title: Fano schemes of determinants and permanents

abstract:
  Let $D_{m,n}^r$ and $P_{m,n}^r$ denote the subschemes of $\mathbb{P}^{mn-1}$
given by the $r\times r$ determinants (respectively the $r\times r$ permanents)
of an $m\times n$ matrix of indeterminates. In this paper, we study the
geometry of the Fano schemes $\mathbf{F}_k(D_{m,n}^r)$ and
$\mathbf{F}_k(P_{m,n}^r)$ parametrizing the $k$-dimensional planes in
$\mathbb{P}^{mn-1}$ lying on $D_{m,n}^r$ and $P_{m,n}^r$, respectively. We
prove results characterizing which of these Fano schemes are smooth,
irreducible, and connected; and we give examples showing that they need not be
reduced. We show that $\mathbf{F}_1(D_{n,n}^n)$ always has the expected
dimension, and we describe its components exactly. Finally, we give a detailed
study of the Fano schemes of $k$-planes on the $3\times 3$ determinantal and
permanental hypersurfaces.


title: Kernel-based Distance Metric Learning in the Output Space

abstract:
  In this paper we present two related, kernel-based Distance Metric Learning
(DML) methods. Their respective models non-linearly map data from their
original space to an output space, and subsequent distance measurements are
performed in the output space via a Mahalanobis metric. The dimensionality of
the output space can be directly controlled to facilitate the learning of a
low-rank metric. Both methods allow for simultaneous inference of the
associated metric and the mapping to the output space, which can be used to
visualize the data, when the output space is 2- or 3-dimensional. Experimental
results for a collection of classification tasks illustrate the advantages of
the proposed methods over other traditional and kernel-based DML approaches.


title:
Quantum Algorithms for Quantum Chemistry based on the sparsity of the
  CI-matrix

abstract:
  Quantum chemistry provides a target for quantum simulation of considerable
scientific interest and industrial importance. The majority of algorithms to
date have been based on a second-quantized representation of the electronic
structure Hamiltonian - necessitating qubit requirements that scale linearly
with the number of orbitals. The scaling of the number of gates for such
methods, while polynomial, presents some serious experimental challenges.
However, because the number of electrons is a good quantum number for the
electronic structure problem it is unnecessary to store the full Fock space of
the orbitals. Representation of the wave function in a basis of Slater
determinants for fixed electron number suffices. However, to date techniques
for the quantum simulation of the Hamiltonian represented in this basis - the
CI-matrix - have been lacking. We show how to apply techniques developed for
the simulation of sparse Hamiltonians to the CI-matrix. We prove a number of
results exploiting the structure of the CI-matrix, arising from the Slater
rules which define it, to improve the application of sparse Hamiltonian
simulation techniques in this case. We show that it is possible to use the
minimal number of qubits to represent the wavefunction, and that these methods
can offer improved scaling in the number of gates required in the limit of
fixed electron number and increasing basis set size relevant for high-accuracy
calculations. We hope these results open the door to further investigation of
sparse Hamiltonian simulation techniques in the context of the quantum
simulation of quantum chemistry.


title:
On Relativistic Generalization of Perelman's W-entropy and Statistical
  Thermodynamic Description of Gravitational Fields

abstract:
  Using double 2+2 and 3+1 nonholonomic fibrations on Lorentz manifolds, we
extend the concept of W-entropy for gravitational fields in the general
relativity, GR, theory. Such F- and W-functionals were introduced in the Ricci
flow theory of three dimensional, 3-d, Riemannian metrics by G. Perelman,
arXiv: math.DG/0211159. Nonrelativistic 3-d Ricci flows are characterized by
associated statistical thermodynamical values determined by W--entropy.
Generalizations for geometric flows of 4-d pseudo-Riemannian metrics are
considered for models with local thermodynamical equilibrium and separation of
dissipative and non-dissipative processes in relativistic hydrodynamics. The
approach is elaborated in the framework of classical filed theories
(relativistic continuum and hydrodynamic models) without an underlying kinetic
description which will be elaborated in other works. The 3+1 splitting allows
us to provide a general relativistic definition of gravitational entropy in the
Lyapunov-Perelman sense. It increases monotonically as structure forms in the
Universe. We can formulate a thermodynamic description of exact solutions in GR
depending, in general, on all spacetime coordinates. A corresponding 2+2
splitting with nonholonomic deformation of linear connection and frame
structures is necessary for generating in very general form various classes of
exact solutions of the Einstein and general relativistic geometric flow
equations. Finally, we speculate on physical macrostates and microstate
interpretations of the W-entropy in GR, geometric flow theories and possible
connections to string theory (a second unsolved problem also contained in
Perelman's works) in the Polyakov's approach.


title: Deployment of VoIP Technology: QoS Concerns

abstract:
  Voice over IP (VoIP) is an emerging communication service allowing voice
transmission over a private or a public IP network. VoIP allows significant
benefits for customers and service providers including cost savings, phone and
service portability, mobility, and the integration with other applications.
Nevertheless, the deployment of the VoIP technology encounters many challenges
such as interoperability issues, security issues, and QoS concerns. Among these
disadvantages, QoS issues are considered the most serious due to the QoS
problems that may arise on IP networks, and the stringent QoS requirements of
voice traffic. The aim of this paper is carry out a deep analysis of the QoS
concerns of the VoIP technology. Firstly, we present a brief overview about the
VoIP technology. Then, we discuss the QoS issues related to the use of the IP
networking technology for voice traffic transmission. After that, we present
the QoS concerns related voice clarity. Finally, we present the QoS mechanisms
proposed to make the IP technology able to support voice traffic QoS
requirements in terms of voice clarity, voice packet delay, packet delay
variation, and packet loss.


title: Boundary integral formulation for cracks at imperfect interfaces

abstract:
  We consider an infinite bi-material plane containing a semi-infinite crack
situated on a soft imperfect interface. The crack is loaded by a general
asymmetrical system of forces distributed along the crack faces. On the basis
of the weight function approach and the fundamental reciprocal identity, we
derive the corresponding boundary integral formulation, relating physical
quantities. The boundary integral equations derived in this paper in the
imperfect interface setting show a weak singularity, in contrast to the perfect
interface case, where the kernel is of the Cauchy type. We further present
three alternative variants of the boundary integral equations which offer
computationally favourable alternatives for certain sets of parameters.


title: Using Gas Kinematics To Constrain 3D Models of Disks: IC 2531

abstract:
  We use deep, longslit spectra of the nearby edge on galaxy IC 2531 to obtain
gas kinematics out to 5 radial scale-lengths (40 kpc) and 4 vertical
scale-heights (1.7 kpc). The large vertical range spanned by our data offers
unique leverage to constrain three-dimensional models. The shape of the
observed emission-line profiles offer insights to line-of-sight density
distributions in the disk, and we discuss the possibility that we are seeing
disk-flaring in the ionized gas. Finally, we begin to quantify measurements of
line shape to allow model galaxies to be compared to data across all radii and
heights simultaneously.


title:
Spatially resolved LMC star formation history: I. Outside in evolution
  of the outer LMC disk

abstract:
  We study the evolution of three fields in the outer LMC disk Rgc=3.5-6.2 Kpc.
Their star formation history indicates a stellar populations gradient such that
younger stellar populations are more centrally concentrated. We identify two
main star forming epochs, separated by a period of lower activity between ~7
and ~4 Gyr ago. Their relative importance varies from a similar amount of stars
formed in the two epochs in the innermost field, to only 40% of the stars
formed in the more recent epoch in the outermost field. The young star forming
epoch continues to the present time in the innermost field, but lasted only
till ~0.8 and 1.3 Gyr ago at Rgc=5.5 degrees and 7.1 degrees, respectively.
This gradient is correlated with the measured HI column density and implies an
outside-in quenching of the star formation, possibly related to a variation of
the size of the HI disk. This could either result from gas depletion due to
star formation or ram-pressure stripping, or from to the compression of the gas
disk as ram-pressure from the Milky Way halo acted on the LMC interstellar
medium. The latter two situations may have occurred when the LMC first
approached the Milky Way.


title:
E-learning for ungraded schools of Kazakhstan: experience,
  implementation, and innovation

abstract:
  The modernization of the educational process in the ungraded schools of the
Republic of Kazakhstan requires the provision of affordable quality education
for students in rural areas on information technology, the creation of
e-learning. It was important to consider two points: how does e-learning
influence the educational process in ungraded schools, and directly on the
quality of teaching, and what results can thus be achieved. The significance of
the work is also to explore innovative approaches to e-learning system of
ungraded schools.


title: Lepton flavour violation from right-handed neutrino thresholds

abstract:
  Charged lepton flavour violation is reappraised in the context of
supersymmetric see-saw mechanism. It is pointed out that a non-trivial flavour
structure of right-handed neutrinos, whose effect has been thus far less
studied, can give rise to significant slepton flavour transitions. Under the
premise that the neutrino Yukawa couplings are of O(1), the right-handed
neutrino mixing contribution could form a basis of the $\mu \rightarrow e
\gamma$ amplitude which by itself might lead to an experimentally accessible
rate, given a typical low-energy sparticle spectrum. Emphasis is placed on the
crucial role of the recently measured lepton mixing angle $\theta_{13}$ as well
as the leptonic CP-violating phases.


title: On the mass of the Local Group

abstract:
  We use recent proper motion measurements of the tangential velocity of M31,
along with its radial velocity and distance, to derive the likelihood of the
sum of halo masses of the Milky Way and M31. This is done using a sample halo
pairs in the Bolshoi cosmological simulation of $\Lambda$CDM cosmology selected
to match properties and environment of the Local Group. The resulting
likelihood gives estimate of the sum of masses of $M_{\rm MW,200}+M_{\rm
M31,200}=$ $2.40_{-1.05}^{+1.95}\times10^{12}\,M_{\odot}$ ($90\%$ confidence
interval). This estimate is consistent with individual mass estimates for the
Milky Way and M31 and is consistent, albeit somewhat on the low side, with the
mass estimated using the timing argument. We show that although the timing
argument is unbiased on average for all pairs, for pairs constrained to have
radial and tangential velocities similar to that of the Local Group the
argument overestimates the sum of masses by a factor of $1.6$. Using similar
technique we estimate the total dark matter mass enclosed within $1$ Mpc from
the Local Group barycenter to be $M_{\rm LG}(r<1\, {\rm
Mpc})=4.2_{-2.0}^{+3.4}\times10^{12}\,M_{\odot}$ ($90\%$ confidence interval).


title:
Evaluating single-scale and/or non-planar diagrams by differential
  equations

abstract:
  We apply a recently suggested new strategy to solve differential equations
for Feynman integrals. We develop this method further by analyzing asymptotic
expansions of the integrals. We argue that this allows the systematic
application of the differential equations to single-scale Feynman integrals.
Moreover, the information about singular limits significantly simplifies
finding boundary constants for the differential equations. To illustrate these
points we consider two families of three-loop integrals. The first are
form-factor integrals with two external legs on the light cone. We introduce
one more scale by taking one more leg off-shell, $p_2^2\neq 0$. We analytically
solve the differential equations for the master integrals in a Laurent
expansion in dimensional regularization with $\epsilon=(4-D)/2$. Then we show
how to obtain analytic results for the corresponding one-scale integrals in an
algebraic way. An essential ingredient of our method is to match solutions of
the differential equations in the limit of small $p_2^2$ to our results at
$p_2^2\neq 0$ and to identify various terms in these solutions according to
expansion by regions. The second family consists of four-point non-planar
integrals with all four legs on the light cone. We evaluate, by differential
equations, all the master integrals for the so-called $K_4$ graph consisting of
four external vertices which are connected with each other by six lines. We
show how the boundary constants can be fixed with the help of the knowledge of
the singular limits. We present results in terms of harmonic polylogarithms for
the corresponding seven master integrals with six propagators in a Laurent
expansion in $\epsilon$ up to weight six.


title: A bound on the charm chromo-EDM and its implications

abstract:
  We derive bounds on the electric and chromo-electric dipole moments of the
charm quark. The second one turns out to be particularly strong, and we
quantify its impact on models that allow for a sizeable flavour violation in
the up quark sector, like flavour alignment and Generic U(2)^3. In particular
we show how the bounds coming from the charm and up CEDMs constrain the size of
new physics contributions to direct flavour violation in D decays. We also
specialize our analysis to the cases of Supersymmetry with split families and
composite Higgs models. The results exposed in this paper motivate both an
increase in experimental sensitivity to fundamental hadronic dipoles, and a
further exploration of the SM contribution to flavour violating D decays.


title: Constraints on a Very Light Sbottom

abstract:
  We investigate the phenomenological viability of a very light bottom squark,
with a mass less than half of the Z boson mass. The decays of the Z and Higgs
bosons to light sbottom pairs are, in a fairly model independent manner,
strongly constrained by the precision electroweak data and Higgs signal
strength measurements, respectively. These constraints are complementary to
direct collider searches, which depend in detail on assumptions regarding the
superpartner spectrum and decays of the sbottom. In particular, if the lightest
sbottom has a mass below about 15 GeV, compatibility with these measurements is
possible only in a special region of parameter space in which the couplings of
the lightest sbottom to the Z and Higgs are suppressed. In this region, the
second sbottom is predicted to be lighter than about 300 GeV and can also be
searched for directly at the LHC. We also survey relevant collider searches for
canonical scenarios with a bino, gravitino, or singlino LSP in the compressed
and stealth kinematic regimes and provide suggestions to cover remaining open
regions of parameter space.


title: CheckMATE: Confronting your Favourite New Physics Model with LHC Data

abstract:
  In the first three years of running, the LHC has delivered a wealth of new
data that is now being analysed. With over 20 fb$^{-1}$ of integrated
luminosity, both ATLAS and CMS have performed many searches for new physics
that theorists are eager to test their model against. However, tuning the
detector simulations, understanding the particular analysis details and
interpreting the results can be a tedious task.
  CheckMATE (Check Models At Terascale Energies) is a program package which
accepts simulated event files in many formats for any model. The program then
determines whether the model is excluded or not at 95% C.L. by comparing to
many recent experimental analyses. Furthermore the program can calculate
confidence limits and provide detailed information about signal regions of
interest. It is simple to use and the program structure allows for easy
extensions to upcoming LHC results in the future.
  CheckMATE can be found at: http://checkmate.hepforge.org


title: Mono-Higgs: a new collider probe of dark matter

abstract:
  We explore the LHC phenomenology of dark matter (DM) pair production in
association with a 125 GeV Higgs boson. This signature, dubbed `mono-Higgs,'
appears as a single Higgs boson plus missing energy from DM particles escaping
the detector. We perform an LHC background study for mono-Higgs signals at
$\sqrt{s} = 8$ and $14$ TeV for four Higgs boson decay channels:
$\gamma\gamma$, $b \bar b$, and $ZZ^* \to 4\ell$, $\ell\ell j j$. We estimate
the LHC sensitivities to a variety of new physics scenarios within the
frameworks of both effective operators and simplified models. For all these
scenarios, the $\gamma\gamma$ channel provides the best sensitivity, whereas
the $b\bar b$ channel suffers from a large $t \bar t$ background. Mono-Higgs is
unlike other mono-$X$ searches ($X$=jet, photon, etc.), since the Higgs boson
is unlikely to be radiated as initial state radiation, and therefore probes the
underlying DM vertex directly.


title: Observational Constraints on Redshift Remapping

abstract:
  There are two redshifts in cosmology: $z_{obs}$, the observed redshift
computed via spectral lines, and the model redshift, $z$, defined by the
effective FLRW scale factor. In general these do not coincide. We place
observational constraints on the allowed distortions of $z$ away from $z_{obs}$
- a possibility we dub redshift remapping. Remapping is degenerate with cosmic
dynamics for either $d_L(z)$ or $H(z)$ observations alone: for example, the
simple remapping $z = \alpha_1 z_{obs} +\alpha_2 z_{obs}^2$ allows a
decelerating Einstein de Sitter universe to fit the observed supernova Hubble
diagram as successfully as $\Lambda$CDM, highlighting that supernova data alone
cannot prove that the universe is accelerating. We show however, that redshift
remapping leads to apparent violations of cosmic distance duality that can be
used to detect its presence even when neither a specific theory of gravity nor
the Copernican Principle are assumed. Combining current data sets favours
acceleration but does not yet rule out redshift remapping as an alternative to
dark energy. Future surveys, however, will provide exquisite constraints on
remapping and any models -- such as backreaction -- that predict it.


title:
Instability of a viscous flow between rotating porous cylinders with
  radial flow

abstract:
  The stability of a two-dimensional viscous flow between two rotating porous
cylinders is studied. The basic steady flow is the most general
rotationally-invariant solution of the Navier-Stokes equations in which the
velocity has both radial and azimuthal components, and the azimuthal velocity
profile depends on the Reynolds number. It is shown that for a wide range of
the parameters of the problem, the basic flow is unstable to small
two-dimensional perturbations. Neutral curves in the space of parameters of the
problem are computed. Calculations show that the stability properties of this
flow are determined by the azimuthal velocity at the inner cylinder when the
direction of the radial flow is from the inner cylinder to the outer one and by
the azimuthal velocity at the outer cylinder when the direction of the radial
flow is reversed. This work is a continuation of our previous study of an
inviscid instability in flows between rotating porous cylinders (see
\cite{IM2013}).


title:
Overlapping Inflow Events as Catalysts for Supermassive Black Hole
  Growth

abstract:
  One of the greatest issues in modelling black hole fuelling is our lack of
understanding of the processes by which gas loses angular momentum and falls
from galactic scales down to the nuclear region where an accretion disc forms,
subsequently guiding the inflow of gas down to the black hole horizon. It is
feared that gas at larger scales might still retain enough angular momentum and
settle into a larger scale disc with very low or no inflow to form or replenish
the inner accretion disc (on ~0.01 pc scales). In this paper we report on
hydrodynamical simulations of rotating infalling gas shells impacting at
different angles onto a pre-existing, primitive large scale (~10 pc) disc
around a super-massive black hole. The aim is to explore how the interaction
between the shell and the disc redistributes the angular momentum on scales
close to the black hole's sphere of influence. Angular momentum redistribution
via hydrodynamical shocks leads to inflows of gas across the inner boundary,
enhancing the inflow rate by more than 2-3 orders of magnitude. In all cases,
the gas inflow rate across the inner parsec is higher than in the absence of
the interaction, and the orientation of the angular momentum of the flow in the
region changes with time due to gas mixing. Warped discs or nested misaligned
rings form depending on the angular momentum content of the infalling shell
relative to the disc. In the cases in which the shell falls in near
counter-rotation, part of the resulting flows settle into an inner dense disc
which becomes more susceptible to mass transfer.


title:
Emergent Criticality and Friedan Scaling in a 2D Frustrated Heisenberg
  Antiferromagnet

abstract:
  We study a two-dimensional frustrated Heisenberg antiferromagnet on the
windmill lattice consisting of triangular and dual honeycomb lattice sites. In
the classical ground state the spins on different sublattices are decoupled,
but quantum and thermal fluctuations drive the system into a coplanar state via
an "order from disorder" mechanism. We obtain the finite temperature phase
diagram using renormalization group approaches. In the coplanar regime, the
relative U$(1)$ phase between the spins on the two sublattices decouples from
the remaining degrees of freedom, and is described by a six-state clock model
with an emergent critical phase. At lower temperatures the system enters a
$\mathbb{Z}_6$ broken phase with long-range phase correlations. We derive these
results by two distinct renormalization group approaches to two-dimensional
magnetism: by Wilson-Polyakov scaling and by Friedan's geometric approach to
nonlinear sigma models where the scaling of the spin-stiffnesses is governed by
the Ricci flow of a 4D metric tensor.


title: Dark D-brane Cosmology

abstract:
  Disformally coupled cosmologies arise from Dirac-Born-Infeld actions in Type
II string theories, when matter resides on a moving hidden sector D-brane.
Since such matter interacts only very weakly with the standard model particles,
this scenario can provide a natural origin for the dark sector of the universe
with a clear geometrical interpretation: dark energy is identified with the
scalar field associated to the D-brane's position as it moves in the internal
space, acting as quintessence, while dark matter is identified with the matter
living on the D-brane, which can be modelled by a perfect fluid. The coupling
functions are determined by the (warped) extra-dimensional geometry, and are
thus constrained by the theory. The resulting cosmologies are studied using
both dynamical system analysis and numerics. From the dynamical system point of
view, one free parameter controls the cosmological dynamics, given by the ratio
of the warp factor and the potential energy scales. The disformal coupling
allows for new scaling solutions that can describe accelerating cosmologies
alleviating the coincidence problem of dark energy. In addition, this scenario
may ameliorate the fine-tuning problem of dark energy, whose small value may be
attained dynamically, without requiring the mass of the dark energy field to be
unnaturally low.


title:
Monitoring voltage collapse margin by measuring the area voltage across
  several transmission lines with synchrophasors

abstract:
  We consider the fast monitoring of voltage collapse margin using
synchrophasor measurements at both ends of transmission lines that transfer
power from two generators to two loads. This shows a way to extend the
monitoring of a radial transmission line to multiple transmission lines. The
synchrophasor voltages are combined into a single complex voltage difference
across an area containing the transmission lines that can be monitored in the
same way as a single transmission line. We identify ideal conditions under
which this reduction to the single line case perfectly preserves the margin to
voltage collapse, and give an example that shows that the error under practical
non-ideal conditions is reasonably small.


title:
Sub-Doppler resonances in the back-scattered light from random porous
  media infused with Rb vapor

abstract:
  We report on the observation of sub-Doppler resonances on the back-scattered
light from a random porous glass medium with rubidium vapor filling its
interstices. The sub-Doppler spectral lines are the consequence of saturated
absorption where the incident laser beam saturates the atomic medium and the
back-scattered light probes it. Some specificities of the observed spectra
reflect the transient atomic evolution under confinement inside the pores.
Simplicity, robustness and potential miniaturization are appealing features of
this system as a spectroscopic reference.


title: KPZ line ensemble

abstract:
  For each $t\geq 1$ we construct an $\mathbf{N}$-indexed ensemble of random
continuous curves with three properties: 1. The lowest indexed curve is
distributed as the time $t$ Hopf-Cole solution to the Kardar-Parisi-Zhang (KPZ)
stochastic PDE with narrow wedge initial data; 2. The entire ensemble satisfies
a resampling invariance which we call the $\mathbf{H}$-Brownian Gibbs property
(with $\mathbf{H}(x)=e^{x}$); 3. Increments of the lowest indexed curve, when
centered by $-t/24$ and scaled down vertically by $t^{1/3}$ and horizontally by
$t^{2/3}$, remain uniformly absolutely continuous (i.e. have tight
Radon-Nikodym derivatives) with respect to Brownian bridges as time $t$ goes to
infinity.
  This construction uses as inputs the diffusion that O'Connell discovered in
relation to the O'Connell-Yor semi-discrete Brownian polymer, the convergence
result of Nica of the lowest indexed curve of that diffusion to the solution of
the KPZ equation with narrow wedge initial data, and the one-point distribution
formula proved by Amir-Corwin-Quastel for the solution of the KPZ equation with
narrow wedge initial data.
  We provide four main applications of this construction: 1. Uniform (as $t$
goes to infinity) Brownian absolute continuity of the time $t$ solution to the
KPZ equation with narrow wedge initial data, even when scaled vertically by
$t^{1/3}$ and horizontally by $t^{2/3}$; 2. Universality of the $t^{1/3}$
one-point (vertical) fluctuation scale for the solution of the KPZ equation
with general initial data; 3. Concentration in the $t^{2/3}$ scale for the
endpoint of the continuum directed random polymer; 4.Exponential upper and
lower tail bounds for the solution at fixed time of the KPZ equation with
general initial data.

categories: math.PR cond-mat.stat-mech math-ph math.MP


title:
Soliton gyroscopes in media with spatially growing repulsive
  nonlinearity

abstract:
  We find that the recently introduced model of self-trapping supported by a
spatially growing strength of a repulsive nonlinearity gives rise to robust
vortex-soliton tori, i.e., three-dimensional vortex solitons, with topological
charges S. The family with S=1 is completely stable, while the one with S=2 has
alternating regions of stability and instability. The families are nearly
exactly reproduced in an analytical form by the Thomas-Fermi approximation
(TFA). Unstable states with S=2 and 3 split into persistently rotating pairs or
triangles of unitary vortices. Application of a moderate torque to the vortex
torus initiates a persistent precession mode, with the torus' axle moving along
a conical surface. A strong torque heavily deforms the vortex solitons, but,
nonetheless, they restore themselves with the axle oriented according to the
vectorial addition of angular momenta.


title:
Non-equilibrium theory of tunneling into localized state in
  superconductor

abstract:
  A single static magnetic impurity in a fully-gapped superconductor leads to
formation of an intragap quasiparticle bound state. At temperatures much below
the superconducting transition, the energy relaxation and spin dephasing of the
state are expected to be exponentially suppressed. The presence of such a state
can be detected in electron tunneling experiments as a pair of conductance
peaks at positive and negative biases. Here we show, that for an arbitrarily
weak tunneling strength, the peaks have to be symmetric with respect to the
applied bias. This is in contrast to the standard result that the tunneling
conductance is proportional to the local (in general particle-hole asymmetric)
density of states. The asymmetry can be recovered is one allows for either a
finite density of impurity states, or that impurities are coupled to another,
non-superconducting, equilibrium bath.


title: Diffusive scaling for all moments of the Markov Anderson model

abstract:
  We consider a tight-binding Schroedinger equation with time dependent
diagonal noise, given as a function of a Markov process. This model was
considered previously by Kang and Schenker (J. Stat. Phys., 134(5-6):1005,
arXiv:0808.2784), who proved that the wave propagates diffusively. We revisit
the proof of diffusion so as to obtain a uniform bound on exponential moments
of the wave amplitude and a central limit theorem that implies, in particular,
diffusive scaling for all position moments of the mean wave amplitude.


title:
The Relationship Between Discrete and Continuous Entropy in EPR-Steering
  Inequalities

abstract:
  This document expands upon the relationship between discrete and continuous
entropy given in (Phys. Rev. Lett. 110 130407), \Violating Continuous Variable
Einstein-Podolsky-Rosen Steering with Discrete Measurements". We provide a
detailed derivation for the inequality relating the continuous conditional
entropy to its discrete approximation, and show how this connection works
between discrete and continuous entropic quantities in general. In addition, we
use this connection to show how to derive the continuous variable
Einstein-Podolsky-Rosen steering inequality with discrete measurements as seen
in (Phys. Rev. Lett. 110 130407), and make an additional comment which
strengthens this result.


title:
Synthesis of sub-5 nm Co-doped SnO$_2$ nanoparticles and their
  structural, microstructural, optical and photocatalytic properties

abstract:
  A swift chemical route to synthesize Co-doped SnO$_2$ nanopowders is
described. Pure and highly stable Sn$_{1-x}$Co$_x$O$_{2-\delta}$ (0 $\le$ x
$\le$ 0.15) crystalline nanoparticles were synthesized, with mean grain sizes <
5 nm and the dopant element homogeneously distributed in substitutional sites
of the SnO$_2$ matrix. The UV-visible diffuse reflectance spectra of the
Sn$_{1-x}$Co$_x$O$_{2-\delta}$ samples reveal red shifts, the optical bandgap
energies decreasing with increasing Co concentration. The Urbach energies of
the samples were calculated and correlated with their bandgap energies. The
photocatalytic activity of the Sn$_{1-x}$Co$_x$O$_{2-\delta}$ samples was
investigated for the 4-hydroxylbenzoic acid (4-HBA) degradation process. A
complete photodegradation of a 10 ppm 4-HBA solution was achieved using 0.02%
(w/w) of Sn$_{0.95}$Co$_{0.05}$O$_{2-\delta}$ nanoparticles in 60 min of
irradiation.


title:
Multi-Task Classification Hypothesis Space with Improved Generalization
  Bounds

abstract:
  This paper presents a RKHS, in general, of vector-valued functions intended
to be used as hypothesis space for multi-task classification. It extends
similar hypothesis spaces that have previously considered in the literature.
Assuming this space, an improved Empirical Rademacher Complexity-based
generalization bound is derived. The analysis is itself extended to an MKL
setting. The connection between the proposed hypothesis space and a Group-Lasso
type regularizer is discussed. Finally, experimental results, with some
SVM-based Multi-Task Learning problems, underline the quality of the derived
bounds and validate the paper's analysis.


title:
Stabilized lowest order finite element approximation for linear
  three-field poroelasticity

abstract:
  A stabilized conforming mixed finite element method for the three-field
(displacement, fluid flux and pressure) poroelasticity problem is developed and
analyzed. We use the lowest possible approximation order, namely piecewise
constant approximation for the pressure and piecewise linear continuous
elements for the displacements and fluid flux. By applying a local pressure
jump stabilization term to the mass conservation equation we ensure stability
and avoid pressure oscillations. Importantly, the discretization leads to a
symmetric linear system. For the fully discretized problem we prove existence
and uniqueness, an energy estimate and an optimal a-priori error estimate,
including an error estimate for the divergence of the fluid flux. Numerical
experiments in 2D and 3D illustrate the convergence of the method, show the
effectiveness of the method to overcome spurious pressure oscillations, and
evaluate the added mass effect of the stabilization term.


title: Fields and Quantum Mechanics

abstract:
  The quantum field theories (QFT) constructed in [1,2] include phenomenology
of interest. The constructions approximate: scattering by $1/r$ and Yukawa
potentials in non-relativistic approximations; and the first contributing order
of the Feynman series for Compton scattering. To have a semi-norm, photon
states are constrained to transverse polarizations and for Compton scattering,
the constructed cross section deviates at large momentum exchanges from the
cross section prediction of the Feynman rules. Discussion includes the
incompatibility of canonical quantization with the constructed interacting
fields, and the role of interpretations of quantum mechanics in realizing QFT.


title: The length and time scales of water's glass transitions

abstract:
  Using a general model for the equilibrium dynamics of supercooled liquids, I
compute from molecular properties the emergent length and time scales that
govern the nonequilibrium relaxation behavior of amorphous ice prepared by
rapid cooling. Upon cooling, the liquid water falls out of equilibrium whereby
the temperature dependence of its relaxation time is predicted to change from
super-Arrhenius to Arrhenius. A consequence of this crossover is that the
location of the apparent glass transition temperature depends logarithmically
on cooling rate. Accompanying vitrification is the emergence of a dynamical
length-scale, the size of which depends on the cooling rate and varies between
angstroms and 10s of nanometers. While this protocol dependence clarifies a
number of previous experimental observations for amorphous ice, the arguments
are general and can be extended to other glass forming liquids.


title: Poisson convergence on the free Poisson algebra

abstract:
  Based on recent findings by Bourguin and Peccati, we give a fourth moment
type condition for an element of a free Poisson chaos of arbitrary order to
converge to a free (centered) Poisson distribution. We also show that free
Poisson chaos of order strictly greater than one do not contain any non-zero
free Poisson random variables. We are also able to give a sufficient and
necessary condition for an element of the first free Poisson chaos to have a
free Poisson distribution. Finally, depending on the parity of the considered
free Poisson chaos, we provide a general counterexample to the naive
universality of the semicircular Wigner chaos established by Deya and Nourdin
as well as a transfer principle between the Wigner and the free Poisson chaos.


title:
The statistical distribution of magnetic field strength in G-band bright
  points

abstract:
  G-band bright points are small-sized features characterized by high
photometric contrast. Theoretical investigations indicate that these features
have associated magnetic field strengths between 1-2 kG. Results from
observations instead lead to contradictory results, indicating magnetic fields
of only kG strength in some and including hG strengths in others. In order to
understand the differences between measurements reported in the literature, and
to reconcile them with results from theory, we analyze the distribution of
magnetic field strength of G-band bright features identified on synthetic
images of the solar photosphere, and its sensitivity to observational and
methodological effects. We investigate the dependence of magnetic field
strength distributions of G-band bright points identified in 3D
magnetohydrodynamic simulations on feature selection method, data sampling,
alignment and spatial resolution. The distribution of magnetic field strength
of G-band bright features shows two peaks, one at about 1.5 kG and one below 1
hG. The former corresponds to magnetic features,the second mostly to bright
granules. Peaks at several hG are obtained only on spatially degraded or
misalligned data. Simulations show that magnetic G-band bright points have
typically associated field strengths of few kG. Field strengths in the hG range
can result from observational effects, thus explaining the discrepancies
presented in the literature. Our results also indicate that outcomes from
spectro-polarimetric inversions with imposed unit filling-factor should be
employed with great caution.


title: A New Variable Step-size Zero-point Attracting Projection Algorithm

abstract:
  This paper proposes a new variable step-size (VSS) scheme for the recently
introduced zero-point attracting projection (ZAP) algorithm. The proposed
variable step-size ZAPs are based on the gradient of the estimated filter
coefficients sparseness that is approximated by the difference between the
sparseness measure of current filter coefficients and an averaged sparseness
measure. Simulation results demonstrate that the proposed approach provides
both faster convergence rate and better tracking ability than previous ones.


title: Median eigenvalues of bipartite graphs

abstract:
  For a graph $G$ of order $n$ and with eigenvalues
$\lambda_1\geqslant\cdots\geqslant\lambda_n$, the HL-index $R(G)$ is defined as
$R(G) ={\max}\left\{|\lambda_{\lfloor(n+1)/2\rfloor}|,
|\lambda_{\lceil(n+1)/2\rceil}|\right\}.$ We show that for every connected
bipartite graph $G$ with maximum degree $\Delta\geqslant3$,
$R(G)\leqslant\sqrt{\Delta-2}$ unless $G$ is the the incidence graph of a
projective plane of order $\Delta-1$. We also present an approach through graph
covering to construct infinite families of bipartite graphs with large
HL-index.


title: Effective bounds for Faltings's delta function

abstract:
  We obtain bounds for the Faltings's delta function for any Riemann surface of
genus greater than one. The bounds are in terms of the genus of the surface and
two basic quantities coming from hyperbolic geometry: The length of the
shortest closed geodesic, and the smallest non-zero eigenvalue of the Laplacian
which acts on smooth functions. In the case when the surface in question is a
finite degree cover of a fixed base surface, then bounds are given in terms of
the degree of the curve and data associated to the base surface.


title:
Electronic and magnetic properties of superconducting
  LnO$_{1-x}$F$_{x}$BiS$_{2}$ (Ln = La, Ce, Pr, and Nd) from first principles

abstract:
  A density functional theory study of the BiS$_{2}$ superconductors containing
rare-earths: \textit{Ln}O$_{1-x}$F$_{x}$BiS$_{2}$ (\textit{Ln} = La, Ce, Pr,
and Nd) is presented. We find that CeO$_{0.5}$F$_{0.5}$BiS$_{2}$ has competing
ferromagnetic and weak antiferromagnetic tendencies, the first one
corresponding to experimental results. We show that
PrO$_{0.5}$F$_{0.5}$BiS$_{2}$ has a strong tendency for magnetic order, which
can be ferromagnetic or antiferromagnetic depending on subtle differences in
4$f$ orbital occupations. We demonstrate that NdO$_{0.5}$F$_{0.5}$BiS$_{2}$ has
a stable magnetic ground state with weak tendency to order. Finally, we show
that the change of rare earth does not affect the Fermi surface, and predict
that CeOBiS$_{2}$ should display a pressure induced phase transition to a
metallic, if not superconducting, phase under pressure.


title:
A high statistics study of the beta-function in the SU(2) lattice
  thermodynamics

abstract:
  The beta-function is investigated on the lattice in SU(2) gluodynamics. It is
determined within a scaling hypothesis while a lattice size fixed to be taken
into account. The functions calculated are compared with the ones obtained in
the continuum limit. Graphics processing units (GPU) are used as a computing
platform that allows gathering a huge amount of statistical data. Numerous
beta-functions are analyzed for various lattices. The coincidence of the
lattice beta-function and the analytical expression in the region of the phase
transition is shown. New method for estimating a critical coupling value is
proposed.


title: Some Families of Polynomial Automorphisms III

abstract:
  We prove that the closure (for the Zariski topology) of the set of polynomial
automorphisms of the complex affine plane whose polydegree is (cd-1,b,a)
contains all triangular automorphisms of degree cd+a, where a,b >1 and c>0 are
integers and d=ab-1. When b=2, this result gives a family of counterexamples to
a conjecture of Furter.


title: Direct Detection with Dark Mediators

abstract:
  We introduce dark mediator Dark matter (dmDM) where the dark and visible
sectors are connected by at least one light mediator $\phi$ carrying the same
dark charge that stabilizes DM. $\phi$ is coupled to the Standard Model via an
operator $\bar q q \phi \phi^*/\Lambda$, and to dark matter via a Yukawa
coupling $y_\chi \overline{\chi^c}\chi \phi$. Direct detection is realized as
the $2\rightarrow3$ process $\chi N \rightarrow \bar \chi N \phi$ at tree-level
for $m_\phi \lesssim 10 \ \mathrm{keV}$ and small Yukawa coupling, or
alternatively as a loop-induced $2\rightarrow2$ process $\chi N \rightarrow
\chi N$. We explore the direct-detection consequences of this scenario and find
that a heavy $\mathcal{O}(100 \ \mathrm{GeV})$ dmDM candidate fakes different
$\mathcal{O}(10 \ \mathrm{GeV})$ standard WIMPs in different experiments. Large
portions of the dmDM parameter space are detectable above the irreducible
neutrino background and not yet excluded by any bounds. Interestingly, for the
$m_\phi$ range leading to novel direct detection phenomenology, dmDM is also a
form of Self-Interacting Dark Matter (SIDM), which resolves inconsistencies
between dwarf galaxy observations and numerical simulations.


title:
Kratzer's molecular potential in quantum mechanics with a generalized
  uncertainty principle

abstract:
  The Kratzer's potential $V(r)=g_{1}/r^{2}-g_{2}/r$ is studied in quantum
mechanics with a generalized uncertainty principle, which includes a minimal
length $\left( \Delta X\right) _{\min}=\hbar\sqrt{5\beta}$. In momentum
representation, the Schr\"{o}dinger equation is a generalized Heun's
differential equation, which reduces to a hypergeometric and to a Heun's
equations in special cases. We explicitly show that the presence of this finite
length regularizes the potential in the range of the coupling constant $g_{1}$
where the corresponding Hamiltonian is not self-adjoint. In coordinate space,
we perturbatively derive an analytical expression for the bound states spectrum
in the first order of the deformation parameter $\beta$. We qualitatively
discuss the effect of the minimal length on the vibration-rotation energy
levels of diatomic molecules, through the Kratzer interaction. By comparison
with an experimental result of the hydrogen molecule, an upper bound for the
minimal length is found to be of about $0.01$ \AA . We argue that the minimal
length would have some physical importance in studying the spectra of such
systems


title: Magnetic fields in cosmological simulations of disk galaxies

abstract:
  Observationally, magnetic fields reach equipartition with thermal energy and
cosmic rays in the interstellar medium of disk galaxies such as the Milky Way.
However, thus far cosmological simulations of the formation and evolution of
galaxies have usually neglected magnetic fields. We employ the moving-mesh code
\textsc{Arepo} to follow for the first time the formation and evolution of a
Milky Way-like disk galaxy in its full cosmological context while taking into
account magnetic fields. We find that a prescribed tiny magnetic seed field
grows exponentially by a small-scale dynamo until it saturates around $z=4$
with a magnetic energy of about $10\%$ of the kinetic energy in the center of
the galaxy's main progenitor halo. By $z=2$, a well-defined gaseous disk forms
in which the magnetic field is further amplified by differential rotation,
until it saturates at an average field strength of $\sim 6 \mug$ in the disk
plane. In this phase, the magnetic field is transformed from a chaotic
small-scale field to an ordered large-scale field coherent on scales comparable
to the disk radius. The final magnetic field strength, its radial profile and
the stellar structure of the disk compare well with observational data. A minor
merger temporarily increases the magnetic field strength by about a factor of
two, before it quickly decays back to its saturation value. Our results are
highly insensitive to the initial seed field strength and suggest that the
large-scale magnetic field in spiral galaxies can be explained as a result of
the cosmic structure formation process.


title:
Quantum statistics of light transmitted through an intracavity Rydberg
  medium

abstract:
  We theoretically investigate the quantum statistical properties of light
transmitted through an atomic medium with strong optical non-linearity induced
by Rydberg-Rydberg van der Waals interactions. In our setup, atoms are located
in a cavity and non-resonantly driven on a two-photon transition from their
ground state to a Rydberg level via an intermediate state by the combination of
the weak signal field and a strong control beam. To characterize the
transmitted light we compute the second-order correlation function
$g^{\left(2\right)}\left(\tau\right)$. The simulations we obtained on the
specific case of rubidium atoms suggest that the bunched or antibunched nature
of the outgoing beam can be chosen at will by appropriately tuning the physical
parameters.


title: Deterministic Chaos in Radioactive Decay

abstract:
  We examine the radioactive decay of iodine in terms of its Kolmogorov
entropy, observing a consistency with the presence of a regime of deterministic
chaos in the vacuum dynamics.


title:
Finite temperature one-point functions in non-diagonal integrable field
  theories: the sine-Gordon model

abstract:
  We study the finite-temperature expectation values of exponential fields in
the sine-Gordon model. Using finite-volume regularization, we give a
low-temperature expansion of such quantities in terms of the connected diagonal
matrix elements, for which we provide explicit formulas. For special values of
the exponent, computations by other methods are available and used to validate
our findings. Our results can also be interpreted as a further support for a
previous conjecture about the connection between finite- and infinite-volume
form factors valid up to terms exponentially decaying in the volume.


title:
Can one use Mueller-Navelet jets at LHC as a clean test of QCD
  resummation effects at high energy?

abstract:
  The measurement of azimuthal correlations of Mueller-Navelet jets is
generally considered as a decisive test to reveal the effect of BFKL dynamics
at hadron colliders. The first experimental study of these correlations at the
LHC has been recently performed by the CMS collaboration. We show that the
ratios of cosine moments of the azimuthal distribution are successfully
described within our next-to-leading logarithmic BFKL treatment. The whole set
of CMS data for the azimuthal correlations can also be consistently described
provided that one uses a larger renormalization/factorization scale than its
natural value.


title: A Distributed IP-Based Telecommunication System using SIP

abstract:
  Voice over Internet Protocol (VoIP) technologies are integral to modern
telecommunications because of their advanced features, flexibility, and
economic benefits. Internet Service Providers initially promoted these
technologies by providing low cost local and international calling. At present,
there is also a great deal of interest in using IP-based technologies to
replace traditional small and large office telephone systems that use
traditional PBXs (Private Branch eXchange). Unfortunately, the large majority
of the emerging VoIP based office telephone systems have followed the
centralized design of traditional public and private telephone systems in which
all the intelligence in the system is at the core, with quite expensive
hardware and software components and appropriate redundancy for adequate levels
of reliability. In this paper, it is argued that a centralized model for an
IP-based telecommunications system fails to exploit the full capabilities of
Internet-inspired communications and that, very simple, inexpensive, elegant
and flexible solutions are possible by deliberately avoiding the centralized
approach. This paper describes the design, philosophy and implementation of a
prototype for a fully distributed IP-based Telecommunication System (IPTS) that
provides the essential feature set for office and home telecommunications,
including IP-based long-distance and local calling, and with the support for
video as well as data and text. The prototype system was implemented with an
Internet-inspired distributed design using open source software, with
appropriate customizations and configurations.


title: Three-dimensional black holes and descendants

abstract:
  We determine the most general three-dimensional vacuum spacetime with a
negative cosmological constant containing a non-singular Killing horizon. We
show that the general solution with a spatially compact horizon possesses a
second commuting Killing field and deduce that it must be related to the BTZ
black hole (or its near-horizon geometry) by a diffeomorphism. We show there is
a general class of asymptotically AdS$_3$ extreme black holes with arbitrary
charges with respect to one of the asymptotic-symmetry Virasoro algebras and
vanishing charges with respect to the other. We interpret these as descendants
of the extreme BTZ black hole.


title:
Multipoint Volterra Series Interpolation and H2 Optimal Model Reduction
  of Bilinear Systems

abstract:
  In this paper, we focus on model reduction of large-scale bilinear systems.
The main contributions are threefold. First, we introduce a new framework for
interpolatory model reduction of bilinear systems. In contrast to the existing
methods where interpolation is forced on some of the leading subsystem transfer
functions, the new framework shows how to enforce multipoint interpolation of
the underlying Volterra series. Then, we show that the first-order conditions
for optimal H2 model reduction of bilinear systems require multivariate Hermite
interpolation in terms of the new Volterra series interpolation framework; and
thus we extend the interpolation-based first-order necessary conditions for H2
optimality of LTI systems to the bilinear case. Finally, we show that
multipoint interpolation on the truncated Volterra series representation of a
bilinear system leads to an asymptotically optimal approach to H2 optimal model
reduction, leading to an efficient model reduction algorithm. Several numerical
examples illustrate the effectiveness of the proposed approach.


title: DeltaTree: A Practical Locality-aware Concurrent Search Tree

abstract:
  As other fundamental programming abstractions in energy-efficient computing,
search trees are expected to support both high parallelism and data locality.
However, existing highly-concurrent search trees such as red-black trees and
AVL trees do not consider data locality while existing locality-aware search
trees such as those based on the van Emde Boas layout (vEB-based trees), poorly
support concurrent (update) operations.
  This paper presents DeltaTree, a practical locality-aware concurrent search
tree that combines both locality-optimisation techniques from vEB-based trees
and concurrency-optimisation techniques from non-blocking highly-concurrent
search trees. DeltaTree is a $k$-ary leaf-oriented tree of DeltaNodes in which
each DeltaNode is a size-fixed tree-container with the van Emde Boas layout.
The expected memory transfer costs of DeltaTree's Search, Insert, and Delete
operations are $O(\log_B N)$, where $N, B$ are the tree size and the unknown
memory block size in the ideal cache model, respectively. DeltaTree's Search
operation is wait-free, providing prioritised lanes for Search operations, the
dominant operation in search trees. Its Insert and {\em Delete} operations are
non-blocking to other Search, Insert, and Delete operations, but they may be
occasionally blocked by maintenance operations that are sometimes triggered to
keep DeltaTree in good shape. Our experimental evaluation using the latest
implementation of AVL, red-black, and speculation friendly trees from the
Synchrobench benchmark has shown that DeltaTree is up to 5 times faster than
all of the three concurrent search trees for searching operations and up to 1.6
times faster for update operations when the update contention is not too high.


title:
Sense, Model and Identify the Load Signatures of HVAC Systems in Metro
  Stations

abstract:
  The HVAC systems in subway stations are energy consuming giants, each of
which may consume over 10, 000 Kilowatts per day for cooling and ventilation.
To save energy for the HVAC systems, it is critically important to firstly know
the "load signatures" of the HVAC system, i.e., the quantity of heat imported
from the outdoor environments and by the passengers respectively in different
periods of a day, which will significantly benefit the design of control
policies. In this paper, we present a novel sensing and learning approach to
identify the load signature of the HVAC system in the subway stations. In
particular, sensors and smart meters were deployed to monitor the indoor,
outdoor temperatures, and the energy consumptions of the HVAC system in
real-time. The number of passengers was counted by the ticket checking system.
At the same time, the cooling supply provided by the HVAC system was inferred
via the energy consumption logs of the HVAC system. Since the indoor
temperature variations are driven by the difference of the loads and the
cooling supply, linear regression model was proposed for the load signature,
whose coefficients are derived via a proposed algorithm . We collected real
sensing data and energy log data from HaiDianHuangZhuang Subway station, which
is in line 4 of Beijing from the duration of July 2012 to Sept. 2012. The data
was used to evaluate the coefficients of the regression model. The experiment
results show typical variation signatures of the loads from the passengers and
from the outdoor environments respectively, which provide important contexts
for smart control policies.


title:
Geometric Aspects and Neutral Excitations in the Fractional Quantum Hall
  Effect

abstract:
  In this thesis, I will present studies on the collective modes of the
fractional quantum Hall states, which are bulk neutral excitations reflecting
the incompressibility that defines the topological nature of these states. It
was first pointed out by Haldane that the non-commutative geometry of the
fractional quantum Hall effects (FQHE) plays an important role in the
intra-Landau-level dynamics. The geometrical aspects of the FQHE will be
illustrated by calculating the linear response to a spatially varying
electromagnetic field, and by a numerical scheme for constructing model
wavefunctions for the neutral bulk excitations. Compared to early studies of
the magneto-roton modes with single mode approximation (SMA), the scheme
presented in this thesis is good not only in the long wavelength limit, but
also for large momenta where the neutral excitations evolve into
quasihole-quasiparticle pair. It is also shown that in the long wavelength
limit, the SMA scheme produces exact model wavefunctions describing a
quadrupole excitation. The same scheme can also extend to describe the neutral
fermion mode in the Moore-Read state, reflecting its non-Abelian nature.
  The numerically generated model wavefunctions are then identified with a
family of analytic wavefunctions that describe both the magneto-roton modes and
the neutral fermion modes. Like the ground state wavefunction of the Laughlin
and Moore-Read state, ...


title: Kernel representation approach to persistence of behavior

abstract:
  The optimal control problem of connecting any two trajectories in a behavior
B with maximal persistence of that behavior is put forth and a compact solution
is obtained for a general class of behaviors. The behavior B is understood in
the context of Willems's behavioral theory and its representation is given by
the kernel of some operator. In general the solution to the problem will not
lie in the same behavior and so a maximally persistent solution is defined as
one that will be as close as possible to the behavior. A vast number of
behaviors can be treated in this framework such as stationary solutions, limit
cycles etc. The problem is linked to the ideas of controllability presented by
Willems. It draws its roots from quasi-static transitions in thermodynamics and
bears connections to morphing theory. The problem has practical applications in
finite time thermodynamics, deployment of tensigrity structures and legged
locomotion.


title:
SEED: Public Energy and Environment Dataset for Optimizing HVAC
  Operation in Subway Stations

abstract:
  For sustainability and energy saving, the problem to optimize the control of
heating, ventilating, and air-conditioning (HVAC) systems has attracted great
attentions, but analyzing the signatures of thermal environments and HVAC
systems and the evaluation of the optimization policies has encountered
inefficiency and inconvenient problems due to the lack of public dataset. In
this paper, we present the Subway station Energy and Environment Dataset
(SEED), which was collected from a line of Beijing subway stations, providing
minute-resolution data regarding the environment dynamics (temperature,
humidity, CO2, etc.) working states and energy consumptions of the HVAC systems
(ventilators, refrigerators, pumps), and hour-resolution data of passenger
flows. We describe the sensor deployments and the HVAC systems for data
collection and for environment control, and also present initial investigation
for the energy disaggregation of HVAC system, the signatures of the thermal
load, cooling supply, and the passenger flow using the dataset.


title:
Interfacial mode coupling as the origin of the enhancement of Tc in FeSe
  films on SrTiO3

abstract:
  Single unit cell films of iron selenide (1UC FeSe) grown on SrTiO3 (STO)
substrates have recently shown superconducting energy gaps opening at
temperatures close to the boiling point of liquid nitrogen (77 K), a record for
iron-based superconductors. Towards understanding why Cooper pairs form at such
high temperatures, a primary question to address is the role, if any, of the
STO substrate. Here, we report high resolution angle resolved photoemission
spectroscopy (ARPES) results which reveal an unexpected and unique
characteristic of the 1UC FeSe/STO system: shake-off bands suggesting the
presence of bosonic modes, most likely oxygen optical phonons in STO, which
couple to the FeSe electrons with only small momentum transfer. Such coupling
has the unusual benefit of helping superconductivity in most channels,
including those mediated by spin fluctuations. Our calculations suggest such
coupling is responsible for raising the superconducting gap opening temperature
in 1UC FeSe/STO. This discovery suggests a pathway to engineer high temperature
superconductors.


title:
A New 2+1 Dimensional Gravity Solution Coupled to Non Linear
  Electrodynamics with a Cosmological Constant

abstract:
  A solution for the Einstein gravity coupled with non linear electrodynamics
is introduced in 2+1 dimensions. Especially, in the case with a non-vanishing
cosmological constant, we obtain a novel black hole solution. To find
fundamental characters of the solution, radial null rays in the space-time
described by the solution are investigated.


title:
First hard X-ray detection of the non-thermal emission around the Arches
  cluster: morphology and spectral studies with NuSTAR

abstract:
  The Arches cluster is a young, densely packed massive star cluster in our
Galaxy that shows a high level of star formation activity. The nature of the
extended non-thermal X-ray emission around the cluster remains unclear. The
observed bright Fe K_alpha line emission at 6.4 keV from material that is
neutral or in a low ionization state can be produced either by X-ray
photoionization or by cosmic-ray particle bombardment or both. In this paper we
report on the first detection of the extended emission around the Arches
cluster above 10 keV with the NuSTAR mission, and present results on its
morphology and spectrum. The spatial distribution of the hard X-ray emission is
found to be consistent with the broad region around the cluster where the 6.4
keV line is observed. The interpretation of the hard X-ray emission within the
context of the X-ray reflection model puts a strong constraint on the
luminosity of the possible illuminating hard X-ray source. The properties of
the observed emission are also in broad agreement with the low-energy
cosmic-ray proton excitation scenario.


title:
Free-running InGaAs single photon detector with 1 dark count per second
  at 10% efficiency

abstract:
  We present a free-running single photon detector for telecom wavelengths
based on a negative feedback avalanche photodiode (NFAD). A dark count rate as
low as 1 cps was obtained at a detection efficiency of 10%, with an afterpulse
probability of 2.2% for 20 {\mu}s of deadtime. This was achieved by using an
active hold-off circuit and cooling the NFAD with a free-piston stirling cooler
down to temperatures of -110${^o}$C. We integrated two detectors into a
practical, 625 MHz clocked quantum key distribution system. Stable, real-time
key distribution in presence of 30 dB channel loss was possible, yielding a
secret key rate of 350 bps.


title: The Throughput-Outage Tradeoff of Wireless One-Hop Caching Networks

abstract:
  We consider a wireless device-to-device (D2D) network where the nodes have
pre-cached information from a library of available files. Nodes request files
at random. If the requested file is not in the on-board cache, then it is
downloaded from some neighboring node via one-hop "local" communication. An
outage event occurs when a requested file is not found in the neighborhood of
the requesting node, or if the network admission control policy decides not to
serve the request. We characterize the optimal throughput-outage tradeoff in
terms of tight scaling laws for various regimes of the system parameters, when
both the number of nodes and the number of files in the library grow to
infinity. Our analysis is based on Gupta and Kumar {\em protocol model} for the
underlying D2D wireless network, widely used in the literature on capacity
scaling laws of wireless networks without caching. Our results show that the
combination of D2D spectrum reuse and caching at the user nodes yields a
per-user throughput independent of the number of users, for any fixed outage
probability in $(0,1)$. This implies that the D2D caching network is
"scalable": even though the number of users increases, each user achieves
constant throughput. This behavior is very different from the classical Gupta
and Kumar result on ad-hoc wireless networks, for which the per-user throughput
vanishes as the number of users increases. Furthermore, we show that the user
throughput is directly proportional to the fraction of cached information over
the whole file library size. Therefore, we can conclude that D2D caching
networks can turn "memory" into "bandwidth" (i.e., doubling the on-board cache
memory on the user devices yields a 100\% increase of the user throughout).


title: Vertex nomination schemes for membership prediction

abstract:
  Suppose that a graph is realized from a stochastic block model where one of
the blocks is of interest, but many or all of the vertices' block labels are
unobserved. The task is to order the vertices with unobserved block labels into
a ``nomination list'' such that, with high probability, vertices from the
interesting block are concentrated near the list's beginning. We propose
several vertex nomination schemes. Our basic - but principled - setting and
development yields a best nomination scheme (which is a Bayes-Optimal
analogue), and also a likelihood maximization nomination scheme that is
practical to implement when there are a thousand vertices, and which is
empirically near-optimal when the number of vertices is small enough to allow
comparison to the best nomination scheme. We then illustrate the robustness of
the likelihood maximization nomination scheme to the modeling challenges
inherent in real data, using examples which include a social network involving
human trafficking, the Enron Graph, a worm brain connectome and a political
blog network.


title:
Charge-orbital-lattice coupling effects in the dd-excitation profile of
  one dimensional cuprates

abstract:
  We identify dd-excitations in the quasi-one dimensional compound
Ca$_2$Y$_2$Cu$_5$O$_{10}$ using resonant inelastic x-ray scattering. By tuning
across the Cu L$_3$-edge, we observe abrupt shifts in the dd-peak positions as
a function of incident photon energy. This observation demonstrates
orbital-specific coupling of the high-energy excited states of the system to
the low-energy degrees of freedom. A Franck-Condon treatment of
electron-lattice coupling, consistent with other measurements in this compound,
reproduces these shifts, explains the Gaussian lineshapes, and highlights
charge-orbital-lattice renormalization in the high energy d-manifold.


title: Kaon Condensation in Neutron Stars with Skyrme-Hartree-Fock Models

abstract:
  We investigate nuclear matter equations of state in neutron star with kaon
condensation. It is generally known that the existence of kaons in neutron star
makes the equation of state soft so that the maximum mass of neutron star is
not likely to be greater than 2.0 $M_{\odot}$, the maximum mass constrained by
current observations. With existing Skyrme force model parameters, we calculate
nuclear equations of state and check the possibility of kaon condensation in
the core of neutron stars. The results show that even with the kaon
condensation, the nuclear equation of state satisfies both the maximum mass and
the allowed ranges of mass and radius.


title: Simultaneous auctions for complementary goods

abstract:
  This paper studies an environment of simultaneous, separate, first-price
auctions for complementary goods. Agents observe private values of each good
before making bids, and the complementarity between goods is explicitly
incorporated in their utility. For simplicity, a model is presented with two
first-price auctions and two bidders. We show that a monotone pure-strategy
Bayesian Nash Equilibrium exists in the environment.


title:
Cellular Automata based Feedback Mechanism in Strengthening biological
  Sequence Analysis Approach to Robotic Soccer

abstract:
  This paper reports on the application of sequence analysis algorithms for
agents in robotic soccer and a suitable representation is proposed to achieve
this mapping. The objective of this research is to generate novel better
in-game strategies with the aim of faster adaptation to the changing
environment. A homogeneous non-communicating multi-agent architecture using the
representation is presented. To achieve real-time learning during a game, a
bucket brigade algorithm is used to reinforce Cellular Automata Based
Classifier. A technique for selecting strategies based on sequence analysis is
adopted.


title:
Symmetry-protected topological order and negative-sign problem for SO(N)
  bilinear-biquadratic chains

abstract:
  Using a generalized Jordan-Wigner transformation combined with the defining
representation of the SO(N) spin, we map the SO(N) bilinear-biquadratic(BLBQ)
spin chain into the N-color bosonic particle model. We find that, when the
Jordan-Wigner transformation disentangles the symmetry-protected topological
entanglement, this bosonic model becomes negative-sign free in the context of
quantum Monte-Carlo simulation. For the SO(3) case, moreover, the
Kennedy-Tasaki transformation for the S=1 BLBQ chain, which is also a
topological disentangler, derives the same bosonic model through the dimer-R
bases. We present the temperature dependence of the energy, entropy and string
order parameter for the SO(N=3, 4, 5) BLBQ chains by a world-line Monte-Carlo
simulation for the N-color bosonic particle model.


title:
Two-way deterministic quantum key distribution against detector side
  channel attacks

abstract:
  In a two-way deterministic quantum key distribution (DQKD) protocol, Bob
randomly prepares qubits in one of four states and sends them to Alice. To
encode a bit, Alice performs an operation on each received qubit and returns it
to Bob. Bob then measures the backward qubits to learn about Alice's operations
and hence the key bits. Recently, we proved the unconditional security of the
final key of this protocol in the ideal device setting. In this paper, we prove
that two-way DQKD protocols are immune to all detector side channel attacks at
Bob's side, while we assume ideal detectors at Alice's side for error testing.
Our result represents a step forward in making DQKD protocols secure against
general detector side channel attacks.


title: Subsampling bootstrap of count features of networks

abstract:
  Analysis of stochastic models of networks is quite important in light of the
huge influx of network data in social, information and bio sciences, but a
proper statistical analysis of features of different stochastic models of
networks is still underway. We propose bootstrap subsampling methods for
finding empirical distribution of count features or ``moments'' (Bickel, Chen
and Levina [Ann. Statist. 39 (2011) 2280-2301]) and smooth functions of these
features for the networks. Using these methods, we cannot only estimate the
variance of count features but also get good estimates of such feature counts,
which are usually expensive to compute numerically in large networks. In our
paper, we prove theoretical properties of the bootstrap estimates of variance
of the count features as well as show their efficacy through simulation. We
also use the method on some real network data for estimation of variance and
expectation of some count features.


title: Guaranteed Model Order Estimation and Sample Complexity Bounds for LDA

abstract:
  The question of how to determine the number of independent latent factors
(topics) in mixture models such as Latent Dirichlet Allocation (LDA) is of
great practical importance. In most applications, the exact number of topics is
unknown, and depends on the application and the size of the data set. Bayesian
nonparametric methods can avoid the problem of topic number selection, but they
can be impracticably slow for large sample sizes and are subject to local
optima. We develop a guaranteed procedure for topic number recovery that does
not necessitate learning the model's latent parameters beforehand. Our
procedure relies on adapting results from random matrix theory. Performance of
our topic number recovery procedure is superior to hLDA, a nonparametric
method. We also discuss some implications of our results on the sample
complexity and accuracy of popular spectral learning algorithms for LDA. Our
results and procedure can be extended to spectral learning algorithms for other
exchangeable mixture models as well as Hidden Markov Models.


title: Localization of $q-$form fields on $AdS_{p+1}$ branes

abstract:
  In this paper, we investigate localization of a free massless $q-$form bulk
field on thin and thick $AdS_{p+1}$ branes with codimension one. It is found
that the zero mode of the $q-$form field with $q>(p+2)/2$ can be localized on
the thin negative tension brane, which is different from the flat brane case
given in [JHEP 10 (2012) 060]. For the thick $AdS_{p+1}$ branes, the $q-$form
field with $q>(p+2)/2$ also has a localized zero mode under some conditions.
Furthermore, we find that there are massive bound KK modes of the $q-$form
field, which are localized on this type $p-$branes.


title:
Vacuum pair production of charged scalar bosons in time-dependent
  electric fields

abstract:
  Based on the quantum mechanical scattering model, the dynamical assist effect
and the multiple-slit interference effect in electron-positron pair production
from vacuum are generalized to vacuum pair production of charged scalar bosons.
For the former effect some combinations of a strong but slowly varying electric
field and a weak but rapidly varying one with different time delay are studied.
Results indicate that the oscillation intensity of momentum spectrum and the
number density of created bosons reduce with increasing of the time delay.
Obviously, they achieve the maximum if the time delay equals zero. For the
latter effect, it is shown that this effect does not exist for equal-sign
$N$-pulse electric field in contrast to its existence for alternating-sign
$N$-pulse. An approximate solution of boson momentum spectrum is got and it is
agreeable well with the exact numerical one in alternating-sign $N$-pulse
electric field, especially for $2$-pulse field and for small longitudinal
momentum. The difference of vacuum pair production between bosons and fermions
are also compared for their longitudinal momentum spectra.


title: Permutation groups generated by binomials

abstract:
  Let G(q) be the group of permutations of the finite field F_q which is
generated by those permutations that can be written as c-->ac^m+bc^n with
0<m<n<q and a,b in F_q with ab nonzero. We show that there are infinitely many
q for which G(q) is the group of all permutations of F_q which fix 0. This
resolves a conjecture of Vasilyev and Rybalkin.


title:
Author Impact Factor: tracking the dynamics of individual scientific
  impact

abstract:
  The impact factor (IF) of scientific journals has acquired a major role in
the evaluations of the output of scholars, departments and whole institutions.
Typically papers appearing in journals with large values of the IF receive a
high weight in such evaluations. However, at the end of the day one is
interested in assessing the impact of individuals, rather than papers. Here we
introduce Author Impact Factor (AIF), which is the extension of the IF to
authors. The AIF of an author A in year $t$ is the average number of citations
given by papers published in year $t$ to papers published by A in a period of
$\Delta t$ years before year $t$. Due to its intrinsic dynamic character, AIF
is capable to capture trends and variations of the impact of the scientific
output of scholars in time, unlike the $h$-index, which is a growing measure
taking into account the whole career path.


title:
Sequences of Periodic Solutions and Infinitely Many Coexisting
  Attractors in the Border-Collision Normal Form

abstract:
  The border-collision normal form is a piecewise-linear continuous map on
$\mathbb{R}^N$ that describes dynamics near border-collision bifurcations of
nonsmooth maps. This paper studies a codimension-three scenario at which the
border-collision normal form with $N=2$ exhibits infinitely many attracting
periodic solutions. In this scenario there is a saddle-type periodic solution
with branches of stable and unstable manifolds that are coincident, and an
infinite sequence of attracting periodic solutions that converges to an orbit
homoclinic to the saddle-type solution. Several important features of the
scenario are shown to be universal, and three examples are given. For one of
these examples infinite coexistence is proved directly by explicitly computing
periodic solutions in the infinite sequence.


title:
The $Z_b(10610)$ and $Z_b(10650)$ as axial-vector tetraquark states in
  the QCD sum rules

abstract:
  In this article, we study the axial-vector mesons $Z_b(10610)$ and
$Z_b(10650)$ with the $C\gamma_\mu-C\gamma_5$ type and
$C\gamma_\mu-C\gamma_\nu$ type interpolating currents respectively by carrying
out the operator product expansion to the vacuum condensates up to
dimension-10. In calculations, we explore the energy scale dependence of the
QCD spectral densities of the hidden bottom tetraquark states in details for
the first time, and suggest a formula
$\mu=\sqrt{M^2_{X/Y/Z}-(2{\mathbb{M}}_b)^2}$ with the effective mass
${\mathbb{M}}_b=5.13\,\rm{GeV}$ to determine the energy scales. The numerical
results favor assigning the $Z_b(10610)$ and $Z_b(10650)$ as the
$C\gamma_\mu-C\gamma_5$ type and $C\gamma_\mu-C\gamma_\nu$ type hidden bottom
tetraquark states, respectively. We obtain the mass of the $J^{PC}=1^{++}$
hidden bottom tetraquark state as a byproduct, which can be compared to the
experimental data in the futures. Furthermore, we study the strong decays
$Z_b^\pm(10610)\to\Upsilon\pi^{\pm}\, ,\,\eta_b\rho^{\pm}$ with the three-point
QCD sum rules, the decay widths also support assigning the $Z_b(10610)$ as the
$C\gamma_\mu-C\gamma_5$ type hidden bottom tetraquark state.


title:
Finite size analysis of zero-temperature jamming transition under
  applied shear stress

abstract:
  By finding local minima of an enthalpy-like energy, we can generate jammed
packings of frictionless spheres under constant shear stress $\sigma$ and
obtain the yield stress $\sigma_y$ by sampling the potential energy landscape.
For three-dimensional systems with harmonic repulsion, $\sigma_y$ satisfies the
finite size scaling with the limiting scaling relation $\sigma_y\sim\phi -
\phi_{_{c,\infty}}$, where $\phi_{_{c,\infty}}$ is the critical volume fraction
of the jamming transition at $\sigma=0$ in the thermodynamic limit. The width
or uncertainty of the yield stress decreases with decreasing $\phi$ and decays
to zero in the thermodynamic limit. The finite size scaling implies a length
$\xi\sim (\phi-\phi_{_{c,\infty}})^{-\nu}$ with $\nu=0.81\pm 0.05$, which turns
out to be a robust and universal length scale exhibited as well in the finite
size scaling of multiple quantities measured without shear and independent of
particle interaction. Moreover, comparison between our new approach and
quasi-static shear reveals that quasi-static shear tends to explore low-energy
states.


title: The dynamic X-ray nebula powered by the pulsar B1259-63

abstract:
  We present observations of the eccentric gamma-ray binary B1259-63/LS2883
with the Chandra X-ray Observatory. The images reveal a variable, extended
about 4'', or about 1000 times the binary orbit size) structure, which appears
to be moving away from the binary with the velocity of 0.05 of the speed of
light. The observed emission is interpreted as synchrotron radiation from
relativistic particles supplied by the pulsar. However, the fast motion through
the circumbinary medium would require the emitting cloud to be loaded with a
large amount of baryonic matter. Alternatively, the extended emission can be
interpreted as a variable extrabinary shock in the pulsar wind outflow launched
near binary apastron. The resolved variable X-ray nebula provides an
opportunity to probe pulsar winds and their interaction with stellar winds in a
previously inaccessible way.


title:
The Kernel Unipotent Conjecture and the vanishing of Massey products for
  odd rigid fields

abstract:
  A major difficult problem in Galois theory is the characterization of
profinite groups which are realizable as absolute Galois groups of fields.
Recently the Kernel $n$-Unipotent Conjecture and the Vanishing $n$-Massey
Conjecture for $n\geq 3$ were formulated. These conjectures evolved in the last
forty years as a byproduct of the application of topological methods to Galois
cohomology. We show that both of these conjectures are true for odd rigid
fields. This is the first case of a significant family of fields where both of
the conjectures are verified besides fields whose Galois groups of $p$-maximal
extensions are free pro-$p$-groups. We also prove the Kernel Unipotent
Conjecture for Demushkin groups of rank 2, and establish a number of further
related results.


title: Causality in Classical Physics

abstract:
  Classical physics encompasses the study of physical phenomena which ranges
from local (a point) to nonlocal (a region) in space and/or time. We discuss
the concept of spatial and temporal nonlocality. However, one of the likely
implications pertaining to nonlocality is non-causality. We study causality in
the context of phenomena involving nonlocality. An appropriate domain of space
and time which preserves causality is identified.


title:
Reflectionless design of optical elements using impedance-tunable
  coordinate transformation

abstract:
  We report a new strategy to remove the reflections resulted from the finite
embedded transformation-optical design by proposing an impedance-tunable
coordinate transformation, on which the functions of impedance coefficients can
be derived in the original space without changing the refractive index. Based
on the new approach, two-dimensional (2D) reflectionless beam
compressors/expanders, bends, shifters and splitters are designed using the
modified anisotropic medium. It is found that the reflections can be removed in
magnetic response materials for TE polarization or dielectric response
materials for TM polarization. The numerical simulations confirm that various
reflectionless optical elements can be realized in the pure transformation
optics. The impedance-tunable coordinate transformation can be generalized to
three-dimensional (3D) cases and be applied to other transformation-optical
designs.


title:
The Study about the Analysis of Responsiveness Pair Clustering to Social
  Network Bipartite Graph

abstract:
  In this study, regional (cities, towns and villages) data and tweet data are
obtained from Twitter, and extract information of purchase information (Where
and what bought) from the tweet data by morphological analysis and rule-based
dependency analysis. Then, the "The regional information" and "The information
of purchase history (Where and what bought information)" are captured as
bipartite graph, and Responsiveness Pair Clustering analysis (a clustering
using correspondence analysis as similarity measure) is conducted. In this
study, since it was found to be difficult to analyze a network such as
bipartite graph having limitations in links by using modularity Q,
responsiveness is used instead of modularity Q as similarity measure. As a
result of this analysis, "regional information cluster" which refers to similar
"The information of purchase history" nodes group is generated. Finally,
similar regions are visualized by mapping the regional information cluster on
the map. This visualization system is expected to contribute as an analytical
tool for customers purchasing behavior and so on.


title:
Synchronization of Coupled Stochastic Systems Driven by Non-Gaussian
  L\'evy Noises

abstract:
  We consider the synchronization of the solutions to coupled stochastic
systems of $N$-stochastic ordinary differential equations (SODEs) driven by
Non-Gaussian L\'evy noises ($N\in \mathbb{N})$. We discuss the synchronization
between two solutions and among different components of solutions under certain
dissipative and integrability conditions. Our results generalize the present
work obtained in Liu et al (2010) and Shen et al (2010).


title:
Thermodynamic Study of Nodal Structure and Multiband Superconductivity
  of KFe2As2

abstract:
  The temperature, field, and field-orientation dependences of the electronic
specific heat Ce of the ironpnictide superconductor KFe2As2 have been
investigated. Thermodynamic evidence of the presence of line nodes is obtained
from the T and $\sqrt{H}$ linear dependences of Ce/T in the low-T and low-H
region. Under a magnetic field rotated within the tetragonal ab plane, a
fourfold oscillation is observed in Ce with a sign change at 0.08Tc. On the
basis of the Doppler-shift analysis, the observed Ce minima in H // [100] at
low T indicate the presence of line nodes somewhere on the Fermi surface where
the Fermi velocity is parallel to the [100] direction; this is consistent with
the octet-line-node scenario proposed recently by a photoemission experiment.
In addition, the low-T Ce/T exhibits an unusual upturn on cooling at moderate
fields only for H // ab, which is understood in terms of the strong Pauli
paramagnetic effect on multiband superconductivity.


title:
Random Attractor For Stochastic Lattice FitzHugh-Nagumo System Driven By
  $\alpha$-stable L\'evy Noises

abstract:
  The present paper is devoted to the existence of a random attractor for
stochastic lattice FitzHugh-Nagumo system driven by $\alpha$-stable L\'evy
noises under some dissipative conditions.


title:
High energy emission of GRB 130821A: constraining the density profile of
  the circum-burst medium as well as the initial Lorentz factor of the outflow

abstract:
  GRB 130821A was detected by Fermi-GBM/LAT, Konus-Wind, SPI-ACS/INTEGRAL,
RHESSI and Mars Odyssey-HEND. Although the data of GRB 130821A are very
limited, we show in this work that the high energy gamma-ray emission (i.e.,
above 100 MeV) alone imposes tight constraint on the density profile of the
circum-burst medium as well as the initial Lorentz factor of the outflow. The
temporal behavior of the high energy gamma-ray emission is consistent with the
forward shock synchrotron radiation model and the circum-burst medium likely
has a constant-density profile. The Lorentz factor is about a few hundred,
similar to other bright GRBs.


title:
Non-Conflicting Ordering Cones and Vector Optimization in Inductive
  Limits

abstract:
  Let $(E,\xi)={\rm ind}(E_n, \xi_n)$ be an inductive limit of a sequence
$(E_n, \xi_n)_{n\in N}$ of locally convex spaces and let every step $(E_n,
\xi_n)$ be endowed with a partial order by a pointed convex (solid) cone $S_n$.
In the framework of inductive limits of partially ordered locally convex
spaces, the notions of lastingly efficient points, lastingly weakly efficient
points and lastingly globally properly efficient points are introduced. For
several ordering cones, the notion of non-conflict is introduced. Under the
requirement that the sequence $(S_n)_{n\in N}$ of ordering cones is
non-conflicting, an existence theorem on lastingly weakly efficient points is
presented. From this, an existence theorem on lastingly globally properly
efficient points is deduced.


title: Parallel family trees for transfer matrices in the Potts model

abstract:
  The computational cost of transfer matrix methods for the Potts model is
directly related to the problem of \textit{into how many ways can two adjacent
blocks of a lattice be connected}. Answering this question leads to the
generation of a combinatorial set of lattice configurations. This set defines
the \textit{configuration space} of the problem, and the smaller it is, the
faster the transfer matrix method can be. The configuration space of generic
transfer matrix methods for strip lattices in the Potts model is in the order
of the Catalan numbers, leading to an asymptotic cost of $O(4^m)$ with $m$
being the width of the strip. Transfer matrix methods with a smaller
configuration space indeed exist but they make assumptions on the temperature,
number of spin states, or restrict the topology of the lattice in order to
work. In this paper we propose a general and parallel transfer matrix method,
based on family trees, that uses a sub-Catalan configuration space of size
$O(3^m)$. The improvement is achieved by grouping the original set of Catalan
configurations into a forest of family trees, in such a way that the solution
to the problem is now computed by just solving the root node of each family. As
a result, the algorithm becomes exponentially faster and highly parallel. An
additional advantage is that the final matrix ends up being compressed, not
only saving space but also making numerical evaluation on $(q,v)$ faster than
in a non-compressed scenario. Experimental results for different sizes of strip
lattices show that the \textit{Parallel family trees (PFT)} strategy indeed
runs exponentially faster than the \textit{Catalan Parallel Method (CPM)},
specially when dealing with dense transfer matrices. We can confirm that a
parallel implementation of the PFT algorithm is highly effective and efficient
for large problem sizes...


title:
Comparative quantum and semi-classical analysis of Atom-Field Systems I:
  density of states and excited-state quantum phase transitions

abstract:
  We study the non-integrable Dicke model, and its integrable approximation,
the Tavis-Cummings model, as functions of both the coupling constant and the
excitation energy. Excited-state quantum phase transitions (ESQPT) are found
analyzing the density of states in the semi-classical limit and comparing it
with numerical results for the quantum case in large Hilbert spaces, taking
advantage of efficient methods recently developed. Two different ESQPTs are
identified in both models, which are signaled as singularities in the
semi-classical density of states, one {\em static} ESQPT occurs for any
coupling, whereas a dynamic ESQPT is observed only in the superradiant phase.
The role of the unstable fixed points of the Hamiltonian semi-classical flux in
the occurrence of the ESQPTs is discussed and determined. Numerical evidence is
provided that shows that the semi-classical result describes very well the
tendency of the quantum energy spectrum for any coupling in both models.
Therefore the semi-classical density of states can be used to study the
statistical properties of the fluctuation in the spectra, a study that is
presented in a companion paper.


title: Genus bounds for min-max minimal surfaces

abstract:
  We prove optimal genus bounds for minimal surfaces arising from the min-max
construction of Simon-Smith. This confirms a conjecture made by
Pitts-Rubinstein in 1986.


title:
Valley-dependent resonant tunneling through double magnetic barriers in
  suspended graphene

abstract:
  We theoretically investigate the effects of strain-induced pseudomagnetic
fields on the transmission probability and the ballistic conductance for Dirac
fermion transport in suspended graphene. We show that resonant tunneling
through double magnetic barriers can be tuned by strain in the suspended
region. The valley-resolved transmission peaks are apparently distinguishable
owing to the sharpness of the resonant tunneling. With the specific strain, the
resonant tunneling is completely suppressed for Dirac fermions occupying the
one valley, but the resonant tunneling exists for the other valley. The
valley-filtering effect is expected to be measurable by strain engineering. The
proposed system can be used to fabricate a graphene valley filter with the
large valley polarization almost 100%.


title:
Optimal compression in natural gas networks: a geometric programming
  approach

abstract:
  Natural gas transmission pipelines are complex systems whose flow
characteristics are governed by challenging non-linear physical behavior. These
pipelines extend over hundreds and even thousands of miles. Gas is typically
injected into the system at a constant rate, and a series of compressors are
distributed along the pipeline to boost the gas pressure to maintain system
pressure and throughput. These compressors consume a portion of the gas, and
one goal of the operator is to control the compressor operation to minimize
this consumption while satisfying pressure constraints at the gas load points.
The optimization of these operations is computationally challenging. Many
pipelines simply rely on the intuition and prior experience of operators to
make these decisions. Here, we present a new geometric programming approach for
optimizing compressor operation in natural gas pipelines. Using models of real
natural gas pipelines, we show that the geometric programming algorithm
consistently outperforms approaches that mimic existing state of practice.


title:
DRSP : Dimension Reduction For Similarity Matching And Pruning Of Time
  Series Data Streams

abstract:
  Similarity matching and join of time series data streams has gained a lot of
relevance in today's world that has large streaming data. This process finds
wide scale application in the areas of location tracking, sensor networks,
object positioning and monitoring to name a few. However, as the size of the
data stream increases, the cost involved to retain all the data in order to aid
the process of similarity matching also increases. We develop a novel framework
to addresses the following objectives. Firstly, Dimension reduction is
performed in the preprocessing stage, where large stream data is segmented and
reduced into a compact representation such that it retains all the crucial
information by a technique called Multi-level Segment Means (MSM). This reduces
the space complexity associated with the storage of large time-series data
streams. Secondly, it incorporates effective Similarity Matching technique to
analyze if the new data objects are symmetric to the existing data stream. And
finally, the Pruning Technique that filters out the pseudo data object pairs
and join only the relevant pairs. The computational cost for MSM is O(l*ni) and
the cost for pruning is O(DRF*wsize*d), where DRF is the Dimension Reduction
Factor. We have performed exhaustive experimental trials to show that the
proposed framework is both efficient and competent in comparison with earlier
works.


title: Tracking quintessence: a dynamical systems study

abstract:
  With the tracking condition, the stability of quintessence solutions are
examined. It is found that there is only one physically relevant fixed point
for the system generically. Two specific examples of quintessence potentials
are worked out in the frame work.


title: Gauge symmetries in 2D field theory

abstract:
  A simple algorithm is proposed for constructing generators of gauge symmetry
as well as reducibility relations for arbitrary systems of field equations in
two dimensions.


title:
Comparative quantum and semi-classical analysis of Atom-Field Systems
  II: Chaos and regularity

abstract:
  The non-integrable Dicke model and its integrable approximation, the
Tavis-Cummings (TC) model, are studied as functions of both the coupling
constant and the excitation energy. The present contribution extends the
analysis presented in the previous paper by focusing on the statistical
properties of the quantum fluctuations in the energy spectrum and their
relation with the excited state quantum phase transitions (ESQPT). These
properties are compared with the dynamics observed in the semi-classical
versions of the models. The presence of chaos for different energies and
coupling constants is exhibited, employing Poincar\'e sections and Peres
lattices in the classical and quantum versions, respectively. A clear
correspondence between the classical and quantum result is found for systems
containing between $\mathcal{N} = 80$ to $200$ atoms. A measure of the Wigner
character of the energy spectrum for different couplings and energy intervals
is also presented employing the statistical Anderson-Darling test. It is found
that in the Dicke Model, for any coupling, a low energy regime with regular
states is always present. The richness of the onset of chaos is discussed both
for finite quantum systems and for the semi-classical limit, which is exact
when the number of atoms in the system tends to infinite.


title:
Stable sheaves with twisted sections and the Vafa-Witten equations on
  smooth projective surfaces

abstract:
  This article describes a Hitchin-Kobayashi style correspondence for the
Vafa-Witten equations on smooth projective surfaces. This is an equivalence
between a suitable notion of stability for a pair $(\mathcal{E}, \varphi)$,
where $\mathcal{E}$ is a locally-free sheaf over a surface $X$ and $\varphi$ is
a section of $\text{End} (\mathcal{E}) \otimes K_{X}$; and the existence of a
solution to certain gauge-theoretic equations, the Vafa-Witten equations, for a
Hermitian metric on $\mathcal{E}$. It turns out to be a special case of results
obtained by Alvarez-Consul and Garcia-Prada. In this article, we give an
alternative proof which uses a Mehta-Ramanathan style argument originally
developed by Donaldson for the Hermitian-Einstein problem, as it relates the
subject with the Hitchin equations on Riemann surfaces, and surely indicates a
similar proof of the existence of a solution under the assumption of stability
for the Donaldson-Thomas instanton equations described in arXiv:0805.2192 on
smooth projective threefolds; and more broadly that for the quiver vortex
equation on higher dimensional smooth projective varieties.