric models with a standard
overabundance of neutralino dark matter are excluded for all values of the
Peccei-Quinn breaking scale. Next generation WIMP direct detection experiments
may be able to discover or exclude mixed axion-neutralino CDM scenarios where
$s\to aa$ is the dominant saxion decay mode.


title: An HI Imaging Survey of Asymptotic Giant Branch Stars

abstract:
  We present an imaging study of a sample of eight asymptotic giant branch
(AGB) stars in the HI 21-cm line. Using observations from the Very Large Array,
we have unambiguously detected HI emission associated with the extended
circumstellar envelopes of six of the targets. The detected HI masses range
from M_HI ~ 0.015-0.055 M_sun. The HI morphologies and kinematics are diverse,
but in all cases appear to be significantly influenced by the interaction
between the circumstellar envelope and the surrounding medium. Four stars (RX
Lep, Y UMa, Y CVn, and V1942 Sgr) are surrounded by detached HI shells ranging
from 0.36 to 0.76 pc across. We interpret these shells as resulting from
material entrained in a stellar outflow being abruptly slowed at a termination
shock where it meets the local medium. RX Lep and TX Psc, two stars with
moderately high space velocities (V_space>56 km/s), exhibit extended gaseous
wakes (~0.3 and 0.6 pc in the plane of the sky), trailing their motion through
space. The other detected star, R Peg, displays a peculiar "horseshoe-shaped"
HI morphology with emission extended on scales up to ~1.7 pc; in this case, the
circumstellar debris may have been distorted by transverse flows in the local
interstellar medium. We briefly discuss our new results in the context of the
entire sample of evolved stars that has been imaged in HI to date.


title: Unveiling environmental entanglement in strongly dissipative qubits

abstract:
  The coupling of a qubit to a macroscopic reservoir plays a fundamental role
in understanding the complex transition from the quantum to the classical
world. Considering a harmonic environment, we use both intuitive arguments and
numerical many-body quantum tomography to study the structure of the complete
wavefunction arising in the strong-coupling regime, reached for intense
qubit-environment interaction. The resulting strongly-correlated many-body
ground state is built from quantum superpositions of adiabatic (polaron-like)
and non-adiabatic (antipolaron-like) contributions from the bath of quantum
oscillators. The emerging Schr\"odinger cat environmental wavefunctions can be
described quantitatively via simple variational coherent states. In contrast to
qubit-environment entanglement, we show that non-classicality and entanglement
among the modes in the reservoir are crucial for the stabilization of qubit
superpositions in regimes where standard theories predict an effectively
classical spin.


title: Testing In Situ Assembly with the Kepler Planet Candidate Sample

abstract:
  We present a Monte Carlo model for the structure of low mass (total mass < 25
earth mass) planetary systems that form by the in situ gravitational assembly
of planetary embryos into final planets. Our model includes distributions of
mass, eccentricity, inclination and period spacing that are based on the
simulation of a disk of 20 earth masses, forming planets around a solar mass
star, and assuming a power law surface density distribution $\propto a^{-1.5}$.
  The output of the Monte Carlo model is then subjected to the selection
effects that mimic the observations of a transiting planet search such as that
performed by the Kepler satellite. The resulting comparison of the output to
the properties of the observed sample yields an encouraging agreement in terms
of the relative frequencies of multiple planet systems and the distribution of
the mutual inclinations, when moderate tidal circularisation is taken into
account. The broad features of the period distribution and radius distribution
can also be matched within this framework, although the model underpredicts the
distribution of small period ratios. This likely indicates that some
dissipation is still required in the formation process.
  The most striking deviation between model and observations is in the ratio of
single to multiple systems, in that there are roughly 50% more single planet
candidates observed than are produced in any model population. This suggests
that some systems must suffer additional attrition to reduce the number of
planets or increase the range of inclinations.


title:
Zero interface tension at the deconfining phase transition for a matrix
  model of a $SU(\infty)$ gauge theory

abstract:
  Using a matrix model, we model the deconfining phase transition at nonzero
temperature for a SU(N) gauge theory at large $N$. At infinite $N$ the matrix
model exhibits a Gross-Witten-Wadia transition. We show that as a consequence,
both the order-disorder and the order-order interface tensions vanish
identically at the critical temperature $T_d$. We estimate how these quantities
vanish in the matrix model as $T \rightarrow T_d$ and as $N \rightarrow
\infty$. The numerical solution of the matrix model suggests possible
non-monotonic behavior in $N$ for relatively small values of $N \sim 5$.


title:
Initial Planetesimal Sizes and the Size Distribution of Small Kuiper
  Belt Objects

abstract:
  We show, by comparing observations with theoretical models, that the observed
Kuiper Belt size distribution is well matched by coagulation models, which
start from an initial planetesimal population with radii of about 1km, and
subsequent collisional evolution. We find that the observed size distribution
for R > 30km has not been modified by collisional evolution over the age of the
solar system, and that the size distribution below R ~ 30km has been modified
by collisions and that its slope is well matched by collisional evolution
models that use published strength laws. We investigate in detail the resulting
size distribution of bodies ranging from 0.01km to 30km and find that its slope
changes several times as a function of radius before approaching the expected
value for an equilibrium collisional cascade of material strength dominated
bodies for R < 0.1km. Compared to a single power law size distribution that
would span the whole range from 0.01km to 30km, we find a strong deficit of
bodies around R ~10km and a strong excess of bodies around 2km. This deficit
and excess are caused by an excess mass in small planetesimals in the km size
range that was left over from the runaway growth phase and that leaves a
signature in the size distribution that is not erased after 4.5 Gyrs of
collisional evolution. Observations of the small KBO size distribution can
therefore test if large KBOs grew as a result of runaway growth and constrain
the initial planetesimal sizes. We find that results from recent KBO
occultation surveys and the observed KBO size distribution can be best matched
by an initial planetesimal population that contained about equal mass per
logarithmic mass bin in bodies ranging from 0.4km to 4km in radius. In
addition, we find that we cannot match the observed KBO size distribution if
most of the planetesimal mass was contained in bodies that were 10km in radius
or larger.


title:
Effect of controlled corrugation on capillary condensation of
  colloid-polymer mixtures

abstract:
  We investigate with Monte Carlo computer simulations the capillary phase
behaviour of model colloid-polymer mixtures confined between a flat wall and a
corrugated wall. The corrugation is modelled via a sine wave as a function of
one of the in-plane coordinates leading to a depletion attraction between
colloids and the corrugated wall that is curvature dependent. We find that for
increased amplitude of corrugation the region of the phase diagram where
capillary condensation occurs becomes larger. We derive a Kelvin equation for
this system and compare its predictions to the simulation results. We find good
agreement between theory and simulation indicating that the primary reason for
the stronger capillary condensation is an increased contact area between the
fluid and the corrugated substrate. On the other hand, the colloid adsorption
curves at colloid gas-liquid coexistence show that the increased area is not
solely responsible for the stronger capillary condensation. Additionally, we
analyse the dimensional crossover from a quasi-2D to a quasi-1D system and find
that the transition is characterised by the appearance of a metastable phase.


title: Topological charge pumping in a one-dimensional optical lattice

abstract:
  A topological charge pump [1] transfers charge in a quantized fashion. The
quantization is stable against the detailed form of the pumping protocols and
external noises and shares the same topological origin as the quantum Hall
effect. We propose an experiment setup to realize topological charge pumping of
cold atoms in a one-dimensional optical lattice. The quantization of the pumped
charge is confirmed by first-principle simulations of the dynamics of uniform
and trapped systems. Quantum effects are shown to be crucial for the
topological protection of the charge quantization. Finite-temperature and
non-adiabatic effect on the experimental observables are discussed. Realization
of such a topological charge pump servers as a firm step towards exploring
topological states and non-equilibrium dynamics using cold atoms.


title: Thermal dilepton rates from quenched lattice QCD

abstract:
  We present new lattice results on the continuum extrapolation of the vector
current correlation function. Lattice calculations have been carried out in the
deconfined phase at a temperature of 1.1 Tc, extending our previous results at
1.45 Tc, utilizing quenched non-perturbatively clover-improved Wilson fermions
and light quark masses. A systematic analysis on multiple lattice spacings
allows to perform the continuum limit of the correlation function and to
extract spectral properties in the continuum limit.
  Our current analysis suggests the results for the electrical conductivity are
proportional to the temperature and the thermal dilepton rates in the quark
gluon plasma are comparable for both temperatures. Preliminary results of the
continuum extrapolated correlation function at finite momenta, which relates to
thermal photon rates, are also presented.


title: Non-Gaussian bias: insights from discrete density peaks

abstract:
  Corrections induced by primordial non-Gaussianity to the linear halo bias can
be computed from a peak-background split or the widespread local bias model.
However, numerical simulations clearly support the prediction of the former, in
which the non-Gaussian amplitude is proportional to the linear halo bias. To
understand better the reasons behind the failure of standard Lagrangian local
bias, in which the halo overdensity is a function of the local mass overdensity
only, we explore the effect of a primordial bispectrum on the 2-point
correlation of discrete density peaks. We show that the effective local bias
expansion to peak clustering vastly simplifies the calculation. We generalize
this approach to excursion set peaks and demonstrate that the resulting
non-Gaussian amplitude, which is a weighted sum of quadratic bias factors,
precisely agrees with the peak-background split expectation, which is a
logarithmic derivative of the halo mass function with respect to the
normalisation amplitude. We point out that statistics of thresholded regions
can be computed using the same formalism. Our results suggest that halo
clustering statistics can be modelled consistently (in the sense that the
Gaussian and non-Gaussian bias factors agree with peak-background split
expectations) from a Lagrangian bias relation only if the latter is specified
as a set of constraints imposed on the linear density field. This is clearly
not the case of standard Lagrangian local bias. Therefore, one is led to
consider additional variables beyond the local mass overdensity.


title: Taming the zoo of supersymmetric quantum mechanical models

abstract:
  We show that in many cases nontrivial and complicated supersymmetric quantum
mechanical (SQM) models can be obtained from the simple model describing free
dynamics in flat complex space by two operations: (i) Hamiltonian reduction and
(ii) similarity transformation of the complex supercharges. We conjecture that
it is true for any SQM model.


title: Coalescing at 8 GeV in the Fermilab Main Injector

abstract:
  For Project X, it is planned to inject a beam of 3 10**11 particles per bunch
into the Main Injector. To prepare for this by studying the effects of higher
intensity bunches in the Main Injector it is necessary to perform coalescing at
8 GeV. The results of a series of experiments and simulations of 8 GeV
coalescing are presented. To increase the coalescing efficiency adiabatic
reduction of the 53 MHz RF is required, resulting in ~70% coalescing efficiency
of 5 initial bunches. Data using wall current monitors has been taken to
compare previous work and new simulations for 53 MHz RF reduction, bunch
rotations and coalescing, good agreement between experiment and simulation was
found. Possible schemes to increase the coalescing efficiency and generate even
higher intensity bunches are discussed. These require improving the timing
resolution of the low level RF and/or tuning the adiabatic voltage reduction of
the 53 MHz.


title: Counterexamples to the $I^{(3)} \subset I^2$ containment

abstract:
  We show that in general the third symbolic power of a radical ideal of points
in the complex projective plane is not contained in the second usual power of
that ideal. This answers in negative a question asked by Huneke and generalized
by Harbourne.


title: Advances in the theory of III-V Nanowire Growth Dynamics

abstract:
  Nanowire (NW) crystal growth via the vapour_liquid_solid mechanism is a
complex dynamic process involving interactions between many atoms of various
thermodynamic states. With increasing speed over the last few decades many
works have reported on various aspects of the growth mechanisms, both
experimentally and theoretically. We will here propose a general continuum
formalism for growth kinetics based on thermodynamic parameters and transition
state kinetics. We use the formalism together with key elements of recent
research to present a more overall treatment of III_V NW growth, which can
serve as a basis to model and understand the dynamical mechanisms in terms of
the basic control parameters, temperature and pressures/beam fluxes.
Self-catalysed GaAs NW growth on Si substrates by molecular beam epitaxy is
used as a model system.


title:
6 Batch Injection and Slipped Beam Tune Measurements in Fermilab's Main
  Injector

abstract:
  During Nova operations it is planned to run the Fermilab Recycler in a 12
batch slip stacking mode. In preparation for this, measurements of the tune
during a six batch injection and then as the beam is slipped by changing the RF
frequency, but without a 7th injection, have been carried out in the Main
Injector. The coherent tune shifts due to the changing beam intensity were
measured and compared well with the theoretically expected tune shift. The tune
shifts due to changing RF frequency, required for slip stacking, also compare
well with the linear theory, although some nonlinear affects are apparent at
large frequency changes. These results give us confidence that the expected
tunes shifts during 12 batch slip stacking Recycler operations can be
accommodated.


title: An OAI-PMH-based Web Service for the Generation of Co-Author Networks

abstract:
  We will present a new component of our technical framework that was built to
provide a brought range of reusable web services for the enhancement of typical
scientific retrieval processes. The proposed component computes betweenness of
authors in co-authorship networks extracted from publicly available metadata
that was harvested using OAI-PMH.


title:
Structural origins of the properties of rare earth nickelate
  superlattices

abstract:
  NiO6 octahedral tilts in the LaNiO3/SrTiO3 superlattices are quantified using
position averaged convergent beam electron diffraction in scanning transmission
electron microscopy. It is shown that maintaining oxygen octahedra connectivity
across the interface controls the octahedral tilts in the LaNiO3 layers, their
lattice parameters and their transport properties. Unlike films and layers that
are connected on one side to the substrate, subsequent LaNiO3 layers in the
superlattice exhibit a relaxation of octahedral tilts towards bulk values. This
relaxation is facilitated by correlated tilts in SrTiO3 layers and is
correlated with the conductivity enhancement of the LaNiO3 layers in the
superlattices relative to individual films.


title:
Symmetry of n-mode positive solutions for two-dimensional H\'enon type
  systems

abstract:
  We provide a symmetry result for n-mode positive solutions of a general class
of semi-linear elliptic systems under cooperative conditions on the
nonlinearities. Moreover, we apply the result to a class of H\'enon systems and
provide the existence of multiple n-mode positive solutions.


title:
Tune Determination of Strongly Coupled Betatron Oscillations in a
  Fast-Ramping Synchrotron

abstract:
  Tune identification - i.e. attribution of the spectral peak to a particular
normal mode of oscillations - can present a significant difficulty in the
presence of strong transverse coupling when the normal mode with a lower
damping rate dominates spectra of Turn-by-Turn oscillations in both planes. The
introduced earlier phased sum algorithm helped to recover the weaker normal
mode signal from the noise, but by itself proved to be insufficient for
automatic peak identification in the case of close phase advance distribution
in both planes. To resolve this difficulty we modified the algorithm by taking
and analyzing Turn-by-Turn data for two different ramps with the beam
oscillation excited in each plane in turn. Comparison of the relative
amplitudes of Fourier components allows for automatic correct tune
identification. The proposed algorithm was implemented in the Fermilab Booster
B38 console application and successfully used in tune, coupling and
chromaticity measurements.


title:
Determining sample alignment in X-ray Reflectometry using thickness and
  density from GaAs/AlAs multilayer certified reference materials

abstract:
  X-ray reflectometry (XRR) provides researchers and manufacturers with a
non-destructive way to determine thickness, roughness, and density of thin
films deposited on smooth substrates. Due to the nested nature of equations
modeling this phenomenon, the inter-relation between instrument alignment and
parameter estimation accuracy is somewhat opaque. In this study, we
intentionally shift incident angle information contained in a high-quality XRR
data set and refine this shifted data using an identical structural model to
assess the effect angle misalignment has on parameter estimation. We develop a
series of calibration curves relating data misalignment to variation with layer
thickness and density for a multilayer GaAs/AlAs Certified Reference Material
on a GaAs substrate. We then test the validity and robustness of several
approaches of using known thickness and density parameters from this structure
to calibrate instrument alignment. We find the highest sensitivity to and
linearity with measurement misalignment from buried AlAs and GaAs layers, in
contrast to the surface layers, which show the most instability. This is a
fortuitous result, as buried AlAs and GaAs exhibit the highest long-term
stability in thickness. Therefore, it is indeed possible to use reference
thickness estimates to validate XRR angle alignment accuracy. Buried layer mass
density information also shows promise as a robust calibration approach. This
is suprising, as electron density of buried layers is both a highly-correlated
phenomenon, and a subtle component in the XRR model.


title:
On the third- and fourth-order constants of incompressible isotropic
  elasticity

abstract:
  Consider the constitutive law for an isotropic elastic solid with the
strain-energy function expanded up to the fourth order in the strain, and the
stress up to the third order in the strain. The stress-strain relation can then
be inverted to give the strain in terms of the stress with a view to
considering the incompressible limit. For this purpose, use of the logarithmic
strain tensor is of particular value. It enables the limiting values of all
nine fourth-order elastic constants in the incompressible limit to be evaluated
precisely and rigorously. In particular, it is explained why the three
constants of fourth-order incompressible elasticity $\mu$, $\bar{A}$, and $\bar
D$ are of the same order of magnitude. Several examples of application of the
results follow, including determination of the acoustoelastic coefficients in
incompressible solids and the limiting values of the coefficients of
nonlinearity for elastic wave propagation.


title: Emergent Space-time Supersymmetry at the Boundary of a Topological Phase

abstract:
  In contrast to ordinary symmetries, supersymmetry interchanges bosons and
fermions. Originally proposed as a symmetry of our universe, it still awaits
experimental verification. Here we theoretically show that supersymmetry
emerges naturally in topological superconductors, which are well-known
condensed matter systems. Specifically, we argue that the quantum phase
transitions at the boundary of topological superconductors in both two and
three dimensions display supersymmetry when probed at long distances and times.
Supersymmetry entails several experimental consequences for these systems, such
as, exact relations between quantities measured in disparate experiments, and
in some cases, exact knowledge of the universal critical exponents. The
topological surface states themselves may be interpreted as arising from
spontaneously broken supersymmetry, indicating a deep relation between
topological phases and SUSY. We discuss prospects for experimental realization
in films of superfluid He$_3$-B.

categories: cond-mat.str-el cond-mat.mes-hall cond-mat.supr-con hep-th


title: Multiplicative functionals on ensembles of non-intersecting paths

abstract:
  The purpose of this article is to develop a theory behind the occurrence of
"path-integral" kernels in the study of extended determinantal point processes
and non-intersecting line ensembles. Our first result shows how determinants
involving such kernels arise naturally in studying ratios of partition
functions and expectations of multiplicative functionals for ensembles of
non-intersecting paths on weighted graphs. Our second result shows how Fredholm
determinants with extended kernels (as arise in the study of extended
determinantal point processes such as the Airy_2 process) are equal to Fredholm
determinants with path-integral kernels. We also show how the second result
applies to a number of examples including the stationary (GUE) Dyson Brownian
motion, the Airy_2 process, the Pearcey process, the Airy_1 and Airy_{2->1}
processes, and Markov processes on partitions related to the z-measures.


title: Constraining General 2HDM by the Evolution of Yukawa Couplings

abstract:
  We analysis the constraints of the general two Higgs doublet models via
evolving the Yukawa coupling constants to high energy under renormalization
group. We consider the appearance of a Landau pole or large off-diagonal Yukawa
couplings which cause tree level flavour changing neutral currents. Our study
shows the latter condition can be used to answer that how much $Z_2$ symmetry
breaking can be allowed in a given 2HDM model.


title:
A bijective proof of Loehr-Warrington's formulas for the statistics
  $\mbox{ctot}_{\frac{q}{p}}$ and $\mbox{midd}_{\frac{q}{p}}$

abstract:
  Loehr and Warrington introduced partitional statistics
$\mbox{ctot}_{\frac{q}{p}}(D)$ and $\mbox{midd}_{\frac{q}{p}}(D)$ and provided
formulas for these statistics in terms of the boundary graph of the Young
diagram $D$. In this paper we give a bijective proof of Loehr-Warrington's
formulas using the following simple combinatorial observation: given a Young
diagram $D$ and two numbers $a$ and $l,$ the number of boxes in $D$ with the
arm length $a$ and the leg length $l$ is one less than the number of boxes with
the same properties in the complement to $D.$ Here the complement is taken
inside the positive quadrant or, equivalently, a very large rectangle.


title: MHD Turbulence and Cosmic Ray Reacceleration in Galaxy Clusters

abstract:
  Cosmological MHD simulations of galaxy cluster formation show a significant
amplification of seed magnetic fields. We developed a novel method to decompose
cluster magnetized turbulence into modes and showed that the fraction of the
fast mode is fairly large, around 1/4 in terms of energy. This is larger than
that was estimated before, which implies that cluster turbulence interacts with
cosmic rays rather efficiently. We propose a framework to deal with electron
and proton reacceleration in galaxy clusters that includes feedback on
turbulence. In particular, we establish a new upper limit on proton and
electron fluxes based on turbulence intensity. These findings, along with
detailed modeling of reacceleration, will help to reconcile the observed giant
radio haloes and the unobserved diffuse gamma-ray emission from these clusters.


title:
Simulating thick atmospheric turbulence in the lab with application to
  orbital angular momentum communication

abstract:
  We describe a procedure by which a long ($\gtrsim 1\,\mathrm{km}$) optical
path through atmospheric turbulence can be experimentally simulated in a
controlled fashion and scaled down to distances easily accessible in a
laboratory setting. This procedure is then used to simulate a 1-km-long
free-space communication link in which information is encoded in orbital
angular momentum (OAM) spatial modes. We also demonstrate that standard
adaptive optics methods can be used to mitigate many of the effects of thick
atmospheric turbulence.


title: Opinion Maximization in Social Networks

abstract:
  The process of opinion formation through synthesis and contrast of different
viewpoints has been the subject of many studies in economics and social
sciences. Today, this process manifests itself also in online social networks
and social media. The key characteristic of successful promotion campaigns is
that they take into consideration such opinion-formation dynamics in order to
create a overall favorable opinion about a specific information item, such as a
person, a product, or an idea.
  In this paper, we adopt a well-established model for social-opinion dynamics
and formalize the campaign-design problem as the problem of identifying a set
of target individuals whose positive opinion about an information item will
maximize the overall positive opinion for the item in the social network. We
call this problem CAMPAIGN. We study the complexity of the CAMPAIGN problem,
and design algorithms for solving it. Our experiments on real data demonstrate
the efficiency and practical utility of our algorithms.


title:
Kinetics of heterogeneous nucleation and growth: An approach based on a
  grain explicit model

abstract:
  A model for phase transitions initiated on grain boundaries is proposed and
tested against numerical simulations: this approach based on a grain explicit
model (GEM) allows to consider the granular structure, yielding accurate
predictions for a wide span of nucleation processes. Comparisons are made with
classical models of homogeneous (JMAK) as well as heterogeneous (Cahn)
nucleation. A transition scale based on material properties is proposed,
allowing to discriminate between random and site saturated regimes. Finally, we
discuss the relationship between an Avrami type exponent and the transition
regime, drawing conditions for its extraction from experiments.


title: Introduction of Intellectual Property Courses in STEM Curriculum

abstract:
  The paper explains and emphasizes the need to include mandatory Intellectual
Property (IP) courses in the undergraduate and graduate curriculum of STEM
students. It prescribes the proposed content of IP to be covered at
undergraduate level, and graduate depending on the degree pursued by the STEM
student. More importantly, this paper advocates for an Integrated PhD/JD degree
to produce highly skilled patent attorneys and agents, to overcome the problem
of poor quality of patents, and the high number of patent related litigations.
A framework is suggested which would enable STEM departments and law schools to
successfully offer this integrated degree, and students to successfully pursue
and complete this degree program in a realistic manner; without compromising
any stake holder's interest.


title:
High Temperature Superconducting Magnets for Efficient Low Energy Beam
  Transport Systems

abstract:
  Modern ion accelerators and ion implantation systems need very short, highly
versatile, Low Energy Beam Transport (LEBT) systems. The need for reliable and
continuous operation requires LEBT designs to be simple and robust. The energy
efficiency of available high temperature superconductors (HTS), with efficient
and simple cryocooler refrigeration, is an additional attraction. Innovative,
compact LEBT systems based on solenoids designed and built with
high-temperature superconductor will be developed using computer models and
prototyped. The parameters will be chosen to make this type of LEBT useful in a
variety of ion accelerators, ion implantation systems, cancer therapy
synchrotrons, and research accelerators, including the ORNL SNS. The benefits
of solenoids made with HTS will be evaluated with analytical and numerical
calculations for a two-solenoid configuration, as will be used in the SNS
prototype LEBT that will replace the electrostatic one at SNS, and a single
solenoid configuration, as was proposed for the Fermilab proton driver that
will be most applicable to ion implantation applications.


title: The pressure metric for Anosov representations

abstract:
  Using the thermodynamics formalism, we introduce a notion of intersection for
projective Anosov representations, show analyticity results for the
intersection and the entropy, and rigidity results for the intersection. We use
the renormalized intersection to produce a $Out(\Gamma)$-invariant Riemannian
metric on the smooth points of the deformation space of irreducible, projective
Anosov representations of a word hyperbolic group $\Gamma$ into $SL(m,R)$ whose
Zariski closure contains a generic element. In particular, we produce mapping
class group invariant Riemannian metrics on Hitchin components which restrict
to the Weil--Petersson metric on the Fuchsian loci. Moreover, we produce
$Out(\Gamma)$-invariant metrics on deformation spaces of convex cocompact
representations into $PSL(2,C)$ and show that the Hausdorff dimension of the
limit set varies analytically over analytic families of convex cocompact
representations into any rank 1 semi-simple Lie group.


title:
Conditioning and Future Plans for a Multi-purpose 805 MHz Pillbox Cavity
  for Muon Acceleration

abstract:
  An 805 MHz RF pillbox cavity has been designed and constructed to investigate
potential muon beam acceleration and cooling techniques for a Muon Collider or
Neutrino Factory. The cavity can operate in vacuum or under pressure to 100
atmospheres, at room temperature or in a liquid nitrogen bath at 77 K. The
cavity has been designed for easy assembly and disassembly with bolted
construction using aluminum seals. To perform vacuum and high pressure
breakdown studies of materials and geometries most suitable for the collider or
factory, the surfaces of the end walls of the cavity can be replaced with
different materials such as copper, aluminum, beryllium, or molybdenum, and
with different geometries such as shaped windows or grid structures. The cavity
has been designed to fit inside the 5-Tesla solenoid in the MuCool Test Area at
Fermilab. In this paper we present the vacuum conditioning results and discuss
plans for testing in a 5-Tesla magnetic field. Additionally, we discuss the
testing plan for beryllium (a material research has shown to be ideal for the
collider or factory) end walls.


title:
Quantum interference and phonon-mediated back-action in lateral quantum
  dot circuits

abstract:
  Spin qubits have been successfully realized in electrostatically defined,
lateral few-electron quantum dot circuits. Qubit readout typically involves
spin to charge information conversion, followed by a charge measurement made
using a nearby biased quantum point contact. It is critical to understand the
back-action disturbances resulting from such a measurement approach. Previous
studies have indicated that quantum point contact detectors emit phonons which
are then absorbed by nearby qubits. We report here the observation of a
pronounced back-action effect in multiple dot circuits where the absorption of
detector-generated phonons is strongly modified by a quantum interference
effect, and show that the phenomenon is well described by a theory
incorporating both the quantum point contact and coherent phonon absorption.
Our combined experimental and theoretical results suggest strategies to
suppress back-action during the qubit readout procedure.


title: A Framework for the Verification of Certifying Computations

abstract:
  Formal verification of complex algorithms is challenging. Verifying their
implementations goes beyond the state of the art of current automatic
verification tools and usually involves intricate mathematical theorems.
Certifying algorithms compute in addition to each output a witness certifying
that the output is correct. A checker for such a witness is usually much
simpler than the original algorithm - yet it is all the user has to trust. The
verification of checkers is feasible with current tools and leads to
computations that can be completely trusted. We describe a framework to
seamlessly verify certifying computations. We use the automatic verifier VCC
for establishing the correctness of the checker and the interactive theorem
prover Isabelle/HOL for high-level mathematical properties of algorithms. We
demonstrate the effectiveness of our approach by presenting the verification of
typical examples of the industrial-level and widespread algorithmic library
LEDA.


title: The role of the droplet deformations in the bouncing droplet dynamics

abstract:
  Droplets bouncing on a vibrated liquid bath open ways to methods of
manipulating droplets, creating double emulsion and performing pilot wave model
experiments. In this work, we focus on the role of the droplet deformations in
the vertical bouncing dynamics by neglecting the deformation of the surface of
the bath. To be under this favorable conditions, low viscous oil droplet are
dropped over a highly viscous oil bath. These droplets bounce vertically on the
surface of the bath and exhibit many periodic trajectories and resonant modes
when tuning the forcing parameters, i.e. the oscillation of the bath. This
complex dynamics emphasizes the interplay between elastic energy storage and
energy dissipation in droplets at each bounce. We propose to model droplets
using a bouncing mass-spring-damper system that mimics a deformable droplet
bouncing on a non-deformable liquid bath. From the experimental measurements,
we constructed bifurcation diagrams of the bouncing trajectories and challenged
our bouncing spring model. The agreement between experiment and the spring
model reveals that this model can be used to rationalize and predict a variety
of bouncing droplets behaviors involving multi-periodicities.


title:
Variable-Length Coding with Feedback: Finite-Length Codewords and
  Periodic Decoding

abstract:
  Theoretical analysis has long indicated that feedback improves the error
exponent but not the capacity of single-user memoryless channels. Recently
Polyanskiy et al. studied the benefit of variable-length feedback with
termination (VLFT) codes in the non-asymptotic regime. In that work,
achievability is based on an infinite length random code and decoding is
attempted at every symbol. The coding rate backoff from capacity due to channel
dispersion is greatly reduced with feedback, allowing capacity to be approached
with surprisingly small expected latency. This paper is mainly concerned with
VLFT codes based on finite-length codes and decoding attempts only at certain
specified decoding times. The penalties of using a finite block-length $N$ and
a sequence of specified decoding times are studied. This paper shows that
properly scaling $N$ with the expected latency can achieve the same performance
up to constant terms as with $N = \infty$. The penalty introduced by periodic
decoding times is a linear term of the interval between decoding times and
hence the performance approaches capacity as the expected latency grows if the
interval between decoding times grows sub-linearly with the expected latency.


title: Effective Martingales with Restricted Wagers

abstract:
  The classic model of computable randomness considers martingales that take
real or rational values. Recent work by Bienvenu et al. (2012) and Teutsch
(2014) shows that fundamental features of the classic model change when the
martingales take integer values.
  We compare the prediction power of martingales whose wagers belong to three
different subsets of rational numbers: (a) all rational numbers, (b) rational
numbers excluding a punctured neighbourhood of 0, and (c) integers. We also
consider three different success criteria: (i) accumulating an infinite amount
of money, (ii) consuming an infinite amount of money, and (iii) making the
accumulated capital oscillate.
  The nine combinations of (a)--(c) and (i)--(iii) define nine notions of
computable randomness. We provide a complete characterization of the relations
between these notions, and show that they form five linearly ordered classes.
  Our results solve outstanding questions raised in Bienvenu et al. (2012),
Teutsch (2014), and Chalcraft et al. (2012), and strengthen existing results.


title: Report on the session QG4 of the 13th Marcel Grossmann Meeting

abstract:
  We summarize the talks presented at the QG4 session (loop quantum gravity:
cosmology and black holes) of the 13th Marcel Grossmann Meeting held in
Stockholm, Sweden.


title:
Neutron matter based on consistently evolved chiral three-nucleon
  interactions

abstract:
  We present the first results for the neutron matter equation of state (EOS)
using nucleon-nucleon and three-nucleon chiral effective field theory
interactions that are consistently evolved in the framework of the Similarity
Renormalization Group (SRG). The dependence of the EOS on the SRG resolution
scale is greatly reduced when induced three-nucleon forces (3NF) are included
and the residual variation, which in part is from missing induced four-body
interactions, is comparable to estimated many-body perturbation theory
truncation errors. The relative growth with decreasing resolution of the 3NF
contributions to the energy per neutron is of natural size, but it accelerates
at the lowest resolutions where strong renormalization of the long-range 3NF
matrix elements is also observed.


title:
On Kakeya-Nikodym averages, $L^p$-norms and lower bounds for nodal sets
  of eigenfunctions in higher dimensions

abstract:
  We extend a result of the second author \cite[Theorem 1.1]{soggekaknik} to
dimensions $d \geq 3$ which relates the size of $L^p$-norms of eigenfunctions
for $2<p<\frac{2(d+1)}{d-1}$ to the amount of $L^2$-mass in shrinking tubes
about unit-length geodesics. The proof uses bilinear oscillatory integral
estimates of Lee \cite{leebilinear} and a variable coefficient variant of an
"$\veps$ removal lemma" of Tao and Vargas \cite{tv1}. We also use H\"ormander's
\cite{HorOsc} $L^2$ oscillatory integral theorem and the Cartan-Hadamard
theorem to show that, under the assumption of nonpositive curvature, the
$L^2$-norm of eigenfunctions $e_\la$ over unit-length tubes of width
$\la^{-\frac12}$ goes to zero. Using our main estimate, we deduce that, in this
case, the $L^p$-norms of eigenfunctions for the above range of exponents is
relatively small. As a result, we can slightly improve the known lower bounds
for nodal sets in dimensions $d\ge3$ of Colding and Minicozzi \cite{CM} in the
special case of (variable) nonpositive curvature.


title:
Classification of Standard Model Particles in $E_6$ Orbifold Grand
  Unified Theories

abstract:
  We classify the standard model fermions, which originate from bulk fields of
the $\bf{27}$ or $\bar{\bf{27}}$ representation after orbifold breaking, in
$E_6$ grand unified theories on 5 or 6-dimensional space-time, under the
condition that $q$, $e^c$ and $u^c$ survive as zero modes.


title:
The origin of the 3.4 micron feature in Wild 2 cometary particles and in
  ultracarbonaceous interplanetary dust particles

abstract:
  We analyzed 2 ultra-carbonaceous interplanetary dust particles and 2 cometary
Wild 2 particles with infrared spectroscopy. We characterized the carrier of
the 3.4 micron band in these samples and compared its profile and the CH2/CH3
ratios to the 3.4 micron band in the diffuse interstellar medium (DISM), in the
insoluble organic matter (IOM) from 3 primitive meteorites, in asteroid 24
Themis and in the coma of comet 103P/Hartley 2. We found that the 3.4 micron
band in both Wild 2 and IDPs is similar, but different from all the other
astrophysical environments that we compared to. The 3.4 micron band in IDPs and
Wild 2 particles is dominated by CH2 groups, the peaks are narrower and
stronger than in the meteorites, asteroid Themis, and the DISM. Also, the
presence of the carbonyl group C=O at 1700 cm-1 (5.8 micron) in most of the
spectra of our samples, indicates that these aliphatic chains have O bonded to
them, which is quite different from astronomical spectra of the DISM. Based on
all these observations we conclude that the origin of the carrier of the 3.4
micron band in IDPs and Wild 2 samples is not interstellar, instead, we suggest
that the origin lies in the outermost parts of the solar nebula.


title: The citation wake of publications detects Nobel laureates' papers

abstract:
  For several decades, a leading paradigm of how to quantitatively assess
scientific research has been the analysis of the aggregated citation
information in a set of scientific publications. Although the representation of
this information as a citation network has already been coined in the 1960s, it
needed the systematic indexing of scientific literature to allow for impact
metrics that actually made use of this network as a whole improving on the then
prevailing metrics that were almost exclusively based on the number of direct
citations. However, besides focusing on the assignment of credit, the paper
citation network can also be studied in terms of the proliferation of
scientific ideas. Here we introduce a simple measure based on the
shortest-paths in the paper's in-component or, simply speaking, on the shape
and size of the wake of a paper within the citation network. Applied to a
citation network containing Physical Review publications from more than a
century, our approach is able to detect seminal articles which have introduced
concepts of obvious importance to the further development of physics. We
observe a large fraction of papers co-authored by Nobel Prize laureates in
physics among the top-ranked publications.


title:
Effects of the two-body and three-body hyperon-nucleon interactions in
  \Lambda-hypernuclei

abstract:
  Background: The calculation of the hyperon binding energy in hypernuclei is
crucial to understanding the interaction between hyperons and nucleons.
  Purpose: We assess the relative importance of two- and three-body
hyperon-nucleon force by studying the effect of the hyperon-nucleon-nucleon
interaction in closed shell \Lambda-hypernuclei from A=5 to 91.
  Methods: The \Lambda-binding energy has been calculated using the auxiliary
field diffusion Monte Carlo method for the first time, to study light and heavy
hypernuclei within the same model.
  Results: Our results show that including a three-body component in the
hyperon-nucleon interaction leads to a saturation of the \Lambda-binding energy
remarkably close to the experimental data. In contrast, the two-body force
alone gives an unphysical limit for the binding energy.
  Conclusions: The repulsive contribution of the three-body
hyperon-nucleon-nucleon force is essential to reproduce, even qualitatively,
the binding energy of the hypernuclei in the mass range considered.


title: Information driven self-organization of complex robotic behaviors

abstract:
  Information theory is a powerful tool to express principles to drive
autonomous systems because it is domain invariant and allows for an intuitive
interpretation. This paper studies the use of the predictive information (PI),
also called excess entropy or effective measure complexity, of the sensorimotor
process as a driving force to generate behavior. We study nonlinear and
nonstationary systems and introduce the time-local predicting information
(TiPI) which allows us to derive exact results together with explicit update
rules for the parameters of the controller in the dynamical systems framework.
In this way the information principle, formulated at the level of behavior, is
translated to the dynamics of the synapses. We underpin our results with a
number of case studies with high-dimensional robotic systems. We show the
spontaneous cooperativity in a complex physical system with decentralized
control. Moreover, a jointly controlled humanoid robot develops a high
behavioral variety depending on its physics and the environment it is
dynamically embedded into. The behavior can be decomposed into a succession of
low-dimensional modes that increasingly explore the behavior space. This is a
promising way to avoid the curse of dimensionality which hinders learning
systems to scale well.


title: Brown-Zagier Relation for Associators

abstract:
  Francis Brown used a certain evaluation formula for multiple zeta values
proved by Zagier to prove the injectivity of the homomorphism from the Motivic
Galois group to the automorphism of fundamental group of projective line
deleted three points. In this paper, we prove that any associators satisfies
this relation. As a consequence, this relation holds for motivic multiple zeta
values which is also proved in Brown's paper. We used certain cohomology theory
and Li's method for the computation.


title: Non-Gaussian continuous-variable entanglement and steering

abstract:
  Two Kerr-squeezed optical beams can be combined in a beamsplitter to produce
non-Gaussian continuous-variable entangled states. We characterize the
non-Gaussian nature of the output by calculating the third-order cumulant of
quadrature variables, and predict the level of entanglement that could be
generated by evaluating the Duan-Simon and Reid Einstein-Podolsky-Rosen
criteria. These states have the advantage over Gaussian states and non-Gaussian
measurement schemes in that the well known, efficient and proven technology of
homodyne detection may be used for their characterisation. A physical
demonstration maintaining the important features of the model could be realised
using two optical fibres, beamsplitters, and homodyne detection.


title:
On the Discrepancy between Theoretical and X-Ray Concentration-Mass
  Relations for Galaxy Clusters

abstract:
  [Abridged] In the past 15 years, the concentration-mass relation has been
investigated diffusely in theoretical studies. On the other hand, only recently
has this relation been derived from X-ray observations. When that happened, the
results caused a certain level of concern: the X-ray normalizations and slopes
were found significantly dissimilar from those predicted by theory.
  We analyzed 52 objects, simulated each time with different physical recipes
for the baryonic component, as well as 60 synthetic X-ray images, to determine
if these discrepancies are real or artificial. In particular, we investigate
how the simulated concentration-mass relation depends (1) on the radial range
used to derive the concentration, (2) on the presence of baryons in the
simulations, and on the prescription used to reproduce the gas. Finally, we
evaluate (3) how the results differ when adopting an X-ray approach for the
analysis and (4) how the selection functions based on X-ray luminosity can
impact the results. All effects studied go in the direction of alleviating the
discrepancy between observations and simulations, although with different
significance: while the fitting radial range and the baryonic component play
only a minor role, the X-ray approach and selection function have profound
repercussion on the resulting concentration-mass relation.


title: Rational material design of mixed-valent high T$_c$ superconductors

abstract:
  We design, from first principles calculations, a novel family of thallium
halide-based compounds as candidates for new high temperature superconductors,
whose superconductivity is mediated by the recently proposed mechanism of
non-local correlation-enhanced strong electron-phonon coupling. Two prototype
compounds namely CsTlF$_3$ and CsTlCl$_3$ are studied with various hole doping
levels and volumes. The critical superconducting temperature T$_c$ are
predicted to be about 30 K and 20 K with $\sim$0.35/f.u. hole doping and
require only modest pressures ($\sim$10 and $\sim$2 GPa), respectively. Our
procedure of designing this class of superconductors is quite general and can
be used to search for other "other high temperature superconductors".


title:
A noncommutative anomaly through Seiberg-Witten map and non-locally
  regularized BV quantization

abstract:
  Anomalies are one essential concept for the renormalization of noncommutative
(NC) gauge theories. A NC space can be visualized as a deformation of the usual
spacetime with the $\star$-product and can be constructed after the
quantization of a given space with its symplectic structure. The Seiberg-Witten
(SW) map connects NC fields, transformations parameters and gauge potential to
their commutative analogs. In this work we used the SW map to calculate the NC
version of the anomaly of the BV quantized chiral Schwinger model with nonlocal
regularization.


title:
Onset of Irreversibility and Chaos in Amorphous Solids Under Periodic
  Shear

abstract:
  An important aspect of the physics of amorphous solids is the onset of
irreversible behavior usually associated with yield. Here we study amorphous
solids under periodic shear using quasi-static molecular dynamics simulations
and observe a transition from reversible to irreversible deformation at a
critical strain amplitude. We find that for small strain amplitudes the system
exhibits a noisy but repetitive limit-cycle, similar to return point memory
\cite{sethna1993hysteresis}. However, for large strain amplitudes the behavior
becomes chaotic (shows sensitivity to initial conditions) and thus
irreversible. We show that the chaotic behavior is a result of the shear band
instabilities that arise for large strains and the convective displacement
fields they create.

categories: cond-mat.soft cond-mat.mtrl-sci cond-mat.stat-mech nlin.CD


title:
A New Sub-Period-Minimum CV with Partial Hydrogen Depletion and Evidence
  of Spiral Disk Structure

abstract:
  We present time-resolved spectroscopy and photometry of CSS
120422:111127+571239 (= SBS1108+574), a recently discovered SU UMa-type dwarf
nova whose 55-minute orbital period is well below the CV period minimum of ~78
minutes. In contrast with most other known CVs, its spectrum features He I
emission of comparable strength to the Balmer lines, implying a hydrogen
abundance less than 0.1 of long period CVs---but still at least 10 times higher
than than in AM CVn stars. Together, the short orbital period and remarkable
helium-to-hydrogen ratio suggest that mass transfer in "CSS 1204" began near
the end of the donor star's main-sequence lifetime, meaning that the system is
probably an AM CVn progenitor as described by Podsiadlowski, Han, and Rappaport
(2003). Moreover, a Doppler tomogram of the Halpha line reveals two distinct
regions of enhanced emission. While one is the result of the stream-disk
impact, the other is probably attributable to spiral disk structure generated
when material in the outer disk achieves a 2:1 orbital resonance with respect
to the donor.


title: Isotopic algebras with non-isomorphic congruence lattices

abstract:
  We give examples of pairs of isotopic algebras with non-isomorphic congruence
lattices. This answers the question of whether all isotopic algebras have
isomorphic congruence lattices.


title:
Technical Report: A Receding Horizon Algorithm for Informative Path
  Planning with Temporal Logic Constraints

abstract:
  This technical report is an extended version of the paper 'A Receding Horizon
Algorithm for Informative Path Planning with Temporal Logic Constraints'
accepted to the 2013 IEEE International Conference on Robotics and Automation
(ICRA). This paper considers the problem of finding the most informative path
for a sensing robot under temporal logic constraints, a richer set of
constraints than have previously been considered in information gathering. An
algorithm for informative path planning is presented that leverages tools from
information theory and formal control synthesis, and is proven to give a path
that satisfies the given temporal logic constraints. The algorithm uses a
receding horizon approach in order to provide a reactive, on-line solution
while mitigating computational complexity. Statistics compiled from multiple
simulation studies indicate that this algorithm performs better than a baseline
exhaustive search approach.


title:
An unconstrained Lagrangian formulation and conservation laws for the
  Schr\"odinger map system

abstract:
  We consider energy-critical Schr\"odinger maps from R^2 into the sphere and
hyperbolic plane. Viewing such maps with respect to orthonormal frames on the
pullback bundle provides a gauge field formulation of the evolution. We show
that this gauge field system is the set of Euler-Lagrange equations
corresponding to an action that includes a Chern-Simons term. We also introduce
the stress-energy tensor and derive conservation laws. In conclusion we offer
comparisons between Schr\"odinger maps and the closely related
Chern-Simons-Schr\"odinger system.


title:
Perturbation analysis for Moore-Penrose inverse of closed operators on
  Hilbert spaces

abstract:
  In this paper, we investigate the perturbation for the Moore-Penrose inverse
of closed operators on Hilbert spaces. By virtue of a new inner product defined
on $H$, we give the expression of the Moore-Penrose inverse $\bar{T}^\dag$ and
the upper bounds of
  $\|\bar{T}^\dag\|$ and $\|\bar{T}^\dag -T^\dag\|$. These results obtained in
this paper extend and improve many related results in this area.


title:
Evidence of alpha particle condensation in $^{12}$C and $^{16}$O and
  Nambu-Goldstone boson

abstract:
  It is suggested that direct evidence of Bose-Einstein condensation of alpha
particles is obtained by observing a phase mode (Nambu-Goldstone boson) with
long wavelength even when characteristic features such as superfluidity is
diffucult to observe. For the 7.65 MeV $0_2^+$ Hoyle state in $^{12}$C and 15.1
MeV $0^+$ state in $^{16}$O, which are candidates for an alpha particle
condensate, it is suggested that the emergent band head $0^+$ state of the
$K=0_2^+$ rotational band with a very large moment of inertia is considered to
be a Nambu-Goldstone boson.


title: On S-duality of the Superconformal Index on Lens Spaces and 2d TQFT

abstract:
  We consider the 4d superconformal index for ${\cal N}=2$ gauge theories on
$S^1 \times L(r,1)$, where $L(r,1)$ is a Lens space. We focus on a
one-parameter slice of the three-dimensional fugacity space and in that sector
we show S-duality. We do so by rewriting the index in a way that resembles a
correlation function of a 2d TFT, which however, we do not identify.


title:
Using Bayesian Analysis and Gaussian Processes to Infer Electron
  Temperature and Density Profiles on the MAST Experiment

abstract:
  A unified, Bayesian inference of midplane electron temperature and density
profiles using both Thompson scattering (TS) and interferometric data is
presented. Beyond the Bayesian nature of the analysis, novel features of the
inference are the use of a Gaussian process prior to infer a mollification
length-scale of inferred profiles and the use of Gauss-Laguerre quadratures to
directly calculate the depolarisation term associated with the TS forward
model. Results are presented from an application of the method to data from the
high resolution TS system on the Mega-Ampere Spherical Tokamak, along with a
comparison to profiles coming from the standard analysis carried out on that
system.


title: A New Spin Gapless Semiconductors Family: Quaternary Heusler Compounds

abstract:
  Using first-principles calculations, we investigate the band structures of a
series of quaternary LiMgPdSn-type Heusler compounds. Our calculation results
show that five compounds CoFeMnSi, CoFeCrAl, CoMnCrSi, CoFeVSi and FeMnCrSb
possess unique electronic structures characterized by a half-metallic gap in
one spin direction while a zero-width gap in the other spin direction showing
spin gapless semiconducting behavior. We further analysis the electronic and
magnetic properties of all quaternary Heusler alloys involved, and reveal a
semi-empirical general rule (total valence electrons number being 26 or 28) for
indentifying spin gapless semiconductors in Heusler compounds. The influences
of lattice distortion and main-group element change have also been discussed.


title:
Structure and magnetic properties of Heusler alloy Fe2NiZ (Z=Al, Ga, Si
  and Ge)

abstract:
  The Heusler alloys Fe2NiZ (Z=Al, Ga, Si and Ge) have been synthesized and
investigated focusing on the phase stability and the magnetic properties. The
experimental and theoretical results reveal the covalent bonding originated
from p-d hybridization takes an important role in these alloys, which dominates
the stability of ordered structure but leads to the decline of the band
splitting. The electronic structure shows the IV group main group element (Si
and Ge) provides stronger covalent effect than that of the III group element
(Al and Ga). It has been found that the variations of the physical parameters,
lattice constants, critical ordering temperature, magnetic moments and Curie
temperature, precisely follow these covalent characters.


title:
Switching of Dipole Coupled Multiferroic Nanomagnets in the Presence of
  Thermal Noise: Reliability of Nanomagnetic Logic

abstract:
  The stress-induced switching behavior of a multiferroic nanomagnet, dipole
coupled to a hard nanomagnet, is numerically studied by solving the stochastic
Landau-Lifshitz-Gilbert (LLG) equation for a single domain macro-spin state.
Different factors were found to affect the switching probability in the
presence of thermal noise at room temperature: (i) dipole coupling strength,
(ii) stress levels, and (iii) stress withdrawal rates (ramp rates). We report
that the thermal broadening of the magnetization distribution causes large
switching error rates. This could render nanomagnetic logic schemes that rely
on dipole coupling to perform Boolean logic operations impractical whether they
are clocked by stress or field or other means.


title: On the Construction and Decoding of Concatenated Polar Codes

abstract:
  A scheme for concatenating the recently invented polar codes with interleaved
block codes is considered. By concatenating binary polar codes with interleaved
Reed-Solomon codes, we prove that the proposed concatenation scheme captures
the capacity-achieving property of polar codes, while having a significantly
better error-decay rate. We show that for any $\epsilon > 0$, and total frame
length $N$, the parameters of the scheme can be set such that the frame error
probability is less than $2^{-N^{1-\epsilon}}$, while the scheme is still
capacity achieving. This improves upon $2^{-N^{0.5-\eps}}$, the frame error
probability of Arikan's polar codes. We also propose decoding algorithms for
concatenated polar codes, which significantly improve the error-rate
performance at finite block lengths while preserving the low decoding
complexity.


title: Particle-scale reversibility in athermal particulate media below jamming

abstract:
  We perform numerical simulations of athermal repulsive frictionless disks and
spheres in two and three spatial dimensions undergoing cyclic quasi-static
simple shear to investigate particle-scale reversible motion. We identify three
classes of steady-state dynamics as a function of packing fraction \phi and
maximum strain amplitude per cycle \gamma_{\rm max}. Point-reversible states,
where particles do not collide and exactly retrace their intra-cycle
trajectories, occur at low \phi and \gamma_{\rm max}. Particles in
loop-reversible states undergo numerous collisions and execute complex
trajectories, but return to their initial positions at the end of each cycle.
Loop-reversible dynamics represents a novel form of self-organization that
enables reliable preparation of configurations with specified structural and
mechanical properties over a broad range of \phi from contact percolation to
jamming onset at \phi_J. For sufficiently large \phi and \gamma_{\rm max},
systems display irreversible dynamics with nonzero self-diffusion.


title:
Using a tunable quantum wire to measure the large out-of-plane spin
  splitting of quasi two-dimensional holes in a GaAs nanostructure

abstract:
  The out-of-plane g-factor g_perp for quasi-2D holes in a (100) GaAs
heterostructure is studied using a variable width quantum wire. A direct
measurement of the Zeeman splitting is performed in a magnetic field applied
perpendicular to the 2D plane. We measure an out-of-plane g-factor up to g_perp
= 5, which is larger than previous optical studies of g_perp, and is
approaching the long predicted but never experimentally verified out-of-plane
g-factor of 7.2 for heavy holes.


title:
Preservation of quantum correlation between separated nitrogen-vacancy
  centers embedded in photonic crystal cavities

abstract:
  We investigate the non-Markovian dynamics of quantum correlation between two
initially entangled nitrogen-vacancy centers (NVC) embedded in photonic crystal
cavities (PCC). We find that a finite quantum correlation is preserved even
asymptotically when the transition frequency of the NVC is within the band gap
of the PCC, which is quantitatively different from the result of approaching
zero under the Born-Markovian approximation. In addition, once the transition
frequency of NVC is far beyond the band gap of the PCC, the quantum correlation
initially prepared in NVC will be fully transferred to the reservoirs in the
long-time limit. Our result reveals that the interplay between the
non-Markovian effect of the structured reservoirs and the existence of
emitter-field bound state plays an essential role in such quantum correlation
preservation. This feature may open new perspectives for devising active
decoherence-immune solid-state optical devices.


title:
Rapid Spin Deceleration of Magnetized Proto-Neutron Stars via Asymmetric
  Neutrino Emission

abstract:
  We calculate the spin deceleration of proto-neutron stars by asymmetric
neutrino absorption in the context of a fully relativistic mean field theory.
We calculate for the first time the spin deceleration of neutron stars due to
asymmetric neutrino absorption in a toroidal magnetic field configurations. We
find a surprising effect that the deceleration can much larger for asymmetric
neutrino absorption in a toroidal magnetic field than the usually presumed
braking due to magnetic dipole radiation. This may explain the observation that
magnetars appear to have had a more rapid deceleration in the past.


title:
On Quality of Monitoring for Multi-channel Wireless Infrastructure
  Networks

abstract:
  Passive monitoring utilizing distributed wireless sniffers is an effective
technique to monitor activities in wireless infrastructure networks for fault
diagnosis, resource management and critical path analysis. In this paper, we
introduce a quality of monitoring (QoM) metric defined by the expected number
of active users monitored, and investigate the problem of maximizing QoM by
judiciously assigning sniffers to channels based on the knowledge of user
activities in a multi-channel wireless network. Two types of capture models are
considered. The user-centric model assumes frame-level capturing capability of
sniffers such that the activities of different users can be distinguished while
the sniffer-centric model only utilizes the binary channel information (active
or not) at a sniffer. For the user-centric model, we show that the implied
optimization problem is NP-hard, but a constant approximation ratio can be
attained via polynomial complexity algorithms. For the sniffer-centric model,
we devise stochastic inference schemes to transform the problem into the
user-centric domain, where we are able to apply our polynomial approximation
algorithms. The effectiveness of our proposed schemes and algorithms is further
evaluated using both synthetic data as well as real-world traces from an
operational WLAN.


title: On the formal affine Hecke algebra

abstract:
  We study the action of the formal affine Hecke algebra on the formal group
algebra, and show that the the formal affine Hecke algebra has a basis indexed
by the Weyl group as a module over the formal group algebra. We also define a
concept called the normal formal group law, which we use to simplify the
relations of the generators of the formal affine Demazure algebra and the
formal affine Hecke algebra.


title:
Including four-gluon interactions into Landau and maximally-Abelian
  gauge Dyson-Schwinger studies

abstract:
  In Dyson-Schwinger studies of the Yang-Mills propagators the four-gluon
interaction has been usually neglected due to the related technical
difficulties with the associated two-loop terms and especially their
renormalization. A possible scenario to renormalize these fully-dressed
two-loop terms is presented. Preliminary results for the Landau gauge gluon
propagator are shown. Implications for the gluon propagators in maximally
Abelian gauge are discussed.


title:
Synchrotron X-ray diagnostics of cutoff shape of nonthermal electron
  spectrum at young supernova remnants

abstract:
  Synchrotron X-rays can be a useful tool to investigate electron acceleration
at young supernova remnants (SNRs). At present, since the magnetic field
configuration around the shocks of SNRs is uncertain, it is not clear whether
electron acceleration is limited by SNR age, synchrotron cooling, or even
escape from the acceleration region. We study whether the acceleration
mechanism can be constrained by the cutoff shape of the electron spectrum
around the maximum energy. We derive analytical formulae of the cutoff shape in
each case where the maximum electron energy is determined by SNR age,
synchrotron cooling and escape from the shock. They are related to the energy
dependence of the electron diffusion coefficient. Next, we discuss whether
information on the cutoff shape can be provided by observations in the near
future which will simply give the photon indices and the flux ratios in the
soft and hard X-ray bands. We find that if the power-law index of the electron
spectrum is independently determined by other observations, then we can
constrain the cutoff shape by comparing theoretical predictions of the photon
indices and/or the flux ratios with observed data which will be measured by
NuSTAR and/or ASTRO-H. Such study is helpful in understanding the acceleration
mechanism. In particular, it will supply another independent constraint on the
magnetic field strength around the shocks of SNRs.


title: Non-zero total correlation means non-zero quantum correlation

abstract:
  We investigated the super quantum discord based on weak measurements. The
super quantum discord is an extension of the standard quantum discord defined
by projective measurements and also describes the quantumness of correlations.
We provide some equivalent conditions for zero super quantum discord by using
quantum discord, classical correlation and mutual information. In particular,
we find that the super quantum discord is zero only for product states, which
have zero mutual information. This result suggests that non-zero correlations
can always be detected using the quantum correlation with weak measurements. As
an example, we present the assisted state-discrimination method.


title:
A 2.5-5 {\mu}m Spectroscopic Study of Hard X-ray Selected AGNs using
  AKARI InfraRed Camera

abstract:
  We present results of the 2.5-5 {\mu}m spectroscopy of a sample of hard X-ray
selected active galactic nuclei (AGNs) using the grism mode of the InfraRed
Camera (IRC) on board the infrared astronomical satellite AKARI. The sample is
selected from the 9-month Swift/BAT survey in the 14-195 keV band, which
provides a fair sample of AGNs including highly absorbed ones. The 2.5-5 {\mu}m
spectroscopy provide a strong diagnostic tool for the circumnuclear environment
of AGNs through the continuum shapes and emission/absorption features such as
the 3.3 {\mu}m polycyclic aromatic hydrocarbon (PAH) emission and the broad 3.1
{\mu}m H2O ice, 3.4 {\mu}m bare carbonaceous dust, 4.26 {\mu}m CO2 and 4.67
{\mu}m CO absorptions. As our first step, we use the 3.3 {\mu}m PAH emission as
a proxy for the star-formation activity and searched for possible difference of
star-formation activity between type 1 (unabsorbed) and type 2 (absorbed) AGNs.
We found no significant dependence of the 3.3 {\mu}m PAH line luminosity,
normalized by the black hole mass, on optical AGNs types or the X-ray measured
column densities.


title: Manifestation of constrained dynamics in a low pressure spark

abstract:
  Some features of neutron emission from dense plasma focus suggest that the
participating deuterons have energy in the range of 105 eV and have a
directionality of toroidal motion. Theoretical models of these devices assume
that the plasma evolves through a purely irrotational flow and thus fail to
predict such solenoidal flow on the scale of the plasma dimensions. Predictions
of a relaxation theory are consistent with experimental data [S K H Auluck,
Physics of Plasmas,18, 032508 (2011)], but the assumptions upon which it is
based are not compatible with known features of these devices. There is thus no
satisfactory theoretical construct which provides the necessity for solenoidal
flow in these devices. This paper proposes such theoretical construct, namely,
the principle of constrained dynamics, and describes an experiment which
provides support for this idea. The experiment consisted of low inductance,
self-breaking spark discharge in helium at a pressure ~100 hPa between two
pointed electrodes separated by 30-50 mm distance kept inside a vacuum chamber
mounted on a low inductance high voltage capacitor. The current derivative
signal showed reproducible sharp dips at all the extrema of the damped
sinusoidal discharge. A planar diamagnetic loop centered with and perpendicular
to the discharge axis consistently showed a signal representing rate of change
of axial magnetic flux. A qualitative explanation of observed phenomena is
obtained using a simple model using the proposed principle.


title:
Finite Length Analysis on Listing Failure Probability of Invertible
  Bloom Lookup Tables

abstract:
  The Invertible Bloom Lookup Tables (IBLT) is a data structure which supports
insertion, deletion, retrieval and listing operations of the key-value pair.
The IBLT can be used to realize efficient set reconciliation for database
synchronization. The most notable feature of the IBLT is the complete listing
operation of the key-value pairs based on the algorithm similar to the peeling
algorithm for low-density generator-matrix (LDGM) codes. In this paper, we will
present a stopping set (SS) analysis for the IBLT which reveals finite length
behaviors of the listing failure probability. The key of the analysis is
enumeration of the number of stopping matrices of given size. We derived a
novel recursive formula useful for computationally efficient enumeration. An
upper bound on the listing failure probability based on the union bound
accurately captures the error floor behaviors. It will be shown that, in the
error floor region, the dominant SS have size 2. We propose a simple
modification on hash functions, which are called SS avoiding hash functions,
for preventing occurrences of the SS of size 2.


title:
Improved Lower Bounds on the Total Variation Distance for the Poisson
  Approximation

abstract:
  New lower bounds on the total variation distance between the distribution of
a sum of independent Bernoulli random variables and the Poisson random variable
(with the same mean) are derived via the Chen-Stein method. The new bounds rely
on a non-trivial modification of the analysis by Barbour and Hall (1984) which
surprisingly gives a significant improvement. A use of the new lower bounds is
addressed.


title: 50 pico arcsecond astrometry of pulsar emission

abstract:
  We use VLBI imaging of the interstellar scattering speckle pattern associated
with the pulsar PSR 0834+06 to measure the astrometric motion of its emission.
The ~ 5AU interstellar baselines, provided by interference between speckles
spanning the scattering disk, enable us to detect motions with sub
nanoarcsecond accuracy. We measure a small pulse deflection of ~18+/-2 km (not
including geometric uncertainties), which is 100 times smaller than the native
resolution of this interstellar interferometer. This implies that the emission
region is small, and at an altitude of a few hundred km, with the exact value
depending on field geometry. This is substantially closer to the star than to
the light cylinder. Future VLBI measurements can improve on this finding. This
new regime of ultra-precise astrometry may enable precision parallax distance
determination of pulsar binary displacements.


title:
A Fully Distributed Opportunistic Network Coding Scheme for Cellular
  Relay Networks

abstract:
  In this paper, we propose an opportunistic network coding (ONC) scheme in
cellular relay networks, which operates depending on whether the relay decodes
source messages successfully or not. A fully distributed method is presented to
implement the proposed opportunistic network coding scheme without the need of
any feedback between two network nodes. We consider the use of proposed ONC for
cellular downlink transmissions and derive its closed-form outage probability
expression considering cochannel interference in a Rayleigh fading environment.
Numerical results show that the proposed ONC scheme outperforms the traditional
non-cooperation in terms of outage probability. We also develop the
diversity-multiplexing tradeoff (DMT) of proposed ONC and show that the ONC
scheme obtains the full diversity and an increased multiplexing gain as
compared with the conventional cooperation protocols.


title:
On the limit of large surface tension for a fluid motion with free
  boundary

abstract:
  We study the free boundary Euler equations in two spatial dimensions. We
prove that if the boundary is sufficiently regular, then solutions of the free
boundary fluid motion converge to solutions of the Euler equations in a fixed
domain when the coefficient of surface tension tends to infinity.

categories: math.AP math-ph math.DG math.MP physics.flu-dyn


title: Characterizing Magnetized Turbulence in M51

abstract:
  We use previously published high-resolution synchrotron polarization data to
perform an angular dispersion analysis with the aim of charactering magnetized
turbulence in M51. We first analyze three distinct regions (the center of the
galaxy, and the northwest and southwest spiral arms) and can clearly discern
the turbulent correlation length scale from the width of the magnetized
turbulent correlation function for two regions and detect the imprint of
anisotropy in the turbulence for all three. Furthermore, analyzing the galaxy
as a whole allows us to determine a two-dimensional Gaussian model for the
magnetized turbulence in M51. We measure the turbulent correlation scales
parallel and perpendicular to the local mean magnetic field to be,
respectively, delta_{para} = 98 +/- 5 pc and delta_{perp} = 54 +/- 3 pc, while
the turbulent to ordered magnetic field strength ratio is found to be Bt/B0 =
1.01 +/- 0.04. These results are consistent with those of Fletcher et al.
(2011), who performed a Faraday rotation dispersion analysis of the same data,
and our detection of anisotropy is consistent with current magnetized
turbulence theories.


title: Slipher and the Nature of the Nebulae

abstract:
  Why do some discoveries, which appear in hindsight to be obviously major
discoveries, have so little impact when they were made. These are discoveries
that were ahead of their time, but for some reason the scientific community was
not ready to absorb them. I got interested in Slipher after learning that by
1914 he had observed nebular redshifts up to 1000 km/s. Why did this not
convince people at the time that the nebulae were extragalactic ? Was this
another example, like Zwicky's (1933) discovery of dark matter in the Coma
cluster, of a discovery which was too far ahead of its time ? I conclude that
Slipher's situation was different from Zwicky's. The significance of Slipher's
nebular redshifts was partly recognised at the time, but I believe that its
full significance was masked by van Maanen's work which turned out to be
erroneous and reduced the impact of Slipher's discoveries.


title: Analytic structure of one-loop coefficients

abstract:
  By the unitarity cut method, analytic expressions of one-loop coefficients
have been given in spinor forms. In this paper, we present one-loop
coefficients of various bases in Lorentz-invariant contraction forms of
external momenta. Using these forms, the analytic structure of these
coefficients becomes manifest. Firstly, coefficients of bases contain only
second-type singularities while the first-type singularities are included
inside scalar bases. Secondly, the highest degree of each singularity is
correlated with the degree of the inner momentum in the numerator. Thirdly, the
same singularities will appear in different coefficients, thus our explicit
results could be used to provide a clear physical picture under various limits
(such as soft or collinear limits) when combining contributions from all bases.


title: Products of Young symmetrizers and ideals in the generic tensor algebra

abstract:
  We describe a formula for computing the product of the Young symmetrizer of a
Young tableau with the Young symmetrizer of a subtableau, generalizing the
classical quasi-idempotence of Young symmetrizers. We derive some consequences
to the structure of ideals in the generic tensor algebra and its partial
symmetrizations. Instances of these generic algebras appear in the work of Sam
and Snowden on twisted commutative algebras, as well as in the work of the
author on the defining ideals of secant varieties of Segre-Veronese varieties,
and in joint work of Oeding and the author on the defining ideals of tangential
varieties of Segre-Veronese varieties.


title: Efficient Algorithms for One-Dimensional k-Center Problems

abstract:
  We consider the problem of finding k centers for n weighted points on a real
line. This (weighted) k-center problem was solved in O(n log n) time previously
by using Cole's parametric search and other complicated approaches. In this
paper, we present an easier O(n log n) time algorithm that avoids the
parametric search, and in certain special cases our algorithm solves the
problem in O(n) time. In addition, our techniques involve developing
interesting data structures for processing queries that find a lowest point in
the common intersection of a certain subset of half-planes. This subproblem is
interesting in its own right and our solution for it may find other
applications as well.


title: Metal Abundances of 12 Dwarf Irregulars from the ADBS Survey

abstract:
  We have analyzed long-slit spectra of 12 dwarf irregular galaxies from the
Arecibo Dual Beam Survey (ADBS). These galaxies represent a heterogeneous
sample of objects detected by ADBS, but on average are relatively gas-rich,
low-surface-brightness, and low-mass, thus represent a region of the galaxian
population that is not commonly included in optical surveys. The
metallicity-luminosity relationship for these galaxies is analyzed; the
galaxies discussed in this paper appear to be under-abundant at a given
luminosity when compared to a sample from the literature. We attempt to
identify a "second parameter" responsible for the intrinsic scatter and
apparent under-abundance of our galaxies. We do not find a definitive second
parameter but note the possible indication that infall or mixing of pristine
gas may be responsible. We derive oxygen abundances for multiple HII regions in
many of our galaxies but do not find any strong indications of metallicity
variation within the galaxies except in one case where we see variation between
an isolated HII region and the rest of the galaxy. Our data set includes the
galaxy with the largest known HI-to-optical size ratio, ADBS 113845+2008. Our
abundance analysis of this galaxy reveals that it is strongly over-enriched
compared to galaxies of similar luminosity, indicating it is not a young object
and confirming the result from Cannon et. al (2009) that this galaxy appears to
be intrinsically rare in the local universe.


title:
Production and decay of a heavy radion in Randall-Sundrum model at the
  LHC

abstract:
  We study production and decay of a radion predicted in the Randall-Sundrum
model at the LHC. The radion is a scalar particle and its production and decay
channels are quite similar to those of the Higgs boson. We find constraints on
the model parameter space taking account of the results of the Higgs boson
search at the LHC. We also study a possibility discriminating the radion from
the scalar particles in the other model such as the supersymmetric standard
model at the LHC experiments.


title:
Energy Efficiency of Network Cooperation for Cellular Uplink
  Transmissions

abstract:
  There is a growing interest in energy efficient or so-called "green" wireless
communication to reduce the energy consumption in cellular networks. Since
today's wireless terminals are typically equipped with multiple network access
interfaces such as Bluetooth, Wi-Fi, and cellular networks, this paper
investigates user terminals cooperating with each other in transmitting their
data packets to a base station (BS) by exploiting the multiple network access
interfaces, referred to as inter-network cooperation, to improve the energy
efficiency in cellular uplink transmission. Given target outage probability and
data rate requirements, we develop a closed-form expression of energy
efficiency in Bits-per-Joule for the inter-network cooperation by taking into
account the path loss, fading, and thermal noise effects. Numerical results
show that when the cooperating users move towards to each other, the proposed
inter-network cooperation significantly improves the energy efficiency as
compared with the traditional non-cooperation and intra-network cooperation.
This implies that given a certain amount of bits to be transmitted, the
inter-network cooperation requires less energy than the traditional
non-cooperation and intra-network cooperation, showing the energy saving
benefit of inter-network cooperation.


title:
Constraining transmission and reflection probabilities by using the
  Miller-Good transformation

abstract:
  Transmission through and reflection from a potential barrier, and the very
closely related issue of particle production from a parametric resonance, are
topics of considerable general interest in quantum physics. We have developed a
rather general bound on quantum transmission probabilities, and recently
applied it to bounding the greybody factors of a Schwarzschild black hole. In
this current paper, we take a different tack -- we report a way of using the
Miller-Good transformation (which maps an initial Schrodinger equation to a
final Schrodinger equation for a different potential) to significantly
generalize the previous bound. We then apply this general formalism in a very
specific manner to derive a rigorous bound that is "as close as possible" to
the usual WKB estimate for barrier penetration.


title:
Content Based Traffic Engineering in Software Defined Information
  Centric Networks

abstract:
  This paper describes a content centric network architecture which uses
software defined networking principles to implement efficient metadata driven
services by extracting content metadata at the network layer. The ability to
access content metadata transparently enables a number of new services in the
network. Specific examples discussed here include: a metadata driven traffic
engineering scheme which uses prior knowledge of content length to optimize
content delivery, a metadata driven content firewall which is more resilient
than traditional firewalls and differentiated treatment of content based on the
type of content being accessed. A detailed outline of an implementation of the
proposed architecture is presented along with some basic evaluation.


title:
Observation of Airy minimum in elastic and inelastic scattering of
  $^3$He from $^{12}$C at 50.5 and 60 MeV and alpha particle condensation in
  $^{12}$C

abstract:
  Angular distributions for elastic and inelastic scattering of $^3$He from
$^{12}$C were measured at energies 50.5 and 60 MeV. The Airy minimum of the
prerainbow scattering was clearly observed in the angular distributions for the
0$_2^+$ (7.65 MeV) state of $^{12}$C (Hoyle state). The experimental results
were analyzed with a coupled channels method with double folding potentials
derived from the microscopic wave functions for the ground 0$_1^+$, 2$^+$ (4.44
MeV), 3$^-$ (9.64 MeV) and 0$_2^+$ states. The analysis supports the view that
the Hoyle state is a three alpha particle condensate with a large radius of
dilute matter distribution.


title: Non-Adaptive Group Testing based on Sparse Pooling Graphs

abstract:
  In this paper, an information theoretic analysis on non-adaptive group
testing schemes based on sparse pooling graphs is presented. The binary status
of the objects to be tested are modeled by i.i.d. Bernoulli random variables
with probability p. An (l, r, n)-regular pooling graph is a bipartite graph
with left node degree l and right node degree r, where n is the number of left
nodes. Two scenarios are considered: a noiseless setting and a noisy one. The
main contributions of this paper are direct part theorems that give conditions
for the existence of an estimator achieving arbitrary small estimation error
probability. The direct part theorems are proved by averaging an upper bound on
estimation error probability of the typical set estimator over an (l,r,
n)-regular pooling graph ensemble. Numerical results indicate sharp threshold
behaviors in the asymptotic regime.


title: Umbral calculus and special polynomials

abstract:
  In this paper, we consider several special polynomials related to associated
sequences of polynomials. Finally, we give some new and interesting identities
of those polynomials arising from transfer formula for the associated
sequences.


title: Homology Groups of Pipeline Petri Nets

abstract:
  We study homology groups of elementary Petri nets for the pipeline systems.
We show that the integral homology groups of these nets in dimensions 0 and 1
equal the group of integers, and they are zero in other dimensions. We prove
that directed homology groups of elementary Petri nets are zero in all
dimensions.


title:
Modeling coronal magnetic field using spherical geometry: cases with
  several active regions

abstract:
  The magnetic fields in the solar atmosphere structure the plasma, store free
magnetic energy and produce a wide variety of active solar phenomena, like
flare and coronal mass ejections(CMEs). The distribution and strength of
magnetic fields are routinely measured in the solar surface(photosphere).
Therefore, there is considerable interest in accurately modeling the 3D
structure of the coronal magnetic field using photospheric vector magnetograms.
Knowledge of the 3D structure of magnetic field lines also help us to interpret
other coronal observations, e.g., EUV images of the radiating coronal plasma.
Nonlinear force-free field (NLFFF) models are thought to be viable tools for
those task. Usually those models use Cartesian geometry. However, the spherical
nature of the solar surface cannot be neglected when the field of view is
large. In this work, we model the coronal magnetic field above multiple active
regions using NLFFF extrapolation code using vector magnetograph data from the
Synoptic Optical Long-term Investigations of the Sun survey (SOLIS)/ Vector
Spectromagnetograph (VSM) as a boundary conditions. We compare projections of
the resulting magnetic field lines solutions with their respective coronal
EUV-images from the Atmospheric Imaging Assembly (SDO/AIA) observed on October
11, 2011 and November 13, 2012. This study has found that the NLFFF model in
spherical geometry reconstructs the magnetic configurations for several active
regions which agrees with observations. During October 11, 2011 observation,
there are substantial number of trans-equatorial loops carrying electric
current.


title:
Constructing, sampling and counting graphical realizations of restricted
  degree sequences

abstract:
  With the current burst of network theory (especially in connection with
social and biological networks) there is a renewed interest on realizations of
given degree sequences. In this paper we propose an essentially new degree
sequence problem: we want to find graphical realizations of a given degree
sequence on labeled vertices, where certain would-be edges are {\em forbidden}.
Then we want to sample uniformly and efficiently all these possible
realizations. (This problem can be considered as a special case of Tutte's
$f$-factor problem, however it has a favorable sampling speed.)
  We solve this {\em restricted degree sequence} (or RDS for short) problem
completely if the forbidden edges form a bipartite graph, which consist of the
union of a (not necessarily maximal) 1-factor and a (possible empty) star. Then
we show how one can sample the space of all realizations of these RDSs
uniformly and efficiently when the degree sequence describes a {\em
half-regular} bipartite graph. Our result contains, as special cases, the
well-known result of Kannan, Tetali and Vempala on sampling regular bipartite
graphs and a recent result of Greenhill on sampling regular directed graphs (so
it also provides new proofs of them).
  The RDS problem descried above is self-reducible, therefore our {\em fully
polynomial almost uniform sampler} (a.k.a. FPAUS) on the space of all
realizations also provides a {\em fully polynomial randomized approximation
scheme} (a.k.a. FPRAS) for approximate counting of all realizations.


title: Bounds on variable-length compound jumps

abstract:
  In Euclidean space there is a trivial upper bound on the maximum length of a
compound "walk" built up of variable-length jumps, and a considerably less
trivial lower bound on its minimum length. The existence of this non-trivial
lower bound is intimately connected to the triangle inequalities, and the more
general "polygon inequalities". Moving beyond Euclidean space, when a modified
version of these bounds is applied in "rapidity space" they provide upper and
lower bounds on the relativistic composition of velocities. Similarly, when
applied to "transfer matrices" these bounds place constraints either (in a
scattering context) on transmission and reflection coefficients, or (in a
parametric excitation context) on particle production. Physically these are
very different contexts, but mathematically there are intimate relations
between these superficially very distinct systems.


title: Optimal dividends in the dual model under transaction costs

abstract:
  We analyze the optimal dividend payment problem in the dual model under
constant transaction costs. We show, for a general spectrally positive L\'{e}vy
process, an optimal strategy is given by a $(c_1,c_2)$-policy that brings the
surplus process down to $c_1$ whenever it reaches or exceeds $c_2$ for some $0
\leq c_1 < c_2$. The value function is succinctly expressed in terms of the
scale function. A series of numerical examples are provided to confirm the
analytical results and to demonstrate the convergence to the no-transaction
cost case, which was recently solved by Bayraktar et al. (2013).


title: PBR theorem and Einstein's quantum hole argument

abstract:
  Upon reading Einstein's views on quantum incompleteness in publications or in
his correspondence after 1935 (the EPR paradox), one gets a very intense
feeling of deja-vu. Einstein presents a quantum hole argument, which somewhat
reminds of the hole argument in his 1914 "Entwurf" theory of general
relativity. PBR write in their paper, "An important step towards the derivation
of our result is the idea that the quantum state is physical if distinct
quantum states correspond to non-overlapping distributions for [physical
states]". PBR then conclude, "The general notion that two distinct quantum
states may describe the same state of reality, however, has a long history. For
example, in a letter to Schr\"odinger containing a variant of the famous EPR
(Einstein-Podolsky-Rosen) argument", and they refer to Einstein's quantum hole
argument. This short paper discusses the PBR theorem, and the connection
between the PBR argument and Einstein's argument and solution.


title: Bounding the greybody factors for the Reissner-Nordstr\"{o}m black holes

abstract:
  A black hole can emit radiation called Hawking radiation. Such radiation seen
by an observer outside the black hole differs from the original radiation near
the horizon of the black hole by the so-called "greybody factor". In this
paper, the bounds of the greybody factors for the Reissner-Nordstr\"{o}m black
holes are obtained. These bounds can be derived by using the 2 x 2 transfer
matrices. It is found that the charges of black holes act as good barriers.


title: Stationary reflection principles and two cardinal tree properties

abstract:
  We study consequences of stationary and semi-stationary set reflection. We
show that the semi stationary reflection principle implies the Singular
Cardinal Hypothesis, the failure of weak square principle, etc. We also
consider two cardinal tree properties introduced recently by Weiss and prove
that they follow from stationary and semi stationary set reflection augmented
with a weak form of Martin's Axiom. We also show that there are some
differences between the two reflection principles which suggest that stationary
set reflection is analogous to supercompactness whereas semi-stationary set
reflection is analogous to strong compactness.