title: Collective Spin-Hall Effect for Electron-Hole Gratings

abstract:
  We show that an electric field parallel to the wavefronts of an electron-hole
grating in a GaAs quantum well generates, via the electronic spin Hall effect,
a spin grating of the same wave vector and with an amplitude that can exceed 1%
of the amplitude of the initial density grating. We refer to this phenomenon as
"collective spin Hall effect". A detailed study of the coupled-spin charge
dynamics for quantum wells grown in different directions reveals rich features
in the time evolution of the induced spin density, including the possibility of
generating a helical spin grating.


title: Intrinsic torsion in quaternionic contact geometry

abstract:
  We investigate quaternionic contact (qc) manifolds from the point of view of
intrinsic torsion. We argue that the natural structure group for this geometry
is a non-compact Lie group K containing Sp(n)H^*, and show that any qc
structure gives rise to a canonical K-structure with constant intrinsic
torsion, except in seven dimensions, when this condition is equivalent to
integrability in the sense of Duchemin.
  We prove that the choice of a reduction to Sp(n)H^* (or equivalently, a
complement of the qc distribution) yields a unique K-connection satisfying
natural conditions on torsion and curvature.
  We show that the choice of a compatible metric on the qc distribution
determines a canonical reduction to Sp(n)Sp(1) and a canonical
Sp(n)Sp(1)-connection whose curvature is almost entirely determined by its
torsion. We show that its Ricci tensor, as well as the Ricci tensor of the
Biquard connection, has an interpretation in terms of intrinsic torsion.


title:
Galaxy triplets in Sloan Digital Sky Survey Data Release 7: II. A
  connection with compact groups?

abstract:
  We analyse a sample of 71 triplets of luminous galaxies derived from the work
of O'Mill et al. (2012). We compare the properties of triplets and their
members with those of control samples of compact groups, the ten brightest
members of rich clusters, and galaxies in pairs. The triplets are restricted to
have members with spectroscopic redshifts in the range 0.01<z<0.14 and
Mr<-20.5. We analyse the stellar mass (SM) content, the star formation rates,
the Dn(4000) parameter and colour index and also analyse different global
properties of these systems as total star formation activity and global
colours. We calculate the probability that the properties of galaxies in
triplets are strongly correlated. We define the triplet compactness as a
measure of the percentage of the system total area that is filled by the light
of member galaxies. Our analysis suggest that triplet galaxy members behave
similarly to compact group members and galaxies in rich clusters. We also find
that systems comprising 3 blue, star-forming, young stellar population galaxies
(blue triplets) are most probably real systems and not a chance configuration
of interloping galaxies. The same holds for triplets composed by 3 red, non
star-forming galaxies, showing the correlation of galaxy properties in these
systems. From the analysis of the triplet as a whole, we conclude that, at a
given total SM content, triplets show a total star formation activity and
global colours similar to compact groups. However, blue triplets show a high
total star formation activity with a lower SM content. From an analysis of the
compactness parameter of the systems we find that light is even more
concentrated in triplets than in compact groups. We propose that triplets
composed by 3 luminous galaxies, should not be considered as an analogous of
galaxy pairs with an extra member, but rather they are a natural extension of
compact groups.


title:
The low-extinction afterglow in the solar-metallicity host galaxy of
  gamma-ray burst 110918A

abstract:
  Metallicity is theoretically thought to be a fundamental driver in gamma-ray
burst (GRB) explosions and energetics, but is still, even after more than a
decade of extensive studies, not fully understood. This is largely related to
two phenomena: a dust-extinction bias, that prevented high-mass and thus likely
high-metallicity GRB hosts to be detected in the first place, and a lack of
efficient instrumentation, that limited spectroscopic studies including
metallicity measurements to the low-redshift end of the GRB host population.
The subject of this work is the very energetic GRB 110918A, for which we
measure a redshift of z=0.984. GRB 110918A gave rise to a luminous afterglow
with an intrinsic spectral slope of b=0.70, which probed a sight-line with
little extinction (A_V=0.16 mag) typical of the established distributions of
afterglow properties. Photometric and spectroscopic follow-up observations of
the galaxy hosting GRB 110918A, including optical/NIR photometry with GROND and
spectroscopy with VLT/X-shooter, however, reveal an all but average GRB host in
comparison to the z~1 galaxies selected through similar afterglows to date. It
has a large spatial extent with a half-light radius of ~10 kpc, the highest
stellar mass for z<1.9 (log(M_*/M_sol) = 10.68+-0.16), and an Halpha-based star
formation rate of 41 M_sol/yr. We measure a gas-phase extinction of ~1.8 mag
through the Balmer decrement and one of the largest host-integrated
metallicities ever of around solar (12 + log(O/H) = 8.93+/-0.13). This presents
one of the very few robust metallicity measurements of GRB hosts at z~1, and
establishes that GRB hosts at z~1 can also be very metal rich. It conclusively
rules out a metallicity cut-off in GRB host galaxies and argues against an
anti-correlation between metallicity and energy release in GRBs.


title: Powers of distances to lower dimensional sets as Muckenhoupt weights

abstract:
  Let $(X,d,\mu)$ be an Ahlfors metric measure space. We give sufficient
conditions on a closed set $F\subseteq X$ and on a real number $\beta$ in such
a way that $d(x,F)^\beta$ becomes a Muckenhoupt weight. We give also some
illustrations to regularity of solutions of partial differential equations and
regarding some classical fractals.


title: Una interpretaci\'on f\'isica de la constante de Planck

abstract:
  According to the commonly accepted interpretation of Quantum Mechanics, it is
only possible to talk about the existence of elementary particles when they are
detected by an experiment or by a classical measurement device. This has led to
distortions with regard to the objective existence of reality, since it would
be necessary an observer to materialize the elementary particle. This issue is
solved when the elementary particle is placed in permanent interaction with the
rest of the universe, so its existence would not depend on any intelligent
observer and thus the objective range of elementary particles would be
recovered. This article explores the interaction between elementary particles
and a background action field of stochastic character and it is also determined
that the standard deviation of the particle-background field interaction is
essentially the Planck constant, since the expressions of the energy according
to the Planck postulate and the momentum according to the Louis de Broglie
thesis follow in a natural way. In addition, the expression for the wave
function of a free particle is obtained from the solution of the integral
equation that relates the momentum and the energy with the wave vector and the
angular frequency of a Gaussian distribution. Also, the Schr\"odinger equation
is deduced from the expression for the wave function of an elementary particle
in a potential field. Finally, the uncertainty principle is obtained. The
theory presented in this article rescues the objective nature of Quantum
Mechanics which implies that elementary particles exist independently of
observers since the classical measurement device in this theory, introduced by
the authors, is the own universe.


title:
Sinkhorn Distances: Lightspeed Computation of Optimal Transportation
  Distances

abstract:
  Optimal transportation distances are a fundamental family of parameterized
distances for histograms. Despite their appealing theoretical properties,
excellent performance in retrieval tasks and intuitive formulation, their
computation involves the resolution of a linear program whose cost is
prohibitive whenever the histograms' dimension exceeds a few hundreds. We
propose in this work a new family of optimal transportation distances that look
at transportation problems from a maximum-entropy perspective. We smooth the
classical optimal transportation problem with an entropic regularization term,
and show that the resulting optimum is also a distance which can be computed
through Sinkhorn-Knopp's matrix scaling algorithm at a speed that is several
orders of magnitude faster than that of transportation solvers. We also report
improved performance over classical optimal transportation distances on the
MNIST benchmark problem.


title:
Finding Numerical Solutions of Diophantine Equations using Ant Colony
  Optimization

abstract:
  The paper attempts to find numerical solutions of Diophantine equations, a
challenging problem as there are no general methods to find solutions of such
equations. It uses the metaphor of foraging habits of real ants. The ant colony
optimization based procedure starts with randomly assigned locations to a fixed
number of artificial ants. Depending upon the quality of these positions, ants
deposit pheromone at the nodes. A successor node is selected from the
topological neighborhood of each of the nodes based on this stochastic
pheromone deposit. If an ant bumps into an already encountered node, the
pheromone is updated correspondingly. A suitably defined pheromone evaporation
strategy guarantees that premature convergence does not take place. The
experimental results, which compares with those of other machine intelligence
techniques, validate the effectiveness of the proposed method.


title:
Urban ozone concentration forecasting with artificial neural network in
  Corsica

abstract:
  Atmospheric pollutants concentration forecasting is an important issue in air
quality monitoring. Qualitair Corse, the organization responsible for
monitoring air quality in Corsica (France) region, needs to develop a
short-term prediction model to lead its mission of information towards the
public. Various deterministic models exist for meso-scale or local forecasting,
but need powerful large variable sets, a good knowledge of atmospheric
processes, and can be inaccurate because of local climatical or geographical
particularities, as observed in Corsica, a mountainous island located in a
Mediterranean Sea. As a result, we focus in this study on statistical models,
and particularly Artificial Neural Networks (ANN) that have shown good results
in the prediction of ozone concentration at horizon h+1 with data measured
locally. The purpose of this study is to build a predictor to realize
predictions of ozone and PM10 at horizon d+1 in Corsica in order to be able to
anticipate pollution peak formation and to take appropriated prevention
measures. Specific meteorological conditions are known to lead to particular
pollution event in Corsica (e.g. Saharan dust event). Therefore, several ANN
models will be used, for meteorological conditions clustering and for
operational forecasting.


title:
The dependence of dark matter profiles on the stellar to halo mass
  ratio: a prediction for cusps vs cores

abstract:
  We use 31 simulated galaxies from the MaGICC project to investigate the
effects of baryonic feedback on the density profiles of dark matter (DM)
haloes. The sample covers a wide mass range: 9.4e9<Mhalo/Msun<7.8e11, hosting
galaxies with stellar masses: 5.0e5<M*/Msun<8.3e10, i.e. from dwarf to L*. The
galaxies are simulated with several baryonic prescriptions, including a range
of stellar feedbacks. The main result is a clear dependence of the inner slope
of the DM density profile, \alpha\ in \rho r^\alpha, on the ratio between
stellar-to-halo mass (M*/Mhalo). This relation is independent of the stellar
feedback scheme, allowing a prediction for cusp vs core formation. When
M*/Mhalo is low, ~0.01%, energy from stellar feedback is insufficient to
significantly alter the inner DM density and the galaxy retains a cuspy
profile. At higher M*/Mhalo, feedback drives the expansion of the DM and
generates cored profiles. The flattest profiles form where M*/Mhalo~0.5%. Above
this ratio, stars formed in the central regions deepen the gravitational
potential enough to oppose this supernova-driven expansion process, resulting
in smaller cores and cuspier profiles. Combining the dependence of \alpha\ on
M*/Mhalo with the abundance matching relation between M* and Mhalo provides a
prediction for how \alpha\ varies with M*. Further, using the Tully-Fisher
relation allows a prediction for the dependence of the DM inner slope on the
observed rotation velocity of galaxies. The most cored galaxies are expected to
have Vrot~50km/s, with \alpha\ decreasing for more massive disc galaxies:
spirals with Vrot~150km/s have central slopes \alpha<-0.8, approaching the NFW
profile. This novel prediction for the dependence of \alpha\ on disc galaxy
mass can be tested using current observational data sets, and can be applied to
theoretical modeling of mass profiles and populations of disc galaxies.


title: Discriminating Higgs production mechanisms using jet energy profiles

abstract:
  We present a new tool for precision measurements of the Higgs boson
production mechanisms at the LHC. We study events with a Higgs boson produced
with two forward jets. Even with fairly stringent cuts, one expects a
significant contamination of gluon fusion (GF) in addition to vector-boson
fusion (VBF) in the event sample. By measuring the jet energy profile of the
most central jet, we find that SM production can be distinguished from either
pure VBF or pure GF at the $5\sigma$ level with 100 fb$^{-1}$ of luminosity at
the 14 TeV LHC. Moreover, this discrimination technique can be used to validate
or rule out new physics models that predict similar observable branching
fractions as the 125 GeV SM Higgs but have different production mechanisms.


title: Multiple accretion events as a trigger for Sgr A* activity

abstract:
  Gas clouds are present in the Galactic centre, where they orbit around the
supermassive black hole. Collisions between these clumps reduce their angular
momentum, and as a result some of the clumps are set on a plunging trajectory.
Constraints can be imposed on the nature of past accretion events based on the
currently observed X-ray reflection from the molecular clouds. We discuss
accretion of clouds in the context of enhanced activity of Sgr A* during the
past few hundred years. We put forward a scenario according to which gas clouds
bring material close to the horizon of the black hole on <~0.1 parsec scale. We
have modelled the source intrinsic luminosity assuming that multiple events
occur at various moments in time. These events are characterized by the amount
of accreted material and the distribution of angular momentum. We parameterized
the activity in the form of a sequence of discrete events, followed the viscous
evolution, and calculated the luminosity of the system from the time-dependent
accretion rate across the inner boundary. Accreting clumps settle near a
circularization radius, spread there during the viscous time, and subsequently
feed the black hole over a certain period. A significant enhancement (by factor
of ten) of the luminosity is only expected if the viscous timescale of the
inflow is very short. On the other hand, the increase in source activity is
expected to be much less prominent if the latter timescale is longer and a
considerable fraction of the material does not reach the centre. A solution is
obtained under two additional assumptions: (i) the radiative efficiency is a
decreasing function of the Eddington ratio; (ii) the viscous decay of the
luminosity proceeds somewhat faster than the canonical L(t)~t^{-5/3} profile.
We applied our scheme to the case of G2 cloud in the Galactic centre to obtain
constraints on the core-less gaseous cloud model.


title:
Mass-sheet degeneracy, power-law models and external convergence: Impact
  on the determination of the Hubble constant from gravitational lensing

abstract:
  The light travel time differences in strong gravitational lensing systems
allows an independent determination of the Hubble constant. This method has
been successfully applied to several lens systems. The formally most precise
measurements are, however, in tension with the recent determination of $H_0$
from the Planck satellite for a spatially flat six-parameters $\Lambda CDM$
cosmology. We reconsider the uncertainties of the method, concerning the mass
profile of the lens galaxies, and show that the formal precision relies on the
assumption that the mass profile is a perfect power law. Simple analytical
arguments and numerical experiments reveal that mass-sheet like transformations
yield significant freedom in choosing the mass profile, even when exquisite
Einstein rings are observed. Furthermore, the characterization of the
environment of the lens does not break that degeneracy which is not physically
linked to extrinsic convergence. We present an illustrative example where the
multiple imaging properties of a composite (baryons + dark matter) lens can be
extremely well reproduced by a power-law model having the same velocity
dispersion, but with predictions for the Hubble constant that deviate by $\sim
20%$. Hence we conclude that the impact of degeneracies between parametrized
models have been underestimated in current $H_0$ measurements from lensing, and
need to be carefully reconsidered.


title:
Exclusion of Cosmic Rays in Protoplanetary Disks: Stellar and Magnetic
  Effects

abstract:
  (Abridged) Cosmic rays (CRs) are thought to provide an important source of
ionization in the outermost and densest regions of protoplanetary disks;
however, it is unknown to what degree they are physically present. As is
observed in the Solar System, stellar winds can inhibit the propagation of
cosmic rays within the circumstellar environment and subsequently into the
disk. In this work, we explore the hitherto neglected effects of cosmic ray
modulation by both stellar winds and magnetic field structures and study how
these processes act to reduce disk ionization rates. We construct a
two-dimensional protoplanetary disk model of a T-Tauri star system, focusing on
ionization from stellar and interstellar FUV, stellar X-ray photons, and cosmic
rays. We show that stellar winds can power a Heliosphere-like analogue, i.e., a
"T-Tauriosphere," diminishing cosmic ray ionization rates by several orders of
magnitude at low to moderate CR energies (E_CR<1 GeV). We explore models of
both the observed solar wind cosmic ray modulation and a highly simplified
estimate for "elevated" cosmic ray modulation as would be expected from a young
T-Tauri star. In the former (solar analogue) case, we estimate the ionization
rate from galactic cosmic rays to be zeta_CR~(0.23-1.4) x 1e-18 s^-1. This
range of values, which we consider to be the maximum CR ionization rate for the
disk, is more than an order of magnitude lower than what is generally assumed
in current models for disk chemistry and physics. In the latter case, i.e., for
a "T-Tauriosphere," the ionization rate by cosmic rays is zeta_CR<1e-20 s^-1,
which is 1000 times smaller than the interstellar value. Indeed, if winds are
as efficient at cosmic ray modulation as predicted here, short-lived
radionuclides (now extinct) would have provided the major source of ionization
(zeta_RN~7.3e-19 s^-1) in the planet-forming zone of the young Solar Nebula.


title:
Radiation from a D-dimensional collision of shock waves: numerical
  methods

abstract:
  We present a pedagogical introduction to the problem of evolving a head on
collision of two Aichelburg-Sexl gravitational shock waves in D-dimensions,
using perturbative techniques. We follow a constructive approach with examples,
going in some detail through: the set up of the exact initial conditions and
their properties; perturbative methods in flat space-time with Green function
solutions; and numerical strategies to evaluate the integral solutions. We also
discuss, briefly, radiation extraction methods adapted to this problem,
together with some of the results for this system.


title:
The HARPS search for southern extra-solar planets. XXXIV. A planetary
  system around the nearby M dwarf GJ163, with a super-Earth possibly in the
  habitable zone

abstract:
  The meter-per-second precision achieved by today velocimeters enables the
search for 1-10 M_Earth planets in the habitable zone of cool stars. This paper
reports on the detection of 3 planets orbiting GJ163 (HIP19394), a M3 dwarf
monitored by our ESO/HARPS search for planets. We made use of the HARPS
spectrograph to collect 150 radial velocities of GJ163 over a period of 8
years. We searched the RV time series for coherent signals and found 5 distinct
periodic variabilities. We investigated the stellar activity and casted doubts
on the planetary interpretation for 2 signals. Before more data can be acquired
we concluded that at least 3 planets are orbiting GJ163. They have orbital
periods of P_b=8.632+-0.002, P_c=25.63+-0.03 and P_d=604+-8 days and minimum
masses msini = 10.6+-0.6, 6.8+-0.9, and 29+-3 M_Earth, respectively. We hold
our interpretations for the 2 additional signals with periods P_(e)=19.4 and
P_(f)=108 days. The inner pair presents an orbital period ratio of 2.97, but a
dynamical analysis of the system shows that it lays outside the 3:1 mean motion
resonance. GJ163c, in particular, is a super-Earth with an equilibrium
temperature of T_eq = (302+-10) (1-A)^(1/4) K and may lie in the so called
habitable zone for albedo values (A=0.34-0.89) moderately higher than that of
Earth (A_Earth=0.2-0.3).


title:
Physical Properties, Star Formation, and Active Galactic Nucleus
  Activity in Balmer Break Galaxies at 0 < z < 1

abstract:
  We present a spectroscopic study with the derivation of the physical
properties of 37 Balmer break galaxies, which have the necessary lines to
locate them in star-forming-AGN diagnostic diagrams. These galaxies span a
redshift range from 0.045 to 0.93 and are somewhat less massive than similar
samples of previous works. The studied sample has multiwavelength photometric
data coverage from the ultraviolet to MIR Spitzer bands. We investigate the
connection between star formation and AGN activity via optical, mass-excitation
(MEx) and MIR diagnostic diagrams. Through optical diagrams, 31 (84%)
star-forming galaxies, 2 (5%) composite galaxies and 3 (8%) AGNs were
classified, whereas from the MEx diagram only one galaxy was classified as AGN.
A total of 19 galaxies have photometry available in all the IRAC/Spitzer bands.
Of these, 3 AGN candidates were not classified as AGN in the optical diagrams,
suggesting they are dusty/obscured AGNs, or that nuclear star formation has
diluted their contributions. Furthermore, the relationship between SFR surface
density (\Sigma_{SFR}) and stellar mass surface density per time unit
(\Sigma_{M_{\ast}/\tau}) as a function of redshift was investigated using the
[OII] \lambda3727, 3729, H\alpha \lambda6563 luminosities, which revealed that
both quantities are larger for higher redshift galaxies. We also studied the
SFR and SSFR versus stellar mass and color relations, with the more massive
galaxies having higher SFR values but lower SSFR values than less massive
galaxies. These results are consistent with previous ones showing that, at a
given mass, high-redshift galaxies have on average larger SFR and SSFR values
than low-redshift galaxies. Finally, bluer galaxies have larger SSFR values
than redder galaxies and for a given color the SSFR is larger for higher
redshift galaxies.


title: Evidence for Elevated X-ray Emission in Local Lyman Break Galaxy Analogs

abstract:
  In this paper, we study the relationship between the 2-10 keV X-ray
luminosity (L_X), assumed to originate from X-ray binaries (XRBs), and star
formation rate (SFR) in UV-selected z<0.1 Lyman break analogs (LBAs). We
present Chandra observations for four new GALEX-selected LBAs. Including
previously studied LBAs, Haro 11 and VV 114, we find that LBAs demonstrate
L_X/SFR ratios that are elevated by ~1.5sigma compared to local galaxies,
similar to the ratios found for stacked LBGs in the early Universe (z>2). We
show that these LBAs are unlikely to harbor AGN, based on their optical and
X-ray spectra and the spatial distribution of the X-rays in three spatially
extended cases. We expect that high-mass X-ray binaries (HMXBs) dominate the
X-ray emission in these galaxies, based on their high specific SFRs
(sSFRs=SFR/M* > 10^{-9}/yr), which suggest the prevalence of young stellar
populations. Since both LBAs and LBGs have lower dust attenuations and
metallicities compared to similar samples of more typical local galaxies, we
investigate the effects of dust extinction and metallicity on the L_X/SFR for
the broader population of galaxies with high sSFRs (>10^{-10}/yr). The
estimated dust extinctions (corresponding to column densities of
N_H<10^{22}/cm^2) are expected to have insignificant effects on observed
L_X/SFR ratio for the majority of galaxy samples. We find that the observed
relationship between L_X/SFR and metallicity appears consistent with
theoretical expectations from X-ray binary population synthesis models.
Therefore, we conclude that lower metallicities, related to more luminous HMXBs
such as ultraluminous X-ray sources (ULXs), drive the elevated L_X/SFR observed
in our sample of z<0.1 LBAs. The relatively metal-poor, active mode of star
formation in LBAs and distant z>2 LBGs may yield higher total HMXB luminosity
than found in typical galaxies in the local Universe.


title:
Probing the extreme realm of AGN feedback in the massive galaxy cluster,
  RX J1532.9+3021

abstract:
  We present a detailed Chandra, XMM-Newton, VLA and HST analysis of one of the
strongest cool core clusters known, RX J1532.9+3021 (z=0.3613). Using new, deep
90 ks Chandra observations, we confirm the presence of a western X-ray cavity
or bubble, and report on a newly discovered eastern X-ray cavity. The total
mechanical power associated with these AGN-driven outflows is (22+/-9)*10^44
erg/s, and is sufficient to offset the cooling, indicating that AGN feedback
still provides a viable solution to the cooling flow problem even in the
strongest cool core clusters. Based on the distribution of the optical
filaments, as well as a jet-like structure seen in the 325 MHz VLA radio map,
we suggest that the cluster harbours older outflows along the north to south
direction. The jet of the central AGN is therefore either precessing or
sloshing-induced motions have caused the outflows to change directions. There
are also hints of an X-ray depression to the north aligned with the 325 MHz
jet-like structure, which might represent the highest redshift ghost cavity
discovered to date. We further find evidence of a cold front (r=65kpc) that
coincides with the outermost edge of the western X-ray cavity and the edge of
the radio mini-halo. The common location of the cold front with the edge of the
radio mini-halo supports the idea that the latter originates from electrons
being reaccelerated due to sloshing induced turbulence. Alternatively, its
coexistence with the edge of the X-ray cavity may be due to cool gas being
dragged out by the outburst. We confirm that the central AGN is highly
sub-Eddington and conclude that a >10^10M_Sun or a rapidly spinning black hole
is favoured to explain both the radiative-inefficiency of the AGN and the
powerful X-ray cavities.


title:
Partially massless gravitons do not destroy general relativity black
  holes

abstract:
  Recent nonlinear completions of Fierz-Pauli theory for a massive spin-2 field
include nonlinear massive gravity and bimetric theories. The spectrum of
black-hole solutions in these theories is rich, and comprises the same vacuum
solutions of Einstein's gravity enlarged to include a cosmological constant. It
was recently shown that Schwarzschild (de Sitter) black holes in these theories
are generically unstable against spherical perturbations. Here we show that a
notable exception is partially massless gravity, where the mass of the graviton
is fixed in terms of the cosmological constant by \mu^2=2\Lambda/3 and a new
gauge invariance emerges. We find that general-relativity black holes are
stable in this limit. Remarkably, the spectrum of massive gravitational
perturbations is isospectral.


title: Inclusive b-jet production in heavy ion collisions at the LHC

abstract:
  Theoretical and experimental advances in understanding light jet production
and modification in Pb+Pb reactions at a center-of-mass energy 2.76 TeV have
been a highlight of the LHC heavy ion program. At the same time, the detailed
mechanisms of heavy quark energy loss in dense QCD matter are not yet fully
understood. With this motivation, we present theoretical predictions for the
nuclear-induced attenuation of the differential cross sections for inclusive
b-jet production in heavy ion collisions at the LHC for comparison to upcoming
data. We find that for transverse momenta pT > 75 GeV both hadronization and
mass effects are negligible and this attenuation is comparable to the one
observed for light jets. We discuss how the detailed b-jet quenching patterns
can be used to gain new insight into the in-medium heavy flavor dynamics.


title:
Sensitivity of JEM-EUSO to Ensemble Fluctuations in the Ultra-High
  Energy Cosmic Ray Flux

abstract:
  The flux of ultra-high energy (UHE) cosmic rays (CRs) depends on the cosmic
distribution of their sources. Data from CR observations are yet inconclusive
about their exact location or distribution, but provide a measure for the
average local density of these emitters. Due to the discreteness of the
emitters the flux is expected to show ensemble fluctuations on top of the
statistical variations, a reflection of the cosmic variance. This effect is
strongest for the most energetic cosmic rays due to the limited propagation
distance in the cosmic radiation background and is hence a local phenomenon. In
this work we study the sensitivity of the JEM-EUSO space mission to ensemble
fluctuations on the assumption of uniform distribution of sources, with local
source density \sim 10^{-5} Mpc^{-3}. We show that in 3 years of observation
JEM-EUSO will be able to probe ensemble fluctuations if the nearest sources are
at 3 Mpc, and that after 10 years orbiting the Earth, this pathfinder mission
will become sensitive to ensemble fluctuations if the nearest sources are 10
Mpc away. The study of spectral fluctuations from the local source
distributions are complementary to but independent of cosmic ray anisotropy
studies.


title: Kasner solutions, climbing scalars and big-bang singularity

abstract:
  We elaborate on a recently discovered phenomenon where a scalar field close
to big-bang is forced to climb a steep potential by its dynamics. We analyze
the phenomenon in more general terms by writing the leading order equations of
motion near the singularity. We formulate the conditions for climbing to exist
in the case of several scalars and after inclusion of higher-derivative
corrections and we apply our results to some models of moduli stabilization. We
analyze an example with steep stabilizing potential and notice again a related
critical behavior: for a potential steepness above a critical value, going
backwards towards big-bang, the scalar undergoes wilder oscillations, with the
steep potential pushing it back at every passage and not allowing the scalar to
escape to infinity. Whereas it was pointed out earlier that there are possible
implications of the climbing phase to CMB, we point out here another potential
application, to the issue of initial conditions in inflation.


title: Manipulation of Molecules with Electromagnetic Fields

abstract:
  The goal of the present article is to review the major developments that have
led to the current understanding of molecule-field interactions and
experimental methods for manipulating molecules with electromagnetic fields.
Molecule-field interactions are at the core of several, seemingly distinct,
areas of molecular physics. This is reflected in the organization of this
article, which includes sections on Field control of molecular beams, External
field traps for cold molecules, Control of molecular orientation and molecular
alignment, Manipulation of molecules by non-conservative forces, Ultracold
molecules and ultracold chemistry, Controlled many-body phenomena, Entanglement
of molecules and dipole arrays, and Stability of molecular systems in
high-frequency super-intense laser fields. The article contains 853 references.

categories: physics.atom-ph physics.atm-clus physics.chem-ph physics.optics quant-ph


title: Cold dark matter: controversies on small scales

abstract:
  The cold dark matter (CDM) cosmological model has been remarkably successful
in explaining cosmic structure over an enormous span of redshift, but it has
faced persistent challenges from observations that probe the innermost regions
of dark matter halos and the properties of the Milky Way's dwarf galaxy
satellites. We review the current observational and theoretical status of these
"small scale controversies." Cosmological simulations that incorporate only
gravity and collisionless CDM predict halos with abundant substructure and
central densities that are too high to match constraints from galaxy dynamics.
The solution could lie in baryonic physics: recent numerical simulations and
analytic models suggest that gravitational potential fluctuations tied to
efficient supernova feedback can flatten the central cusps of halos in massive
galaxies, and a combination of feedback and low star-formation efficiency could
explain why most of the dark matter subhalos orbiting the Milky Way do not host
visible galaxies. However, it is not clear that this solution can work in the
lowest mass galaxies where discrepancies are observed. Alternatively, the
small-scale conflicts could be evidence of more complex physics in the dark
sector itself. For example, elastic scattering from strong dark matter
self-interactions can alter predicted halo mass profiles, leading to good
agreement with observations across a wide range of galaxy mass. Gravitational
lensing and dynamical perturbations of tidal streams in the stellar halo
provide evidence for an abundant population of low mass subhalos in accord with
CDM predictions. These observational approaches will get more powerful over the
next few years.


title:
Approximation of Nonnegative Systems by Finite Impulse Response
  Convolutions

abstract:
  We pose the deterministic, nonparametric, approximation problem for scalar
nonnegative input/output systems via finite impulse response convolutions,
based on repeated observations of input/output signal pairs. The problem is
converted into a nonnegative matrix factorization with special structure for
which we use Csisz\'ar's I-divergence as the criterion of optimality.
Conditions are given, on the input/output data, that guarantee the existence
and uniqueness of the minimum. We propose a standard algorithm of the
alternating minimization type for I-divergence minimization, and study its
asymptotic behavior. We also provide a statistical version of the minimization
problem and give its large sample properties.


title:
Interlayer coupling in spin valves studied by broadband ferromagnetic
  resonance

abstract:
  Magnetization dynamic response of coupled and uncoupled spin valves with
structure NiFe(20 nm)/Cu(t_Cu)/NiFe(20 nm)/IrMn(10nm) were probed using
broadband ferromagnetic resonance absorption measurements. By varying the Cu
thickness t_Cu we were able to tailor the coupling intensity between the free
and pinned layers. Broadband spectra show two resonant modes for each measured
field. It is noticed that the coupling among NiFe layers modifies the amplitude
of the absorption peaks and, moreover, the dispersion relations of the modes,
which are distorted specially at the anti-parallel state. A numerical model is
proposed and applied to address the underlying physics and the observed
properties of these systems.


title:
GaN / VO2 heteroepitaxial p-n junctions: Band offset and minority
  carrier dynamics

abstract:
  We report on experimental realization of p-n heterojunctions based on p-type
GaN, and an n-type correlated oxide, VO2. The band offsets are evaluated by
current-voltage and capacitance voltage measurements at various temperatures. A
band diagram based on the conventional band bending picture is proposed to
explain the evolution of the apparent barier height from electrical
measurements and it suggests that the work function of VO2 decreases by ~0.2 eV
when it goes through the insulator to metal transtion, in qualitative agreement
with Kelvin force microscopy measurements reported in literature. The frequency
dependent capacitance measurements allows us to differentiate the miniority
carrier effect from the interface states and series resistance contributions,
and estimate the minority carrier lifetime in insulating phase of VO2 to be of
the order of few microseconds. The nitride-oxide based p-n heterojunctions
provide a new dimension


title: Non-adiabatic Chaplygin gas

abstract:
  The split of a generalised Chaplygin gas with an equation of state p =
-A/\rho^{\alpha} into an interacting mixture of pressureless matter and a
dark-energy component with equation of state p_{\Lambda} = - \rho_{\Lambda}
implies the existence of non-adiabatic pressure perturbations. We demonstrate
that the square of the effective (non-adiabatic) sound speed c_s of the medium
is proportional to the ratio of the perturbations of the dark energy to those
of the dark matter. Since, as demonstrated explicitly for the particular case
\alpha = -1/2, dark-energy perturbations are negligible compared with
dark-matter perturbations on scales that are relevant for structure formation,
we find |c_s^2| << 1. Consequently, there are no oscillations or instabilities
which have plagued previous adiabatic Chaplygin-gas models.


title: Predicting Human Behavior in Unrepeated, Simultaneous-Move Games

abstract:
  It is common to assume that agents will adopt Nash equilibrium strategies;
however, experimental studies have demonstrated that Nash equilibrium is often
a poor description of human players' behavior in unrepeated normal-form games.
In this paper, we analyze five widely studied models (Quantal Response
Equilibrium, Level-k, Cognitive Hierarchy, QLk, and Noisy Introspection) that
aim to describe actual, rather than idealized, human behavior in such games. We
performed what we believe is the most comprehensive meta-analysis of these
models, leveraging ten different data sets from the literature recording human
play of two-player games. We began by evaluating the models' generalization or
predictive performance, asking how well a model fits unseen test data after
having had its parameters calibrated based on separate training data.
Surprisingly, we found that what we dub the QLk model of Stahl & Wilson (1994)
consistently achieved the best performance. Motivated by this finding, we
describe methods for analyzing the posterior distributions over a model's
parameters. We found that QLk's parameters were being set to values that were
not consistent with their intended economic interpretations. We thus explored
variations of QLk, ultimately identifying a new model family that has fewer
parameters, gives rise to more parsimonious parameter values, and achieves
better predictive performance.


title: The resummation of the low-phistar domain of Z production

abstract:
  The presence of large logarithms in QCD corrections to observables spoils the
validity of a calculation truncated at finite order and calls for an all-orders
approach. The transverse momentum, $Q_T$, spectrum of massive lepton pairs,
produced in hadron colliders by the Drell-Yan mechanism, has received a great
deal of attention in electroweak phenomenology. We present and discuss a
next-to-next-to-leading log (NNLL) resummed calculation of a related
observable, namely $\phi^*$ (phistar), that was recently introduced because of
its distinct experimental advantages, but which is nonetheless sensitive to
similar physics: soft-collinear gluon emission in the initial state. We also
present various comparisons to collision data at the Tevatron and the LHC.


title:
Effects of Lyman alpha scattering in the IGM on clustering statistics of
  Lyman alpha emitters

abstract:
  We investigate the correlations between the observed fraction of Lyman alpha
emission from star-forming galaxies and the large scale structure by
post-processing snapshots of a large, high resolution hydrodynamical simulation
with a Lyman alpha radiative transfer code at redshifts z=4, 3, 2. We find
correlations of the observed fraction with density, density gradient along the
line of sight, velocity and velocity gradient along the line of sight, all
within the same order of magnitude (tens of percent). Additionally, a
correlation with the angular momentum of the dark matter halo is detected. In
contrast to a previous study, we find no significant deformation of the 2-point
correlation function due to selection effects from radiative transfer in the
IGM within the limited statistics of the simulation volume.


title: Fractionalized Non-Self-Dual Solutions in the CP(N-1) Model

abstract:
  We study non-self-dual classical solutions in the CP(N-1) model with Z_N
twisted boundary conditions on the spatially compactified cylinder. These
solutions have finite, and fractional, classical action and topological charge,
and are `unstable' in the sense that the corresponding fluctuation operator has
negative modes. We propose a physical interpretation of these solutions as
saddle point configurations whose contributions to a resurgent semi-classical
analysis of the quantum path integral are imaginary non-perturbative terms
which must be cancelled by infrared renormalon terms generated in the
perturbative sector.


title:
Discontinuous Almost Automorphic Functions and Almost Automorphic
  Solutions of Differential Equations with Piecewise Constant Argument

abstract:
  In this article we introduce a class of discontinuous almost automorphic
functions which appears naturally in the study of almost automorphic solutions
of differential equations with piecewise constant argument. Their fundamental
properties are used to prove the almost automorphicity of bounded solutions of
a system of differential equations with piecewise constant argument. Due to the
strong discrete character of these equations, the existence of a unique
discrete almost automorphic solution of a non-autonomous almost automorphic
difference system is obtained, for which conditions of exponential dichotomy
and discrete Bi-almost automorphicity are fundamental.


title:
Bifurcation Diagrams and Generalized Bifurcation Diagrams for a
  rotational model of an oblate satellite

abstract:
  This paper presents bifurcation and generalized bifurcation diagrams for a
rotational model of an oblate satellite. Special attention is paid to parameter
values describing one of Saturn's moons, Hyperion. For various oblateness the
largest Lyapunov Characteristic Exponent (LCE) is plotted. The largest LCE in
the initial condition as well as in the mixed parameter-initial condition space
exhibits a fractal structure, for which the fractal dimension was calculated.
It results from the bifurcation diagrams of which most of the parameter values
for preselected initial conditions lead to chaotic rotation. The First
Recurrence Time (FRT) diagram provides an explanation of the birth of chaos and
the existence of quasi-periodic windows occuring in the bifurcation diagrams.


title:
Graph theory enables drug repurposing. How a mathematical model can
  drive the discovery of hidden Mechanisms of Action

abstract:
  We introduced a methodology to efficiently exploit natural-language expressed
biomedical knowledge for repurposing existing drugs towards diseases for which
they were not initially intended. Leveraging on developments in Computational
Linguistics and Graph Theory, a methodology is defined to build a graph
representation of knowledge, which is automatically analysed to discover hidden
relations between any drug and any disease: these relations are specific paths
among the biomedical entities of the graph, representing possible Modes of
Action for any given pharmacological compound. These paths are ranked according
to their relevance, exploiting a measure induced by a stochastic process
defined on the graph. Here we show, providing real-world examples, how the
method successfully retrieves known pathophysiological Mode of Actions and
finds new ones by meaningfully selecting and aggregating contributions from
known bio-molecular interactions. Applications of this methodology are
presented, and prove the efficacy of the method for selecting drugs as
treatment options for rare diseases.


title:
Understanding the effects of leakage in superconducting quantum error
  detection circuits

abstract:
  The majority of quantum error detection and correction protocols assume that
the population in a qubit does not leak outside of its computational subspace.
For many existing approaches, however, the physical qubits do possess more than
two energy levels and consequently are prone to such leakage events. Analyzing
the effects of leakage is therefore essential to devise optimal protocols for
quantum gates, measurement, and error correction. In this work, we present a
detailed study of leakage in a two-qubit superconducting stabilizer measurement
circuit. We simulate the repeated ancilla-assisted measurement of a single
$\sigma^z$ operator for a data qubit, record the outcome at the end of each
measurement cycle, and explore the signature of leakage events in the obtained
readout statistics. An analytic model is also developed that closely
approximates the results of our numerical simulations. We find that leakage
leads to destructive features in the quantum error detection scheme, making
additional hardware and software protocols necessary.


title: Self-Iterating Soft Equalizer

abstract:
  A self-iterating soft equalizer (SISE) consisting of a few relatively weak
constituent equalizers is shown to provide robust performance even in severe
intersymbol interference (ISI) channels that exhibit deep nulls and valleys
within the signal band. Constituent equalizers are allowed to exchange soft
information in the absence of interleavers based on the method that are
designed to suppress significant correlation among their soft outputs. The
resulting SISE works well as a stand-alone equalizer or as the equalizer
component of a turbo equalization system. The performance advantages over
existing methods are validated with bit-error-rate (BER) simulations and
extrinsic information transfer (EXIT) chart analysis. It is shown that in turbo
equalizer setting the SISE achieves performance closer to the maximum a
posteriori probability equalizer than any other known schemes in very severe
ISI channels.


title: A CSO Broadband Spectral Line Survey of Sgr B2(N)-LMH from 260 - 286 GHz

abstract:
  Presented here are the results of a broadband spectral line survey of the Sgr
B2(N) - LMH region from 260 - 286 GHz using the Caltech Submillimeter
Observatory. The data were taken over the course of a single night (May 26,
2013) during the course of science testing of the remote observational
capabilities of the facility. The data are freely available to public both as
raw, double-side band observational data and as a minimally-reduced ascii
spectrum. The procedural scripts used for the preliminary data reduction using
CLASS are provided as well. The observational parameters and preliminary data
reduction procedures are detailed. Finally, we provide instructions for
accessing the data as well as comment on the robustness of the preliminary
reduction.


title: Metamaterial Loadings for Waveguide Miniaturization

abstract:
  We show that a rectangular metallic waveguide loaded with metamaterial
elements consisting of electric-field coupled (ELC) resonators placed at the
side walls can operate well below the cutoff frequency of the respective
unloaded waveguide. The dispersion diagrams indicate that propagating modes in
ELC-loaded waveguides are of forward-type for both TE and TM modes. We also
study the dispersion diagram and transmission characteristics of rectangular
metallic waveguides simultaneously loaded with ELCs and split ring resonators
(SRRs). Such doubly-loaded waveguides can support both forward wave and
backward waves, and provide independent control of the propagation
characteristics for the respective modes.


title: Finite cycles of indecomposable modules

abstract:
  We solve a long standing open problem concerning the structure of finite
cycles in the category mod A of finitely generated modules over an arbitrary
artin algebra A, that is, the chains of homomorphisms $M_0
\stackrel{f_1}{\rightarrow} M_1 \to \cdots \to M_{r-1}
\stackrel{f_r}{\rightarrow} M_r=M_0$ between indecomposable modules in mod A
which do not belong to the infinite radical of mod A. In particular, we
describe completely the structure of an arbitrary module category mod A whose
all cycles are finite. The main structural results of the paper allow to derive
several interesting combinatorial and homological properties of indecomposable
modules lying on finite cycles. For example, we prove that for all but finitely
many isomorphism classes of indecomposable modules M lying on finite cycles of
a module category mod A the Euler characteristic of M is well defined and
nonnegative. As an another application of these results we obtain a
characterization of all cycle-finite module categories mod A having only a
finite number of functorially finite torsion classes. Moreover, new types of
examples illustrating the main results of the paper are presented.


title:
Stationary States and Asymptotic Behaviour of Aggregation Models with
  Nonlinear Local Repulsion

abstract:
  We consider a continuum aggregation model with nonlinear local repulsion
given by a degenerate power-law diffusion with general exponent. The steady
states and their properties in one dimension are studied both analytically and
numerically, suggesting that the quadratic diffusion is a critical case. The
focus is on finite-size, monotone and compactly supported equilibria. We also
investigate numerically the long time asymptotics of the model by simulations
of the evolution equation. Issues such as metastability and local/ global
stability are studied in connection to the gradient flow formulation of the
model.


title:
Energy-conserving discontinuous Galerkin methods for the
  Vlasov-Amp\`{e}re system

abstract:
  In this paper, we propose energy-conserving numerical schemes for the
Vlasov-Amp\`{e}re (VA) systems. The VA system is a model used to describe the
evolution of probability density function of charged particles under self
consistent electric field in plasmas. It conserves many physical quantities,
including the total energy which is comprised of the kinetic and electric
energy. Unlike the total particle number conservation, the total energy
conservation is challenging to achieve. For simulations in longer time ranges,
negligence of this fact could cause unphysical results, such as plasma self
heating or cooling. In this paper, we develop the first Eulerian solvers that
can preserve fully discrete total energy conservation. The main components of
our solvers include explicit or implicit energy-conserving temporal
discretizations, an energy-conserving operator splitting for the VA equation
and discontinuous Galerkin finite element methods for the spatial
discretizations. We validate our schemes by rigorous derivations and benchmark
numerical examples such as Landau damping, two-stream instability and
bump-on-tail instability.


title:
Superradiant instability of extremal brane-world Reissner-Nordstr\"{o}m
  black holes to charged scalar perturbations

abstract:
  We examine the stability of extremal braneworld Reissner-Nordstr\"{o}m black
holes under massive charged scalar perturbations. We show that similar to the
four-dimensional case, the superradiant amplification can occur in braneworld
charged holes. More interestingly we find that when the spacetime dimension is
higher than four, a trapping potential well can emerge outside the braneworld
black hole. This potential well is the extra dimensional effect and does not
exist in four dimensions. It triggers the superradiant instability of the
extremal braneworld charged holes.


title: Analytic results in the position-dependent mass Schrodinger problem

abstract:
  We investigate the Schrodinger equation for a particle with a nonuniform
solitonic mass density. First, we discuss in extent the (nontrivial)
position-dependent mass $V(x)=0$ case whose solutions are hypergeometric
functions in $\tanh^2(x)$. Then, we consider an external hyperbolic-tangent
potential. We show that the effective quantum mechanical problem is given by a
Heun class equation and find analytically an eigenbasis for the space of
solutions. We also compute the eigenstates for a potential of the form
$V(x)=V_0 \sinh^2(x)$.


title: Derivation of a Matrix-valued Boltzmann Equation for the Hubbard Model

abstract:
  For the spin-$\{1}{2}$ Fermi-Hubbard model we derive the kinetic equation
valid for weak interactions by using time-dependent perturbation expansion up
to second order. In recent theoretical and numerical studies the kinetic
equation has been merely stated without further details. In this contribution
we provide the required background material.


title: Quick-MESS: A fast statistical tool for Exoplanet Imaging Surveys

abstract:
  Several tools have been developed in the past few years for the statistical
analysis of the exoplanet search surveys, mostly using a combination of
Monte-Carlo simulations or a Bayesian approach.Here we present the Quick-MESS,
a grid-based, non-Monte Carlo tool aimed to perform statistical analyses on
results from and help with the planning of direct imaging surveys. Quick-MESS
uses the (expected) contrast curves for direct imaging surveys to assess for
each target the probability that a planet of a given mass and semi-major axis
can be detected. By using a grid-based approach Quick-MESS is typically more
than an order of magnitude faster than tools based on Monte-Carlo sampling of
the planet distribution. In addition, Quick-MESS is extremely flexible,
enabling the study of a large range of parameter space for the mass and
semi-major axes distributions without the need of re-simulating the planet
distribution. In order to show examples of the capabilities of the Quick-MESS,
we present the analysis of the Gemini Deep Planet Survey and the predictions
for upcoming surveys with extreme-AO instruments.


title:
Benchmarking the Immersed Finite Element Method for Fluid-Structure
  Interaction Problems

abstract:
  We present an implementation of a fully variational formulation of an
immersed method for fluid-structure interaction problems based on the finite
element method. While typical implementation of immersed methods are
characterized by the use of approximate Dirac delta distributions, fully
variational formulations of the method do not require the use of said
distributions. In our implementation the immersed solid is general in the sense
that it is not required to have the same mass density and the same viscous
response as the surrounding fluid. We assume that the immersed solid can be
either viscoelastic of differential type or hyperelastic. Here we focus on the
validation of the method via various benchmarks for fluid-structure interaction
numerical schemes. This is the first time that the interaction of purely
elastic compressible solids and an incompressible fluid is approached via an
immersed method allowing a direct comparison with established benchmarks.


title:
The paradox of the many-state catastrophe of fundamental limits and the
  three-state conjecture

abstract:
  The calculation of the fundamental limits of nonlinear susceptibilities
posits that when a quantum system has a nonlinear response at the fundamental
limit, only three energy eigenstates contribute to the first and second
hyperpolarizability. This is called the three-level ansatz and is the only
unproven assumption in the theory of fundamental limits. All calculations that
are based on direct solution of the Schrodinger equation yield intrinsic
hyperpolarizabilities less than 0.709 and intrinsic second
hyperpolarizabilities less than 0.6. In this work, we show that relaxing the
three-level ansatz and allowing an arbitrary number of states to contribute
leads to divergence of the optimized intrinsic hyperpolarizability in the limit
of an infinite number of states - what we call the many-state catastrophe. This
is not surprising given that the divergent systems are most likely not
derivable from the Schrodinger equation, yet obey the sum rules. The sums rules
are the second ingredient in limit theory, and apply also to systems with more
general Hamiltonians. These exotic Hamiltonians may not model any real systems
found in nature. Indeed, a class of transition moments and energies that come
form the sum rules do not have a corresponding Hamiltonian that is expressible
in differential form. In this work, we show that the three-level ansatz acts as
a constraint that excludes many of the nonphysical Hamiltonians and prevents
the intrinsic hyperpolarizability from diverging. We argue that this implies
that the true fundamental limit is smaller than previously calculated. Since
the three-level ansatz does not lead to the largest possible nonlinear
response, contrary to its assertion, we propose the intriguing possibility that
the three-level ansatz is true for any system that obeys the Schrodinger
equation, yet this assertion may be unprovable.


title:
The Dirichlet Portfolio Model: Uncovering the Hidden Composition of
  Hedge Fund Investments

abstract:
  Hedge funds have long been viewed as a veritable "black box" of investing
since outsiders may never view the exact composition of portfolio holdings.
Therefore, the ability to estimate an informative set of asset weights is
highly desirable for analysis. We present a compositional state space model for
estimation of an investment portfolio's unobserved asset allocation weightings
on a set of candidate assets when the only observed information is the time
series of portfolio returns and the candidate asset returns. In this paper, we
exhibit both sequential Monte Carlo numerical and conditionally Normal
analytical approaches to solve for estimates of the unobserved asset weight
time series. This methodology is motivated by the estimation of monthly asset
class weights on the aggregate hedge fund industry from 1996 to 2012.
Furthermore, we show how to implement the results as predictive investment
weightings in order to construct hedge fund replicating portfolios.


title: Laser-Machined Ultra-High-Q Microrod Resonators for Nonlinear Optics

abstract:
  Optical whispering-gallery microresonators are useful tools in
microphotonics, and nonlinear optics at very low threshold powers. Here, we
present details about the fabrication of ultra-high-Q whispering-gallery-mode
resonators made by CO2-laser lathe machining of fused-quartz rods. The
resonators can be fabricated in less than one minute and the obtained optical
quality factors exceed Q = 10^9. Demonstrated resonator diameters are in the
range between 170 {\mu}m and 8 mm (free spectral ranges between 390 GHz and 8
GHz). Using these microresonators, a variety of optical nonlinearities are
observed, including Raman scattering, Brillouin scattering and four-wave
mixing.


title: (More) Efficient Reinforcement Learning via Posterior Sampling

abstract:
  Most provably-efficient learning algorithms introduce optimism about
poorly-understood states and actions to encourage exploration. We study an
alternative approach for efficient exploration, posterior sampling for
reinforcement learning (PSRL). This algorithm proceeds in repeated episodes of
known duration. At the start of each episode, PSRL updates a prior distribution
over Markov decision processes and takes one sample from this posterior. PSRL
then follows the policy that is optimal for this sample during the episode. The
algorithm is conceptually simple, computationally efficient and allows an agent
to encode prior knowledge in a natural way. We establish an $\tilde{O}(\tau S
\sqrt{AT})$ bound on the expected regret, where $T$ is time, $\tau$ is the
episode length and $S$ and $A$ are the cardinalities of the state and action
spaces. This bound is one of the first for an algorithm not based on optimism,
and close to the state of the art for any reinforcement learning algorithm. We
show through simulation that PSRL significantly outperforms existing algorithms
with similar regret bounds.


title: Quadratic Equations in Hyperbolic Groups are NP-complete

abstract:
  We prove that in a torsion-free hyperbolic group $\Gamma$, the length of the
value of each variable in a minimal solution of a quadratic equation $Q=1$ is
bounded by $N|Q|^3$ for an orientable equation, and by $N|Q|^{4}$ for a
non-orientable equation, where $|Q|$ is the length of the equation, and the
constant $N$ can be computed. We show that the problem, whether a quadratic
equation in $\Gamma$ has a solution, is in NP, and that there is a PSpace
algorithm for solving arbitrary equations in $\Gamma$. If additionally $\Gamma$
is non-cyclic, then this problem (of deciding existence of a solution) is
NP-complete. We also give a slightly larger bound for minimal solutions of
quadratic equations in a toral relatively hyperbolic group.


title: Bipolar electrical switching in metal-metal contacts

abstract:
  Electrical switching has been observed in carefully designed
metal-insulator-metal devices built at small geometries. These devices are also
commonly known as memristors and consist of specific materials such as
transition metal oxides, chalcogenides, perovskites, oxides with valence
defects, or a combination of an inert and an electrochemically active
electrode. No simple physical device has been reported to exhibit electrical
switching. We have discovered that a simple point-contact or a granular
arrangement formed of metal pieces exhibits bipolar switching. These devices,
referred to as coherers, were considered as one-way electrical fuses. We have
identified the state variable governing the resistance state and can program
the device to switch between multiple stable resistance states. Our
observations render previously postulated thermal mechanisms for their
resistance-change as inadequate. These devices constitute the missing canonical
physical implementations for memristor, often referred as the fourth passive
element. Apart from the theoretical advance in understanding metallic contacts,
the current discovery provides a simple memristor to physicists and engineers
for widespread experimentation, hitherto impossible.


title: Extremal Problems for Subset Divisors

abstract:
  Let $A$ be a set of $n$ positive integers. We say that a subset $B$ of $A$ is
a divisor of $A$, if the sum of the elements in $B$ divides the sum of the
elements in $A$. We are interested in the following extremal problem. For each
$n$, what is the maximum number of divisors a set of $n$ positive integers can
have? We determine this function exactly for all values of $n$. Moreover, for
each $n$ we characterize all sets that achieve the maximum. We also prove
results for the $k$-subset analogue of our problem. For this variant, we
determine the function exactly in the special case that $n=2k$. We also
characterize all sets that achieve this bound when $n=2k$.


title: An Exact Path-Loss Density Model for Mobiles in a Cellular System

abstract:
  In trying to emulate the spatial position of wireless nodes for purpose of
analysis, we rely on stochastic simulation. And, it is customary, for mobile
systems, to consider a base-station radiation coverage by an ideal cell shape.
For cellular analysis, a hexagon contour is always preferred mainly because of
its tessellating nature. Despite this fact, largely due to its intrinsic
simplicity, in literature only random dispersion model for a circular shape is
known. However, if considered, this will result an unfair nodes density
specifically at the edges of non-circular contours. As a result, in this paper,
we showed the exact random number generation technique required for nodes
scattering inside a hexagon. Next, motivated from a system channel perspective,
we argued the need for the exhaustive random mobile dropping process, and hence
derived a generic close-form expression for the path-loss distribution density
between a base-station and a mobile. Last, simulation was used to reaffirm the
validity of the theoretical analysis using values from the new IEEE 802.20
standard.


title: Notes on extremality of the Choi map

abstract:
  It is widely believed that the Choi map generates an extremal ray in the cone
$\mathcal P(M_3)$ of all positive linear maps between $C^*$-algebra $M_3$ of
all $n\times n$ matrices over the complex field. But the only proven fact is
that the Choi map generates the extremal ray in the cone of all positive linear
map preserving all real symmetric $3\times 3$ matrices. In this note, we show
that the Choi map is indeed extremal in the cone $\mathcal P(M_3)$. We also
clarify some misclaims about the correspondence between positive semi-definite
biquadratic real forms and postive linear maps, and discuss possible positive
linear maps which coincide with the Choi map on symmetric matrices.


title: Closed-Form Path-Loss Predictor for Gaussianly Distributed Nodes

abstract:
  The emulation of wireless nodes spatial position is a practice used by
deployment engineers and network planners to analyze the characteristics of a
network. In particular, nodes geolocation will directly impact factors such as
connectivity, signals fidelity, and service quality. In literature, in addition
to typical homogenous scattering, normal distribution is frequently used to
model mobiles concentration in a cellular system. Moreover, Gaussian dropping
is often considered as an effective placement method for airborne sensor
deployment. Despite the practicality of this model, getting the network channel
loss distribution still relies on exhaustive Monte Carlo simulation. In this
paper, we argue the need for this inefficient approach and hence derived a
generic and exact closed-form expression for the path-loss distribution density
between a base-station and a network of nodes. Simulation was used to reaffirm
the validity of the theoretical analysis using values from the new IEEE 802.20
standard.


title:
Big Pharma, little science? A bibliometric perspective on big pharma's
  R&D decline

abstract:
  There is a widespread perception that pharmaceutical R&D is facing a
productivity crisis characterised by stagnation in the numbers of new drug
approvals in the face of increasing R&D costs. This study explores
pharmaceutical R&D dynamics by examining the publication activities of all R&D
laboratories of the major European and US pharmaceutical firms during the
period 1995-2009. The empirical findings present an industry in
transformation.In the first place, we observe a decline of the total number of
publications by large firms. Second, we show a relative increase of their
external collaborations suggesting a tendency to outsource, and a
diversification of the disciplinary base, in particular towards computation,
health services and more clinical approaches. Also evident is a more pronounced
decline in publications by both R&D laboratories located in Europe and by firms
with European headquarters. Finally, while publications by Big Pharma in
emerging economies sharply increase, they remain extremely low compared with
those in developed countries. In summary, the trend in this transformation is
one of a gradual decrease in internal research efforts and increasing reliance
on external research. These empirical insights support the view that large
pharmaceutical firms are increasingly becoming networks integrators rather than
the prime locus of drug discovery.


title: Bounded length intervals containing two primes and an almost-prime II

abstract:
  Zhang has shown there are infinitely many intervals of bounded length
containing two primes. It appears that the current techniques cannot prove that
there are infinitely many intervals of bounded length containing three primes,
even if strong conjectures such as the Elliott-Halberstam conjecture are
assumed. We show that there are infinitely many intervals of length at most
$10^8$ which contain two primes and a number with at most 31 prime factors.


title:
Simulation and Visualization of Chaos in a Driven Nonlinear Pendulum: An
  Aid to Introducing Chaotic Systems in Physics

abstract:
  The presence of physical systems whose characteristics change in a seemingly
erratic manner gives rise to the study of chaotic systems. The characteristics
of these systems are due to their hypersensitivity to changes in initial
conditions. In order to understand chaotic systems, some sort of simulation and
visualization is pertinent. Consequently, in this work, we have simulated and
graphically visualized chaos in a driven nonlinear pendulum as a means of
introducing chaotic systems. The visualized results obtained which highlight
the hypersensitivity of the pendulum to initial conditions can be used to
effectively introduce the physics of chaotic system. The simulation and
visualization programme is written in Python codes.


title: Correlation quantum beats induced by non-Markovian effect

abstract:
  For two qubits independently coupled to their respective structured
reservoirs (Lorentzian spectrum), quantum beats for entanglement and discord
are found which are the result of quantum interference between correlation
oscillations induced by local non-Markovian environments. We also discuss the
preservation of quantum correlations by the effective suppression of the
spontaneous emission.


title:
Velocity bunching in travelling wave accelerator with low acceleration
  gradient

abstract:
  We present the analytical and simulated results concerning the influences of
the acceleration gradient in the velocity bunching process, which is a bunch
compression scheme that uses a traveling wave accelerating structure as a
compressor. Our study shows that the bunch compression application with low
acceleration gradient is more tolerant to phase jitter and more successful to
obtain compressed electron beam with symmetrical longitudinal distribution and
low energy spread. We also present a transverse emittance compensation scheme
to compensate the emittance growth caused by the increasing of the space charge
force in the compressing process that is easy to be adjusted for different
compressing factors.


title:
White dwarf-main sequence binaries from SDSS DR8: unveiling the cool
  white dwarf population

abstract:
  The spectroscopic catalogue of white dwarf-main sequence (WDMS) binaries from
the Sloan Digital Sky Survey (SDSS) is the largest and most homogeneous sample
of compact binary stars currently known. However, because of selection effects,
the current sample is strongly biased against systems containing cool white
dwarfs and/or early type companions, which are predicted to dominate the
intrinsic population. In this study we present colour selection criteria that
combines optical (ugriz DR8 SDSS) plus infrared (yjhk DR9 UKIRT Infrared Sky
Survey (UKIDSS), JHK Two Micron All Sky Survey (2MASS) and/or w1w2 Wide-Field
Infrared Survey Explorer (WISE)) magnitudes to select 3419 photometric
candidates of harbouring cool white dwarfs and/or dominant (M dwarf)
companions. We demonstrate that 84 per cent of our selected candidates are very
likely genuine WDMS binaries, and that the white dwarf effective temperatures
and secondary star spectral types of 71 per cent of our selected sources are
expected to be below <~10000-15000K, and concentrated at ~M2-3, respectively.
We also present an updated version of the spectroscopic SDSS WDMS binary
catalogue, which incorporates 47 new systems from SDSS DR8. The bulk of the DR8
spectroscopy is made up of main-sequence stars and red giants that were
targeted as part of the Sloan Extension for Galactic Understanding and
Exploration (SEGUE) Survey, therefore the number of new spectroscopic WDMS
binaries in DR8 is very small compared to previous SDSS data releases. Despite
their low number, DR8 WDMS binaries are found to be dominated by systems
containing cool white dwarfs and therefore represent an important addition to
the spectroscopic sample. The updated SDSS DR8 spectroscopic catalogue of WDMS
binaries consists of 2316 systems.


title: Detection of Widespread Hot Ammonia in the Galactic Center

abstract:
  We present the detection of metastable inversion lines of ammonia from energy
levels high above the ground state. We detect these lines in both emission and
absorption toward fifteen of seventeen positions in the central 300 parsecs of
the Galaxy. In total, we observe seven metastable transitions of ammonia:
(8,8), (9,9), (10,10), (11,11), (12,12), (13,13) and (15,15), with energies (in
Kelvins) ranging from 680 to 2200 K. We also map emission from ammonia (8,8)
and (9,9) in two clouds in the Sgr A complex (M-0.02-0.07 and M-0.13-0.08), and
we find that the line emission is concentrated toward the the dense centers of
these molecular clouds. The rotational temperatures derived from the metastable
lines toward M-0.02-0.07 and M-0.13-0.08 and an additional cloud (M0.25+0.01)
range from 350 to 450 K. Similarly highly-excited lines of ammonia have
previously been observed toward Sgr B2, where gas with kinetic temperatures of
~600 K has been inferred. Our observations show that the existence of a hot
molecular gas component is not unique to Sgr B2, but rather appears common to
many Galactic center molecular clouds. In M-0.02-0.07, we find that the hot
ammonia, contributes ~10% of the cloud's total ammonia column density, and
further, that the hot ammonia in this cloud arises in gas which is extended or
uniformly distributed on ~10 arcsecond scales. We discuss the implications of
these constraints upon the nature of this hot gas component. In addition to the
detection of hot metastable ammonia line emission, we also detect for the first
time emission from nonmetastable inversion transitions of ammonia in both
M-0.02-0.07 and M-0.13-0.08.


title:
Chemical abundances of the Milky Way thick disk and stellar halo II.:
  sodium, iron-peak and neutron-capture elements

abstract:
  We present chemical abundance analyses of sodium, iron-peak and
neutron-capture elements for 97 kinematically selected thick disk, inner halo
and outer halo stars with metallicities -3.3<[Fe/H]<-0.5. The main aim of this
study is to examine chemical similarities and differences among metal-poor
stars belonging to these old Galactic components as a clue to determine their
early chemodynamical evolution. In our previous paper, we obtained abundances
of alpha elements by performing a one-dimensional LTE abundance analysis based
on the high-resolution (R~50000) spectra obtained with the Subaru/HDS. In this
paper, a similar analysis is performed to determine abundances of an additional
17 elements. We show that, in metallicities below [Fe/H]~-2, the abundance
ratios of many elements in the thick disk, inner halo, and outer halo
subsamples are largely similar. In contrast, in higher metallicities
([Fe/H]>-1.5), differences in some of the abundance ratios among the three
subsamples are identified. Specifically, the [Na/Fe], [Ni/Fe], [Cu/Fe], and
[Zn/Fe] ratios in the inner and outer halo subsamples are found to be lower
than those in the thick disk subsample. In contrast to what was observed for
[Mg/Fe] in our previous paper, [Eu/Fe] ratios are more enhanced in the two halo
subsamples rather than in the thick disk subsample. The observed distinct
chemical abundances of some elements between the thick disk and inner/outer
halo subsamples with [Fe/H]>-1.5 support the hypothesis that these components
formed through different mechanisms. In particular, our results favor the
scenario that the inner and outer halo components formed through an assembly of
multiple progenitor systems that experienced various degrees of chemical
enrichments, while the thick disk formed through rapid star formation with an
efficient mixing of chemical elements.


title: Directional dependence of CMB parity asymmetry

abstract:
  Parity violation in the cosmic microwave background (CMB) radiation has been
confirmed by recent Planck observation. In this paper, we extend our previous
work [P. Naselsky et al. Astrophys. J. {\bf 749}, 31 (2012)] on the directional
properties of CMB parity asymmetry by considering the Planck data of the CMB
temperature anisotropy. We define six kinds of the directional statistics and
find that they all indicate the odd-parity preference of CMB data. In addition,
we find the preferred axes of all these statistics strongly correlate with the
preferred axes of the CMB kinematic dipole, quadrupole, and octopole. The
alignment between them is confirmed at more than $3\sigma$ confidence level,
which implies that the CMB parity asymmetry, and the anomalies of the CMB
quadrupole and octopole, may have the common physical, contaminated or
systematic origin. In addition, they all should be connected with the possible
contamination of the residual dipole component.


title:
An interferometric study of the Fomalhaut inner debris disk. III.
  Detailed models of the exozodiacal disk and its origin

abstract:
  [Abridged] Debris disks are extrasolar analogs to the solar system
planetesimal belts. The star Fomalhaut harbors a cold debris belt at 140 AU as
well as evidence of a warm dust component, which is suspected of being a bright
analog to the solar system's zodiacal dust.
  Interferometric observations obtained with the VLTI and the KIN have
identified near- and mid-infrared excesses attributed to hot and warm
exozodiacal dust in the inner few AU of the star.
  We performed parametric modeling of the exozodiacal disk using the GRaTeR
radiative transfer code to reproduce the interferometric data, complemented by
mid- to far-infrared measurements. A detailed treatment of sublimation
temperatures was introduced to explore the hot population at the sublimation
rim. We then used an analytical approach to successively testing several source
mechanisms.
  A good fit to the data is found by two distinct dust populations: (1) very
small, hence unbound, hot dust grains confined in a narrow region at the
sublimation rim of carbonaceous material; (2) bound grains at 2 AU that are
protected from sublimation and have a higher mass despite their fainter flux
level. We propose that the hot dust is produced by the release of small carbon
grains following the disruption of aggregates that originate from the warm
component. A mechanism, such as gas braking, is required to further confine the
small grains for a long enough time. In situ dust production could hardly be
ensured for the age of the star, so the observed amount of dust must be
triggered by intense dynamical activity.
  Fomalhaut may be representative of exozodis that are currently being surveyed
worldwide. We propose a framework for reconciling the hot exozodi phenomenon
with theoretical constraints: the hot component of Fomalhaut is likely the tip
of the iceberg since it could originate from a warm counterpart residing near
the ice line.


title: Dual codes of product semi-linear codes

abstract:
  Let $\mathbb{F}_q$ be a finite field with $q$ elements and denote by $\theta
: \mathbb{F}_q\to\mathbb{F}_q$ an automorphism of $\mathbb{F}_q$. In this
paper, we deal with linear codes of $\mathbb{F}_q^n$ invariant under a
semi-linear map $T:\mathbb{F}_q^n\to\mathbb{F}_q^n$ for some $n\geq 2$. In
particular, we study three kind of their dual codes, some relations between
them and we focus on codes which are products of module skew codes in the
non-commutative polynomial ring $\mathbb{F}_q[X,\theta]$ as a subcase of linear
codes invariant by a semi-linear map $T$. In this setting we give also an
algorithm for encoding, decoding and detecting errors and we show a method to
construct codes invariant under a fixed $T$.


title:
SArF Map: Visualizing Software Architecture from Feature and Layer
  Viewpoints

abstract:
  To facilitate understanding the architecture of a software system, we
developed SArF Map technique that visualizes software architecture from feature
and layer viewpoints using a city metaphor. SArF Map visualizes implicit
software features using our previous study, SArF dependency-based software
clustering algorithm. Since features are high-level abstraction units of
software, a generated map can be directly used for high-level decision making
such as reuse and also for communications between developers and non-developer
stakeholders. In SArF Map, each feature is visualized as a city block, and
classes in the feature are laid out as buildings reflecting their software
layer. Relevance between features is represented as streets. Dependency links
are visualized lucidly. Through open source and industrial case studies, we
show that the architecture of the target systems can be easily overviewed and
that the quality of their packaging designs can be quickly assessed.


title: Testing goodness-of-fit for logistic regression

abstract:
  Explicitly accounting for all applicable independent variables, even when the
model being tested does not, is critical in testing goodness-of-fit for
logistic regression. This can increase statistical power by orders of
magnitude.


title: A simple and efficient all-optical production of spinor condensates

abstract:
  We present a simple and optimal experimental scheme for an all-optical
production of a sodium spinor Bose-Einstein condensate (BEC). With this scheme,
we demonstrate that the number of atoms in a pure BEC can be greatly boosted by
a factor of 5 in a simple setup that includes a single-beam optical trap or a
crossed optical trap. This optimal scheme avoids technical challenges
associated with some all-optical BEC methods, and can be applied to other
optically trappable atomic species. In addition, we find a good agreement
between our theoretical model and data. The upper limit for the efficiency of
evaporative cooling in all-optical BEC approaches is also discussed.


title:
Ultracold atoms in superlattices as quantum simulators for a spin
  ordering model and phenomena

abstract:
  Cold atoms in optical lattices is the application of two formerly distinct
aspects of physics: quantum gases from atomic physics and laser theory from
quantum optics. Its use to simulate quantum phenomena and models in condensed
matter physics is a growing field. The major goal is to use cold fermonic atoms
in these superlattices for the simulations. We present here a theoretical
proposal for simulating a spin ordering model using fermions. We demonstrate
superexchange interaction in the double well and resonating valence bond (RVB)
states in kagome lattice which is important for understanding the CuO2 plane of
the superconducting cuprates and other magnetic frustrated materials.


title: Studies on the discrete integrable equations over finite fields

abstract:
  Discrete dynamical systems over finite fields are investigated and their
integrability is discussed. In particular, the discrete Painlev\'{e} equations
and the discrete KdV equation are defined over finite fields and their special
solutions are obtained. Their investigation over the finite fields has not been
done thoroughly, partly because of the indeterminacies that appear in defining
the equations. In this paper we introduce two methods to well-define the
equations over the finite fields and apply the methods to several classes of
discrete integrable equations. One method is to extend the space of initial
conditions through blowing-up at the singular points. In case of discrete
Painlev\'{e} equations, we prove that an finite field analog of the Sakai
theory can be applied to construct the space of initial conditions. The other
method is to define the equations over the field of $p$-adic numbers and then
reduce them to the finite fields. The mapping whose time evolutions commute
with the reduction is said to have a `good reduction'. We generalize good
reduction in order to be applied to integrable mappings. The generalized good
reduction is formulated as `almost good reduction' and is proved to be a
$p$-adic analog of the singularity confinement test. (*Note that this paper is
intended for the author's thesis and it draws from several of our already
published papers. Also note that several minor modifications have been made
from the original thesis.)


title:
Inferring Robot Task Plans from Human Team Meetings: A Generative
  Modeling Approach with Logic-Based Prior

abstract:
  We aim to reduce the burden of programming and deploying autonomous systems
to work in concert with people in time-critical domains, such as military field
operations and disaster response. Deployment plans for these operations are
frequently negotiated on-the-fly by teams of human planners. A human operator
then translates the agreed upon plan into machine instructions for the robots.
We present an algorithm that reduces this translation burden by inferring the
final plan from a processed form of the human team's planning conversation. Our
approach combines probabilistic generative modeling with logical plan
validation used to compute a highly structured prior over possible plans. This
hybrid approach enables us to overcome the challenge of performing inference
over the large solution space with only a small amount of noisy data from the
team planning session. We validate the algorithm through human subject
experimentation and show we are able to infer a human team's final plan with
83% accuracy on average. We also describe a robot demonstration in which two
people plan and execute a first-response collaborative task with a PR2 robot.
To the best of our knowledge, this is the first work that integrates a logical
planning technique within a generative model to perform plan inference.


title:
Optimal Tests of Treatment Effects for the Overall Population and Two
  Subpopulations in Randomized Trials, using Sparse Linear Programming

abstract:
  We propose new, optimal methods for analyzing randomized trials, when it is
suspected that treatment effects may differ in two predefined subpopulations.
Such sub-populations could be defined by a biomarker or risk factor measured at
baseline. The goal is to simultaneously learn which subpopulations benefit from
an experimental treatment, while providing strong control of the familywise
Type I error rate. We formalize this as a multiple testing problem and show it
is computationally infeasible to solve using existing techniques. Our solution
involves a novel approach, in which we first transform the original multiple
testing problem into a large, sparse linear program. We then solve this problem
using advanced optimization techniques. This general method can solve a variety
of multiple testing problems and decision theory problems related to optimal
trial design, for which no solution was previously available. In particular, we
construct new multiple testing procedures that satisfy minimax and Bayes
optimality criteria. For a given optimality criterion, our new approach yields
the optimal tradeoff? between power to detect an effect in the overall
population versus power to detect effects in subpopulations. We demonstrate our
approach in examples motivated by two randomized trials of new treatments for
HIV.


title: Computing untwisted Dijkgraaf-Witten invariants for arborescent links

abstract:
  We briefly survey 3-dimensional untwisted Dijkgraaf-Witten theory over a
finite group $\Gamma$, and present a method of computing untwisted
Dijkgraaf-Witten invariants for arborescent links. Some explicit formulas are
given when $\Gamma=\mathbb{Z}/p\mathbb{Z}\rtimes\mathbb{Z}/(p-1)\mathbb{Z}$ for
an odd prime $p$.


title:
A Financial Risk Analysis: Does the 2008 Financial Crisis Give Impact on
  Weekends Returns of the U.S. Movie Box Office?

abstract:
  The Financial Crisis of 2008 is a worldwide financial crisis causing a
worldwide economic decline that is the most severe since the 1930s. According
to the International Monetary Fund (IMF), the global financial crisis gave
impact on USD 3.4 trillion losses from financial institutions around the world
between 2007 and 2010. Does the crisis give impact on the returns of the U.S.
movie Box Office? It will be answered by doing an analysis on the financial
risk model based on Extreme Value Theory (EVT) and calculations of Value at
Risk (VaR) and Expected Shortfall (ES). The values of VaR and ES from 2
periods, 1982 to 1995 and 1996 to 2010, are compared. Results show that the
possibility of loss for an investment in the movie industry is relatively lower
than the possibility of gain for both periods of time. The values of VaR and ES
for the second period are higher than the first period. We are able to conclude
that the 2008 financial crisis gave no significant effect on these measurement
values in the second period. This result describes the high potential
opportunity in the investment of the U.S. movie makers.


title: Sub-Compton quantum non-equilibrium and Majorana systems

abstract:
  We study the Majorana equation from the point of view of the de Broglie-Bohm
pilot-wave theory (according to which a quantum ensemble of fermions is not
only described by a spinor but also by a distribution of position
configurations). Although the Majorana equation involves a mass parameter, we
show that the positions undergo luminal motion. In the case of free systems, we
also show that the trajectory can be strongly helical (the diameter of the
helix being the Compton wavelength). On a coarse-grained level (coarse-graining
with respect to the Compton wavelength), these trajectories appear subluminal.
The peculiar nature of the Majorana trajectory suggests a study of the temporal
evolution of quantum non-equilibrium distributions, which are distributions
allowed in the pilot-wave theory, in which the configurations are not
distributed according to Born's law. We do such simulations for Dirac and
Majorana systems, and we investigate whether quantum non-equilibrium might
survive at the sub-Compton scale in systems described by Majorana spinors.


title:
BER Analysis of Decision-Feedback Multiple Symbol Detection in
  Noncoherent MIMO Ultra-Wideband Systems

abstract:
  In this paper, we investigate noncoherent multiple-input multiple-output
(MIMO) ultra-wideband (UWB) systems where the signal is encoded by differential
space-time block code (DSTBC). DSTBC enables noncoherent MIMO UWB systems to
achieve diversity gain. However, the traditional noncoherent symbol-by-symbol
differential detection (DD) for DSTBC-UWB suffers from performance degradation
compared with the coherent detection. We introduce a noncoherent multiple
symbol detection (MSD) scheme to enhance the performance of DSTBC-UWB system.
Although the MSD scheme can boost the performance more as the observation
window size gets to larger, the complexity of the exhaustive search for MSD
also exponentially increases in terms of the window size. To decrease the
computational complexity, the concept of decision-feedback (DF) is introduced
to MSD for DSTBC-UWB in this paper. The resultant DF-MSD yields reasonable
complexity and also solid performance improvement. We provide the bit error
rate (BER) analysis for the proposed DF-MSD. Both theoretical analysis and
simulation results validate the proposed scheme.


title: Secrecy Wireless Information and Power Transfer with MISO Beamforming

abstract:
  The dual use of radio signals for simultaneous wireless information and power
transfer (SWIPT) has recently drawn significant attention. To meet the
practical requirement that energy receivers (ERs) operate with much higher
received power than information receivers (IRs), ERs need to be deployed closer
to the transmitter than IRs. However, due to the broadcast nature of wireless
channels, one critical issue is that the messages sent to IRs cannot be
eavesdropped by ERs, which possess better channels from the transmitter. In
this paper, we address this new secrecy communication problem in a multiuser
multiple-input single-output (MISO) SWIPT system where a multi-antenna
transmitter sends information and energy simultaneously to one IR and multiple
ERs, each with a single antenna. By optimizing transmit beamforming vectors and
their power allocation, we maximize the weighted sum-energy transferred to ERs
subject to a secrecy rate constraint for the information sent to the IR. We
solve this non-convex problem optimally by reformulating it into a two-stage
problem. First, we fix the signal-to-interference-plus-noise ratio (SINR) at
the IR and obtain the optimal beamforming solution by applying the technique of
semidefinite relaxation (SDR). Then the original problem is solved by a
one-dimension search over the optimal SINR value for the IR. Furthermore, two
suboptimal low-complexity beamforming schemes are proposed, and their
achievable (secrecy) rate-energy (R-E) regions are compared against that by the
optimal scheme.


title:
Astrophysical ZeV acceleration in the relativistic jet from an accreting
  supermassive blackhole

abstract:
  An accreting supermassive blackhole, the central engine of active galactic
nucleus (AGN), is capable of exciting extreme amplitude Alfven waves whose
wavelength (wave packet) size is characterized by its clumpiness. The
pondermotive force and wakefield are driven by these Alfven waves propagating
in the AGN (blazar) jet and accelerate protons/nuclei to extreme energies
beyond Zetta-electron volt (ZeV$=10^{21}$ eV). Such acceleration is prompt,
localized, and does not suffer from the multiple scattering/bending enveloped
in the Fermi acceleration that causes excessive synchrotron radiation loss
beyond $10^{19}$ eV. The production rate of ZeV cosmic rays is found to be
consistent with the observed gamma-ray luminosity function of blazars and their
time variabilities.


title: Australian Aboriginal Astronomy: Overview

abstract:
  The traditional cultures of Aboriginal Australians include a significant
astronomical component, perpetuated through oral tradition, ceremony, and art.
This astronomical component includes a deep understanding of the motion of
objects in the sky, and this knowledge was used for practical purposes, such as
constructing calendars. There is also evidence that traditional Aboriginal
Australians made careful records and measurements of cyclical phenomena, paid
careful attention to unexpected phenomena such as eclipses and meteorite
impacts, and could determine the cardinal points to an accuracy of a few
degrees.


title:
A New Class of Optical Beams for Large Baseline Interferometric
  Gravitational Wave Detectors

abstract:
  A folded resonant Fabry-Perot cavity has the potential to significantly
reduce the impact of coating thermal noise on the performance of kilometer
scale gravitational wave detectors. When constructed using only spherical
mirror surfaces it is possible to utilize the extremely robust $TEM_{00}$ mode
optical mode. In this paper we investigate the potential thermal noise
improvements that can be achieved for third generation gravitational wave
detectors using realistic constraints. Comparing the previously proposed beam
configurations such as e.g. higher order Laguerre-Gauss modes, we find that
similar or better thermal noise improvement factors can be achieved, while
avoiding degeneracy issues associated with those beams.


title:
Atmospheric mass loss and evolution of short-period exoplanets: the
  examples of CoRoT-7b and Kepler-10b

abstract:
  Short-period exoplanets potentially lose envelope masses during their
evolution because of atmospheric escape caused by the intense XUV radiation
from their host stars. We develop a combined model of atmospheric mass loss
calculation and thermal evolution calculation of a planet to simulate its
evolution and explore the dependences on the formation history of the planet.
Thermal atmospheric escape as well as the Roche-lobe overflow contributes to
mass loss. The maximum initial planetary model mass depends primarily on the
assumed evolution model of the stellar XUV luminosity. We adapt the model to
CoRoT-7b and Kepler-10b to explore the evolution of both planets and the
maximum initial mass of these planets. We take the recent X-ray observation of
CoRoT-7 into account and exploring the effect of different XUV evolution models
on the planetary initial mass. Our calculations indicate that both hot super
Earths could be remnants of Jupiter mass gas planets.


title:
Distributed Bayesian inference for consistent labeling of tracked
  objects in non-overlapping camera networks

abstract:
  One of the fundamental requirements for visual surveillance using
non-overlapping camera networks is the correct labeling of tracked objects on
each camera in a consistent way,in the sense that the captured tracklets, or
observations in this paper, of the same object at different cameras should be
assigned with the same label. In this paper, we formulate this task as a
Bayesian inference problem and propose a distributed inference framework in
which the posterior distribution of labeling variable corresponding to each
observation, conditioned on all history appearance and spatio-temporal evidence
made in the whole networks, is calculated based solely on local information
processing on each camera and mutual information exchanging between neighboring
cameras. In our framework, the number of objects presenting in the monitored
region, i.e. the sampling space of labeling variables, does not need to be
specified beforehand. Instead, it can be determined automatically on the fly.
In addition, we make no assumption about the appearance distribution of a
single object, but use similarity scores between appearance pairs, given by
advanced object re-identification algorithm, as appearance likelihood for
inference. This feature makes our method very flexible and competitive when
observing condition undergoes large changes across camera views. To cope with
the problem of missing detection, which is critical for distributed inference,
we consider an enlarged neighborhood of each camera during inference and use a
mixture model to describe the higher order spatio-temporal constraints. The
robustness of the algorithm against missing detection is improved at the cost
of slightly increased computation and communication burden at each camera node.
Finally, we demonstrate the effectiveness of our method through experiments on
an indoor Office Building dataset and an outdoor Campus Garden dataset.