title:
Measurement with the ATLAS detector of multi-particle azimuthal
  correlations in p+Pb collisions at sqrt(s_NN)=5.02 TeV

abstract:
  In order to study further the long-range correlations ("ridge") observed
recently in p+Pb collisions at sqrt(s_NN) =5.02 TeV, the second-order azimuthal
anisotropy parameter of charged particles, v_2, has been measured with the
cumulant method using the ATLAS detector at the LHC. In a data sample
corresponding to an integrated luminosity of approximately 1 microb^(-1), the
parameter v_2 has been obtained using two- and four-particle cumulants over the
pseudorapidity range |eta|<2.5. The results are presented as a function of
transverse momentum and the event activity, defined in terms of the transverse
energy summed over 3.1<eta<4.9 in the direction of the Pb beam. They show
features characteristic of collective anisotropic flow, similar to that
observed in Pb+Pb collisions. A comparison is made to results obtained using
two-particle correlation methods, and to predictions from hydrodynamic models
of p+Pb collisions. Despite the small transverse spatial extent of the p+Pb
collision system, the large magnitude of v_2 and its similarity to hydrodynamic
predictions provide additional evidence for the importance of final-state
effects in p+Pb reactions.


title: Hierarchy depth in directed networks

abstract:
  We explore depth measures for flow hierarchy in directed networks. We define
two measures -- rooted depth and relative depth, and discuss differences
between them. We investigate how the two measures behave in random Erdos-Renyi
graphs of different sizes and densities and explain obtained results.


title:
Landau confining replica model from an explicitly breaking of a SU(3)
  group without auxiliary fields

abstract:
  We propose a mechanism displaying gluon confinement, as defined by the
behavior of the propagators, in a model of SU(2) gauge fields. The model
originates from an explicitly broken SU(3) gauge theory giving rise to a
replica model composed of three mixed SU(2) groups. The mechanism consists in
the usual SU(3) Yang-Mills theory in the Landau gauge, with a soft breaking
term in such a way as to change the field propagation and group content at low
energies. The relation of this soft mass term with the Gribov problem is
presented and the link between soft terms and the scaling and decoupling
solutions is discussed.


title:
Capacity Bounds and Sum Rate Capacities of a CLass of Discrete
  Memoryless Interference Channels

abstract:
  This paper studies the capacity of a class of discrete memoryless
interference channels where interference is defined analogous to that of
Gaussian interference channel with one-sided weak interference. The sum-rate
capacity of this class of channels is determined. As with the Gaussian case,
the sum-rate capacity is achieved by letting the transceiver pair subject to
interference communicate at a rate such that its message can be decoded at the
unintended receiver using single user detection. It is also established that
this class of discrete memoryless interference channels is equivalent in
capacity region to certain degraded interference channels. This allows the
construction of capacity outer-bounds using the capacity regions of associated
degraded broadcast channels. The same technique is then used to determine the
sum-rate capacity of discrete memoryless interference channels with mixed
interference as defined in the paper. The obtained capacity bounds and sum-rate
capacities are used to resolve the capacities of several new discrete
memoryless interference channels.


title: Plasmons Driven by Single Electrons in Graphene Nanoislands

abstract:
  Plasmons produce large confinement and enhancement of light that enable
applications as varied as cancer therapy and catalysis. Adding to these
appealing properties, graphene has emerged as a robust, electrically tunable
material exhibiting plasmons that strongly depend on the density of doping
charges. Here we show that adding a single electron to a graphene nanoisland
consisting of hundreds or thousands of atoms switches on infrared plasmons that
were previously absent from the uncharged structure. Remarkably, the addition
of each further electron produces a dramatic frequency shift. Plasmons in these
islands are shown to be tunable down to near infrared wavelengths. These
phenomena are highly sensitive to carbon edges. Specifically, armchair
nanotriangles display sharp plasmons that are associated with intense
near-field enhancement, as well as absorption cross-sections exceeding the
geometrical area occupied by the graphene. In contrast, zigzag triangles do not
support these plasmons. Our conclusions rely on realistic quantum-mechanical
calculations, which are in ostensible disagreement with classical
electromagnetic simulations, thus revealing the quantum nature of the plasmons.
This study shows a high sensitivity of graphene nanoislands to elementary
charges, therefore emphasizing their great potential for novel
nano-optoelectronics applications.


title: Quantum Junction Plasmons in Graphene Dimers

abstract:
  The interaction between doped graphene nanoislands connected by narrow
junctions constitutes an ideal testbed to probe quantum effects in plasmonic
systems. Here, the interaction between graphene plasmons in neighboring
nanoislands is predicted to be extremely sensitive to the size and shape of the
junctions. The reported {\it ab initio} calculations reveal three different
regimes of interaction: (1) for narrow bridges ($<4$ carbon-atom rows), the
conductance of the junction is too low to allow electron transport and the
optical response is dominated by a characteristic bonding dipolar dimer mode
that also appears in a classical description; (2) for wider junctions (4-8
carbon rows), a strong charge polarization is induced across the junction,
which gives rise to a novel {\it junction plasmon} that has no counterpart in a
classical description; (3) for even wider junctions ($\ge8$ rows), their
conductance is sufficiently large to allow charge transport between the two
graphene islands, resulting in a pronounced charge-transfer plasmon, which can
also be described classically. This work opens a new path for the investigation
of intrinsic plasmon quantum effects.


title:
A generalization of the Lax pair for the pure spinor superstring in AdS5
  x S5

abstract:
  We show that the Lax pair of the pure spinor superstring in AdS5xS5 admits a
generalization where the generators of the superconformal algebra are replaced
by the generators of some infinite-dimensional Lie superalgebra.


title: Fermi LAT gamma-ray observations of the supernova remnant HB21

abstract:
  We present the analysis of Fermi Large Area Telescope (LAT) {\gamma}-ray
observations of HB 21, a mixed-morphology supernova remnant. Such supernova
remnants are characterized by an interior thermal X-ray plasma, surrounded by a
wider nonthermal shell emitting at radio frequencies. HB 21 has a large angular
size, making it a good candidate for detailed morphological and spectral
studies with the LAT. The radio extension is 2{\deg}x1{\deg}.5, compared to the
LAT 68% containment angle of ~1{\deg} at 1 GeV. To understand the origin of
{\gamma}-ray emission, we compare LAT observations with other wavelengths that
trace non-thermal radio synchrotron, nearby molecular clouds, shocked molecular
clumps, and the central X-ray plasma. Finally, we model possible hadronic and
leptonic emission mechanisms. We conclude that {\gamma}-rays from HB 21 are
likely the result of electron bremsstrahlung or proton-proton collisions with
dense material due to interaction with the nearby clouds.


title: On a class of growth-maximal hard-core processes

abstract:
  Generalizing the well-known lilypond model we introduce a growth-maximal
hard-core model based on a space-time point process of convex particles. Using
a purely deterministic algorithm we prove under fairly general assumptions that
the model exists and is uniquely determined by the point process. Under an
additional stationarity assumption we show that the model does not percolate.
Our model generalizes the lilypond model considerably even if all grains are
born at the same time. In that case and under a Poisson assumption we prove a
central limit theorem in a large volume scenario.


title: Ultra High Energy Electrons Powered by Pulsar Rotation

abstract:
  A new mechanism of particle acceleration to ultra high energies, driven by
the rotational slow down of a pulsar (Crab pulsar, for example), is explored.
The rotation, through the time dependent centrifugal force, can very
efficiently excite unstable Langmuir waves in the e-p plasma of the star
magnetosphere via a parametric process. These waves, then, Landau damp on
electrons accelerating them in the process. The net transfer of energy is
optimal when the wave growth and the Landau damping times are comparable and
are both very short compared to the star rotation time. We show, by detailed
calculations, that these are precisely the conditions for the parameters of the
Crab pulsar. This highly efficient route for energy transfer allows the
electrons in the primary beam to be catapulted to multiple TeV ($\sim 100$ TeV)
and even PeV energy domain. It is expected that the proposed mechanism may,
partially, unravel the puzzle of the origin of ultra high energy cosmic ray
electrons.


title:
Toward a Spectroscopic Census of White Dwarfs Within 40 parsecs of the
  Sun

abstract:
  We present the preliminary results of a survey aimed at significantly
increasing the range and completeness of the local census of spectroscopically
confirmed white dwarfs. The current census of nearby white dwarfs is reasonably
complete only to about 20 parsecs of the Sun, a volume that includes around 130
white dwarfs, a sample too small for detailed statistical analyses. This census
is largely based on follow-up investigations of stars with very large proper
motions. We describe here the basis of a method that will lead to a catalog of
white dwarfs within 40 parsecs of the Sun and north of the celestial equator,
thus increasing by a factor of 8 the extent of the northern sky census. White
dwarf candidates are identified from the SUPERBLINK proper motion database,
allowing us to investigate stars down to a proper motion limit mu>40 mas yr-1,
while minimizing the kinematic bias for nearby objects. The selection criteria
and distance estimates are based on a combination of color-magnitude and
reduced proper motion diagrams. Our follow-up spectroscopic observation
campaign has so far uncovered 193 new white dwarfs, among which we identify 127
DA (including 9 DA+dM and 4 magnetic), 1 DB, 56 DC, 3 DQ, and 6 DZ stars. We
perform a spectroscopic analysis on a subsample of 84 DAs, and provide their
atmospheric parameters. In particular, we identify 11 new white dwarfs with
spectroscopic distances within 25 pc of the Sun, including 5 candidates to the
D<20 pc subset.


title:
The Contrasting Nature of Gamma-Ray/Optical Variability in the Blazar
  PKS 0208-512 During Successive Outbursts

abstract:
  The Yale/SMARTS optical-near-IR monitoring program has followed the
variations in emission of the Fermi-LAT monitored blazars in the southern sky
with closely spaced observations since 2008. We report the discovery of an
optical-near-IR (OIR) outburst with no accompanying gamma-rays in the blazar
PKS 0208-512, one of the targets of this program. While the source undergoes
three outbursts of 1 mag or more at OIR wavelengths lasting for longer than 3
months during 2008-2011, only interval 1 and 3 have corresponding bright phases
in GeV energies lasting longer than 1 month. The OIR outburst during interval 2
is comparable in brightness and temporal extent to the OIR flares during
intervals 1 and 3 which do have gamma-ray counterparts. Gamma-ray and OIR
variability are very well-correlated in most cases in the Fermi blazars and the
lack of correlation in this case is anomalous. By analyzing the gamma-ray, OIR,
and supporting multi-wavelength variability data in details, we speculate that
the location of the outburst in the jet during interval 2 was closer to the
black hole where the jet is more compact and the magnetic field strength is
higher, and the bulk Lorentz factor of the material in the jet is smaller.
These result in a much lower Compton dominance and no observable gamma-ray
outburst during interval 2.


title: Gene-Machine, a new search heuristic algorithm

abstract:
  This paper introduces Gene-Machine, an efficient and new search heuristic
algorithm, based in the building-block hypothesis. It is inspired by natural
evolution, but does not use some of the concepts present in genetic algorithms
like population, mutation and generation. This heuristic exhibits good
performance in comparison with genetic algorithms, and can be used to generate
useful solutions to optimization and search problems.


title:
El Fenomeno de Maduracion de Ostwald. Predicciones de las Simulaciones
  de Estabilidad de Emulsiones sobre la Evolucion del Radio Cubico Promedio de
  una Dispersion de Aceite en Agua

abstract:
  In this chapter, the theory of Lifshitz, Slesov and Wagner and the technique
of Emulsion Stability Simulations (ESS) are reviewed. Complementary algorithms
required to incorporate the phenomenon of Ostwald ripening in ESS are
presented. The simulations are used to study the behavior of dodecane-in-water
nanoemulsions as a function of time. The influence of electrostatic
interactions, hydration forces, the initial drop size distributions, and the
deformability of the drops, are studied. In particular, the behavior of the
cube average radius of the dispersion and the variation of the drop size
distribution a few minutes after the preparation of the emulsion are described.


title:
Hadron production and QGP Hadronization in Pb--Pb collisions at
  $\sqrt{s_{NN}}=2.76$ TeV

abstract:
  We show that all central rapidity hadron yields measured in Pb--Pb collisions
at $\sqrt{s_{NN}}=2.76$ TeV are well described by the chemical non-equilibrium
statistical hadronization model (SHM), where the chemically equilibrated QGP
source breaks up directly into hadrons. SHM parameters are obtained as a
function of centrality of colliding ions, and we compare CERN Large Hadron
Collider (LHC) with Brookhaven National Laboratory Relativistic Heavy Ion
Collider (RHIC) results. We predict yields of unobserved hadrons and address
anti-matter production. The physical properties of the quark--gluon plasma
fireball particle source show universality of hadronization conditions at LHC
and RHIC.


title:
Effective crystal field and Fermi surface topology: a comparison of d-
  and dp-orbital models

abstract:
  The effective crystal field in multi-orbital correlated materials can be
either enhanced or reduced by electronic correlations with crucial consequences
for the topology of the Fermi surface and, hence, on the physical properties of
these systems. In this respect, recent local density approximation (LDA) plus
dynamical mean-field theory (DMFT) studies of Ni-based heterostructure have
shown contradicting results, depending on whether the less correlated
$p$-orbitals are included or not. We investigate the origin of this problem and
identify the key parameters controlling the Fermi surface properties of these
systems. Without the $p$-orbitals the model is quarter filled, while the $d$
manifold moves rapidly towards half-filling when the $p$-orbitals are included.
This implies that the local Hund's exchange, while rather unimportant for the
former case, can play a predominant role in controlling the orbital
polarization for the extended basis-set by favoring the formation of a larger
local magnetic moment.


title: Aberration-corrected quantum temporal imaging system

abstract:
  We describe the design of a temporal imaging system that simultaneously
reshapes the temporal profile and converts the frequency of a photonic
wavepacket, while preserving its quantum state. A field lens, which imparts a
temporal quadratic phase modulation, is used to correct for the residual phase
caused by field curvature in the image, thus enabling temporal imaging for
phase-sensitive quantum applications. We show how this system can be used for
temporal imaging of time-bin entangled photonic wavepackets and compare the
field lens correction technique to systems based on a temporal telescope and
far-field imaging. The field-lens approach removes the residual phase using
four dispersive elements. The group delay dispersion (GDD) $D$ is constrained
by the available bandwidth $\Delta\nu$ by $D>t/\Delta\nu$, where $t$ is the
temporal width of the waveform associated with the dispersion $D$. This is
compared to the much larger dispersion $D\gg \pi t^2/8$ required to satisfy the
Fraunhofer condition in the far field approach.


title:
Electron dynamics inside a vacuum tube diode through linear differential
  equations

abstract:
  In this paper we analyze the motion of charged particles in a vacuum tube
diode by solving linear differential equations. Our analysis is based on
expressing the volume charge density as a function of the current density and
coordinates only, while in the usual scheme the volume charge density is
expressed as a function of the current density and electrostatic potential. Our
approach gives the well known behavior of the classical current density
proportional to the three-halves power of the bias potential and inversely
proportional to the square of the gap distance between the electrodes, and does
not require the solution of the nonlinear differential equation normally
associated with the Child-Langmuir formulation.


title: VHE gamma-ray emission from the FSRQs observed by the MAGIC telescopes

abstract:
  Among more than fifty blazars detected in very high energy (VHE, E>100GeV)
gamma-rays, only three belong to the subclass of Flat Spectrum Radio Quasars
(FSRQs): PKS 1510-089, PKS 1222+216 and 3C 279. The detection of FSRQs in the
VHE range is challenging, mainly because of their steep soft spectra in the
GeV-TeV regime. MAGIC has observed and detected all FSRQs known to be VHE
emitters up to now and found that they exhibit very different behavior. The
2010 discovery of PKS 1222+216 (z = 0.432) with the fast variability observed,
challenges simple one-zone emission models and more complicated scenarios have
been proposed. 3C 279 is the most distant VHE gamma-ray emitting AGN (z =
0.536), which was discovered by MAGIC in 2006 and detected again in 2007. In
2011 MAGIC observed 3C 279 two times: first during a monitoring campaign and
later observations were triggered by a flare detected with Fermi-LAT. We
present the MAGIC results and the multiwavelength behavior during this flaring
epoch. Finally, we report the 2012 detection of PKS 1510-089 (z = 0.36),
together with its simultaneous multiwavelength data from optical to gamma-rays.


title: Exactly $m$-coloured complete infinite subgraphs

abstract:
  Given an edge colouring of a graph with a set of $m$ colours, we say that the
graph is (exactly) $m$-coloured if each of the colours is used. The question of
finding exactly $m$-coloured complete subgraphs was first considered by
Erickson in 1994; in 1999, Stacey and Weidl partially settled a conjecture made
by Erickson and raised some further questions. In this paper, we shall study,
for a colouring of the edges of the complete graph on $\mathbb{N}$ with exactly
$k$ colours, how small the set of natural numbers $m$ for which there exists an
$m$-coloured complete infinite subgraph can be. We prove that this set must
have size at least $\sqrt{2k}$; this bound is tight for infinitely many values
of $k$. We also obtain a version of this result for colourings that use
infinitely many colours.


title:
Transfer Learning for Voice Activity Detection: A Denoising Deep Neural
  Network Perspective

abstract:
  Mismatching problem between the source and target noisy corpora severely
hinder the practical use of the machine-learning-based voice activity detection
(VAD). In this paper, we try to address this problem in the transfer learning
prospective. Transfer learning tries to find a common learning machine or a
common feature subspace that is shared by both the source corpus and the target
corpus. The denoising deep neural network is used as the learning machine.
Three transfer techniques, which aim to learn common feature representations,
are used for analysis. Experimental results demonstrate the effectiveness of
the transfer learning schemes on the mismatch problem.


title:
Ab initio analysis of the tight-binding parameters and magnetic
  interactions in Na2IrO3

abstract:
  By means of density functional theory (DFT) calculations (with and without
inclusion of spin-orbit (SO) coupling) we present a detailed study of the
electronic structure and corresponding microscopic Hamiltonian parameters of
Na2IrO3. In particular, we address the following aspects: (i) We investigate
the role of the various structural distortions and show that the electronic
structure of Na2IrO3 is exceptionally sensitive to structural details. (ii) We
discuss both limiting descriptions for Na2IrO3; quasi-molecular orbitals (small
SO limit, itinerant) versus relativistic orbitals (large SO limit, localized)
and show that the description of Na2IrO3 lies in an intermediate regime. (iii)
We investigate whether the nearest neighbor Kitaev-Heisenberg model is
sufficient to describe the electronic structure and magnetism in Na2IrO3. In
particular, we verify the recent suggestion of an antiferromagnetic Kitaev
interaction and show that it is not consistent with actual or even plausible
electronic parameters. Finally, (iv) we discuss correlation effects in Na2IrO3.
We conclude that while the Kitaev-Heisenberg Hamiltonian is the most general
expression of the quadratic spin-spin interaction in the presence of spin-orbit
coupling (neglecting single-site anisotropy), the itinerant character of the
electrons in Na2IrO3 makes other terms beyond this model (including, but not
limited to 2nd and 3rd neighbor interactions) essential.


title:
Symmetry of solutions of some semilinear elliptic equations with
  singular nonlinearities

abstract:
  We consider positive solutions to a singular semilinear elliptic equation in
bounded smooth domains, with zero Dirichlet boundary conditions. We provide
some weak and strong maximum principles for the H^1_0 part of the solution that
allow to deduce symmetry and monotonicity properties of the solutions, via the
Moving Plane Method.


title:
The precision and accuracy of early Epoch of Reionization foreground
  models: comparing MWA and PAPER 32-antenna source catalogs

abstract:
  As observations of the Epoch of Reionization (EoR) in redshifted 21cm
emission begin, we asses the accuracy of the early catalog results from the
Precision Array for Probing the Epoch of Reionization (PAPER) and the Murchison
Widefield Array. The MWA EoR approach derives much of its sensitivity from
subtracting foregrounds to <1% precision while the PAPER approach relies on the
stability and symmetry of the primary beam. Both require an accurate flux
calibration to set the amplitude of the measured power spectrum. The two
instruments are very similar in resolution, sensitivity, sky coverage and
spectral range and have produced catalogs from nearly contemporaneous data. We
use a Bayesian MCMC fitting method to estimate that the two instruments are on
the same flux scale to within 20% and find that the images are mostly in good
agreement. We then investigate the source of the errors by comparing two
overlapping MWA facets where we find that the differences are primarily related
to an inaccurate model of the primary beam but also correlated errors in bright
sources due to CLEAN. We conclude with suggestions for mitigating and better
characterizing these effects.


title:
Classification of Segments in PolSAR Imagery by Minimum Stochastic
  Distances Between Wishart Distributions

abstract:
  A new classifier for Polarimetric SAR (PolSAR) images is proposed and
assessed in this paper. Its input consists of segments, and each one is
assigned the class which minimizes a stochastic distance. Assuming the complex
Wishart model, several stochastic distances are obtained from the h-phi family
of divergences, and they are employed to derive hypothesis test statistics that
are also used in the classification process. This article also presents, as a
novelty, analytic expressions for the test statistics based on the following
stochastic distances between complex Wishart models: Kullback-Leibler,
Bhattacharyya, Hellinger, R\'enyi, and Chi-Square; also, the test statistic
based on the Bhattacharyya distance between multivariate Gaussian distributions
is presented. The classifier performance is evaluated using simulated and real
PolSAR data. The simulated data are based on the complex Wishart model, aiming
at the analysis of the proposal well controlled data. The real data refer to
the complex L-band image, acquired during the 1994 SIR-C mission. The results
of the proposed classifier are compared with those obtained by a Wishart
per-pixel/contextual classifier, and we show the better performance of the
region-based classification. The influence of the statistical modeling is
assessed by comparing the results using the Bhattacharyya distance between
multivariate Gaussian distributions for amplitude data. The results with
simulated data indicate that the proposed classification method has a very good
performance when the data follow the Wishart model. The proposed classifier
also performs better than the per-pixel/contextual classifier and the
Bhattacharyya Gaussian distance using SIR-C PolSAR data.


title: Cosmic Acceleration and Brans-Dicke Theory

abstract:
  This paper is devoted to study the accelerated expansion of the universe by
exploring the Brans-Dicke parameter in different eras. For this purpose, we
take FRW universe model with viscous fluid (without potential) and Bianchi type
I universe model with barotropic fluid (with and without potential). We
evaluate deceleration parameter as well as Brans-Dicke parameter to explore
cosmic acceleration. It is concluded that accelerated expansion of the universe
can also be achieved for higher values of the Brans-Dicke parameter in some
cases.


title:
Econophysics of adaptive power markets: When a market does not dampen
  fluctuations but amplifies them

abstract:
  The average economic agent is often used to model the dynamics of simple
markets, based on the assumption that the dynamics of many agents can be
averaged over in time and space. A popular idea that is based on this seemingly
intuitive notion is to dampen electric power fluctuations from fluctuating
sources (as e.g. wind or solar) via a market mechanism, namely by variable
power prices that adapt demand to supply. The standard model of an average
economic agent predicts that fluctuations are reduced by such an adaptive
pricing mechanism.
  However, the underlying assumption that the actions of all agents average out
on the time axis is not always true in a market of many agents. We numerically
study an econophysics agent model of an adaptive power market that does not
assume averaging a priori. We find that when agents are exposed to source noise
via correlated price fluctuations (as adaptive pricing schemes suggest), the
market may amplify those fluctuations. In particular, small price changes may
translate to large load fluctuations through catastrophic consumer
synchronization. As a result, an adaptive power market may cause the opposite
effect than intended: Power fluctuations are not dampened but amplified
instead.


title:
The Redshift Distribution of Intervening Weak MgII Quasar Absorbers and
  a Curious Dependence on Quasar Luminosity

abstract:
  We have identified 469 MgII doublet systems having W_r >= 0.02 {\AA} in 252
Keck/HIRES and UVES/VLT quasar spectra over the redshift range 0.1 < z < 2.6.
Using the largest sample yet of 188 weak MgII systems (0.02 {\AA} <= W_r < 0.3
{\AA}), we calculate their absorber redshift path density, dN/dz. We find clear
evidence of evolution, with dN/dz peaking at z ~ 1.2, and that the product of
the absorber number density and cross section decreases linearly with
increasing redshift; weak MgII absorbers seem to vanish above z ~ 2.7. If the
absorbers are ionized by the UV background, we estimate number densities of
10^6 - 10^9 per Mpc^3 for spherical geometries and 10^2 - 10^5 per Mpc^3 for
more sheetlike geometries. We also find that dN/dz toward intrinsically faint
versus bright quasars differs significantly for weak and strong (W_r >= 1.0
{\AA}) absorbers. For weak absorption, dN/dz toward bright quasars is ~ 25%
higher than toward faint quasars (10 sigma at low redshift, 0.4 <= z <= 1.4,
and 4 sigma at high redshift, 1.4 < z <= 2.34). For strong absorption the trend
reverses, with dN/dz toward faint quasars being ~ 20% higher than toward bright
quasars (also 10 sigma at low redshift and 4 sigma at high redshift). We
explore scenarios in which beam size is proportional to quasar luminosity and
varies with absorber and quasar redshifts. These do not explain dN/dz's
dependence on quasar luminosity.


title:
X-ray reflected spectra from accretion disk models. III. A complete grid
  of ionized reflection calculations

abstract:
  We present a new and complete library of synthetic spectra for modeling the
component of emission that is reflected from an illuminated accretion disk. The
spectra were computed using an updated version of our code XILLVER that
incorporates new routines and a richer atomic data base. We offer in the form
of a table model an extensive grid of reflection models that cover a wide range
of parameters. Each individual model is characterized by the photon index
\Gamma of the illuminating radiation, the ionization parameter \xi at the
surface of the disk (i.e., the ratio of the X-ray flux to the gas density), and
the iron abundance A_{Fe} relative to the solar value. The ranges of the
parameters covered are: 1.2 \leq \Gamma \leq 3.4, 1 \leq \xi \leq 10^4, and 0.5
\leq A_{Fe} \leq 10. These ranges capture the physical conditions typically
inferred from observations of active galactic nuclei, and also stellar-mass
black holes in the hard state. This library is intended for use when the
thermal disk flux is faint compared to the incident power-law flux. The models
are expected to provide an accurate description of the Fe K emission line,
which is the crucial spectral feature used to measure black hole spin. A total
of 720 reflection spectra are provided in a single FITS
file{\url{http://hea-www.cfa.harvard.edu/~javier/xillver/}} suitable for the
analysis of X-ray observations via the atable model in XSPEC. Detailed
comparisons with previous reflection models illustrate the improvements
incorporated in this version of XILLVER.


title: Low-Mass Higgs Bosons in the NMSSM and Their LHC Implications

abstract:
  We study the Higgs sector of the Next to Minimal Supersymmetric Standard
Model (NMSSM) in light of the discovery of the SM-like Higgs boson at the LHC.
We perform a broad scan over the NMSSM parameter space and identify the regions
that are consistent with current Higgs search results at colliders. In contrast
to the commonly studied "decoupling" scenario in the literature where the
Minimal Supersymmetric Standard Model CP-odd Higgs boson mass is large mA >>
mZ, we pay particular attention to the light Higgs states in the case when mA
<~ 2mZ . The Higgs bosons in the NMSSM, namely three CP-even states, two CP-odd
states, and two charged Higgs states, could all be rather light, near or below
the electroweak scale, although the singlet-like states can be heavier. The
SM-like Higgs boson could be either the lightest CP-even scalar or the second
lightest CP-even scalar, but is unlikely to be the heaviest scalar. These NMSSM
parameter regions have unique properties and offer rich phenomenology. The
decay branching fractions for the SM-like Higgs boson may be modified
appreciably. The correlations of gamma gamma/V V and V V/b b can be
substantially altered. The new Higgs bosons may be readily produced at the LHC
and may decay to non-standard distinctive final states, most notably a pair of
Higgs bosons when kinematically accessible. We evaluate the production and
decay of the Higgs bosons and comment on further searches at the LHC to probe
the Higgs sector of the NMSSM.


title:
Bond order in two-dimensional metals with antiferromagnetic exchange
  interactions

abstract:
  We present an unrestricted Hartree-Fock computation of charge-ordering
instabilities of two-dimensional metals with antiferromagnetic exchange
interactions, allowing for arbitrary ordering wavevectors and internal
wavefunctions of the particle-hole pair condensate. We find that the ordering
has a dominant d symmetry of rotations about lattice points for a range of
ordering wavevectors, including those observed in recent experiments at low
temperatures on YBCO. This d symmetry implies the charge ordering is primarily
on the bonds of the Cu lattice, and we propose incommensurate bond order
parameters for the underdoped cuprates. The field theory for the onset of Neel
order in a metal has an emergent pseudospin symmetry which `rotates' d-wave
Cooper pairs to particle-hole pairs (Metlitski et al. arXiv:1005.1288): our
results show that this symmetry has consequences even when the spin
correlations are short-ranged and incommensurate.


title: The S2 star as a probe of the accretion disk of Sgr A*

abstract:
  How accretion proceeds around the massive black hole in the Galactic center
and other highly sub-Eddington accretors remains poorly understood. The orbit
of the S2 star in the Galactic center passes through the accretion disk of the
massive black hole and any observational signature from such interaction may be
used as an accretion probe. Because of its early stellar type, S2 is expected
to possess a fairly powerful wind. We show here that the ram pressure of the
accretion disk shocks the stellar wind fairly close to the star. The shocked
fluid reaches a temperature of ~ 1 keV and cools efficiently through optically
thin, thermal bremsstrahlung emission. The radiation from the shocked wind
peaks around the epoch of the pericenter passage of the star at a luminosity
potentially comparable to the quiescent emission detected from Sgr A*.
Detection of shocked wind radiation can constrain the density of the accretion
disk at a distance of several thousands of gravitational radii from the black
hole.


title:
Spectral hardening as a viable alternative to disc truncation in black
  hole state transitions

abstract:
  Constraining the accretion flow geometry of black hole binaries in outburst
is complicated by the inability of simplified multi-colour disc models to
distinguish between changes in the inner disc radius and alterations to the
emergent spectrum, parameterised by the phenomenological colour correction
factor, f_col. We analyse Rossi X-ray Timing Explorer observations of the low
mass Galactic black hole X-ray binary, GX 339-4, taken over seven epochs when
the source was experiencing a state transition. The accretion disc component is
isolated using a pipeline resulting in robust detections for disc luminosities,
0.001 < L_disc / L_Edd < 0.5. Assuming that the inner disc remains situated at
the innermost stable circular orbit over the course of a state transition, we
measure the relative degree of change in f_col required to explain the spectral
evolution of the disc component. A variable f_col that increases by a factor of
~ 2.0 - 3.5 as the source transitions from the high/soft state to the low/hard
state can adequately explain the observed disc spectral evolution. For the
observations dominated by a disc component, the familiar scaling between the
disc luminosity and effective temperature, L_disc ~ T_eff^4, is observed;
however, significant deviations from this relation appear when GX 339-4 is in
the hard intermediate and low/hard states. Allowing for an evolving f_col
between spectral states, the L_disc-T_eff^4 law is recovered over the full
range of disc luminosities, although this depends heavily on the physically
conceivable range of f_col. We demonstrate that physically reasonable changes
in f_col provide a viable description for multiple state transitions of a black
hole binary without invoking radial motion of the inner accretion disc.


title:
An improved prescription for merger time-scales from controlled
  simulations

abstract:
  We compare three analytical prescriptions for merger times available from the
literature to simulations of isolated mergers. We probe three different
redshifts, and several halo concentrations, mass ratios, orbital circularities
and orbital energies of the satellite. We find that prescriptions available in
the literature significantly under-predict long timescales for mergers at high
redshift. We argue that these results have not been highlighted previously
either because the evolution of halo concentration of satellite galaxies has
been neglected (in previous isolated merger simulations), or because long
merger times and mergers with high initial orbital circularities are
under-represented (for prescriptions based on cosmological simulations).
Motivated by the evolution of halo concentration at fixed mass, an explicit
dependence on redshift added as t_merger,modified(z) = (1+z)^0.44 t_merger to
the prescription based on isolated mergers gives a significant improvement in
the predicted merger times up to ~20 t_dyn in the redshift range 0<z<2. When
this modified prescription is used to compute galaxy stellar mass functions, we
find that it leads up to a 25 per cent increase in the number of low mass
galaxies surviving at z=0, and a 10 per cent increase for more massive
galaxies. This worsen the known over-prediction in the number of low mass
galaxies by hierarchical models of galaxy formation.


title:
Cores, filaments, and bundles: hierarchical core formation in the
  L1495/B213 Taurus region

abstract:
  (Abridged) Context. Core condensation is a critical step in the
star-formation process, but is still poorly characterized observationally.
Aims. We have studied the 10 pc-long L1495/B213 complex in Taurus to
investigate how dense cores have condensed out of the lower-density cloud
material. Results. From the N$_2$H$^+$ emission, we identify 19 dense cores,
some starless and some protostellar. They are not distributed uniformly, but
tend to cluster with relative separations on the order of 0.25 pc. From the
C$^{18}$O emission, we identify multiple velocity components in the gas. We
have characterized them by fitting gaussians to the spectra, and by studying
the distribution of the fits in position-position-velocity space. In this
space, the C$^{18}$O components appear as velocity-coherent structures, and we
have identified them automatically using a dedicated algorithm (FIVe: Friends
In Velocity). Using this algorithm, we have identified 35 filamentary
components with typical lengths of 0.5 pc, sonic internal velocity dispersions,
and mass-per-unit-length close to the stability threshold of isothermal
cylinders at 10 K. Core formation seems to have occurred inside the filamentary
components via fragmentation, with a small number of fertile components with
larger mass-per-unit-length being responsible for most cores in the cloud. At
large scales, the filamentary components appear grouped into families, which we
refer to as bundles. Conclusions. Core formation in L1495/B213 has proceeded by
hierarchical fragmentation. The cloud fragmented first into several pc-scale
regions. Each of these regions later fragmented into velocity-coherent
filaments of about 0.5 pc in length. Finally, a small number of these filaments
fragmented quasi-statically and produced the individual dense cores we see
today.


title: Non-Gaussianity Unleashed

abstract:
  The Hamilton-Jacobi (HJ) approach for exploring inflationary trajectories is
employed in the generation of generalised inflationary non-Gaussian signals
arising from single field inflation. Scale dependent solutions for $f_{NL}$ are
determined via the numerical integration of the three--point function in the
curvature perturbation. This allows the full exploration of single field
inflationary dynamics in the out-of-slow-roll regime and opens up the
possibility of using future observations of non-Gaussianity to constraint the
inflationary potential using model-independent methods. The distribution of
`equilateral' $f_{NL}$ arising from single field inflation with both canonical
and non-canonical kinetic terms are show as an example of the application of
this procedure.


title: K-inflationary Power Spectra at Second Order

abstract:
  Within the class of inflationary models, k-inflation represents the most
general single field framework that can be associated with an effective
quadratic action for the curvature perturbations and a varying speed of sound.
The incoming flow of high-precision cosmological data, such as those from the
Planck satellite and small scale Cosmic Microwave Background (CMB) experiments,
calls for greater accuracy in the inflationary predictions. In this work, we
calculate for the first time the next-to-next-to-leading order scalar and
tensor primordial power spectra in k-inflation needed in order to obtain robust
constraints on the inflationary theory. The method used is the uniform
approximation together with a second order expansion in the Hubble and sound
flow functions. Our result is checked in various limits in which it reduces to
already known situations.


title: Extreme TeV Blazars and Lower Limits on Intergalactic Magnetic Fields

abstract:
  The intergalactic magnetic field (IGMF) in cosmic voids can be indirectly
probed through its effect on electromagnetic cascades initiated by a source of
TeV gamma rays, such as blazars, a subclass of active galactic nuclei. Blazars
that are sufficiently luminous at TeV energies, "extreme TeV blazars", can
produce detectable levels of secondary radiation from inverse Compton
scattering of the electrons in the cascade, provided that the IGMF is not too
large. We reveiw recent work in the literature which utilizes this idea to
derive constraints on the IGMF for three TeV-detected blazars-1ES 0229+200, 1ES
1218+304, and RGB J0710+591, and we also investigate four other hard-spectrum
TeV blazars in the same framework. Through a recently developed detailed 3D
particle tracking Monte Carlo simulation code, incorporating all major effects
of QED and cosmological expansion, we research effects of major uncertainties
such as the spectral properties of the source, uncertainty in the intensity of
the UV - far IR extragalactic background light (EBL), under-sampled Very High
Energy (VHE; energy > 100 GeV) coverage, past history of gamma-ray emission,
source vs. observer geometry, and jet AGN Doppler factor. The implications of
these effects on the recently reported lower limits of the IGMF are thoroughly
examined to conclude that presently available data are compatible with a zero
IGMF hypothesis.


title: Cohn path algebras have Invariant Basis Number

abstract:
  For any finite directed graph $E$ and any field $K$ we show that the Cohn
path algebra $C_K(E)$ has the Invariant Basis Number property.


title: Inconsistency of Carnot's theorem's proof by R. Clausius

abstract:
  R. Clausius proved Carnot's theorem basing on postulate "Heat cannot, of
itself, pass from a colder to a hotter body". Alexander Gukhman demonstrated
that Carnot's theorem can be proved based on the postulate "Heat cannot, of
itself, pass from a hotter to a colder body". He concluded that Carnot's
theorem does not follow from Clausius' postulate. The following paper gives a
detailed justification of Gukhman's derivation.


title:
Laser-heater assisted plasma channel formation in capillary discharge
  waveguides

abstract:
  A method of creating plasma channels with controllable depth and transverse
profile for the guiding of short, high power laser pulses for efficient
electron acceleration is proposed. The plasma channel produced by the
hydrogen-filled capillary discharge waveguide is modified by a ns-scale laser
pulse, which heats the electrons near the capillary axis. This interaction
creates a deeper plasma channel within the capillary discharge that evolves on
a ns-time scale, allowing laser beams with smaller spot sizes than would
otherwise be possible in the unmodified capillary discharge.


title:
Orthogonal non-Gaussianity in DBI Galileon: prospect for Planck
  polarisation and post-Planck experiments

abstract:
  In this note, we study cosmic microwave background (CMB) constraints on
primordial non-Gaussianity in DBI galileon models in which an induced gravity
term is added to the Dirac-Born-Infeld (DBI) action. In this model, the
non-Gaussianity of orthogonal shape can be generated. We provide a relation
between theoretical parameters and orthogonal/equilateral non-linear parameters
using the Fisher matrix approach for the CMB bispectrum. In doing so, we
include the effect of the CMB transfer functions and experimental noise
properties by employing the recently developed \textsf{SONG} code. The relation
is also shown in the language of effective theory so that it can be applied to
general single-field models. Using the bispectrum Fisher matrix and the central
values for equilateral and orthogonal non-Gaussianities found by the Planck
temperature survey, we provide forecasts on the theoretical parameters of the
DBI galileon model. We consider the upcoming Planck polarisation data and the
proposed post-Planck experiments COrE and PRISM. We find that Planck
polarisation measurements may provide a hint for a non-canonical sound speed at
the 68% confidence level. COrE and PRISM will not only confirm a non-canonical
sound speed but also exclude the conventional DBI inflation model at more than
the 95% and 99% confidence level respectively, assuming that the central values
will not change. This indicates that improving constraints on non-Gaussianity
further by future CMB experiments is invaluable to constrain the physics of the
early universe.


title:
Nucleon and Delta axial-vector couplings in 1/Nc - Baryon Chiral
  Perturbation Theory

abstract:
  In this contribution, baryon axial-vector couplings are studied in the
framework of the combined 1/Nc and chiral expansions. This framework is
implemented on the basis of the emergent spin-flavor symmetry in baryons at
large Nc and HBChPT, and linking both expansions (\xi-expansion), where 1/Nc is
taken to be a quantity O(p). The study is carried out including one-loop
contributions, which corresponds to O(\xi^3) for baryon masses and O(\xi^2) for
the axial couplings. An analysis of the Lattice QCD results for the axial
couplings of both N and \Delta is presented.


title: Real-time resilient focusing through a bending multimode fiber

abstract:
  We introduce a system capable of focusing light through a multimode fiber in
37ms, one order of magnitude faster than demonstrated in previous reports. As a
result, the focus spot can be maintained during significant bending of the
fiber, opening numerous opportunities for endoscopic imaging and energy
delivery applications. We measure the transmission matrix of the fiber by
projecting binary-amplitude computer generated holograms using a digital
micromirror device and a field programmable gate array controller. The system
shows two orders of magnitude enhancements of the focus spot relative to the
background.


title: Legendrian theta-graphs

abstract:
  In this article we give necessary and sufficient conditions for two triples
of integers to be realized as the Thurston-Bennequin number and the rotation
number of a Legendrian theta-graph with all cycles unknotted. We show that
these invariants are not enough to determine the Legendrian class of a
topologically planar theta-graph. We define the transverse push-off of a
Legendrian graph and we determine its self linking number for Legendrian
theta-graphs. In the case of topologically planar theta-graphs, we prove that
the topological type of the transverse push-off is that of a pretzel link.


title:
Evolution of the helicity and transversity Transverse-Momentum-Dependent
  parton distributions

abstract:
  We examine the QCD evolution of the helicity and transversity parton
distribution functions when including also their dependence on transverse
momentum. Using an appropriate definition of these polarized transverse
momentum distributions (TMDs), we describe their dependence on the
factorization scale and rapidity cutoff, which is essential for
phenomenological applications.


title: Convex Discriminative Multitask Clustering

abstract:
  Multitask clustering tries to improve the clustering performance of multiple
tasks simultaneously by taking their relationship into account. Most existing
multitask clustering algorithms fall into the type of generative clustering,
and none are formulated as convex optimization problems. In this paper, we
propose two convex Discriminative Multitask Clustering (DMTC) algorithms to
address the problems. Specifically, we first propose a Bayesian DMTC framework.
Then, we propose two convex DMTC objectives within the framework. The first
one, which can be seen as a technical combination of the convex multitask
feature learning and the convex Multiclass Maximum Margin Clustering (M3C),
aims to learn a shared feature representation. The second one, which can be
seen as a combination of the convex multitask relationship learning and M3C,
aims to learn the task relationship. The two objectives are solved in a uniform
procedure by the efficient cutting-plane algorithm. Experimental results on a
toy problem and two benchmark datasets demonstrate the effectiveness of the
proposed algorithms.


title:
OVRO 40 m Blazar Monitoring Program: Location of the gamma-ray emission
  region in blazars by the study of correlated variability at radio and
  gamma-rays

abstract:
  Blazars are powerful, variable emitters from radio to gamma-ray wavelengths.
Even though the general picture of synchrotron emission at low energies and
inverse Compton at the high energy end is well established, many important
aspects of these remarkable objects are still not well understood. For example,
even the location of the gamma-ray emission region is still not clearly
established, with some theories locating it close to the black hole/accretion
disk while others place it at parsec scales in the radio jet. Since mid-2007 we
have carried out a large scale monitoring program at 15 GHz using the OVRO 40 m
telescope. We are currently observing about 1700 blazars twice per week. The
sample includes all the Fermi-LAT detected blazars north of declination -20
degrees. Here, we study the existence of correlated variability between these
two bands for 86 sources bright enough to be detected weekly by LAT. The
existence of correlated variability can be interpreted as an indication of a
related spatial locations for the radio and gamma-ray emission, making the
evaluation of its statistical significance a key goal of our program. A study
of the statistical significance of these cross-correlations is presented along
with a discussion of the Monte Carlo simulations used to evaluate them. More
information about the conditions on the radio emission zone can be obtained
through polarization monitoring which tells us about the configuration of the
magnetic fields in this region. To study radio polarization variability we are
building KuPol, a radio polarization receiver for the 12 to 18 GHz band that
will replace the current total power receiver at the OVRO 40 meter telescope.


title:
Heuristic Ternary Error-Correcting Output Codes Via Weight Optimization
  and Layered Clustering-Based Approach

abstract:
  One important classifier ensemble for multiclass classification problems is
Error-Correcting Output Codes (ECOCs). It bridges multiclass problems and
binary-class classifiers by decomposing multiclass problems to a serial
binary-class problems. In this paper, we present a heuristic ternary code,
named Weight Optimization and Layered Clustering-based ECOC (WOLC-ECOC). It
starts with an arbitrary valid ECOC and iterates the following two steps until
the training risk converges. The first step, named Layered Clustering based
ECOC (LC-ECOC), constructs multiple strong classifiers on the most confusing
binary-class problem. The second step adds the new classifiers to ECOC by a
novel Optimized Weighted (OW) decoding algorithm, where the optimization
problem of the decoding is solved by the cutting plane algorithm. Technically,
LC-ECOC makes the heuristic training process not blocked by some difficult
binary-class problem. OW decoding guarantees the non-increase of the training
risk for ensuring a small code length. Results on 14 UCI datasets and a music
genre classification problem demonstrate the effectiveness of WOLC-ECOC.


title:
Probabilistic temperature forecasting with statistical calibration in
  Hungary

abstract:
  Weather forecasting is mostly based on the outputs of deterministic numerical
weather forecasting models. Multiple runs of these models with different
initial conditions result in forecast ensembles which is are used for
estimating the distribution of future atmospheric variables. However, these
ensembles are usually under-dispersive and uncalibrated, so post-processing is
required.
  In the present work Bayesian Model Averaging (BMA) is applied for calibrating
ensembles of temperature forecasts produced by the operational Limited Area
Model Ensemble Prediction System of the Hungarian Meteorological Service (HMS).
  We describe two possible BMA models for temperature data of the HMS and show
that BMA post-processing significantly improves calibration and probabilistic
forecasts although the accuracy of point forecasts is rather unchanged.


title: Simultaneous quantitative imaging of surface and magnetic forces

abstract:
  We demonstrate quantitative force imaging of long-range magnetic forces
simultaneously with near-surface van-der-Waals and contact-mechanics forces
using intermodulation atomic force microscopy. Magnetic forces at the 200 pN
level are separated from near-surface forces at the 30 nN level. Imaging of
these forces is performed in both the contact and non-contact regimes of
near-surface interactions.


title: Inverse Problem of Electro-seismic Conversion

abstract:
  When a porous rock is saturated with an electrolyte, electrical fields are
coupled with seismic waves via the electro-seismic conversion. Pride derived
the governing models, in which Maxwell equations are coupled with Biot
equations through the electro-kinetic mobility parameter. The inverse problem
of the linearized electro-seismic conversion consists in two step, namely the
inversion of Biot equations and the inversion of Maxwell equations. We analyze
the reconstruction of conductivity and electro-kinetic mobility parameter in
Maxwell equations with internal measurements, while the internal measurements
are provided by the results of the inversion of Biot equations. We show that
knowledge of two internal data based on well-chosen boundary conditions
uniquely determine these two parameters. Moreover, a Lipschitz type stability
is proved based on the same sets of well-chosen boundary conditions.


title: Preamble-based Channel Estimation in OFDM/OQAM Systems: A Review

abstract:
  Filter bank-based multicarrier communications (FBMC) have recently attracted
increased interest in both wired (e.g., xDSL, PLC) and wireless (e.g.,
cognitive radio) applications, due to their enhanced flexibility, higher
spectral efficiency, and better spectral containment compared to conventional
OFDM. A particular type of FBMC, the so-called FBMC/OQAM or OFDM/OQAM system,
consisting of pulse shaped OFDM carrying offset QAM (OQAM) symbols, has
received increasing attention due to, among other features, its higher spectral
efficiency and implementation simplicity. It suffers, however, from an
imaginary inter-carrier/inter-symbol interference that complicates signal
processing tasks such as channel estimation. This paper focuses on channel
estimation for OFDM/OQAM systems based on a known preamble. A review of the
existing preamble structures and associated channel estimation methods is
given, for both single- (SISO) and multiple-antenna (MIMO) systems. The various
preambles are compared via simulations in both mildly and highly frequency
selective channels.


title:
On the Aharonov-Bohm Effect and Why Heisenberg Captures Nonlocality
  Better Than Schr\"odinger

abstract:
  I discuss in detail the history of the Aharonov-Bohm effect in Bristol and my
encounters with Akira Tonomura later on. I then propose an idea that developed
following the publication of the Aharonov-Bohm effect, namely the importance of
modulo momentum and Heisenberg representation in dealing with non-local quantum
phenomena.


title: On smooth Gorenstein polytopes

abstract:
  A Gorenstein polytope of index r is a lattice polytope whose r-th dilate is a
reflexive polytope. These objects are of interest in combinatorial commutative
algebra and enumerative combinatorics, and play a crucial role in Batyrev's and
Borisov's computation of Hodge numbers of mirror-symmetric generic Calabi-Yau
complete intersections. In this paper, we report on what is known about smooth
Gorenstein polytopes, i.e., Gorenstein polytopes whose normal fan is
unimodular. We classify d-dimensional smooth Gorenstein polytopes with index
larger than (d+3)/3. Moreover, we use a modification of Oebro's algorithm to
achieve classification results for smooth Gorenstein polytopes in low
dimensions. The first application of these results is a database of all toric
Fano d-folds whose anticanonical divisor is divisible by an integer r larger
than d-8. As a second application we verify that there are only finitely many
families of Calabi-Yau complete intersections of fixed dimension that are
associated to a smooth Gorenstein polytope via the Batyrev-Borisov
construction.


title: Iterated crossed products

abstract:
  We define a "mirror version" of Brzezinski's crossed product and we prove
that, under certain circumstances, a Brzezinski crossed product D\otimes_{R,
\sigma}V and a mirror version W\bar{\otimes}_{P, \nu}D may be iterated,
obtaining an algebra structure on W\otimes D\otimes V. Particular cases of this
construction are the iterated twisted tensor product of algebras and the
quasi-Hopf two-sided smash product.


title: Possible Directions for Improving Dependency Versioning in R

abstract:
  One of the most powerful features of R is its infrastructure for contributed
code. The built-in package manager and complementary repositories provide a
great system for development and exchange of code, and have played an important
role in the growth of the platform towards the de-facto standard in statistical
computing that it is today. However, the number of packages on CRAN and other
repositories has increased beyond what might have been foreseen, and is
revealing some limitations of the current design. One such problem is the
general lack of dependency versioning in the infrastructure. This paper
explores this problem in greater detail, and suggests approaches taken by other
open source communities that might work for R as well. Three use cases are
defined that exemplify the issue, and illustrate how improving this aspect of
package management could increase reliability while supporting further growth
of the R community.


title:
Non-equilibrium Approach to Thermodynamics using Jarzynski Equality and
  Diagonal Entropy

abstract:
  We combine the formalisms of diagonal entropy and Jarzynski Equality to study
the thermodynamic properties of closed quantum systems. Applying this approach
to a quantum harmonic oscillator, the diagonal entropy offers a notion of
temperature for closed systems away from equilibrium, and allows computing
free-energy profiles. We also apply this approach to a hard-core boson lattice
model, and discuss measures how to estimate temperature, entropy and measure
work distribution functions. This technique offers a path to investigate the
non-equilibrium quantum dynamics by means of performing work in a series of
quenches.


title: VERITAS Observations of High-Frequency-Peaked BL Lac Objects

abstract:
  Here we present highlights from VERITAS observations of high-frequency-peaked
BL Lac objects (HBLs). We discuss the key science motivations for observing
these sources -- including performing multiwavelength campaigns critical to
understanding the emission mechanisms at work in HBLs, constraining the
intensity and spectra shape of the extragalactic background light, and placing
limits on the strength of the intergalactic magnetic field.


title:
The separation problem for regular languages by piecewise testable
  languages

abstract:
  Separation is a classical problem in mathematics and computer science. It
asks whether, given two sets belonging to some class, it is possible to
separate them by another set of a smaller class. We present and discuss the
separation problem for regular languages. We then give a direct polynomial time
algorithm to check whether two given regular languages are separable by a
piecewise testable language, that is, whether a $B{\Sigma}1(<)$ sentence can
witness that the languages are indeed disjoint. The proof is a reformulation
and a refinement of an algebraic argument already given by Almeida and the
second author.


title: An improvement of a result of Zverovich--Zverovich

abstract:
  We give an improvement of a result of Zverovich and Zverovich which gives a
condition on the first and last elements in a decreasing sequence of positive
integers for the sequence to be graphic, that is, the degree sequence of a
finite graph.


title: Symmetric Bipartite Graphs and Graphs with Loops

abstract:
  We show that if the two parts of a finite bipartite graph have the same
degree sequence, then there is a bipartite graph, with the same degree
sequences, which is symmetric, in that it has an involutive graph automorphism
that interchanges its two parts. To prove this, we study the relationship
between symmetric bipartite graphs and graphs with loops.


title:
A nonexistence result for a nonlinear elliptic equation with singular
  and decaying potential

abstract:
  The paper deals with positive radial solutions to a nonlinear elliptic
equation with singular and decaying potential, for which several existence and
nonexistence results are known, resting upon suitable compatibility conditions
between the decaying rate of the potential and the growth rate of the
nonlinearity. The problem of the existence is still open for essentially three
cases and we give a negative answer to one of such cases.


title:
On Influence, Stable Behavior, and the Most Influential Individuals in
  Networks: A Game-Theoretic Approach

abstract:
  We introduce a new approach to the study of influence in strategic settings
where the action of an individual depends on that of others in a
network-structured way. We propose \emph{influence games} as a
\emph{game-theoretic} model of the behavior of a large but finite networked
population. Influence games allow \emph{both} positive and negative
\emph{influence factors}, permitting reversals in behavioral choices. We
embrace \emph{pure-strategy Nash equilibrium (PSNE)}, an important solution
concept in non-cooperative game theory, to formally define the \emph{stable
outcomes} of an influence game and to predict potential outcomes without
explicitly considering intricate dynamics. We address an important problem in
network influence, the identification of the \emph{most influential
individuals}, and approach it algorithmically using PSNE computation.
\emph{Computationally}, we provide (a) complexity characterizations of various
problems on influence games; (b) efficient algorithms for several special cases
and heuristics for hard cases; and (c) approximation algorithms, with provable
guarantees, for the problem of identifying the most influential individuals.
\emph{Experimentally}, we evaluate our approach using both synthetic influence
games as well as several real-world settings of general interest, each
corresponding to a separate branch of the U.S. Government.
\emph{Mathematically,} we connect influence games to important game-theoretic
models: \emph{potential and polymatrix games}.


title:
Transverse optical instability patterns in semiconductor microcavities:
  polariton scattering and low-intensity all-optical switching

abstract:
  We present a detailed theoretical study of transverse exciton-polariton
patterns in semiconductor quantum-well microcavities. These patterns are
initiated by directional instabilities in the uniform pump-generated polariton
field and are measured as optical patterns in a transverse plane in the far
field. Based on a microscopic many-particle theory, we investigate the
spatio-temporal dynamics of the formation, selection, and optical control of
these patterns. An emphasis is placed on a previously proposed low-intensity,
all-optical switching scheme designed to exploit these instability-driven
patterns. Simulations and detailed analyses of simplified and more physically
transparent models are used. Two aspects are studied in detail. First we study
the dependencies of the stability behaviors of various patterns, as well as
transition time scales, on parameters relevant to the switching action(the
degree of built-in azimuthal anisotropy in the system and the switching beam
intensity). It is found that if the parameters are varied, the pattern system
undergoes abrupt transitions at threshold parameter values which are
accompanied by multiple-stability and hysteresis behaviors. Moreover, during a
real-time switching action, the transient dynamics of the system may depend
significantly on the proximity of unstable patterns. The second aspect is a
classification and detailed analysis of the polariton scattering processes
contributing to the pattern dynamics, giving us an understanding of the
selection and control of patterns as results of these processes' intricate
interplay. The crucial role played by the relative phases of the polariton
field in determining the gains or losses of polariton densities in various
momentum modes is highlighted, and interpretation of the actions of the various
processes in terms of concepts commonly used in classical pattern-forming
systems is given.


title:
Optimal Equivocation in Secrecy Systems a Special Case of
  Distortion-based Characterization

abstract:
  Recent work characterizing the optimal performance of secrecy systems has
made use of a distortion-like metric for partial secrecy as a replacement for
the more traditional metric of equivocation. In this work we use the log-loss
function to show that the optimal performance limits characterized by
equivocation are, in fact, special cases of distortion-based counterparts. This
observation illuminates why equivocation doesn't tell the whole story of
secrecy. It also justifies the causal-disclosure framework for secrecy (past
source symbols and actions revealed to the eavesdropper).


title:
The Mass of KOI-94d and a Relation for Planet Radius, Mass, and Incident
  Flux

abstract:
  We measure the mass of a modestly irradiated giant planet, KOI-94d. We wish
to determine whether this planet, which is in a 22-day orbit and receives 2700
times as much incident flux as Jupiter, is as dense as Jupiter or rarefied like
inflated hot Jupiters. KOI-94 also hosts 3 smaller transiting planets, all of
which were detected by the Kepler Mission. With 26 radial velocities of KOI-94
from the W. M. Keck Observatory and a simultaneous fit to the Kepler light
curve, we measure the mass of the giant planet and determine that it is not
inflated. Support for the planetary interpretation of the other three
candidates comes from gravitational interactions through transit timing
variations, the statistical robustness of multi-planet systems against false
positives, and several lines of evidence that no other star resides within the
photometric aperture. The radial velocity analyses of KOI-94b and KOI-94e offer
marginal (>2\sigma) mass detections, whereas the observations of KOI-94c offer
only an upper limit to its mass. Using the KOI-94 system and other planets with
published values for both mass and radius (138 exoplanets total, including 35
with M < 150 Earth masses), we establish two fundamental planes for exoplanets
that relate their mass, incident flux, and radius from a few Earth masses up to
ten Jupiter masses. These equations can be used to predict the radius or mass
of a planet.


title: Haagerup property for quantum reflection groups

abstract:
  In this paper we prove that the duals of the quantum reflection groups have
the Haagerup property for all $N\ge4$ and $s\in[1,\infty)$. We use the
canonical arrow onto the quantum permutation groups, and we describe how the
characters of the quantum reflection groups behave with respect to this
canonical morphism thanks to the description of the fusion rules binding
irreducible corepresentations of $H_N^{s+}$. This allows us to construct states
on the central algebra of $H_{N}^{s+}$ and to use a fundamental theorem proved
by M.Brannan giving a method to construct nets of trace-preserving, normal,
unital and completely positive maps on the von Neumann algebra of a compact
quantum group of Kac type.


title:
Connection Between Mid-Infrared Emission Properties and Narrow Line
  Region Outflows in Type 1 Active Galactic Nuclei

abstract:
  The location of warm dust producing the Mid-infrared (MIR) emission in Type 1
Active Galactic Nuclei (AGNs) is complex and not yet fully known. We explore
this problem by studying how the MIR covering factor (CF_{MIR}
=L_{MIR}/L_{bol}) correlates with the fundamental parameters of AGN accretion
process (such as L_{bol}, black hole mass MBH, and Eddington ratio L/LEdd) and
the properties of narrow emission lines (as represented by [O III] 5007), using
large data sets derived from the Sloan Digital Sky Spectroscopic Survey (SDSS)
and the Wide Infrared Sky Survey (WISE). Firstly we find that the luminosity of
the [O III] wing component (Lwing) correlates more tightly with the continuum
luminosity (L5100) than the luminosity of the line core component (Lcore) does,
which is in line with our previous conclusion that the wing component,
generally blueshifted, originates from the polar outflows in the inner
narrow-line region (NLR). We then find that the MIR CF shows the strongest
correlation with Lwing/L_{bol} rather than with Lcore/L_{bol} or the above
fundamental AGN parameters, and the correlation becomes stronger as the
infrared wavelength increases. We also confirm the anti-correlations of
CF_{MIR} with L_{bol} and MBH, and the lack of dependence of CF_{MIR} on the
Eddington ratio. These results suggest that a large fraction of the warm dust
producing MIR emission in AGNs is likely embedded in polar outflows in the NLR
instead of in the torus.


title:
Relativistic Positron-Electron-Ion Shear Flows and Application to
  Gamma-Ray Bursts

abstract:
  We present Particle-in-Cell simulation results of relativistic shear flows
for hybrid positron-electron-ion plasmas and compare to those for pure e+e- and
pure e-ion plasmas. Among the three types of relativistic shear flows, we find
that only hybrid shear flow is able to energize the electrons to form a
high-energy spectral peak plus a hard power-law tail. Such electron spectra are
needed to model the observational properties of gamma-ray bursts.


title:
Dark Matter implications of Fermi-LAT measurement of anisotropies in the
  diffuse gamma-ray background

abstract:
  The detailed origin of the diffuse gamma-ray background is still unknown.
However, the contribution of unresolved sources is expected to induce
small-scale anisotropies in this emission, which may provide a way to identify
and constrain the properties of its contributors. Recent studies have predicted
the contributions to the angular power spectrum (APS) from extragalactic and
galactic dark matter (DM) annihilation or decay. The Fermi-LAT collaboration
reported detection of angular power with a significance larger than $3\sigma$
in the energy range from 1 GeV to 10 GeV on 22 months of data [Ackermann et al.
2012]. For these preliminary results the already published Fermi-LAT APS
measurements [Ackermann et al. 2012] are compared to the accurate predictions
for DM anisotropies from state-of-the-art cosmological simulations as presented
in [Fornasa et al. 2013] to derive constraints on different DM candidates.


title: Prompt VERITAS Observations Triggered by High Energy Fermi-LAT Photons

abstract:
  In any given 24-hour period, the Fermi-LAT detects photons with energies of
order 100 GeV not associated with any known VHE emitter. The RA/Dec of these
photons frequently falls into the field of view of VERITAS the following
evening. A single photon in the LAT can potentially mean many detectable
photons on the ground due to the superior collection area of the IACT (Imaging
Atmospheric Cherenkov Technique) method. During the 2011-2012 observing season,
VERITAS implemented a new target-of-opportunity (ToO) program to trigger
VERITAS observations on a small sample of the highest energy LAT photons. Each
photon that triggered observation was detected by the LAT within the previous
24-hour period and was not spatially associated with a known VHE emitter. We
present here the results of these ToO observations, a discussion of the method
used, and our future plans.


title:
The Powerful Model Adpredictor for Search Engine Switching Detection
  Challenge

abstract:
  The purpose of the Switching Detection Challenge in the 2013 WSCD workshop
was to predict users' search engine swithcing actions given records about
search sessions and logs.Our solution adopted the powerful prediction model
Adpredictor and utilized the method of feature engineering. We successfully
applied the click through rate (CTR) prediction model Adpredicitor into our
solution framework, and then the discovery of effective features and the
multiple classification of different switching type make our model outperforms
many competitors. We achieved an AUC score of 0.84255 on the private
leaderboard and ranked the 5th among all the competitors in the competition.


title:
Dynamic phase transition in the three-dimensional kinetic Ising model in
  an oscillating field

abstract:
  Using numerical simulations we investigate the properties of the dynamic
phase transition that is encountered in the three-dimensional Ising model
subjected to a periodically oscillating magnetic field. The values of the
critical exponents are determined through finite-size scaling. Our results show
that the studied non-equilibrium phase transition belongs to the universality
class of the equilibrium three-dimensional Ising model.


title:
Transition of the Stellar Initial Mass Function Explored with Binary
  Population Synthesis

abstract:
  The stellar initial mass function (IMF) plays a crucial role in determining
the number of surviving stars in galaxies, the chemical composition of the
interstellar medium, and the distribution of light in galaxies. A key unsolved
question is whether the IMF is universal in time and space. Here we use
state-of-the-art results of stellar evolution to show that the IMF of our
Galaxy made a transition from an IMF dominated by massive stars to the
present-day IMF at an early phase of the Galaxy formation. Updated results from
stellar evolution in a wide range of metallicities have been implemented in a
binary population synthesis code, and compared with the observations of
carbon-enhanced metal-poor (CEMP) stars in our Galaxy. We find that applying
the present-day IMF to Galactic halo stars causes serious contradictions with
four observable quantities connected with the evolution of AGB stars.
Furthermore, a comparison between our calculations and the observations of CEMP
stars may help us to constrain the transition metallicity for the IMF which we
tentatively set at [Fe/H] = -2. A novelty of the current study is the inclusion
of mass loss suppression in intermediate-mass AGB stars at low-metallicity.
This significantly reduces the overproduction of nitrogen-enhanced stars that
was a major problem in using the high-mass star dominated IMF in previous
studies. Our results also demonstrate that the use of the present day IMF for
all time in chemical evolution models results in the overproduction of Type I.5
supernovae. More data on stellar abundances will help to understand how the IMF
has changed and what caused such a transition.


title:
Uniqueness for inverse boundary value problems by Dirichlet-to -Neumann
  map on subboundaries

abstract:
  We consider inverse boundary value problems for elliptic equations of second
order of determining coefficients by Dirichlet-to-Neumann map on subboundaries,
that is, the mapping from Dirichlet data supported on $\partial\Omega\setminus
\Gamma_-$ to Neumann data on $\partial\Omega\setminus \Gamma_+$. First we prove
uniqueness results in three dimensions under some conditions such as
$\bar{\Gamma_+ \cup \Gamma_-} = \partial\Omega$. Next we survey uniqueness
results in two dimensions for various elliptic systems for arbitrarily given
$\Gamma_- = \Gamma_+$. Our proof is based on complex geometric optics solutions
which are constructed by a Carleman estimate.


title: Studying the Proton "Radius" Puzzle with \mu p Elastic Scattering

abstract:
  The Proton Radius Puzzle is the inconsistency between the proton radius
determined from muonic hydrogen and the proton radius determined from atomic
hydrogen level transitions and ep elastic scattering. No generally accepted
resolution to the Puzzle has been found. Possible solutions generally fall into
one of three categories: the two radii are different due to novel
beyond-standard-model physics, the two radii are different due to novel aspects
of nucleon structure, and the two radii are the same, but there are
underestimated uncertainties or other issues in the ep experiments.
  The MUon proton Scattering Experiment (MUSE) at the Paul Scherrer Institut is
a simultaneous measurement of \mu^+ p and e^+ p elastic scattering, as well as
\mu^- p and e^- p elastic scattering, which will allow a determination of the
consistency of the \mu p and the ep interactions. The differences between + and
- charge scattering are sensitive to two-photon exchange effects, higher-order
corrections to the scattering process. The slopes of the cross sections as Q^2
-> 0 determine the proton "radius". We plan to measure relative cross sections
at a typical level of a few tenths of a percent, which should allow the proton
radius to be determined at the level of ~0.01 fm, similar to previous ep
measurements. The measurements will test several possible explanations of the
proton radius puzzle, including some models of beyond-standard-model physics,
some models of novel hadronic physics, and some issues in the radius extraction
from scattering data.


title:
A two-step energy injection explanation for the rebrightenings of the
  multi-band afterglow of GRB 081029

abstract:
  The afterglow of GRB 081029 showed unusual behavior, with a significant
rebrightening being observed at optical wavelength at about 3000 s after the
burst. One possible explanation is that the rebrightening is resulted from
energy injection. Here, we present a detailed numerical study of the energy
injection process and interpret the X-ray and optical afterglow light curves of
GRB 081029. In our model, we have assumed two periods of energy injection, each
with a constant injection power. One injection starts at $2.8\times10^{3}$ s
and lasts for about 2500 s, with a power of $7.0\times10^{47}$ ${\rm erg}$
${\rm s^{-1}}$. This energy injection is mainly engaged to account for the
rapid rebrightening at about 3000 s. The other injection starts at
$8.0\times10^{3}$ s and lasts for about 5000 s. The injection power is
$3.5\times10^{47}$ ${\rm erg}$ ${\rm s^{-1}}$. This energy injection can help
to explain the slight rebrightening at about 10000 s. It is shown that the
observed optical afterglow, especially the marked rebrightening at about 3000
s, can be well reproduced. In X-ray band, the predicted amplitude of the
rebrightening is much shallower, which is also consistent with the observed
X-ray afterglow light curve. It is argued that the two periods of energy
injection can be produced by the falling of clumpy materials onto the central
compact object of the burster, which leads to an enhancement of accretion and
gives birth to a strong outflow temporarily.


title:
New Hardness Results for Guarding Orthogonal Polygons with Sliding
  Cameras

abstract:
  Let $P$ be an orthogonal polygon. Consider a sliding camera that travels back
and forth along an orthogonal line segment $s\in P$ as its \emph{trajectory}.
The camera can see a point $p\in P$ if there exists a point $q\in s$ such that
$pq$ is a line segment normal to $s$ that is completely inside $P$. In the
\emph{minimum-cardinality sliding cameras problem}, the objective is to find a
set $S$ of sliding cameras of minimum cardinality to guard $P$ (i.e., every
point in $P$ can be seen by some sliding camera) while in the
\emph{minimum-length sliding cameras problem} the goal is to find such a set
$S$ so as to minimize the total length of trajectories along which the cameras
in $S$ travel.
  In this paper, we first settle the complexity of the minimum-length sliding
cameras problem by showing that it is polynomial tractable even for orthogonal
polygons with holes, answering a question asked by Katz and Morgenstern (2011).
We next show that the minimum-cardinality sliding cameras problem is
\textsc{NP}-hard when $P$ is allowed to have holes, which partially answers
another question asked by Katz and Morgenstern (2011).


title:
Feedback and harmonic locking of slot-type optomechanical oscillators to
  external low-noise reference clocks

abstract:
  We demonstrate feedback and harmonic locking of chip-scale slot-type
optomechanical oscillators to external low-noise reference clocks, with
suppressed timing jitter by three orders of magnitude. The feedback and
compensation techniques significantly reduce the close-to-carrier phase noise,
especially within the locking bandwidth for the integral root-mean-square
timing jitter. Harmonic locking via high-order carrier signals is also
demonstrated with similar phase noise and integrated root-mean-square timing
jitter reduction. The chip-scale optomechanical oscillators are tunable over an
80-kHz range by tracking the reference clock, with potential applications in
tunable radio-frequency photonics platforms.


title:
Searching for low-workfunction phases in the Cs-Te system: the case of
  Cs2Te5

abstract:
  We have computationally explored workfunction values of Cs2Te5, an existing
crystalline phase of the Cs-Te system and a small bandgap semiconductor, in
order to search for reduced workfunction alternatives of Cs2Te that preserve
the exceptionally high quantum efficiency of the Cs2Te seasoned photoemissive
material. We have found that the Cs2Te5(010) surface exhibits a workfunction
value of ~ 1.9 eV when it is covered by Cs atoms. Cs2Te5 is analogous to our
recently proposed low-workfunction materials, Cs2TeC2 and other ternary
acetylides [J. Z. Terdik, et al., Phys. Rev. B 86, 035142 (2012)], in as much
as it also contains quasi one-dimensional substructures embedded in a
Cs-matrix, forming the foundation for anomalous workfunction anisotropy, and
low workfunction values. The one-dimensional substructures in Cs2Te5 are
polytelluride ions in a tetragonal rod packing. Cs2Te5 has the advantage of
simpler composition and availability as compared to Cs2TeC2, however its low
workfunction surface is less energetically favored to the other surfaces than
in Cs2TeC2.


title:
Ready, set and no action: A static perspective on potential energy
  surfaces commonly used in gas-surface dynamics

abstract:
  In honoring the seminal contribution of Henry Eyring and Michael Polanyi who
first introduced the concept of potential energy surfaces (PESs) to describe
chemical reactions in gas-phase [Z. Phys. Chem. 12, 279-311, (1931)], this work
comes to review and assess state-of-the-art approaches towards first-principle
based modeling in the field of gas-surface dynamics. Within the
Born-Oppenheimer and frozen surface approximations, the O2-Ag(100) interaction
energetics are used as a showcase system to accentuate the complex landscape
exhibited by the PESs employed to describe the impingement of diatomics on
metal substrates and draw attention to the far-from-trivial task of
continuously representing them within all six molecular degrees of freedom. To
this end, the same set of ab initio reference data obtained within Density
Functional Theory (DFT) are continuously represented by two different
state-of-the-art high-dimensional approaches, namely the Corrugation-Reducing
Procedure and Neural Networks. Exploiting the numerically undemanding nature of
the resulting representations, a detailed static evaluation is performed on
both PESs based on an extensive global minima search. The latter proved
particularly illuminating in revealing representation deficiencies which affect
the dynamical picture yet go otherwise unnoticed within the so-called
"divide-and-conquer" approach.

categories: cond-mat.mtrl-sci cond-mat.dis-nn physics.chem-ph physics.comp-ph


title:
Earth Occultation Imaging Applied to BATSE -- Application to a Combined
  BATSE-GBM Survey of the Hard X-Ray Sky

abstract:
  A combined BATSE-GBM hard X-ray catalog is presented based on Earth
Occultation Imaging applied to a reanalysis of BATSE data. An imaging approach
has been developed for the reanalysis of Earth Occultation analysis of BATSE
data. The standard occultation analysis depends on a predetermined catalog of
potential sources, so that a real source not present in the catalog may induce
systematic errors when source counts associated with an uncatalogued source are
incorrectly attributed to catalog sources. The goal of the imaging analysis is
to find a complete set of hard X-ray sources, including sources not in the
original BATSE occultation catalog. Using the imaging technique, we have
identified 15 known sources and 17 unidentified sources and added them to the
BATSE occultation catalog. The resulting expanded BATSE catalog of sources
observed during 1991-2000 is compared to the ongoing GBM survey.


title:
A New Multiferroic State with Large Electric Polarization in Tensile
  Strained TbMnO3

abstract:
  By performing first-principles calculations, we systematically explore the
effect of epitaxial strain on the structure and properties of multiferroic
TbMnO3. We show that, although the unstrained bulk TbMnO3 displays a
non-collinear antiferromagnetic spin order, TbMnO3 can be ferromagnetic under
compressive strain, in agreement with the experimental results on TbMnO3 grown
on SrTiO3. By increasing the tensile strain up to 5%, we predict that TbMnO3
transforms into a new multiferroic state with a large ferroelectric
polarization,two orders of magnitude larger than that in the unstrained bulk,
and with a relatively high Neel temperature E-type antiferromagnetic order. We
also find that the ferroelectric domain and antiferromagnetic domain are
interlocked with each other, thus an external electric field can switch the
ferroelectric domain and the antiferromagnetic domain simultaneously. Our work
demonstrates that strain engineering can be used to improve the multiferroic
properties of TbMnO3.


title: New Understanding of the Bethe Approximation and the Replica Method

abstract:
  In this thesis, new generalizations of the Bethe approximation and new
understanding of the replica method are proposed. The Bethe approximation is an
efficient approximation for graphical models, which gives an asymptotically
accurate estimate of the partition function for many graphical models. The
Bethe approximation explains the well-known message passing algorithm, belief
propagation, which is exact for tree graphical models. It is also known that
the cluster variational method gives the generalized Bethe approximation,
called the Kikuchi approximation, yielding the generalized belief propagation.
In the thesis, a new series of generalization of the Bethe approximation is
proposed, which is named the asymptotic Bethe approximation. The asymptotic
Bethe approximation is derived from the characterization of the Bethe free
energy using graph covers, which was recently obtained by Vontobel. The
asymptotic Bethe approximation can be expressed in terms of the edge zeta
function by using Watanabe and Fukumizu's result about the Hessian of the Bethe
entropy. The asymptotic Bethe approximation is confirmed to be better than the
conventional Bethe approximation on some conditions. For this purpose, Chertkov
and Chernyak's loop calculus formula is employed, which shows that the error of
the Bethe approximation can be expressed as a sum of weights corresponding to
generalized loops, and generalized for non-binary finite alphabets by using
concepts of information geometry.


title: Distributed Fuzzy Optimal Spectrum Sensing In Cognitive Radio

abstract:
  The spectrum is a scarce resource and must utilize efficiently, the cognitive
radio is a prospective solution for underutilized spectrum. The spectrum
sensing is a key functionality to alleviate interference of secondary user to
primary. The cognitive radios must detect the existence of the primary user and
vacate the band for the primary immediately if the primary user detected. In
cooperative sensing, every cognitive radio communicates their decision to
fusion center via reporting channel. The reporting channels are not error free,
which results corruption in the secondary's decision or information due to
multipath fading and shadowing. This paper investigates the distributed fuzzy
optimal cooperative spectrum sensing. The data and decision fusion with fuzzy
detection is investigated in this paper. The simulation result shows the
significant improvement in sensing performance over AND, OR and majority rules.
The optimality in spectrum sensing is achieved by the proposed method with 1/3
of total malicious secondary users. The proposed scheme outperforms in the
presence of malicious users.


title:
A Model-Based Analysis of GC-Biased Gene Conversion in the Human and
  Chimpanzee Genomes

abstract:
  GC-biased gene conversion (gBGC) is a recombination-associated process that
favors the fixation of G/C alleles over A/T alleles. In mammals, gBGC is
hypothesized to contribute to variation in GC content, rapidly evolving
sequences, and the fixation of deleterious mutations, but its prevalence and
general functional consequences remain poorly understood. gBGC is difficult to
incorporate into models of molecular evolution and so far has primarily been
studied using summary statistics from genomic comparisons. Here, we introduce a
new probabilistic model that captures the joint effects of natural selection
and gBGC on nucleotide substitution patterns, while allowing for correlations
along the genome in these effects. We implemented our model in a computer
program, called phastBias, that can accurately detect gBGC tracts ~1 kilobase
or longer in simulated sequence alignments. When applied to real primate genome
sequences, phastBias predicts gBGC tracts that cover roughly 0.3% of the human
and chimpanzee genomes and account for 1.2% of human-chimpanzee nucleotide
differences. These tracts fall in clusters, particularly in subtelomeric
regions; they are enriched for recombination hotspots and fast-evolving
sequences; and they display an ongoing fixation preference for G and C alleles.
We also find some evidence that they contribute to the fixation of deleterious
alleles, including an enrichment for disease-associated polymorphisms. These
tracts provide a unique window into historical recombination processes along
the human and chimpanzee lineages; they supply additional evidence of long-term
conservation of megabase-scale recombination rates accompanied by rapid
turnover of hotspots. Together, these findings shed new light on the
evolutionary, functional, and disease implications of gBGC. The phastBias
program and our predicted tracts are freely available.


title: CPU and/or GPU: Revisiting the GPU Vs. CPU Myth

abstract:
  Parallel computing using accelerators has gained widespread research
attention in the past few years. In particular, using GPUs for general purpose
computing has brought forth several success stories with respect to time taken,
cost, power, and other metrics. However, accelerator based computing has
signifi- cantly relegated the role of CPUs in computation. As CPUs evolve and
also offer matching computational resources, it is important to also include
CPUs in the computation. We call this the hybrid computing model. Indeed, most
computer systems of the present age offer a degree of heterogeneity and
therefore such a model is quite natural.
  We reevaluate the claim of a recent paper by Lee et al.(ISCA 2010). We argue
that the right question arising out of Lee et al. (ISCA 2010) should be how to
use a CPU+GPU platform efficiently, instead of whether one should use a CPU or
a GPU exclusively. To this end, we experiment with a set of 13 diverse
workloads ranging from databases, image processing, sparse matrix kernels, and
graphs. We experiment with two different hybrid platforms: one consisting of a
6-core Intel i7-980X CPU and an NVidia Tesla T10 GPU, and another consisting of
an Intel E7400 dual core CPU with an NVidia GT520 GPU. On both these platforms,
we show that hybrid solutions offer good advantage over CPU or GPU alone
solutions. On both these platforms, we also show that our solutions are 90%
resource efficient on average.
  Our work therefore suggests that hybrid computing can offer tremendous
advantages at not only research-scale platforms but also the more realistic
scale systems with significant performance gains and resource efficiency to the
large scale user community.


title:
Towards Determining the energy of the UHECRs observed by the ANITA
  detector

abstract:
  The Antarctic Impulsive Transient Antenna (ANITA) is a balloon-borne radio
experiment designed to discover ultra-high energy cosmic neutrinos. The ANITA
detector has completed one prototype and two full-scale flights above the
Antarctic continent. Two direct and fourteen reflected cosmic ray events of
ultra-high energy were observed during the first full scale flight and several
others in the second flight. We present a Monte Carlo technique and analysis
developed to determine the energy of the primary cosmic ray particles from the
ANITA data.


title:
Throughput Analysis of Cognitive Wireless Networks with Poisson
  Distributed Nodes Based on Location Information

abstract:
  This paper provides a statistical characterization of the individual
achievable rates in bits/s/Hz and the spatial throughput of bipolar Poisson
wireless networks in bits/s/Hz/m$^2$. We assume that all transmitters have a
cognitive ability to know the distance to their receiver's closest interferers
so they can individually tune their coding rates to avoid outage events for
each spatial realization. Considering that the closest interferer approximates
the aggregate interference of all transmitters treated as noise, we derive
closed-form expressions for the probability density function of the achievable
rates under two decoding rules: treating interference as noise, and jointly
detecting the strongest interfering signals treating the others as noise. Based
on these rules and the bipolar model, we approximate the expected maximum
spatial throughput, showing the best performance of the latter decoding rule.
These results are also compared to the reference scenario where the
transmitters do not have cognitive ability, coding their messages at
predetermined rates that are chosen to optimize the expected spatial throughput
-- regardless of particular realizations -- which yields outages. We prove
that, when the same decoding rule and network density are considered, the
cognitive spatial throughput always outperforms the other option.


title: Techniques for targeted Fermi-GBM follow-up of gravitational-wave events

abstract:
  The Advanced LIGO and Advanced Virgo ground-based gravitational-wave
detectors are projected to come online 2015-2016, reaching a final sensitivity
sufficient to observe dozens of binary neutron star mergers per year by 2018.
We present a fully-automated, targeted search strategy for prompt gamma-ray
counterparts in offline Fermi-GBM data. The multi-detector method makes use of
a detailed model response of the instrument, and benefits from time and sky
location information derived from the gravitational-wave signal.


title: An efficient cntfet-based 7-input minority gate

abstract:
  Complementary metal oxide semiconductor technology (CMOS) has been faced
critical challenges in nano-scale regime. CNTFET (Carbon Nanotube Field effect
transistor) technology is a promising alternative for CMOS technology. In this
paper, we proposed a novel 7-input minority gate in CNTFET technology that has
only 9 CNTFETs. Minority function is utilized in the voting systems for
decision making and also it is used in data mining. This proposed 7-input
minority gate is utilized less fewer transistors than the conventional CMOS
method which utilizes many transistors for implementing sum of products. By
means of this proposed 7-input minority gate, a 4-input NAND gate can be
implemented, which gets better the conventional design in terms of delay and
energy efficiency and has much more deriving power at its output.