title:
Search for long-lived stopped R-hadrons decaying out-of-time with pp
  collisions using the ATLAS detector

abstract:
  An updated search is performed for gluino, top squark, or bottom squark
R-hadrons that have come to rest within the ATLAS calorimeter, and decay at
some later time to hadronic jets and a neutralino, using 5.0 and 22.9 fb-1 of
pp collisions at 7 and 8 TeV, respectively. Candidate decay events are
triggered in selected empty bunch crossings of the LHC in order to remove pp
collision backgrounds. Selections based on jet shape and muon-system activity
are applied to discriminate signal events from cosmic ray and beam-halo muon
backgrounds. In the absence of an excess of events, improved limits are set on
gluino, stop, and sbottom masses for different decays, lifetimes, and
neutralino masses. With a neutralino of mass 100 GeV, the analysis excludes
gluinos with mass below 832 GeV (with an expected lower limit of 731 GeV), for
a gluino lifetime between 10 microseconds and 1000 s in the generic R-hadron
model with equal branching ratios for decays to qqbar+neutralino and
gluon+neutralino. Under the same assumptions for the neutralino mass and squark
lifetime, top squarks and bottom squarks in the Regge R-hadron model are
excluded with masses below 379 and 344 GeV, respectively.


title:
Pseudodifferential calculus on manifolds with fibred corners : the
  groupoid of phi-calculus

abstract:
  This paper is concerned with pseudodifferential calculus on manifolds with
fibred corners. Following work of Connes, Monthubert, Skandalis and
Androulidakis, we associate to every manifold with fibred corners a
longitudinally smooth groupoid which algebraic and differential structure is
explicitely described. This groupoid has a natural geometric meaning as a
holonomy groupoid of singular foliation, it is a singular leaf space in the
sense of Androulidakis and Skandalis. We then show that the associated
compactly supported pseudodifferential calculus coincides with Mazzeo and
Melrose's phi-calculus and we introduce an extended algebra of smoothing
operators that is shown to be stable under holomorphic functional calculus.
This result allows the interpretation of phi-calculus as the pseudodifferential
calculus associated with the holonomy groupoid of the singular foliation
defined by the manifold with fibred corners. It is a key step to set the index
theory of those singular manifolds in the noncommutative geometry framework.


title: Ammonia Thermometry of Star Forming Galaxies

abstract:
  With a goal toward deriving the physical conditions in external galaxies, we
present a study of the ammonia (NH$_3$) emission and absorption in a sample of
star forming systems. Using the unique sensitivities to kinetic temperature
afforded by the excitation characteristics of several inversion transitions of
NH$_3$, we have continued our characterization of the dense gas in star forming
galaxies by measuring the kinetic temperature in a sample of 23 galaxies and
one galaxy offset position selected for their high infrared luminosity. We
derive kinetic temperatures toward 13 galaxies, 9 of which possess multiple
kinetic temperature and/or velocity components. Eight of these galaxies exhibit
kinetic temperatures $>100$ K, which are in many cases at least a factor of two
larger than kinetic temperatures derived previously. Furthermore, the derived
kinetic temperatures in our galaxy sample, which are in many cases at least a
factor of two larger than derived dust temperatures, point to a problem with
the common assumption that dust and gas kinetic temperatures are equivalent. As
previously suggested, the use of dust emission at wavelengths greater than 160
$\mu$m to derive dust temperatures, or dust heating from older stellar
populations, may be skewing derived dust temperatures in these galaxies to
lower values. We confirm the detection of high-excitation OH $^2\Pi_{3/2}$
J=9/2 absorption toward Arp220 (Ott et. al. 2011). We also report the first
detections of non-metastable NH$_3$ inversion transitions toward external
galaxies in the (2,1) (NGC253, NGC660, IC342, and IC860), (3,1), (3,2), (4,3),
(5,4) (all in NGC660) and (10,9) (Arp220) transitions.


title: Symplectic structures on the integration of exact Courant algebroids

abstract:
  We construct an infinite-dimensional symplectic 2-groupoid as the integration
of an exact Courant algebroid. We show that every integrable Dirac structure
integrates to a "Lagrangian" sub-2-groupoid of this symplectic 2-groupoid. As a
corollary, we recover a result of Bursztyn-Crainic-Weinstein-Zhu that every
integrable Dirac structure integrates to a presymplectic groupoid.


title: High-Speed DC Magnetricity in Spinor Polariton Condensates

abstract:
  We investigate the spin dynamics of half-solitons in polariton Bose-Einstein
condensates. Half-solitons, which behave as magnetic monopoles, can be
accelerated in the presence of the effective magnetic field of the microcavity.
We study the generation of DC magnetic currents in a gas of half-solitons. At
low densities, the current is suppressed due to the dipolar oscillations. At
moderate densities, a magnetic current is recovered as a consequence of the
collisions between the carriers. We show a deviation from Ohm's law due to the
competition between magnetic dipoles and monopoles.


title: On 2-Class field towers of some imaginary quadratic number fields

abstract:
  We construct an infinite family of imaginary quadratic number fields with
2-class groups of type (2,2,2) whose Hilbert 2-class fields are finite.


title:
Discovery of Phylogenetic Relevant Y-chromosome Variants in 1000 Genomes
  Project Data

abstract:
  Current Y chromosome research is limited in the poor resolution of Y
chromosome phylogenetic tree. Entirely sequenced Y chromosomes in numerous
human individuals have only recently become available by the advent of
next-generation sequencing technology. The 1000 Genomes Project has sequenced Y
chromosomes from more than 1000 males. Here, we analyzed 1000 Genomes Project Y
chromosome data of 1269 individuals and discovered about 25,000 phylogenetic
relevant SNPs. Those new markers are useful in the phylogeny of Y chromosome
and will lead to an increased phylogenetic resolution for many Y chromosome
studies.


title: Rational Quartic Reciprocity

abstract:
  We provide a simple proof of the general rational quartic reciprocity law due
to Williams, Hardy and Friesen.


title: Revealing travel patterns and city structure with taxi trip data

abstract:
  Detecting regional spatial structures based on spatial interactions is
crucial in applications ranging from urban planning to traffic control. In the
big data era, various movement trajectories are available for studying spatial
structures. This research uses large scale Shanghai taxi trip data extracted
from GPS-enabled taxi trajectories to reveal traffic flow patterns and urban
structure of the city. Using the network science methods, 15 temporally stable
regions reflecting the scope of people's daily travels are found using
community detection method on the network built from short trips, which
represent residents' daily intra-urban travels and exhibit a clear pattern. In
each region, taxi traffic flows are dominated by a few 'hubs' and 'hubs' in
suburbs impact more trips than 'hubs' in urban areas. Land use conditions in
urban regions are different from those in suburban areas. Additionally, 'hubs'
in urban area associate with office buildings and commercial areas more,
whereas residential land use is more common in suburban hubs. The taxi flow
structures and land uses reveal the polycentric and layered concentric
structure of Shanghai. Finally, according to the temporal variations of taxi
flows and the diversity levels of taxi trip lengths, we explore the total taxi
traffic properties of each region and proved the city structure we find.
External trips across regions also take large proportion of the total traffic
in each region, especially in suburbs. The results could help transportation
policy making and shed light on the way to reveal urban structures with big
data.


title:
From Chirps to Random-FM Excitations in Pulse Compression Ultrasound
  Systems

abstract:
  Pulse compression is often practiced in ultrasound Non Destructive Testing
(NDT) systems using chirps. However, chirps are inadequate for setups where
multiple probes need to operate concurrently in Multiple Input Multiple Output
(MIMO) arrangements. Conversely, many coded excitation systems designed for
MIMO miss some chirp advantages (constant envelope excitation, easiness of
bandwidth control, etc.) and may not be easily implemented on hardware
originally conceived for chirp excitations. Here, we propose a system based on
random-FM excitations, capable of enabling MIMO with minimal changes with
respect to a chirp-based setup. Following recent results, we show that
random-FM excitations retain many advantages of chirps and provide the ability
to frequency-shape the excitations matching the transducers features.


title:
Some remarks on Leibniz algebras whose semisimple part related with
  $sl_2$

abstract:
  In this paper we identify the structure of complex finite-dimensional Leibniz
algebras with associated Lie algebras $sl_2^1\oplus sl_2^2\oplus \dots \oplus
sl_2^s\oplus R,$ where $R$ is a solvable radical. The classifications of such
Leibniz algebras in the cases $dim R=2, 3$ and $dim I\neq 3$ have been
obtained. Moreover, we classify Leibniz algebras with $L/I\cong sl_2^1\oplus
sl_2^2$ and some conditions on ideal $I=id<[x,x] \ | \ x\in L>.$


title:
Long-range proximity-induced superconductivity in polycrystalline Co
  nanowires

abstract:
  We report an experimental study of proximity effect-induced superconductivity
in crystalline Cu and Co nanowires and a nanogranular Co nanowire structure in
contact with a superconducting W floating electrode which we call inducer. The
nanowires were grown by electrochemical deposition in heavy-ion-track etched
polycarbonate templates. The nanogranular Co structure was fabricated by
focused electron beam induced deposition (FEBID), while the amorphous W inducer
was obtained by focused ion beam induced deposition (FIBID). For electrical
resistance measurements up to three pairs of Pt voltage leads were deposited by
FIBID at different distances beside the inner inducer electrode, thus allowing
us to probe the proximity effect over a length of 2-12 $\mu$m. Relative $R(T)$
drops of the same order of magnitude have been observed for the Co and Cu
nanowires when sweeping the temperature below 5.2 K ($T_c$ of the
FIBID-deposited W inducer). By contrast, relative $R(T)$ drops were found to be
an order of magnitude smaller for the nanogranular Co nanowire structure. Our
analysis of the resistance data shows that the superconducting proximity length
in crystalline Cu and Co is about 1 $\mu$m at low temperatures, attesting to a
long-range proximity effect in the case of ferromagnetic Co. Moreover, this
long-range proximity effect has been revealed to be insusceptible to magnetic
fields up to 11 T, which is indicative of spin-triplet pairing. At the same
time, in the nanogranular Co structure proximity-induced superconductivity is
strongly suppressed due to the dominating Cooper pair scattering caused by the
intrinsic microstructure of the FEBID deposit.


title: Interdigitated ring electrodes: Theory and experiment

abstract:
  The oxidation of potassium ferrocyanide, K_4Fe(CN)_6, in aqueous solution
under fully supported conditions is carried out at interdigitated band and ring
electrode arrays, and compared to theoretical models developed to simulate the
processes. Simulated data is found to fit well with experimental results using
literature values of diffusion coefficients for Fe(CN)_6^(4-) and
Fe(CN)_6^(3-). The theoretical models are used to compare responses from
interdigitated band and ring arrays, and the size of ring array required to
approximate the response to a linear band array is investigated. An equation is
developed for the radius of ring required for a pair of electrodes in a ring
array to give a result with 5% of a pair of electrodes in a band array. This
equation is found to be independent of the scan rate used over six orders of
magnitude.


title: Rational Quartic Reciprocity II

abstract:
  We continue investigating rational quartic reciprocity laws and, at the
suggestion of the editor of AA, provide details of a proof of a remark in the
first article with this title.


title: Designer Topological Insulators in Superlattices

abstract:
  Gapless Dirac surface states are protected at the interface of topological
and normal band insulators. In a binary superlattice bearing such interfaces,
we establish that valley-dependent dimerization of symmetry-unrelated Dirac
surface states can be exploited to induce topological quantum phase
transitions. This mechanism leads to a rich phase diagram that allows us to
design strong, weak, and crystalline topological insulators. Our ab initio
simulations further demonstrate this mechanism in [111] and [110] superlattices
of calcium and tin tellurides.


title: A Supplement to Scholz's Reciprocity Law

abstract:
  In this note we will present a supplement to Scholz's reciprocity law and
discuss applications to the structure of 2-class groups of quadratic number
fields.


title: Moduli Problems in Abelian Categories and the Reconstruction Theorem

abstract:
  We give a moduli-theoretic proof of the classical theorem of Gabriel, stating
that a scheme can be reconstructed from the abelian category of quasi-coherent
sheaves over it. The methods employed are elementary and allow us to extend the
theorem to (quasi-compact and separated) algebraic spaces. Using more advanced
technology (and assuming flatness) we also give a proof of the folklore result
that the group of autoequivalences of the category of quasi-coherent sheaves
consists of automorphisms of the underlying space and twists by line bundles.
We apply our strategy to prove analogous statements for categories of sheaves
twisted by a Gm-gerbe. Our methods allow us to treat even gerbes not coming
from a Brauer class. As a pleasant consequence, we deduce a Morita theory for
sheaves of abelian categories.


title:
Development of a camera casing suited for cryogenic and vacuum
  applications

abstract:
  We report on the design, construction, and operation of a PID temperature
controlled and vacuum tight camera casing. The camera casing contains a
commercial digital camera and a lighting system. The design of the camera
casing and its components are discussed in detail. Pictures taken by this
cryo-camera while immersed in argon vapour and liquid nitrogen are presented.
The cryo-camera can provide a live view inside cryogenic set-ups and allows to
record video.


title: Adaptive Shrinkage of singular values

abstract:
  To recover a low rank structure from a noisy matrix, truncated singular value
decomposition has been extensively used and studied. Recent studies suggested
that the signal can be better estimated by shrinking the singular values. We
pursue this line of research and propose a new estimator offering a continuum
of thresholding and shrinking functions. To avoid an unstable and costly
cross-validation search, we propose new rules to select two thresholding and
shrinking parameters from the data. In particular we propose a generalized
Stein unbiased risk estimation criterion that does not require knowledge of the
variance of the noise and that is computationally fast. A Monte Carlo
simulation reveals that our estimator outperforms the tested methods in terms
of mean squared error on both low-rank and general signal matrices across
different signal to noise ratio regimes. In addition, it accurately estimates
the rank of the signal when it is detectable.


title:
Noise and disturbance in quantum measurements: an information-theoretic
  approach

abstract:
  We introduce information-theoretic definitions for noise and disturbance in
quantum measurements and prove a state-independent noise-disturbance tradeoff
relation that these quantities have to satisfy in any conceivable setup.
Contrary to previous approaches, the information-theoretic quantities we define
are invariant under relabelling of outcomes, and allow for the possibility of
using quantum or classical operations to `correct' for the disturbance. We also
show how our bound implies strong tradeoff relations for mean square
deviations.


title:
On the Riesz potential and its commutators on generalized Orlicz-Morrey
  spaces

abstract:
  We consider generalized Orlicz-Morrey spaces $M_{\Phi,\varphi}(\Rn)$
including their weak versions $WM_{\Phi,\varphi}(\Rn)$. In these spaces we
prove the boundedness of the Riesz potential from $M_{\Phi,\varphi_1}(\Rn)$ to
$M_{\Psi,\varphi_2}(\Rn)$ and from $M_{\Phi,\varphi_1}(\Rn)$ to
$WM_{\Psi,\varphi_2}(\Rn)$. As applications of those results, the boundedness
of the commutators of the Riesz potential on generalized Orlicz-Morrey space is
also obtained. In all the cases the conditions for the boundedness are given
either in terms of Zygmund-type integral inequalities on
$(\varphi_{1},\varphi_{2})$, which do not assume any assumption on monotonicity
of $\varphi_{1}(x,r)$, $\varphi_{2}(x,r)$ in r.


title: Euler, Goldbach, and "Fermat's Theorem"

abstract:
  While preparing the correspondence between Leonhard Euler and Christian
Goldbach for publication, Martin Mattmueller asked whether the lemma given in
the postscript of Euler's letter dated July 26, 1749, was enough for completing
the proof of Fermat's Four Squares Theorem. In this article we will show that
Euler's result can in fact be used for proving this result via induction.


title: Unramified Quaternion Extensions of Quadratic Number Fields

abstract:
  We show how to construct unramified qoaternion extensions of quadratic number
fields.


title: The 4-class group of real quadratic number fields

abstract:
  In this paper we give an elementary proof of results on the structure of
4-class groups of real quadratic number fields originally due to A. Scholz. In
a second (and independent) section we strengthen C. Maire's result that the
2-class field tower of a real quadratic number field is infinite if its ideal
class group has 4-rank at least $4$, using a technique due to F. Hajir.


title: Small Norms in Quadratic Fields

abstract: We study elements of small norm in quadratic fields of Riachaud-Degert type.


title:
Which one of the two atomic potential is better -- the newest or the
  "ancient" one?

abstract:
  Recently, there appeared the tables of atomic potential by Maldonado et al.
We show that this potential, when used to calculate some quantities which can
be compared with experiment, gives worse results than the more than 40 years
old tables by Lu et al.


title: A new method to analyse pulsar nulling phenomenon

abstract:
  Pulsar nulling is a phenomenon of sudden cessation of pulse emission for a
number of periods. The nulling fraction was often used to characterize the
phenomenon. We propose a new method to analyse pulsar nulling phenomenon, by
involving two key parameters, the nulling degree, $\chi$, which is defined as
the angle in a rectangular coordinates for the numbers of nulling periods and
bursting periods, and the nulling scale, $ N $, which is defined as the
effective length of the consecutive nulling periods and bursting periods. The
nulling degree $\chi$ can be calculated by $\tan \chi = N_{\rm nulling} /
N_{\rm bursting} $ and the mean is related to the nulling fraction, while the
nulling scale, $ N $, is also a newly defined fundamental parameter which
indicates how often the nulling occurs. We determined the distributions of
$\chi$ and $ N $ for 10 pulsars by using the data in literature. We found that
the nulling degree $\chi$ indicates the relative length of nulling to that of
bursting, and the nulling scale $ N $ is found to be related to the derivative
of rotation frequency and hence the loss rate of rotational energy of pulsars.
Their deviations reflect the randomness of the nulling process.


title: Heavy quark impact factor in kT-factorization

abstract:
  We present the calculation of the finite part of the heavy quark impact
factor at next-to-leading logarithmic accuracy in a form suitable for
phenomenological studies such as the calculation of the cross-section for
single bottom quark production at the LHC within the kT-factorization scheme.


title: Aitken delta-squared generalized Juncgk-type iterative procedure

abstract:
  This paper discusses a general Aitken delta-squared generalized
Jungck-modified iterative scheme. The study applies generalized versions of
Aitken delta squared procedure and Venter theorem to discuss positivity and
global stability of the generalized Jungck iterative scheme which is of
interest in numerical methods and its acceleration of convergence.


title: Photometric brown-dwarf classification

abstract:
  We have developed a method "photo-type" to identify and accurately classify L
and T dwarfs, onto the standard system, from photometry alone. We combine SDSS,
UKIDSS and WISE data and classify point sources by comparing the izYJHKW1W2
colours against template colours for quasars, stars, and brown dwarfs. In a
sample of $6.5\times10^6$ bright point sources, J$<$17.5, from 3150 deg$^2$, we
identify and type 898 L and T dwarfs, making this the largest homogeneously
selected sample of brown dwarfs to date. The sample includes 713 (125) new
(previously known) L dwarfs and 21 (39) T dwarfs. For the previously-known
sources, the scatter in the plot of photo-type vs spectral type indicates that
our photo-types are accurate to 1.5 (1.0) sub-types rms for L (T) dwarfs.
Peculiar objects and candidate unresolved binaries are identified.


title: Near-threshold correlations of neutrons

abstract:
  The appearance of charged-particle clustering in near-threshold configuration
is a phenomenon that can be explained in the Open Quantum System description of
the atomic nucleus. In this work we apply the realistic Shell Model Embedded in
the Continuum to elucidate the emergence of neutron correlations in
near-threshold many-body states coupled to l=1,2 neutron decay channels.
Spectral consequences of such continuum coupling are briefly discussed together
with the emergence of complex multi-neutron correlations.


title: Geometric Allocation Approaches in Markov Chain Monte Carlo

abstract:
  The Markov chain Monte Carlo method is a versatile tool in statistical
physics to evaluate multi-dimensional integrals numerically. For the method to
work effectively, we must consider the following key issues: the choice of
ensemble, the selection of candidate states, the optimization of transition
kernel, algorithm for choosing a configuration according to the transition
probabilities. We show that the unconventional approaches based on the
geometric allocation of probabilities or weights can improve the dynamics and
scaling of the Monte Carlo simulation in several aspects. Particularly, the
approach using the irreversible kernel can reduce or sometimes completely
eliminate the rejection of trial move in the Markov chain. We also discuss how
the space-time interchange technique together with Walker's method of aliases
can reduce the computational time especially for the case where the number of
candidates is large, such as models with long-range interactions.


title: N(H I)/E(B-V)

abstract:
  We explore the relationship between dust-emission derived reddening \EBV\ and
atomic hydrogen column density N(H I) derived from 21 cm emission surveys. We
consider measurements at galactic latitude $|b| \ga 20$\degr\ and \EBV\ $\la$
0.1 mag where the interstellar gas is predominantly neutral and atomic and
opacity corrections to 21cm H I profiles are small. Over the Galaxy at large at
lower resolution in H I, and on smaller scales at higher resolution, we find
that the reddening is always much smaller than would be expected from the
usually-quoted relation N(H) $ = 5.8\times 10^{21}\pcc$ \EBV\ based on stellar
reddening and {\it uv} absorption toward early-type stars. On wide scales, we
find N(H I) = $8.3 \times 10^{21}\pcc$ \EBV. We cite various precedents for
such a large N(H I)/\EBV\ ratio whenever wide-field 21cm emission surveys are
considered, including when reddening based on galaxy counts or colors is
substituted for the dust-emission derived reddening measure.


title: A Poisson formula for the sparse resultant

abstract:
  We present a Poisson formula for sparse resultants and a formula for the
product of the roots of a family of Laurent polynomials, which are valid for
arbitrary families of supports. To obtain these formulae, we show that the
sparse resultant associated to a family of supports can be identified with the
resultant of a suitable multiprojective toric cycle in the sense of Remond.
This connection allows to study sparse resultants using multiprojective
elimination theory and intersection theory of toric varieties.


title: A mixed FEM for the quad-curl eigenvalue problem

abstract:
  The quad-curl problem arises in the study of the electromagnetic interior
transmission problem and magnetohydrodynamics (MHD). In this paper, we study
the quad-curl eigenvalue problem and propose a mixed method using edge elements
for the computation of the eigenvalues. To the author's knowledge, it is the
first numerical treatment for the quad-curl eigenvalue problem. Under suitable
assumptions on the domain and mesh, we prove the optimal convergence. In
addition, we show that the divergence-free condition can be bypassed. Numerical
results are provided to show the viability of the method.


title: Sub-Hardy Hilbert spaces on the circle and torus

abstract:
  Sahni and Singh settled a problem posed by Yousefi & Hesameddini by
generalizing their main result with a simple proof in the setting of
sub-Hilbert spaces in $H^2(T)$. In this paper, we extend the main result of
Sahni and Singh to the setting of the Banach spaces $H^p$, $1\le p\le\infty$ on
the circle and the torus.


title:
Comment on "Multiconfiguration Dirac-Fock energy levels and radiative
  rates for Br-like tungsten" by S. Aggarwal, A.K.S. Jha, and M. Mohan [Can .
  J. Phys. 91 (2013) 394]

abstract:
  We report calculations of energy levels and oscillator strengths for
transitions in W XL, undertaken with the general-purpose relativistic atomic
structure package ({\sc grasp}) and flexible atomic code ({\sc fac}).
Comparisons are made with existing results and the accuracy of the data is
assessed. Discrepancies with the most recent results of S. Aggarwal et al.
[Can. J. Phys. {\bf 91} (2013) 394] are up to 0.4 Ryd and up to two orders of
magnitude for energy levels and oscillator strengths, respectively.
Discrepancies for lifetimes are even larger, up to four orders of magnitude for
some levels. Our energy levels are estimated to be accurate to better than 0.5%
(i.e. 0.2 Ryd), whereas results for oscillator strengths and lifetimes should
be accurate to better than 20%.


title:
Reduced dimensionality and spatial entanglement in highly anisotropic
  Bose-Einstein condensates

abstract:
  We investigate the reduced dimensionality of highly anisotropic Bose-Einstein
condensates (BECs) in connection to the entanglement between its spatial
degrees of freedom. We argue that the reduced-dimensionality of the BEC is
physically meaningful in a regime where spatial correlations are negligible. We
handle the problem analytically within the mean-field approximation for general
quasi-one-dimensional and -two-dimensional geometries, and obtain the optimal
reduced-dimension, pure-state description of the condensate mean field. We give
explicit solutions to the case of harmonic potentials, which we compare against
exact numerical integration of the three-dimensional Gross-Pitaevskii equation.


title: Singularity formation for Prandtl's equations

abstract:
  We consider Prandtl's equations for the impulsively started disk and follow
the process of the formation of the singularity in the complex plane using the
singularity tracking method. We classify Van Dommelen and Shen's singularity as
a cubic root singularity.
  We introduce a class of initial data which have a dipole singularity in the
complex plane. These data are uniformly bounded in $H^1$ and lead to an earlier
singularity formation. The presence of a small viscosity in the streamwise
direction changes the behavior of the singularities.


title:
High Reynolds number Navier-Stokes solutions and boundary layer
  separation induced by a rectilinear vortex

abstract:
  We compute the solutions of Prandtl's and Navier-Stokes equations for the two
dimensional flow induced by a rectilinear vortex interacting with a boundary in
the half plane. For this initial datum Prandtl's equation develops, in a finite
time, a separation singularity. We investigate the different stages of unsteady
separation for Navier-Stokes solution at different Reynolds numbers
$Re=10^3-10^5$, and we show the presence of a large-scale interaction between
the viscous boundary layer and the inviscid outer flow. We also see a
subsequent stage, characterized by the presence of a small-scale interaction,
which is visible only for moderate-high Re numbers $Re=10^4-10^5$. We also
investigate the asymptotic validity of boundary layer theory by comparing
Prandtl's solution to Navier-Stokes solutions during the various stages of
unsteady separation.


title: Q-Systems, Factorization Dynamics, and the Twist Automorphism

abstract:
  We provide a concrete realization of the cluster algebras associated with
Q-systems as amalgamations of cluster structures on double Bruhat cells in
simple algebraic groups. For nonsimply-laced groups, this provides a
cluster-algebraic formulation of Q-systems of twisted type. It also yields a
uniform proof of the discrete integrability of these Q-systems by identifying
them with the dynamics of factorization mappings on quotients of double Bruhat
cells. On the double Bruhat cell itself, we find these dynamics are closely
related to those of the Fomin-Zelevinsky twist map. This leads to an explicit
formula expressing twisted cluster variables as Laurent monomials in the
untwisted cluster variables obtained from the corresponding mutation sequence.
This holds for Coxeter double Bruhat cells in any symmetrizable Kac-Moody
group, and we show that in affine type the analogous factorization mapping is
also integrable.


title:
Non-equilibrium noise in transport across a tunneling contact between
  $\nu = 2/3$ fractional quantum Hall edges

abstract:
  In a recent experimental paper [1] a qualitative confirmation of the
existence of upstream neutral modes at $\nu = 2/3$ quantum Hall edge was
reported. Using the chiral Luttinger liquid theory of quantum Hall edge we
develop a quantitative model of the experiment [1]. A good quantitative
agreement of our theory with the experimental data reinforces the conclusion of
existence of the upstream neutral mode. Our model also enables us to extract
important quantitative information about non-equilibrium processes in Ohmic and
tunneling contacts from the experimental data. In particular, for $\nu = 2/3$,
we find a power-law dependence of the neutral mode temperature on the charge
current injected from the Ohmic contact.


title:
On the ideal of the shortest vectors in the Leech lattice and other
  lattices

abstract:
  Let $X \subset {\mathbb R}^m$ be a spherical code (i.e., a finite subset of
the unit sphere) and consider the ideal of all polynomials in $m$ variables
which vanish on $X$. Motivated by a study of cometric ($Q$-polynomial)
association schemes and spherical designs, we wish to determine certain
properties of this ideal. After presenting some background material and
preliminary results, we consider the case where $X$ is the set of shortest
vectors of one of the exceptional lattices $E_6$, $E_7$, $E_8$, $\Lambda_{24}$
(the Leech lattice) and determine for each: (i) the smallest degree of a
non-trivial polynomial in the ideal, and (ii) the smallest $k$ for which the
ideal admits a generating set of polynomials all of degree $k$ or less. As it
turns out, in all four cases mentioned above, these two values coincide, as
they also do for the icosahedron, our introductory example. The paper concludes
with a discussion of these two parameters, two open problems regarding their
equality, and a few remarks concerning connections to cometric association
schemes.


title:
A high order ADI scheme for the two-dimensional time fractional
  diffusion-wave equation

abstract:
  In this paper, a compact alternating direction implicit (ADI) finite
difference scheme for the two-dimensional time fractional diffusion-wave
equation is developed, with temporal and spatial accuracy order equal to two
and four respectively. The second order accuracy in the time direction has not
been achieved in previous studies.


title:
Discovery of periodic dips in the light curve of GX 13+1: the X-ray
  orbital ephemeris of the source

abstract:
  The bright low-mass X-ray binary (LMXB) GX 13+1 is one of the most peculiar
Galactic binary systems. A periodicity of 24.27 d with a formal statistical
error of 0.03 d was observed in its power spectrum density obtained with RXTE
All Sky Monitor (ASM) data spanning 14 years. Starting from a recent study,
indicating GX 13+1 as a possible dipping source candidate, we systematically
searched for periodic dips in the X-ray light curves of GX 13+1 from 1996 up to
2013 using RXTE/ASM, and MAXI data to determine for the first time the X-ray
orbital ephemeris of GX 13+1. We searched for a periodic signal in the ASM and
MAXI light curves, finding a common periodicity of 24.53 d. We folded the 1.3-5
keV and 5-12.1 keV ASM light curves and the 2-4 and 4-10 keV MAXI light curves
at the period of 24.53 d finding a periodic dip. To refine the value of the
period we used the timing technique dividing the ASM light curve in eight
intervals and the MAXI light curve in two intervals, obtaining four and two dip
arrival times from the ASM and MAXI light curves, respectively. We improved the
X-ray position of GX 13+1 using a recent Chandra observation. The new X-ray
position is discrepant by $\sim 7\arcsec$ from the previous one, while it is
compatible with the infrared and radio counterpart positions. We detected an
X-ray dip, that is totally covered by the Chandra observation, in the light
curve of GX 13+1 and showed, a-posteriori, that it is a periodic dip. We
obtained seven dip arrival times from ASM, MAXI, and Chandra light curves. We
calculated the delays of the detected dip arrival times with respect to the
expected times for a 24.52 d periodicity. Fitting the delays with a linear
function we find that the orbital period and the epoch of reference of GX 13+1
are 24.5274(2) days and 50,086.79(3) MJD, respectively.(Abridged)


title: Entropy, subentropy and the elementary symmetric functions

abstract:
  We use complex contour integral techniques to study the entropy H and
subentropy Q as functions of the elementary symmetric polynomials, revealing a
series of striking properties. In particular for these variables, derivatives
of -Q are equal to derivatives of H of one higher order and the first
derivatives of H and Q are seen to be completely monotone functions. It then
follows that exp (-H) and exp(-Q) are Laplace transforms of infinitely
divisible probability distributions.


title: Exact solutions and zero modes in scalar field theory

abstract:
  We provide a set of exact solutions in field theory of scalar fields with
$Z_2$ symmetry that involve Jacobi elliptic functions. These solutions have the
interesting property to provide massive waves even if one starts from a
massless equation. We analyze them classically providing also exact solutions
to the corresponding equations for the Green functions needed to completely
solve them in a strong coupling limit. This is accomplished using a functional
expansion into powers of the current. It is shown that the spontaneous breaking
of the $Z_2$ symmetry is due to the existence of a zero mode that persists also
in the case of the Higgs mechanism. In this latter case, the zero mode seems to
play a role similar to the Goldstone boson in the breaking of a continuous
symmetry and so, it should be important at lower momenta as a long range
excitation.


title: Bound state techniques to solve the multiparticle scattering problem

abstract:
  Solution of the scattering problem turns to be very difficult task both from
the formal as well as from the computational point of view. If the last two
decades have witnessed decisive progress in ab initio bound state calculations,
rigorous solution of the scattering problem remains limited to A$\leq$4 case.
Therefore there is a rising interest to apply bound-state-like methods to
handle non-relativistic scattering problems. In this article the latest
theoretical developments in this field are reviewed. Five fully rigorous
methods will be discussed, which address the problem of nuclear collisions in
full extent (including the break-up problem) at the same time avoiding
treatment of the complicate boundary conditions or integral kernel
singularities. These new developments allows to use modern bound-state
techniques to advance significantly rigorous solution of the scattering
problem.

categories: nucl-th cond-mat.quant-gas math-ph math.MP quant-ph


title:
Nonequilibrium grain size distribution with generalized growth and
  nucleation rates

abstract:
  We determine the non-equilibrium grain size distribution during the
crystallization of a solid in $d$ dimensions at fixed thermodynamic conditions,
for the random nucleation and growth model, and in absence of grain
coalescence. Two distinct generalizations of the theory established earlier are
considered. A closed analytic expression of the grain size distribution useful
for experimental studies is derived for anisotropic growth rates. The main
difference from the isotropic growth case is the appearance of a constant
prefactor in the distribution. The second generalization considers a Gaussian
source term: nuclei are stable when their volume is within a finite range
determined by the thermodynamics of the crystallization process. The numerical
results show that this generalization does not change the qualitative picture
of our previous study. The generalization only affects quantitatively the early
stage of crystallization, when nucleation is dominant. The remarkable result of
these major generalizations is that the non-equilibrium grain size distribution
is robust against anisotropic growth of grains and fluctuations of nuclei
sizes.


title:
Existence of mild solutions for a system of partial differential
  equations with time-dependent generators

abstract:
  We give sufficient conditions for global existence of positive mild solutions
for the weak coupled system: \begin{eqnarray*} \frac{\partial u_{1}}{\partial
t}
&=&\rho_{1}t^{\rho_{1}-1}\Delta_{\alpha_{1}}u_{1}+t^{\sigma_{1}}u_{2}^{\beta_{1}},\
\ u_{1}\left(0\right) =\varphi_{1}, \\ \frac{\partial u_{2}}{\partial t}
&=&\rho_{2}t^{\rho_{2}-1}\Delta_{\alpha_{2}}u_{2}+t^{\sigma_{2}}u_{1}^{\beta_{2}},\
\ u_{2}\left(0\right) =\varphi_{2}, \end{eqnarray*} where $\Delta_{\alpha_{i}}$
is a fractional Laplacian, $0<\alpha_{i}\leq 2,\ \beta_{i}>1,\ \rho_{i}>0,\
\sigma_{i}>-1\ $are constants and the initial data $\varphi_{i}$ are positive,
bounded and integrable functions.


title:
Application of Scanning Mid-IR-Laser Microscopy for Characterization of
  Semiconductor Materials for Photovoltaics

abstract:
  The scanning mid-IR-laser microscopy was previously demonstrated as an
effective tool for characterization of different semiconductor crystals. Now
the technique has been successfully applied for the investigation of CZ
Si$_x$Ge$_{1-x}$---a promising material for photovoltaics---and
multicrystalline silicon for solar cells.


title: Network Coded TCP (CTCP) Performance over Satellite Networks

abstract:
  We show preliminary results for the performance of Network Coded TCP (CTCP)
over large latency networks. While CTCP performs very well in networks with
relatively short RTT, the slow-start mechanism currently employed does not
adequately fill the available bandwidth when the RTT is large. Regardless, we
show that CTCP still outperforms current TCP variants (i.e., Cubic TCP and
Hybla TCP) for high packet loss rates (e.g., >2.5%). We then explore the
possibility of a modified congestion control mechanism based off of H-TCP that
opens the congestion window quickly to overcome the challenges of large latency
networks. Preliminary results are provided that show the combination of network
coding with an appropriate congestion control algorithm can provide gains on
the order of 20 times that of existing TCP variants. Finally, we provide a
discussion of the future work needed to increase CTCP's performance in these
networks.


title:
Iteration-Complexity of a Generalized Forward Backward Splitting
  Algorithm

abstract:
  In this paper, we analyze the iteration-complexity of Generalized
Forward--Backward (GFB) splitting algorithm, as proposed in \cite{gfb2011}, for
minimizing a large class of composite objectives $f + \sum_{i=1}^n h_i$ on a
Hilbert space, where $f$ has a Lipschitz-continuous gradient and the $h_i$'s
are simple (\ie their proximity operators are easy to compute). We derive
iteration-complexity bounds (pointwise and ergodic) for the inexact version of
GFB to obtain an approximate solution based on an easily verifiable termination
criterion. Along the way, we prove complexity bounds for relaxed and inexact
fixed point iterations built from composition of nonexpansive averaged
operators. These results apply more generally to GFB when used to find a zero
of a sum of $n > 0$ maximal monotone operators and a co-coercive operator on a
Hilbert space. The theoretical findings are exemplified with experiments on
video processing.


title:
A language independent web data extraction using vision based page
  segmentation algorithm

abstract:
  Web usage mining is a process of extracting useful information from server
logs i.e. users history. Web usage mining is a process of finding out what
users are looking for on the internet. Some users might be looking at only
textual data, where as some others might be interested in multimedia data. One
would retrieve the data by copying it and pasting it to the relevant document.
But this is tedious and time consuming as well as difficult when the data to be
retrieved is plenty. Extracting structured data from a web page is challenging
problem due to complicated structured pages. Earlier they were used web page
programming language dependent; the main problem is to analyze the html source
code. In earlier they were considered the scripts such as java scripts and
cascade styles in the html files. When it makes different for existing
solutions to infer the regularity of the structure of the Web Pages only by
analyzing the tag structures. To overcome this problem we are using a new
algorithm called VIPS algorithm i.e. independent language. This approach
primary utilizes the visual features on the webpage to implement web data
extraction.


title: Community Detection in Quantum Complex Networks

abstract:
  Determining community structure is a central topic in the study of complex
networks, be it technological, social, biological or chemical, in static or
interacting systems. In this paper, we extend the concept of community
detection from classical to quantum systems---a crucial missing component of a
theory of complex networks based on quantum mechanics. We demonstrate that
certain quantum mechanical effects cannot be captured using current classical
complex network tools and provide new methods that overcome these problems. Our
approaches are based on defining closeness measures between nodes, and then
maximizing modularity with hierarchical clustering. Our closeness functions are
based on quantum transport probability and state fidelity, two important
quantities in quantum information theory. To illustrate the effectiveness of
our approach in detecting community structure in quantum systems, we provide
several examples, including a naturally occurring light-harvesting complex,
LHCII. The prediction of our simplest algorithm, semiclassical in nature,
mostly agrees with a proposed partitioning for the LHCII found in quantum
chemistry literature, whereas our fully quantum treatment of the problem
uncovers a new, consistent, and appropriately quantum community structure.

categories: quant-ph cond-mat.dis-nn cond-mat.stat-mech physics.soc-ph


title: Some homological properties of skew PBW extensions

abstract:
  We prove that if R is a left Noetherian and left regular ring then the same
is true for any bijective skew PBW extension A of R. From this we get Serre's
Theorem for such extensions. We show that skew PBW extensions and its
localizations include a wide variety of rings and algebras of interest for
modern mathematical physics such as PBW extensions, well known classes of Ore
algebras, operator algebras, diffusion algebras, quantum algebras, quadratic
algebras in 3-variables, skew quantum polynomials, among many others. We
estimate the global, Krull and Goldie dimensions, and also Quillen's K-groups.


title: Ap stars with variable periods

abstract:
  The majority of magnetic chemically peculiar (mCP) stars exhibit periodic
light, magnetic, radio, and spectroscopic variations that can be adequately
modelled as a rigidly-rotating main-sequence star with persistent surface
structures. Nevertheless, there is a small sample of diverse mCP stars whose
rotation periods vary on timescales of decades while the shapes of their phase
curves remain unchanged. Alternating period increases and decreases have been
suspected in the hot CP stars CU Vir and V901 Ori, while rotation in the
moderately cool star BS Cir has been decelerating. These examples bring new
insight into this theoretically unpredicted phenomenon. We discuss possible
causes of such behaviour and propose that dynamic interactions between a thin,
outer, magnetically-confined envelope braked by the stellar wind, and an inner
faster-rotating stellar body are able to explain the observed rotational
variability


title: A reference solution of the flow over a circular cylinder at Re=40

abstract:
  The classical problem of the flow over a circular cylinder at Reynolds number
40 is considered using an accurate pseudo-spectral code. A new set of boundary
conditions is proposed to improve the representation of the infinite flow
domain, especially in the far wake area. It is shown that the resulting
accuracy of the computed flow allows its use as a reference solution for code
validation. This reference solution is reachable at any location up to 50
cylinder diameters far from the cylinder centre through spectral interpolation
with a user-friendly script provided in appendix. It is shown how this solution
offers the opportunity to perform a convergence study and to investigate the
spatial distribution of numerical errors. The main goal of this study is to
propose this reference solution as an helpful tool for numerical validation and
development, especially for the improvement of immersed boundary methods toward
high-order accuracy.


title:
One-parameter families of supersymmetric isospectral potentials from
  Riccati solutions in function composition form

abstract:
  In the context of supersymmetric quantum mechanics, we define a potential
through a particular Riccati solution of the composition form, F(f(x)), and
obtain a generalized Mielnik construction of one-parameter isospectral
potentials when we use the general Riccati solution. Some examples for special
cases of F and f are given to illustrate the method. An interesting result is
obtained in the case of a parametric double well potential generated by this
method, for which it is shown that the parameter of the potential controls the
heights of the localization probability in the two wells, and for certain
values of the parameter the height of the localization probability can be
higher in the smaller well


title:
Instrumental Variables Estimation of a Generalized Correlated Random
  Coefficients Model

abstract:
  We study identification and estimation of the average treatment effect in a
correlated random coefficients model that allows for first stage heterogeneity
and binary instruments. The model also allows for multiple endogenous variables
and interactions between endogenous variables and covariates. Our
identification approach is based on averaging the coefficients obtained from a
collection of ordinary linear regressions that condition on different
realizations of a control function. This identification strategy suggests a
transparent and computationally straightforward estimator of a trimmed average
treatment effect constructed as the average of kernel-weighted linear
regressions. We develop this estimator and establish its
$\sqrt{n}$--consistency and asymptotic normality. Monte Carlo simulations show
excellent finite-sample performance that is comparable in precision to the
standard two-stage least squares estimator. We apply our results to analyze the
effect of air pollution on house prices, and find substantial heterogeneity in
first stage instrument effects as well as heterogeneity in treatment effects
that is consistent with household sorting.


title: Infinite strict gammoids

abstract:
  Finite strict gammoids, introduced in the early 1970's, are matroids defined
via finite digraphs equipped with some set of sinks: a set of vertices is
independent if it admits a linkage to these sinks. An independent set is
maximal precisely if it admits a linkage onto the sinks.
  In the infinite setting, this characterization of the maximal independent
sets need not hold. We identify a type of substructure as the unique
obstruction to the characterization. We then show that the sets linkable onto
the sinks form the bases of a (possibly non-finitary) matroid precisely when
the substructure does not occur.


title: Sign problem and subsets in one-dimensional QCD

abstract:
  We present a subset method that solves the sign problem for QCD at nonzero
quark chemical potential in 0+1 dimensions. The subsets of gauge configurations
are constructed using the center symmetry of the SU(3) group. These subsets
completely solve the sign problem for up to five flavors. For a larger number
of flavors the sign problem slowly reappears, and we propose an extension of
the subsets that also solves the sign problem for these cases. The subset
method allows for numerical simulations of the model at nonzero chemical
potential. We also present some preliminary results on subsets for QCD in two,
three, and four dimensions.


title: Stabilization of Radiation Reaction with Vacuum Polarization

abstract:
  From the development of the electron theory by H. A. Lorentz in 1906, many
authors have tried to reformulate this model. P. A. M. Dirac derived the
relativistic-classical electron model in 1938, which is now called the
Lorentz-Abraham-Dirac model. But this model has the big difficulty of the
run-away solution. Recently, this equation has become important for
ultra-intense laser-electron (plasma) interactions. For simulations in this
research field, it is desirable to stabilize this model of the radiation
reaction. In this paper, we will discuss this ability for radiation reaction
with the inclusion of vacuum polarization.
  [Submitted to Progress of Theoretical and Experimental Physics (PTEP)]


title: Symplectic embeddings into four-dimensional concave toric domains

abstract:
  ECH capacities give obstructions to symplectically embedding one symplectic
four-manifold with boundary into another. We compute the ECH capacities of a
large family of symplectic four-manifolds with boundary, called "concave toric
domains". Examples include the (nondisjoint) union of two ellipsoids in
$\mathbb{R}^4$. We use these calculations to find sharp obstructions to certain
symplectic embeddings involving concave toric domains. For example: (1) we
calculate the Gromov width of every concave toric domain; (2) we show that many
inclusions of an ellipsoid into the union of an ellipsoid and a cylinder are
"optimal"; and (3) we find a sharp obstruction to ball packings into certain
unions of an ellipsoid and a cylinder.


title: Leavitt path algebras of Cayley graphs arising from cyclic groups

abstract:
  For any positive integer $n$ we describe the Leavitt path algebra of the
Cayley graph $C_n$ corresponding to the cyclic group $\Z/n\Z$. Using a
Kirchberg-Phillips-type realization result, we show that there are exactly four
isomorphism classes of such Leavitt path algebras, arising as the algebras
corresponding to the graphs $C_i$ ($3\leq i \leq 6$).


title: The Potential Importance of Low Luminosity and High Energy at the LHC

abstract:
  Low luminosity runs at higher LHC energy could provide definitive evidence
for an electroweak scale sextet quark sector of QCD that produces electroweak
symmetry breaking and dark matter within the bound-state S-Matrix of QUD - a
massless, weak coupling, infra-red fixed-point, SU(5) field theory that might
underly and unify the full Standard Model.


title: Polar Coded HARQ Scheme with Chase Combining

abstract:
  A hybrid automatic repeat request scheme with Chase combing (HARQ-CC) of
polar codes is proposed. The existing analysis tools of the underlying
rate-compatible punctured polar (RCPP) codes for additive white Gaussian noise
(AWGN) channels are extended to Rayleigh fading channels. Then, an
approximation bound of the throughput efficiency for the polar coded HARQ-CC
scheme is derived. Utilizing this bound, the parameter configurations of the
proposed scheme can be optimized. Simulation results show that, the proposed
HARQ-CC scheme under a low-complexity SC decoding is only about $1.0$dB away
from the existing schemes with incremental redundancy (\mbox{HARQ-IR}).
Compared with the polar coded \mbox{HARQ-IR} scheme, the proposed HARQ-CC
scheme requires less retransmissions and has the advantage of good
compatibility to other communication techniques.


title: Quantum dynamics of a particle constrained to lie on a surface

abstract:
  We consider the quantum dynamics of a charged particle in Euclidean space
subjected to electric and magnetic fields under the presence of a potential
that forces the particle to stay close to a compact surface. We prove that, as
the strength of this constraining potential tends to infinity, the motion of
this particle converges to a motion generated by a Hamiltonian over the surface
superimposed by an oscillatory motion in the normal directions. Our result
extend previous results by allowing magnetic potentials and more general
constraining potentials.


title:
Quenching the magnetic flux in 1d fermionic ring: Loschmidt echo and
  edge singularity

abstract:
  We consider the non-equilibrium dynamics of a system of interacting massless
fermions in a ring threaded by a magnetic flux. We focus on the quench where
the flux is initially vanishing and is then turned on. We show that the
definition of the limit of abrupt quench is problematic due to the presence of
gauge invariance that has to be taken into account. We then propose a specific
protocol where the dynamics is non-trivial. Employing techniques coming from
the Algebraic Bethe-Ansatz, we present an exact formula for the Loschmidt echo
valid at all times as a Fredholm determinant at the free fermionic point. From
the analysis of the asymptotic behavior of the Fredholm determinant, we show
that the distribution of work done at small energies present an edge
singularity whose exponent can be explicitly computed. Using the correspondence
between the edge singularity and the decay of the fidelity at finite-size we
propose a general formula for the exponent valid also in the interacting case.


title:
TADPOL: A 1.3 mm Survey of Dust Polarization in Star-forming Cores and
  Regions

abstract:
  We present {\lambda}1.3 mm CARMA observations of dust polarization toward 30
star-forming cores and 8 star-forming regions from the TADPOL survey. We show
maps of all sources, and compare the ~2.5" resolution TADPOL maps with ~20"
resolution polarization maps from single-dish submillimeter telescopes. Here we
do not attempt to interpret the detailed B-field morphology of each object.
Rather, we use average B-field orientations to derive conclusions in a
statistical sense from the ensemble of sources, bearing in mind that these
average orientations can be quite uncertain. We discuss three main findings:
(1) A subset of the sources have consistent magnetic field (B-field)
orientations between large (~20") and small (~2.5") scales. Those same sources
also tend to have higher fractional polarizations than the sources with
inconsistent large-to-small-scale fields. We interpret this to mean that in at
least some cases B-fields play a role in regulating the infall of material all
the way down to the ~1000 AU scales of protostellar envelopes. (2) Outflows
appear to be randomly aligned with B-fields; although, in sources with low
polarization fractions there is a hint that outflows are preferentially
perpendicular to small-scale B-fields, which suggests that in these sources the
fields have been wrapped up by envelope rotation. (3) Finally, even at ~2.5"
resolution we see the so-called "polarization hole" effect, where the
fractional polarization drops significantly near the total intensity peak. All
data are publicly available in the electronic edition of this article.


title:
Pseudo vs. True Defect Classification in Printed Circuits Boards using
  Wavelet Features

abstract:
  In recent years, Printed Circuit Boards (PCB) have become the backbone of a
large number of consumer electronic devices leading to a surge in their
production. This has made it imperative to employ automatic inspection systems
to identify manufacturing defects in PCB before they are installed in the
respective systems. An important task in this regard is the classification of
defects as either true or pseudo defects, which decides if the PCB is to be
re-manufactured or not. This work proposes a novel approach to detect most
common defects in the PCBs. The problem has been approached by employing highly
discriminative features based on multi-scale wavelet transform, which are
further boosted by using a kernalized version of the support vector machines
(SVM). A real world printed circuit board dataset has been used for
quantitative analysis. Experimental results demonstrated the efficacy of the
proposed method.


title:
On the Backward Uniqueness Property for the Heat Equation in
  Two-Dimensional Conical Domains

abstract:
  In this article we deal with the backward uniqueness property of the heat
equation in conical domains in two spatial dimensions via Carleman inequality
techniques. Using a microlocal interpretation of the pseudoconvexity condition,
we improve the bounds of \v{S}ver\'ak and Li on the minimal angle in which the
backward uniqueness property is displayed: We reach angles of slightly less
than $95^{\circ}$. Via two-dimensional limiting Carleman weights we obtain the
uniqueness of possible controls of the heat equation with lower order
perturbations in conical domains with opening angles larger than $90^{\circ}$


title: QCD under extreme conditions: an informal discussion

abstract:
  We present an informal discussion of some aspects of strong interactions
under extreme conditions of temperature and density at an elementary level.
This summarizes lectures delivered at the 2013 CERN -- Latin-American School of
High-Energy Physics and is aimed at students working in experimental
high-energy physics.


title:
MISO Broadcast Channel with Imperfect and (Un)matched CSIT in the
  Frequency Domain: DoF Region and Transmission Strategies

abstract:
  In this contribution, we focus on a frequency domain two-user
Multiple-Input-Single-Output Broadcast Channel (MISO BC) where the transmitter
has imperfect and (un)matched Channel State Information (CSI) of the two users
in two subbands. We provide an upper-bound to the Degrees-of-Freedom (DoF)
region, which is tight compared to the state of the art. By decomposing the
subbands into subchannels according to the CSI feedback qualities, we interpret
the DoF region as the weighted-sum of that in each subchannel. Moreover, we
study the sum \emph{DoF} loss when employing sub-optimal schemes, namely
Frequency Division Multiple Access (FDMA), Zero-Forcing Beamforming (ZFBF) and
the $S_3^{3/2}$ scheme proposed by Tandon et al. The results show that by
switching among the sub-optimal strategies, we can obtain at least 80% and
66.7% of the optimal sum \emph{DoF} performance for the unmatched and matched
CSIT scenario respectively.


title: About a class of Calabi-Yau differential equations

abstract:
  We explain an experimental method to find CY-type differential equations of
order $3$ related to modular functions of genus zero. We introduce a similar
class of Calabi-Yau differential equations of order $5$, show several examples
and make a conjecture related to some geometric invariants. We finish the paper
with a few examples of seven order.


title: Generalized entropy and higher derivative Gravity

abstract:
  We derive an extension of the Ryu-Takayanagi prescription for curvature
squared theories of gravity in the bulk, and comment on a prescription for more
general theories. This results in a new entangling functional, that contains a
correction to Wald's entropy. The new term is quadratic in the extrinsic
curvature. The coefficient of this correction is a second derivative of the
lagrangian with respect to the Riemann tensor. For Gauss-Bonnet gravity, the
new functional reduces to Jacobson-Myers'.


title:
Disentangling the Decay Observables in $B^- \to
  \pi^+\pi^-\ell^-\bar\nu_\ell$

abstract:
  We study the semileptonic $b\to u$ transition in the decay mode $B^-\to
\pi^+\pi^-\ell^-\bar\nu_\ell$. We define $B\to \pi \pi$ form factors in the
helicity basis, and study their properties in various kinematic limits,
including form factor relations in the heavy-mass and large-energy limits, the
decomposition into partial waves of the dipion system, and the resonant
contribution of vector and scalar mesons. We show how angular observables in
$B^-\to \pi^+\pi^-\ell^-\bar\nu_\ell$ can be used to measure dipion form
factors or to perform null tests of the Standard Model.


title:
A note on the times of first passage for `nearly right-continuous'
  random walks

abstract:
  A natural extension of a right-continuous integer-valued random walk is one
which can jump to the right by one or two units. First passage times above a
given fixed level then admit a tractable Laplace transform (probability
generating function). Explicit expressions for the probabilities that the
respective overshoots are either $0$ or $1$, according as the random walk
crosses a given level for the first time either continuously or not, also
obtain. An interesting non-obvious observation, which follows from the
analysis, is that any such (non-degenerate) random walk will, eventually in
$n\in \mathbb{N}\cup \{0\}$, always be more likely to pass over the level $n$
for the first time with overshoot zero, rather than one. Some applications are
considered.


title:
A proposal for measuring photon temporal coherence in continuum
  radiation

abstract:
  A technique complementary to those for spectral lines is proposed for the
observation of continuum radiation. As, quantum mechanically, the radiation is
a mixture of pure states, it should be possible to measure the temporal
coherence of the states as a function of energy. We propose here experiments
with just this possibility, showing the empirical grounds on which it is based.
A simple means of measuring temporal coherence is with the extent of the
interference pattern produced in a Young's double-slit experiment. Thus, we
propose the use of such an experiment, but with a screen of energy measuring
photon detectors, small enough and sensitive enough to delineate the
interference patterns according to photon energy. We then only register a
detection if the absorbed photon is found to have the energy of interest. In
this way, we have allowed the interference, i.e., the wave aspect of the
experiment, to proceed as normal, recovering the interference pattern by
accumulating just those registered detections. We, also, explain why this form
of filtering does not actually violate the conventional wisdom that, when using
an optical filter with incident continuum radiation to separate out the photons
of a particular energy, only the temporal coherence of the filter's passband
would be measured. It naturally then introduces the concept of a detections
filter, differentiating it from an optical filter.

categories: quant-ph astro-ph.IM physics.optics physics.plasm-ph


title: Gate dependent Raman spectroscopy of graphene on hexagonal boron nitride

abstract:
  Raman spectroscopy, a fast and nondestructive imaging method, can be used to
monitor the doping level in graphene devices. We fabricated chemical vapor
deposition (CVD) grown graphene on atomically flat hexagonal boron nitride
(hBN) flakes and SiO$_2$ substrates. We compared their Raman response as a
function of charge carrier density using an ion gel as a top gate. The G peak
position, 2D peak position, 2D peak width and the ratio of the 2D peak area to
the G peak area show a dependence on carrier density that differs for hBN
compared to SiO$_2$. Histograms of two-dimensional mapping are used to compare
the fluctuations in the Raman peak properties between the two substrates. The
hBN substrate has been found to produce fewer fluctuations at the same charge
density owing to its atomically flat surface and reduced charged impurities.


title:
Loss tolerant device-independent quantum key distribution: a proof of
  principle

abstract:
  We here present the rate analysis and a proof of principle realization of a
device-independent quantum key distribution (QKD) protocol requiring the lowest
detection efficiency necessary to achieve a secure key compared to
device-independent protocols known so far. The protocol is based on
non-maximally entangled state and its experimental realization has been
performed by two-photon bipartite entangled states. The improvement with
respect to protocols involving maximally entangled states has been estimated.


title: The Bridge Theorem for totally disconnected LCA groups

abstract:
  For a totally disconnected locally compact abelian group, we prove that the
topological entropy of a continuous endomorphism coincides with the algebraic
entropy of the dual endomorphism with respect to the Pontryagin duality.
Moreover, this result is extended to all locally compact abelian groups under
the assumption of additivity with respect to some fully invariant subgroups for
both the topological and the algebraic entropy.


title:
Post-Newtonian approximations in the Ho\v{r}ava-Lifshitz gravity with
  extra U(1) symmetry

abstract:
  In this paper, we first propose a universal coupling between the gravity and
matter in the framework of the Ho\v{r}ava-Lifshitz theory of gravity with an
extra U(1) symmetry for both the projectable and non-projectable cases. Then,
using this universal coupling we study the post-Newtonian approximations and
obtain the parameterized post-Newtonian (PPN) parameters in terms of the
coupling constants of the theory. Contrary to the previous works in which only
two PPN parameters were calculated, we obtain {\it all} PPN parameters. We
then, for the first time in either projectable or non-projectable case, find
that all the solar system tests carried out so far are satisfied in a large
region of the parameters space. In particular, the same results obtained in
general relativity can be easily realized here. A remarkable feature is that
the solar system tests impose no constraint on the parameter $\lambda$
appearing in the kinetic part of the action. As a result, the solar system
tests, when combined with the condition for avoidance of strong coupling, do
not lead to an upper bound on the energy scale $M_{*}$ that suppresses higher
dimensional operators in the theory. This is in sharp contrast to other
versions of the HL theory.


title: Electronic structure and optical band gap determination of NiFe2O4

abstract:
  In a theoretical study we investigate the electronic structure and the band
gap of the inverse spinel ferrite NiFe2O4. The experimental optical absorption
spectrum is accurately reproduced by fitting the Tran-Blaha parameter in the
modified Becke-Johnson potential. The accuracy of the commonly applied Tauc
plot to find the optical gap is assessed based on the computed spectra and we
find that this approach can lead to a misinterpretation of the experimental
data. The minimum gap of NiFe2O4 is found to be a 1.53eV wide indirect gap,
which is located in the minority spin channel.


title: Dirac cohomology for the degenerate affine Hecke Clifford algebra

abstract:
  We define an analogue of the Dirac operator for the degenerate affine
Hecke-Clifford algebra. A main result is to relate the central characters of
the degenerate affine Hecke-Clifford algebra with the central characters of the
Sergeev algebra via Dirac cohomology. The action of the Dirac operator on
certain modules is also computed. Results in this paper could be viewed as a
projective version of the Dirac cohomology of the degenerate affine Hecke
algebra.


title:
Degrees-of-Freedom Region of MISO-OFDMA Broadcast Channel with Imperfect
  CSIT

abstract:
  This contribution investigates the Degrees-of-Freedom region of a two-user
frequency correlated Multiple-Input-Single-Output (MISO) Broadcast Channel (BC)
with imperfect Channel State Information at the transmitter (CSIT). We assume
that the system consists of an arbitrary number of subbands, denoted as $L$.
Besides, the CSIT state varies across users and subbands. A tight outer-bound
is found as a function of the minimum average CSIT quality between the two
users. Based on the CSIT states across the subbands, the DoF region is
interpreted as a weighted sum of the optimal DoF regions in the scenarios where
the CSIT of both users are perfect, alternatively perfect and not known.
Inspired by the weighted-sum interpretation and identifying the benefit of the
optimal scheme for the unmatched CSIT proposed by Chen et al., we also design a
scheme achieving the upper-bound for the general $L$-subband scenario in
frequency domain BC, thus showing the optimality of the DoF region.


title: Distributed CTL Model Checking in the Cloud

abstract:
  The recent extensive availability of "big data" platforms calls for a more
widespread adoption by the formal verification community. In fact, formal
verification requires high performance data processing software for extracting
knowledge from the unprecedented amount of data which come from analyzed
systems. Since cloud based computing resources have became easily accessible,
there is an opportunity for verification techniques and tools to undergo a deep
technological transition to exploit the new available architectures. This has
created an increasing interest in parallelizing and distributing verification
techniques. In this paper we introduce a distributed approach which exploits
techniques typically used by the "big data" community to enable verification of
Computation Tree Logic (CTL) formulas on very large state spaces using
distributed systems and cloud computing facilities. The outcome of several
tests performed on benchmark specifications are presented, thus showing the
convenience of the proposed approach.


title:
Probing eigenfunction nonorthogonality by parametric shifts of resonance
  widths

abstract:
  Recently, it has been shown that the change of resonance widths in an open
system under a perturbation of its interior is a sensitive indicator of the
nonorthogonality of resonance states. We apply this measure to quantify
parametric motion of the resonances. In particular, a strong redistribution of
the widths is linked with the maximal degree of nonorthogonality. Then for
weakly open chaotic systems we discuss the effect of spectral rigidity on the
statistical properties of the parametric width shifts, and derive the
distribution of the latter in a picket-fence model with equidistant spectrum.

categories: quant-ph cond-mat.mes-hall nlin.CD nucl-th


title: Counting independent sets in hypergraphs

abstract:
  Let $G$ be a triangle-free graph with $n$ vertices and average degree $t$. We
show that $G$ contains at least \[ e^{(1-n^{-1/12})\frac{1}{2}\frac{n}{t}\ln t
(\frac{1}{2}\ln t-1)} \] independent sets. This improves a recent result of the
first and third authors \cite{countingind}. In particular, it implies that as
$n \to \infty$, every triangle-free graph on $n$ vertices has at least
$e^{(c_1-o(1)) \sqrt{n} \ln n}$ independent sets, where $c_1 = \sqrt{\ln 2}/4 =
0.208138..$. Further, we show that for all $n$, there exists a triangle-free
graph with $n$ vertices which has at most $e^{(c_2+o(1))\sqrt{n}\ln n}$
independent sets, where $c_2 = 1+\ln 2 = 1.693147..$. This disproves a
conjecture from \cite{countingind}.
  Let $H$ be a $(k+1)$-uniform linear hypergraph with $n$ vertices and average
degree $t$. We also show that there exists a constant $c_k$ such that the
number of independent sets in $H$ is at least \[ e^{c_{k}
\frac{n}{t^{1/k}}\ln^{1+1/k}{t}}. \] This is tight apart from the constant
$c_k$ and generalizes a result of Duke, Lefmann, and R\"odl
\cite{uncrowdedrodl}, which guarantees the existence of an independent set of
size $\Omega(\frac{n}{t^{1/k}} \ln^{1/k}t)$. Both of our lower bounds follow
from a more general statement, which applies to hereditary properties of
hypergraphs.


title:
H{\alpha} photometry of low mass stars in 47 Tucanae: chromospheric
  activity and exotica

abstract:
  We have used archival Hubble Space Telescope observations obtained with the
Advanced Camera for Surveys to study the H{\alpha} emission properties of main
sequence stars in the globular cluster 47 Tucanae. Using a combination of
multi-band observations in the F606W, F814W and F658N bands, we search for
stars showing H{\alpha} excess emission. An accurate photometric measurement of
their H{\alpha} equivalent width allows us to identify objects with large
H{\alpha} emission, which we attribute to mass accretion rather than enhanced
chromospheric activity. The spatial position of some of these stars is
coincident with that of known X-ray sources and their location in the
colour-magnitude diagram allows us to classify them as active binaries or
cataclysmic variables (CVs). We show that this method, commonly adopted to
study accreting discs in young stellar objects, can be successfully used to
identify and characterise candidate CVs.


title:
Dealing with Interference in Distributed Large-scale MIMO Systems: A
  Statistical Approach

abstract:
  This paper considers the problem of interference control through the use of
second-order statistics in massive MIMO multi-cell networks. We consider both
the cases of co-located massive arrays and large-scale distributed antenna
settings. We are interested in characterizing the low-rankness of users'
channel covariance matrices, as such a property can be exploited towards
improved channel estimation (so-called pilot decontamination) as well as
interference rejection via spatial filtering. In previous work, it was shown
that massive MIMO channel covariance matrices exhibit a useful finite rank
property that can be modeled via the angular spread of multipath at a MIMO
uniform linear array. This paper extends this result to more general settings
including certain non-uniform arrays, and more surprisingly, to two dimensional
distributed large scale arrays. In particular our model exhibits the dependence
of the signal subspace's richness on the scattering radius around the user
terminal, through a closed form expression. The applications of the
low-rankness covariance property to channel estimation's denoising and
low-complexity interference filtering are highlighted.


title:
Optimization-based Islanding of Power Networks using Piecewise Linear AC
  Power Flow

abstract:
  In this paper, a flexible optimization-based framework for intentional
islanding is presented. The decision is made of which transmission lines to
switch in order to split the network while minimizing disruption, the amount of
load shed, or grouping coherent generators. The approach uses a piecewise
linear model of AC power flow, which allows the voltage and reactive power to
be considered directly when designing the islands. Demonstrations on standard
test networks show that solution of the problem provides islands that are
balanced in real and reactive power, satisfy AC power flow laws, and have a
healthy voltage profile.


title: Comment on "Adiabatic Quantum Algorithm for Search Engine Ranking"

abstract:
  In their Letter, Garnerone et al. claim that an adiabatic quantum algorithm
can extract information about a PageRank vector with either a polynomial or
exponential reduction in time resources over the classical algorithm with
comparable space resources. Here we argue that the quantum algorithm offers no
obvious advantage over the classical algorithm and fails to preserve the
fundamental stability property of the classical PageRank algorithm.


title: Recent Atmospheric Neutrino Results from Super-Kamiokande

abstract:
  The Super-Kamiokande experiment has collected more than 11 live-years of
atmospheric neutrino data. Atmospheric neutrinos cover a wide phase space in
both energy and distance travelled, the parameters relevant for studying
neutrino oscillations. We present here recent measurements of the three-flavor
neutrino oscillation parameters using this atmospheric neutrino data, as well
as new limits on mixing with a fourth sterile neutrino state.


title: New Parameter in Polymer - Assisted Sol - Gel Deposition

abstract:
  In this work a new parameter for the Polymer Assisted Sol- Gel Deposition
method is proposed. It is shaking of the sol stabilized by the polymer prior to
the deposition. It was found in attempt to decrease the amount of [111]-
oriented CeO2 grains on a monocrystalline substrate SrTiO3 (001). It was found
that the shaking decreases this amount significantly.


title: The free energy in a multi-species Sherrington-Kirkpatrick model

abstract:
  The authors of [Ann. Henri Poincar\'{e} 16 (2015) 691-708] introduced a
multi-species version of the Sherrington-Kirkpatrick model and suggested the
analogue of the Parisi formula for the free energy. Using a variant of Guerra's
replica symmetry breaking interpolation, they showed that, under certain
assumption on the interactions, the formula gives an upper bound on the limit
of the free energy. In this paper we prove that the bound is sharp. This is
achieved by developing a new multi-species form of the Ghirlanda-Guerra
identities and showing that they force the overlaps within species to be
completely determined by the overlaps of the whole system.


title:
Quantitative Comparison of Methods for Predicting the Arrival of Coronal
  Mass Ejections at Earth based on multi-view imaging

abstract:
  We investigate the performance of six methods for predicting the CME time of
arrival (ToA) and velocity at Earth using a sample of nine Earth-impacting CMEs
between May 2010 and June 2011. The CMEs were tracked continuously from the Sun
to near Earth in multi-viewpoint imaging data from STEREO SECCHI and SOHO
LASCO. We use the Graduate Cylindrical Shell (GCS) model to estimate the
three-dimensional direction and height of the CMEs in every image out to
$\sim$200 R$_\odot$. We fit the derived three-dimensional (deprojected) height
and time data with six different methods to extrapolate the CME ToA and
velocity at Earth. We compare the fitting results with the in situ data from
the WIND spacecraft. We find that a simple linear fit after a height of
50$R_\odot$ gives the best ToA with a total error $\pm$13 hours. For seven
(78%) of the CMEs, we are able to predict the ToA to within $\pm$6 hours. These
results are a full day improvement over past CME arrival time methods that only
used SOHO LASCO data. We conclude that heliographic measurements, beyond the
coronagraphic field of view, of the CME front made away from the Sun-Earth line
are essential for accurate predictions of their time of arrival.


title: Multiphoton effects in coherent radiation spectra

abstract:
  At measurements of gamma-radiation spectra from ultra-relativistic electrons
in periodic structures, pileup of events in the calorimeter may cause
significant deviation of the detector signal from the classically evaluated
spectrum. That requires appropriate resummation of multiphoton contributions.
We describe the resummation procedure for the photon spectral intensity and for
the photon multiplicity spectrum, and apply it to the study of spectra of
coherent radiation with an admixture of incoherent component. Impact of
multiphoton effects on the shape of the radiation spectrum is investigated. The
limit of high photon multiplicity for coherent radiation is explored. A method
for reconstruction of the underlying single-photon spectrum from the
multiphoton one is proposed.


title: Parametric Galois Extensions

abstract:
  Given a field $k$ and a finite group $H$, {\it{an $H$-parametric extension
over $k$}} is a finite Galois extension of $k(T)$ of Galois group containing
$H$ which is regular over $k$ and has all the Galois extensions of $k$ of group
$H$ among its specializations. We are mainly interested in producing non
$H$-parametric extensions, which relates to classical questions in inverse
Galois theory like the Beckmann-Black problem and the existence of one
parameter generic polynomials. We develop a general approach started in a
preceding paper and provide new non parametricity criteria and new examples.


title:
Linearized eigenvalues for a free boundary problem modeling two-phase
  tumor growth

abstract:
  In this paper we study a linearized eigenvalue problem derived from a a free
boundary problem modeling the growth of a tumor containing two species of
cells: proliferating cells and quiescent cells. The reduced form of this
eigenvalue problem is a $2$-system of a first-order nonlocal singular
differential-integral equation in a ball coupled by a third-order elliptic
pseudo-differential equation in the unit sphere. The singularity joined with
non-localness of the first-order equation causes the main difficulty of this
problem. By using Fourier expansion via a basis of spherical harmonic functions
and some techniques for solving singular differential integral equations
developed in some previous literature, we prove that there exists a null
sequence $\{\gamma_k\}_{k=2}^{\infty}$ for the surface tension coefficient
$\gamma$, with each of them being an eigenvalue of the linearized problem,
i.e., if $\gamma=\gamma_k$ for some $k\geq 2$ then the linearized problem has
extra nontrivial solutions besides the standard nontrivial solutions, and if
$\gamma\neq\gamma_k$ for all $k\geq 2$ then the linearized problem does not
have other nontrivial solutions than the standard nontrivial solutions.
Invertibility of some linear operators related to the linearized problem in
suitable function spaces is also studied.


title: Tropical approach to Nagata's conjecture in positive characteristic

abstract:
  Suppose that there exists a hypersurface with the Newton polytope $\Delta$,
which passes through a given set of subvarieties. Using tropical geometry, we
associate a subset of $\Delta$ to each of these subvarieties. We prove that a
weighted sum of the volumes of these subsets estimates the volume of $\Delta$
from below.
  As a particular application of our method we consider a planar algebraic
curve $C$ which passes through generic points $p_1,\dots,p_n$ with prescribed
multiplicities $m_1,\dots,m_n$. Suppose that the minimal lattice width
$\omega(\Delta)$ of the Newton polygon $\Delta$ of the curve $C$ is at least
$\max(m_i)$. Using tropical floor diagrams (a certain degeneration of
$p_1,\dots, p_n$ on a horizontal line) we prove that
$$\mathrm{area}(\Delta)\geq \frac{1}{2}\sum_{i=1}^n m_i^2-S,\ \ \text{where }
S=\frac{1}{2}\max \left(\sum_{i=1}^n s_i^2 \Big| s_i\leq m_i, \sum_{i=1}^n
s_i\leq \omega(\Delta)\right).$$
  In the case $m_1=m_2=\ldots =m\leq \omega(\Delta)$ this estimate becomes
$\mathrm{area}(\Delta)\geq \frac{1}{2}(n-\frac{\omega(\Delta)}{m})m^2$. That
rewrites as $d\geq (\sqrt{n}-\frac{1}{2}-\frac{1}{2\sqrt n})m$ for the curves
of degree $d$.
  We consider an arbitrary toric surface (i.e. arbitrary $\Delta$) and our
ground field is an infinite field of any characteristic, or a finite field
large enough. The latter constraint arises because it is not {\it \`a priori}
clear what is {\it a collection of generic points} in the case of a small
finite field. We construct such collections for fields big enough, and that may
be also interesting for the coding theory.


title: Generalized Choquet spaces

abstract:
  We introduce an analog to the notion of Polish space for spaces of weight
$\leq\kappa$, where $\kappa$ is an uncountable regular cardinal such that
$\kappa^{<\kappa}=\kappa$. Specifically, we consider spaces in which player II
has a winning strategy in a variant of the strong Choquet game which runs for
$\kappa$ many rounds. After discussing the basic theory of these games and
spaces, we prove that there is a surjectively universal such space and that
there are exactly $2^\kappa$ many such spaces up to homeomorphism. We also
establish a Kuratowski-like theorem that under mild hypotheses, any two such
spaces of size $>\kappa$ are isomorphic by a $\kappa$-Borel function. We then
consider a dynamic version of the Choquet game and show that in this case the
existence of a winning strategy for player II implies the existence of a
winning tactic, that is, a strategy that depends only on the most recent move.
We also study a generalization of Polish ultrametric spaces where the
ultrametric is allowed to take values in a set of size $\kappa$. We show that
in this context, there is a family of universal Urysohn-type spaces, and we
give a characterization of such spaces which are hereditarily $\kappa$-Baire.


title:
Estado Actual de la Pr\'actica de la Ingenier\'ia de Software en
  M\'exico

abstract:
  The software engineering is a relatively new discipline compared to other
sciences, since the origins of the term itself dates back to the years 1968 and
1969. At present, the market and the software industry have a significant
relevance in several countries of the world; however, although Mexico is
immersed in this race, has not even reached the level of success achieved in
other countries in this sector. This paper presents an overview of the
situation that keeps the practice of software engineering in Mexico, with
emphasis on the academic realm. It shows a compilation of scientific research
activity carried out in universities, as well as a brief analysis of
undergraduate educational programs including the software engineering
discipline . At the end, future work to be done is proposed in order to find a
point of convergence between academia and industry, and also to support the
flourishing of this business which somehow will have a positive impact on the
economy of our country.


title: Quantum Behavior of Water Molecules Confined to Nanocavities in Gemstone

abstract:
  When water is confined to nanocavities, its quantum-mechanical behavior can
be revealed by terahertz spectroscopy. We place H2O molecules in the nanopores
of a beryl crystal-lattice and observe a rich and highly anisotropic set of
absorption lines in the terahertz spectral range. Two bands can be identified,
which originate from translational and librational motions of the water
molecule isolated within the cage; they correspond to the analogous broad bands
in liquid water and ice. In the present case of well-defined and highly
symmetric nanocavities, the observed fine structure can be explained by
macroscopic tunneling of the H2O molecules within a six-fold potential caused
by the interaction of the molecule with the cavity walls.


title: DAMIC: a novel dark matter experiment

abstract:
  DAMIC (Dark Matter in CCDs) is a novel dark matter experiment that has unique
sensitivity to dark matter particles with masses below 10 GeV. Due to its low
electronic readout noise (R.M.S. ~3 e-) this instrument is able to reach a
detection threshold below 0.5 keV nuclear recoil energy, making the search for
dark matter particles with low masses possible. We report on early results and
experience gained from a detector that has been running at SNOLAB from Dec
2012. We also discuss the measured and expected backgrounds and present the
plan for future detectors to be installed in 2014.


title:
Low-dimensional functionality of complex network dynamics: Neuro-sensory
  integration in the Caenorhabditis elegans connectome

abstract:
  We develop a biophysical model of neuro-sensory integration in the model
organism Caenorhabditis elegans. Building on recent experimental findings of
the neuron conductances and their resolved connectome, we posit the first full
dynamic model of the neural voltage excitations that allows for a
characterization of input stimuli to behavioral responses. Thus a clear
connection between receptory cell inputs to downstream motor-responses is
illustrated, showing that robust, low-dimensional bifurcation structures
dominate neural pathways of activity. The underlying bifurcation structures
discovered, i.e. an induced Hopf bifurcation, are critical in explaining
behavioral responses such as swimming and crawling. More broadly, we
demonstrate that complex dynamical networks can produce robust functionality
from underlying low-dimensional bifurcations.


title:
Universality in Similarity Renormalization Group Evolved Potential
  Matrix Elements and T-Matrix Equivalence

abstract:
  We examine how the universality of two-nucleon interactions evolved using
similarity renormalization group (SRG) transformations correlates with T-matrix
equivalence, with the ultimate goal of gaining insight into universality for
three-nucleon forces. With sufficient running of the SRG flow equations, the
low-energy matrix elements of different realistic potentials evolve to a
universal form. Because these potentials are fit to low-energy data, they are
(approximately) phase equivalent only up to a certain energy, and we find
universality in evolved potentials up to the corresponding momentum. More
generally we find universality in local energy regions, reflecting a local
decoupling by the SRG. The further requirements for universality in evolved
potential matrix elements are explored using two simple alternative potentials.
We see evidence that in addition to predicting the same observables, common
long-range potentials (i.e., explicit pion physics) is required for
universality in the potential matrix elements after SRG flow. In agreement with
observations made previously for Vlowk evolution, regions of universal
potential matrix elements are restricted to where half-on-shell T-matrix
equivalence holds.


title:
Sur une question de N. Chevallier li\'ee \`a l'approximation
  Diophantienne simultan\'ee

abstract:
  We prove a conjecture due to Nicolas Chevallier concerning unimodular
matrices related to simultaneous Diophantine approximation to real numbers.


title: Iterated logarithm law for sizes of clusters in Arratia flow

abstract:
  The asymptotics of sizes of clusters for the Arratia flow is considered, the
Arratia flow being a system of coalescing Wiener processes starting from the
real axis and independent before they meet. A cluster at time t is defined as a
set of particles that have glued together not later than at t. The results
obtained are remarked to hold for any Arratia flow with a Lipschitz drift.


title:
Density functional theory calculation of edge stresses in monolayer
  MoS$_2$

abstract:
  We utilize density functional theory to calculate the edge energy and edge
stress for monolayer MoS$_{2}$ nanoribbons. In contrast to previous reports for
graphene, for both armchair and zigzag chiralities, the edge stresses for
MoS$_{2}$ nanoribbons are found to be tensile, indicating that their lowest
energy configuration is one of compression in which Mo-S bond lengths are
shorter than those in a bulk, periodic MoS$_{2}$ monolayer. The edge energy and
edge stress is found to converge for both chiralities for nanoribbon widths
larger than about 1 nm.


title: A Note on the Magnitude of the Flux Superpotential

abstract:
  The magnitude of the flux superpotential $W_{flux}$ plays a crucial role in
determining the scales of IIB string compactifications after moduli
stabilisation. It has been argued that values of $W_{flux}$ much less than one
are preferred, and even required for physical and consistency reasons. This
note revisits these arguments. We establish that the coupling (g) of heavy
Kaluza-Klein modes to light states scales as ${M_{KK} / M_{Pl}}$ (hence is
suppressed by two third powers of the inverse volume of compactification) and
argue that consistency of the superspace derivative expansion requires $gF/M^2
\sim m_{3/2}/ M_{KK} << 1$, where $F$ is the auxiliary field of the light
fields and $M$ the ultraviolet cutoff. This gives only a mild constraint on the
flux superpotential, $W_{flux} << V^{1/3}$ (where V is the volume of the
compactification), which can be easily satisfied for order one values of
$W_{flux}$. This regime is also statistically favoured and makes the
Bousso-Polchinski mechanism for the vacuum energy hierarchically more
efficient.


title:
The Physical Conditions, Metallicity and Metal Abundance Ratios In a
  Highly Magnified Galaxy at z = 3.6252

abstract:
  We present optical and near-IR imaging and spectroscopy of SGAS
J105039.6$+$001730, a strongly lensed galaxy at z $=$ 3.6252 magnified by
$>$30$\times$, and derive its physical properties. We measure a stellar mass of
log(M$_{*}$/M$_{\odot}$) $=$ 9.5 $\pm$ 0.35, star formation rates from [O
II]$\lambda$$\lambda$3727 and H-$\beta$ of 55 $\pm$ 20 and 84 $\pm$ 17
M$_{\odot}$ yr$^{-1}$, respectively, an electron density of n$_{e} \leq$
10$^{3}$ cm$^{-2}$, an electron temperature of T$_{e} \leq$ 14000 K, and a
metallicity of 12+log(O/H) $=$ 8.3 $\pm$ 0.1. The strong C
III]$\lambda$$\lambda$1907,1909 emission and abundance ratios of C, N, O and Si
are consistent with well-studied starbursts at z $\sim$ 0 with similar
metallicities. Strong P Cygni lines and He II$\lambda$1640 emission indicate a
significant population of Wolf-Rayet stars, but synthetic spectra of individual
populations of young, hot stars do not reproduce the observed integrated P
Cygni absorption features. The rest-frame UV spectral features are indicative
of a young starburst with high ionization, implying either 1) an ionization
parameter significantly higher than suggest by rest-frame optical nebular
lines, or 2) differences in one or both of the initial mass function and the
properties of ionizing spectra of massive stars. We argue that the observed
features are likely the result of a superposition of star forming regions with
different physical properties. These results demonstrate the complexity of star
formation on scales smaller than individual galaxies, and highlight the
importance of systematic effects that result from smearing together the
signatures of individual star forming regions within galaxies.


title: Bordered Heegaard Floer homology and graph manifolds

abstract:
  We perform two explicit computations of bordered Heegaard Floer invariants.
The first is the type D trimodule associated to the trivial S^1 bundle over the
pair of pants P. The second is a bimodule that is necessary for self-gluing,
when two torus boundary components of a bordered manifold are glued to each
other. Using the results of these two computations, we describe an algorithm
for computing HF-hat of any graph manifold.


title:
The effect of an ordered azimuthal magnetic field on a migrating planet
  in a non-turbulent disc

abstract:
  In this work, we consider the physics of the interaction between a planet and
a magnetized gaseous protoplanetary disc. We investigate the migration of a
planet in a disc that is threaded with an azimuthal magnetic field. We find
that, for a larger magnetic field amplitude, there is an increasingly large
positive torque on the planet from the disc, resulting in slowed and even
outward migration. Our results indicate that magnetic resonances due to a
purely azimuthal, ordered magnetic field can slow or stop the inward migration
of Jupiter-mass, Saturn-mass, and $5 M_{\oplus}$ planets.


title: Some Monotonicity Properties of Convex Functions with Applications

abstract:
  We mainly establish a monotonicity property between some special Riemann sums
of a convex function $f$ on $[a,b]$, which in particular yields that
$\frac{b-a}{n+1}\sum_{i=0}^n f\left(a+i\frac{b-a}{n}\right)$ is decreasing
while $\frac{b-a}{n-1}\sum_{i=1}^{n-1} f\left(a+i\frac{b-a}{n}\right)$ is an
increasing sequence. These give us a new refinement of the Hermitt-Hadamard
inequality.
  Moreover, we give a refinement of the classical Alzer's inequality together
with a suitable converse to it. Applications regarding to some important convex
functions are also included.


title: Matrix Roots of Eventually Positive Matrices

abstract:
  Eventually positive matrices are real matrices whose powers become and remain
strictly positive. As such, eventually positive matrices are a fortiori matrix
roots of positive matrices, which motivates us to study the matrix roots of
primitive matrices. Using classical matrix function theory and Perron-Frobenius
theory, we characterize, classify, and describe in terms of the real Jordan
canonical form the $p$th-roots of eventually positive matrices.


title: FACT Contributions to the 33rd ICRC, 2013

abstract:
  List of all contributions from the First G-APD Cherenkov Telescope (FACT)
Collaboration to the 33rd International Cosmic Ray Conference (ICRC)