title:
Optimization under second order constraints: are the finite element
  discretizations consistent ?

abstract:
  It is proved in Chon{\'e} and Le Meur (2001) that the problem of minimizing a
Dirichlet-like functional of the function $u\_h$ discretized with $P\_1$ Finite
Elements, under the constraint that $u\_h$ be convex, cannot converge. Here, we
first improve this result by proving that non-convergence is due to the mesh
refinment lack of richness, remains local and is true even for any mesh. Then,
we investigate the consistency of various natural discretizations ($P\_1$ and
$P\_2$) of second order constraints (subharmonicity and convexity) without
discussing the convergence. We also numerically illustrate convergence of a
method proposed in the literature that is simpler than existing methods.


title: Near IR Astrometry of Magnetars

abstract:
  We report on the progress of our five-year program for astrometric monitoring
of magnetars using high-resolution NIR observations using the laser guide star
adaptive optics (LGS-AO) supported NIRC2 camera on the 10-meter Keck telescope.
We have measured the proper motion of two of the youngest magnetars,
SGR\,1806$-$20 and SGR\,1900+14, which have counterparts with K $\sim$21\,mag,
and have placed a preliminary upper limit on the motion of the young
AXP\,1E\,1841$-$045. The precision of the proper motion measurement is at the
milliarcsecond per year level. Our proper motion measurements now provide
evidence to link SGR\,1806$-$20 and SGR\,1900+14 with neighboring young star
clusters. At the distances of these magnetars, their proper motion corresponds
to transverse space velocities of $350\pm100\,\mathrm{km\,s^{-1}}$ and
$130\pm30\,\mathrm{km\,s^{-1}}$ respectively. The upper limit on the proper
motion of AXP\,1E\,1841$-$045 is $160\,\mathrm{km\,s^{-1}}$. With the sample of
proper motions available, we conclude that the kinematics of the magnetar
family are not distinct from that of pulsars.


title:
Structure of unbound neutron-rich $^{9}$He studied using single-neutron
  transfer

abstract:
  The 8He(d,p) reaction was studied in inverse kinematics at 15.4A MeV using
the MUST2 Si-CsI array in order to shed light on the level structure of 9He.
The well known 16O(d,p)17O reaction, performed here in reverse kinematics, was
used as a test to validate the experimental methods. The 9He missing mass
spectrum was deduced from the kinetic energies and emission angles of the
recoiling protons. Several structures were observed above the neutron-emission
threshold and the angular distributions were used to deduce the multipolarity
of the transitions. This work confirms that the ground state of 9He is located
very close to the neutron threshold of 8He and supports the occurrence of
parity inversion in 9He.


title: On One Function Defined on the Cartesian Product and Guinness Numbers

abstract:
  New numbers, called Guinness numbers, are introduced using certain function
of natural argument. Few problems related to these numbers are formulated.


title:
A small remark on the derivation of the plateau angle conditions for the
  vector-valued Allen-Cahn equation

abstract:
  We clarify a point in arXiv:1210.0231 concerning the derivation of the
Plateau angle conditions for the vector-valued Allen-Cahn equation


title:
From scale properties of physical amplitudes to a predictive formulation
  of the Nambu-Jona-Lasinio model

abstract:
  The predictive power of the NJL model is considered in the light of a novel
strategy to handle the divergences typical of perturbative calculations. The
referred calculational strategy eliminates unphysical dependencies on the
arbitrary choices for the routing of internal momenta and symmetry violating
terms. In the present work we extend a previous one on the same issue by
including vector interactions and performing the discussion in a more general
context: it is considered the role of scale arbitrariness for the consistency
of the calculations. We show that the imposition of arbitrary scale
independence for the consistent regularized amplitudes lead to additional
properties for the irreducible divergent objects. These properties allow us to
parametrize the remaining freedom in terms of a unique constant where resides
all the arbitrariness involved. By searching for the best value for the
arbitrary parameter we find a critical condition for the existence of an
acceptable physical value for the dynamically generated quark mass. Such
critical condition fixes the remaining arbitrariness turning the NJL into a
predictive model in the sense that its phenomenological consequences do not
depend on possible choices made in intermediary steps. Numerical results are
obtained for physical quantities like the vector and axial-vector masses and
their coupling constants as genuine predictions.


title:
Numerical solution of gravitational dynamics in asymptotically anti-de
  Sitter spacetimes

abstract:
  A variety of gravitational dynamics problems in asymptotically anti-de Sitter
(AdS) spacetime are amenable to efficient numerical solution using a common
approach involving a null slicing of spacetime based on infalling geodesics,
convenient exploitation of the residual diffeomorphism freedom, and use of
spectral methods for discretizing and solving the resulting differential
equations. Relevant issues and choices leading to this approach are discussed
in detail. Three examples, motivated by applications to non-equilibrium
dynamics in strongly coupled gauge theories, are discussed as instructive test
cases. These are gravitational descriptions of homogeneous isotropization,
collisions of planar shocks, and turbulent fluid flows in two spatial
dimensions.


title:
Improved Ti II log(gf) Values and Abundance Determinations in the
  Photospheres of the Metal-Poor Star HD 84937

abstract:
  Atomic transition probability measurements for 364 lines of Ti II in the UV
through near IR are reported. Branching fractions from data recorded using a
Fourier transform spectrometer and a new echelle spectrometer are combined with
published radiative lifetimes to determine these transition probabilities. The
new results are in generally good agreement with previously reported FTS
measurements. Use of the new echelle spectrometer, independent radiometric
calibration methods, and independent data analysis routines enables a reduction
of systematic errors and overall improvement in transition probability accuracy
over previous measurements. The new Ti II data are applied to high resolution
visible and UV spectra of the Sun and metal-poor star HD 84937 to derive new,
more accurate Ti abundances. Lines covering a range of wavelength and
excitation potential are used to search for non-LTE effects. The Ti abundances
derived using Ti II for these two stars match those derived using Ti I and
support the relative Ti/Fe abundance ratio versus metallicity seen in previous
studies.


title: Quantum Joule-Thomson Effect in a Saturated Homogeneous Bose Gas

abstract:
  We study the thermodynamics of Bose-Einstein condensation in a weakly
interacting quasi-homogeneous atomic gas, prepared in an optical-box trap. We
characterise the critical point for condensation and observe saturation of the
thermal component in a partially condensed cloud, in agreement with Einstein's
textbook picture of a purely statistical phase transition. Finally, we observe
the quantum Joule-Thomson effect, namely isoenthalpic cooling of an
(essentially) ideal gas. In our experiments this cooling occurs spontaneously,
due to energy-independent collisions with the background gas in the vacuum
chamber. We extract a Joule-Thomson coefficient $\mu_{\rm JT} > 10^9$ K/bar,
about ten orders of magnitude larger than observed in classical gases.

categories: cond-mat.quant-gas cond-mat.stat-mech physics.atom-ph quant-ph


title: Soft-gluon resummations and NNNLO expansions

abstract:
  I discuss the effectiveness of soft-gluon resummations in describing
higher-order corrections. I present a comparison of recent resummation
approaches and their relative successes in approximating complete NNLO
corrections. I also discuss fixed-order expansions through NNNLO and present
some recent applications to QCD hard-scattering processes, including
top-antitop pair production, single-top production, and W production at large
transverse momentum.


title: Adiabatic graph-state quantum computation

abstract:
  Measurement-based quantum computation (MBQC) and holonomic quantum
computation (HQC) are two very different computational methods. The computation
in MBQC is driven by adaptive measurements executed in a particular order on a
large entangled state. In contrast in HQC the system starts in the ground
subspace of a Hamiltonian which is slowly changed such that a transformation
occurs within the subspace. Following the approach of Bacon and Flammia, we
show that any measurement-based quantum computation on a graph state with
\emph{gflow} can be converted into an adiabatically driven holonomic
computation, which we call \emph{adiabatic graph-state quantum computation}
(AGQC). We then investigate how properties of AGQC relate to the properties of
MBQC, such as computational depth. We identify a trade-off that can be made
between the number of adiabatic steps in AGQC and the norm of $\dot{H}$ as well
as the degree of $H$, in analogy to the trade-off between the number of
measurements and classical post-processing seen in MBQC. Finally the effects of
performing AGQC with orderings that differ from standard MBQC are investigated.


title:
Morphological Parameters of Spitzer Survey of Stellar Structure in
  Galaxies (S4G)

abstract:
  The morphology of galaxies can be quantified to some degree using a set of
scale-invariant parameters. Concentration (C), Asymmetry (A), Smoothness (S),
the Gini index (G), relative contribution of the brightest pixels to the second
order moment of the flux (M20), ellipticity (E), and the Gini index of the
second order moment (GM) have all been applied to morphologically classify
galaxies at various wavelengths. Here we present a catalog of these parameters
for the Spitzer Survey of Stellar Structure in Galaxies (S4G), a volume-limited
near-infrared imaging survey of nearby galaxies using the 3.6 and 4.5 micron
channels of the IRAC camera. Our goal is to provide a reference catalog of
near-infrared quantified morphology for high-redshift studies and galaxy
evolution models with enough detail to resolve stellar mass morphology.
  We explore where normal, non-interacting galaxies -those typically found on
the Hubble tuning fork- lie in this parameter space and show that there is a
tight relation between Concentration and M20 for normal galaxies. M20 can be
used to classify galaxies into earlier and later types (e.g., to separate
spirals from irregulars). Several criteria using these parameters exist to
select systems with a disturbed morphology, i.e., those that appear to be
undergoing a tidal interaction. We examine the applicability of these criteria
to Spitzer near-infrared imaging. We find that four relations, based on the
parameters A&S, G&M20, GM, and C&M20, respectively, select outliers in the
morphological parameter space, but each selects different subsets of galaxies.
Two criteria (GM > 0.6, G > -0.115 x M20 + 0.384) seem most appropriate to
identify possible mergers and the merger fraction in near-infrared surveys. We
find no strong relation between lopsidedness and most of these morphological
parameters, except for a weak dependence of lopsidedness on Concentration and
M20.


title: Homologies are infinitely complex

abstract:
  We show that for any k>1, stratified sets of finite complexity are
insufficient to realize all homology classes of codimension k in all smooth
manifolds. We also prove a similar result concerning smooth generic maps whose
double-point sets are co-oriented.


title:
Quadratic growth and critical point stability of semi-algebraic
  functions

abstract:
  We show that quadratic growth of a semi-algebraic function is equivalent to
strong metric subregularity of the subdifferential --- a kind of stability of
generalized critical points. In contrast, this equivalence can easily fail
outside of the semi-algebraic setting. As a consequence, we derive necessary
conditions and sufficient conditions for optimality in subdifferential terms.


title: Averaging on thin sets of diagonal forms

abstract:
  We investigate one-dimensional families of diagonal forms, considering the
evolution of the asymptotic formula and error term. We then discuss properties
of the average asymptotic formula obtained. The subsequent second moment
analysis precipitates an effective means of computing $p$-adic densities of
zeros for large primes $p$.


title:
Ground state of the one dimensional Gross-Pitaevskii equation with a
  Morse potential

abstract:
  We have studied the ground state of the Gross-Pitaevskii equation (nonlinear
Schrodinger equation) for a Morse potential via a variational approach. It is
seen that the ground state ceases to be bound when the coupling constant of the
nonlinear term reaches a critical value. The disappearence of the ground state
resembles a saddle node bifurcation.


title:
Unified treatment of Explicit and Trace Formulas via Poisson-Newton
  formula

abstract:
  We prove that a Poisson-Newton formula, in a broad sense, is associated to
each Dirichlet series with a meromorphic extension to the whole complex plane
of finite order. These formulas simultaneously generalize the classical Poisson
formula and Newton formulas for Newton sums. Classical Poisson formulas in
Fourier analysis, explicit formulas in number theory and Selberg trace formulas
in Riemannian geometry appear as special cases of our general Poisson-Newton
formula.


title: Canonical forms for free {\kappa}-semigroups

abstract:
  The implicit signature k consists of the multiplication and the
({\omega}-1)-power. We describe a procedure to transform each {\kappa}-term
over a finite alphabet A into a certain canonical form and show that different
canonical forms have different interpretations over some finite semigroup. The
procedure of construction of the canonical forms, which is inspired in
McCammond's normal form algorithm for {\omega}-terms interpreted over the
pseudovariety A of all finite aperiodic semigroups, consists in applying
elementary changes determined by an elementary set {\Sigma} of
pseudoidentities. As an application, we deduce that the variety of
{\kappa}-semigroups generated by the pseudovariety S of all finite semigroups
is defined by the set {\Sigma} and that the free {\kappa}-semigroup generated
by the alphabet A in that variety has decidable word problem. Furthermore, we
show that each {\omega}-term has a unique {\omega}-term in canonical form with
the same value over A. In particular, the canonical forms provide new, simpler,
representatives for {\omega}-terms interpreted over that pseudovariety.


title:
Global algebras of nonlinear generalized functions with applications in
  general relativity

abstract:
  We give an overview of the development of algebras of generalized functions
in the sense of Colombeau and recent advances concerning diffeomorphism
invariant global algebras of generalized functions and tensor fields. We
furthermore provide a survey on possible applications in general relativity in
light of the limitations of distribution theory.


title:
Nematic twist-bend phase with nanoscale modulation of molecular
  orientation

abstract:
  A state of matter in which molecules show a long-range orientational order
and no positional order is called a nematic liquid crystal. The best known and
most widely used (for example, in modern displays) is the uniaxial nematic,
with the rod-like molecules aligned along a single axis, called the director.
When the molecules are chiral, the director twists in space, drawing a
right-angle helicoid and remaining perpendicular to the helix axis; the
structure is called a chiral nematic. In this work, using transmission electron
and optical microscopy, we experimentally demonstrate a new nematic order,
formed by achiral molecules, in which the director follows an oblique helicoid,
maintaining a constant oblique angle with the helix axis and experiencing twist
and bend. The oblique helicoids have a nanoscale pitch. The new twist-bend
nematic represents a structural link between the uniaxial nematic (no tilt) and
a chiral nematic (helicoids with right-angle tilt).

categories: cond-mat.soft cond-mat.mes-hall cond-mat.mtrl-sci physics.chem-ph


title:
Parallel machine scheduling with step deteriorating jobs and setup times
  by a hybrid discrete cuckoo search algorithm

abstract:
  This article considers the parallel machine scheduling problem with
step-deteriorating jobs and sequence-dependent setup times. The objective is to
minimize the total tardiness by determining the allocation and sequence of jobs
on identical parallel machines. In this problem, the processing time of each
job is a step function dependent upon its starting time. An individual extended
time is penalized when the starting time of a job is later than a specific
deterioration date. The possibility of deterioration of a job makes the
parallel machine scheduling problem more challenging than ordinary ones. A
mixed integer programming model for the optimal solution is derived. Due to its
NP-hard nature, a hybrid discrete cuckoo search algorithm is proposed to solve
this problem. In order to generate a good initial swarm, a modified heuristic
named the MBHG is incorporated into the initialization of population. Several
discrete operators are proposed in the random walk of L\'{e}vy Flights and the
crossover search. Moreover, a local search procedure based on variable
neighborhood descent is integrated into the algorithm as a hybrid strategy in
order to improve the quality of elite solutions. Computational experiments are
executed on two sets of randomly generated test instances. The results show
that the proposed hybrid algorithm can yield better solutions in comparison
with the commercial solver CPLEX with one hour time limit, discrete cuckoo
search algorithm and the existing variable neighborhood search algorithm.


title: Gravitino Leptogenesis

abstract:
  We explore here a new mechanism by which the out of equilibrium decay of
heavy gravitinos, followed by possible R-parity violating decays in the Minimal
Supersymmetric Standard Model (MSSM) can generate the baryon asymmetry of the
universe. In this mechanism, gravitino decay produces a CP-asymmetry that is
carried by squarks or sleptons. These particles then decay through R-parity
violating operators generating a lepton asymmetry. The lepton asymmetry is
converted into a baryon asymmetry by weak sphalerons, as in the familiar case
of leptogenesis by Majorana neutrino decays. To ensure that the gravitino
decays while the sphaleron is still in equilibrium, we obtain a lower bound on
the gravitino mass, $m_{3/2} \gtrsim 10^{8} \GeV$, and therefore our mechanism
requires a high scale of SUSY breaking, as well as minimum reheating
temperature after inflation of $T\gtrsim 10^{12} \GeV$ in order to for the
gravitino density to be sufficiently large to generate the baryon asymmetry
today. We consider each of the MSSM's relevant R-parity violating operators in
turn, and derive constraints on parameters in order to give rise to a baryon
asymmetry comparable to that observed today, consistent with low energy
phenomenological bounds on SUSY models.


title:
A nearly relaxation-free opto-electronic memory from ultra-thin
  graphene-MoS$_2$ binary hybrids

abstract:
  Ultra-thin planar heterostructures of graphene and other two-dimensional
crystals have recently attracted much interest. Very high carrier mobility in a
graphene-on-boron nitride assembly is now well-established, but it has been
anticipated that appropriately designed hybrids could perform other tasks as
well. A heterostructure of graphene and molybdenum disulphide (MoS$_2$) is
expected to be sensitive to photo illumination due to the optical bandgap in
MoS$_2$. Despite significant advances in device architectures with both
graphene and MoS$_2$, binary graphene-MoS$_2$ hybrids have not been realized so
far, and the promising opto-electronic properties of such structures remain
elusive. Here we demonstrate experimentally that graphene-on-MoS$_2$ binary
heterostructures display an unexpected and remarkable persistent
photoconductivity under illumination of white light. The photoconductivity can
not only be tuned independently with both light intensity and back gate
voltage, but in response to a suitable combination of light and gate voltage
pulses the device functions as a re-writable optoelectronic switch or memory.
The persistent, or `ON', state shows virtually no relaxation or decay within
the the experimental time scales for low and moderate photoexcitation
intensity, indicating a near-perfect charge retention. A microscopic model
associates the persistence with strong localization of carriers in MoS$_2$.
These effects are also observable at room temperature, and with chemical vapour
deposited graphene, and hence are naturally scalable for large area
applications.


title: Continuum Lowering -- A New Perspective

abstract:
  What is meant by continuum lowering and ionization potential depression (IPD)
in a Coulomb system depends upon precisely what question is being asked. It is
shown that equilibrium (equation-of-state) phenomena and non-equilibrium
dynamical processes like photoionization are characterised by different values
of the IPD. In the former, the ionization potential of an atom embedded in
matter is the difference in the free energy of the many-body system between
states of thermodynamic equilibrium differing by the ionization state of just
one atom. Typically, this energy is less than that required to ionize the same
atom in vacuo. Probably, the best known example of such an IPD is that of
Stewart and Pyatt (SP). However, it is a common misconception that this formula
should apply directly to the energy of a photon causing photoionization, since
this is a local adiabatic process that occurs in the absence of a response from
the surrounding plasma. To achieve the prescribed final equilibrium state,
additional energy, in the form of heat and work, is transferred between the
atom and its surroundings. This additional relaxation energy is sufficient to
explain the discrepancy between recent spectroscopic measurements of IPD in
dense plasmas and the predictions of the SP formula. This paper provides a
detailed account of an analytical approach to calculating thermodynamic and
spectroscopic (adiabatic) IPDs in multicomponent Coulomb systems of arbitrary
coupling strength. The ramifications are carefully examined in order to
elucidate the roles of the various IPD forms. A formulation in terms of free
energy leads to an analytical equation of state (EoS) that is thermodynamically
self-consistent, provided that the bound and free electrons are dynamically
separable. Of the various proposed formulae, the Spectroscopic (adiabatic) IPD
gives the most consistent agreement with spectroscopic measurements.


title: Qatar-1: indications for possible transit timing variations

abstract:
  Variations in the timing of transiting exoplanets provide a powerful tool
detecting additional planets in the system. Thus, the aim of this paper is to
discuss the plausibility of transit timing variations on the Qatar-1 system by
means of primary transit light curves analysis. Furthermore, we provide an
interpretation of the timing variation. We observed Qatar-1 between March 2011
and October 2012 using the 1.2 m OLT telescope in Germany and the 0.6 m PTST
telescope in Spain. We present 26 primary transits of the hot Jupiter Qatar-1b.
In total, our light curves cover a baseline of 18 months. We report on
indications for possible long-term transit timing variations (TTVs). Assuming
that these TTVs are true, we present two different scenarios that could explain
them. Our reported $\sim$ 190 days TTV signal can be reproduced by either a
weak perturber in resonance with Qatar-1b, or by a massive body in the brown
dwarf regime. More observations and radial velocity monitoring are required to
better constrain the perturber's characteristics. We also refine the ephemeris
of Qatar-1b, which we find to be \mbox{$T_0 = 2456157.42204 \pm 0.0001$
\bjdtdb} and \mbox{$P = 1.4200246 \pm 0.0000007$ days}, and improve the system
orbital parameters.


title: Generation of arbitrary complex quasi-non-diffracting optical patterns

abstract:
  Due to their unique ability to maintain an intensity distribution upon
propagation, non-diffracting light fields are used extensively in various areas
of science, including optical tweezers, nonlinear optics and quantum optics, in
applications where complex transverse field distributions are required.
However, the number and type of rigorously non-diffracting beams is severely
limited because their symmetry is dictated by one of the coordinate system
where the Helmholtz equation governing beam propagation is separable. Here, we
demonstrate a powerful technique that allows the generation of a rich variety
of quasi-non-diffracting optical beams featuring nearly arbitrary intensity
distributions in the transverse plane. These can be readily engineered via
modifications of the angular spectrum of the beam in order to meet the
requirements of particular applications. Such beams are not rigorously
non-diffracting but they maintain their shape over large distances, which may
be tuned by varying the width of the angular spectrum. We report the generation
of unique spiral patterns and patterns involving arbitrary combinations of
truncated harmonic, Bessel, Mathieu, or parabolic beams occupying different
spatial domains. Optical trapping experiments illustrate the opto-mechanical
properties of such beams.


title: A sharp bound for the inscribed radius under mean curvature flow

abstract:
  We consider a family of embedded, mean convex hypersurfaces which evolve by
the mean curvature flow. It follows from general results of White that the
inscribed radius at each point on the surface is at least $\frac{c}{H}$, where
$c$ is a constant that depends only on the initial data. Andrews recently gave
a new proof of that fact using a direct monotonicity argument. In this paper,
we improve this result and show that the inscribed radius is at least
$\frac{1}{(1+\delta) \, H}$ at each point where the curvature is large.


title:
Spin Coated Plasmonic Nanoparticle Interfaces for Photocurrent
  Enhancement in Thin Film Si Solar Cells

abstract:
  Nanoparticle (NP) arrays of noble metals strongly absorb light in the visible
to infrared wavelengths through resonant interactions between the incident
electromagnetic field and the metal's free electron plasma. Such plasmonic
interfaces enhance light absorption and photocurrent in solar cells. We report
a cost effective and scalable room temperature/pressure spin-coating route to
fabricate broadband plasmonic interfaces consisting of silver NPs. The NP
interface yields photocurrent enhancement (PE) in thin film silicon devices by
up to 200% which is significantly greater than previously reported values. For
coatings produced from Ag nanoink containing particles with average diameter of
40 nm, an optimal NP surface coverage of 7% was observed. Scanning electron
microscopy of interface morphologies revealed that for low surface coverage,
particles are well-separated, resulting in broadband PE. At higher surface
coverage, formation of particle strings and clusters caused red-shifting of the
PE peak and a narrower spectral response.


title:
Mean curvature flow with surgery of mean convex surfaces in
  $\mathbb{R}^3$

abstract:
  We define a notion of mean curvature flow with surgery for two-dimensional
surfaces in $\mathbb{R}^3$ with positive mean curvature. Our construction
relies on the earlier work of Huisken and Sinestrari in the higher dimensional
case. One of the main ingredients in the proof is a new estimate for the
inscribed radius established by the first author.


title:
The Gemini NICI Planet-Finding Campaign: The Frequency of Planets around
  Young Moving Group Stars

abstract:
  We report results of a direct imaging survey for giant planets around 80
members of the Beta Pic, TW Hya, Tucana-Horologium, AB Dor, and Hercules-Lyra
moving groups, observed as part of the Gemini NICI Planet-Finding Campaign. For
this sample, we obtained median contrasts of \Delta H=13.9 mag at 1" in
combined CH4 narrowband ADI+SDI mode and median contrasts of \Delta H=15.1 mag
at 2" in H-band ADI mode. We found numerous (>70) candidate companions in our
survey images. Some of these candidates were rejected as common-proper motion
companions using archival data; we reobserved with NICI all other candidates
that lay within 400 AU of the star and were not in dense stellar fields. The
vast majority of candidate companions were confirmed as background objects from
archival observations and/or dedicated NICI campaign followup. Four co-moving
companions of brown dwarf or stellar mass were discovered in this moving group
sample: PZ Tel B (36+-6 MJup, 16.4+-1.0 AU, Biller et al. 2010), CD -35 2722B
(31+-8 MJup, 67+-4 AU, Wahhaj et al. 2011), HD 12894B (0.46+-0.08 MSun,
15.7+-1.0 AU), and BD+07 1919C (0.20+-0.03 MSun, 12.5+-1.4 AU). From a Bayesian
analysis of the achieved H band ADI and ASDI contrasts, using power-law models
of planet distributions and hot-start evolutionary models, we restrict the
frequency of 1--20 MJup companions at semi-major axes from 10--150 AU to <18%
at a 95.4% confidence level using DUSTY models and to <6% at a 95.4% using COND
models.


title:
On the geometry of the rescaled Riemannian metric on tensor bundles of
  arbitrary type

abstract:
  Let $(M,g)$ be an $n-$dimensional Riemannian manifold and $T_{1}^{1}(M)$ be
its $(1,1)-$tensor bundle equipped with the rescaled Sasaki type metric $%
^{S}g_{f}$ which rescale the horizontal part by a nonzero differentiable
function $f$. In the present paper, we discuss curvature properties of the
Levi-Civita connection and another metric connection of $T_{1}^{1}(M)$. We
construct almost paracomplex Norden structures on $T_{1}^{1}(M)$ and
investigate conditions for these structures to be para-K\"{a}hler
(paraholomorphic) and quasi-K\"{a}hler. Also, some properties of almost
paracomplex Norden structures in context of almost product Riemannian manifolds
are presented. Finally we introduce the rescaled Sasaki type metric $^{S}g_{f}$
on the $(p,q)-$\ tensor bundle and characterize the geodesics on the
$(p,q)$-tensor bundle with respect to the Levi-Civita connection of
\textit{${}$}$^{S}g_{f}$ and another metric connection of
\textit{${}$}$^{S}g_{f}.$


title:
Unraveling the Origin of Overionized Plasma in the Galactic Supernova
  Remnant W49B

abstract:
  Recent observations have shown several supernova remnants (SNRs) have
overionized plasmas, those where ions are stripped of more electrons than they
would be if in equilibrium with the electron temperature. Rapid electron
cooling is necessary to produce this situation, yet the physical origin of that
cooling remains uncertain. To assess the cooling scenario responsible for
overionization, in this paper, we identify and map the overionized plasma in
the Galactic SNR W49B based on a 220 ks Chandra Advanced CCD Imaging
Spectrometer (ACIS) observation. We performed a spatially-resolved
spectroscopic analysis, measuring the electron temperature by modeling the
continuum and comparing it to the temperature given by the flux ratio of the
He-like and H-like lines of sulfur and of argon. Using these results, we find
that W49B is overionized in the west, with a gradient of increasing
overionization from east to west. As the ejecta expansion is impeded by
molecular material in the east but not in the west, our overionization maps
suggest the dominant cooling mechanism is adiabatic expansion of the hot
plasma.


title: Naturalness from stop decays

abstract:
  In supersymmetric theories, there is a scalar quartic related to the top and
bottom yukawas that gives LHC observable decays of the stop or sbottom. After
electroweak symmetry breaking, this quartic induces the decay of the stop
(sbottom) to a charged Higgs and the sbottom (stop) without allowing for the
corresponding channel involving the W boson. Unlike other scalar quartics, this
scalar quartic is measurable at the LHC and for compressed spectra may even be
the discovery channel for the stop or sbottom. Observing this decay and
measuring the value of the quartic interaction would give direct evidence that
the underlying theory is supersymmetric as only a fermionic symmetry can relate
a scalar quartic to a yukawa interaction. This decay pathway is explored and
situations where it can be the dominant decay mode for either the stop or the
sbottom are highlighted. Measurement of this decay mode at the LHC would
unambiguously show that the underlying theory of nature was supersymmetric.


title:
Star - Planet - Debris Disk Alignment in the HD 82943 system: Is
  planetary system coplanarity actually the norm?

abstract:
  Recent results suggest that the two planets in the HD 82943 system are
inclined to the sky plane by 20 +/- 4deg. Here, we show that the debris disk in
this system is inclined by 27 +/- 4deg, thus adding strength to the derived
planet inclinations and suggesting that the planets and debris disk are
consistent with being aligned at a level similar to the Solar System. Further,
the stellar equator is inferred to be inclined by 28 +/- 4deg, suggesting that
the entire star - planet - disk system is aligned, the first time such
alignment has been tested for radial velocity discovered planets on ~AU wide
orbits. We show that the planet-disk alignment is primordial, and not the
result of planetary secular perturbations to the disk inclination. In addition,
we note three other systems with planets at >10AU discovered by direct imaging
that already have good evidence of alignment, and suggest that empirical
evidence of system-wide star - planet - disk alignment is therefore emerging,
with the exception of systems that host hot Jupiters. While this alignment
needs to be tested in a larger number of systems, and is perhaps unsurprising,
it is a reminder that the system should be considered as a whole when
considering the orientation of planetary orbits.


title: Solar System Moons as Analogs for Compact Exoplanetary Systems

abstract:
  The field of exoplanetary science has experienced a recent surge of new
systems that is largely due to the precision photometry provided by the Kepler
mission. The latest discoveries have included compact planetary systems in
which the orbits of the planets all lie relatively close to the host star,
which presents interesting challenges in terms of formation and dynamical
evolution. The compact exoplanetary systems are analogous to the moons orbiting
the giant planets in our Solar System, in terms of their relative sizes and
semi-major axes. We present a study that quantifies the scaled sizes and
separations of the Solar System moons with respect to their hosts. We perform a
similar study for a large sample of confirmed Kepler planets in multi-planet
systems. We show that a comparison between the two samples leads to a similar
correlation between their scaled sizes and separation distributions. The
different gradients of the correlations may be indicative of differences in the
formation and/or long-term dynamics of moon and planetary systems.


title:
The Size of the Narrow-Line Emitting Region in the Seyfert 1 Galaxy NGC
  5548 from Emission-Line Variability

abstract:
  The narrow [O III] 4959, 5007 emission-line fluxes in the spectrum of the
well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this
we show that the narrow line-emitting region has a radius of only 1-3 pc and is
denser (n ~ 10^5 cm^{-3}) than previously supposed. The [O III] line width is
consistent with virial motions at this radius given previous determinations of
the black hole mass.Since the [O III] emission-line flux is usually assumed to
be constant and is therefore used to calibrate spectroscopic monitoring data,
the variability has ramifications for the long-term secular variations of
continuum and emission-line fluxes, though it has no effect on shorter-term
reverberation studies. We present corrected optical continuum and broad Hbeta
emission-line light curves for the period 1988 to 2008.


title: Probabilistic image reconstruction for radio interferometers

abstract:
  We present a novel, general-purpose method for deconvolving and denoising
images from gridded radio interferometric visibilities using Bayesian inference
based on a Gaussian process model. The method automatically takes into account
incomplete coverage of the uv-plane, signal mode coupling due to the primary
beam, and noise mode coupling due to uv sampling. Our method uses Gibbs
sampling to efficiently explore the full posterior distribution of the
underlying signal image given the data. We use a set of widely diverse mock
images with a realistic interferometer setup and level of noise to assess the
method. Compared to results from a proxy for point source- based CLEAN method
we find that in terms of RMS error and signal-to-noise ratio our approach
performs better than traditional deconvolution techniques, regardless of the
structure of the source image in our test suite. Our implementation scales as
O(np log np), provides full statistical and uncertainty information of the
reconstructed image, requires no supervision, and provides a robust, consistent
framework for incorporating noise and parameter marginalizations and foreground
removal.


title: Unconventional scaling of resistivity in two-dimensional Fermi liquids

abstract:
  We study the temperature dependence of the electrical resistivity of
interacting two-dimensional metallic systems. We perform a numerical simulation
of the nonequilibrium state based on semiclassical Boltzmann transport theory.
Through our simulation, we demonstrate that deviations from the predictions of
standard Fermi-liquid theory can arise due to the special scattering geometry
of umklapp processes, in special cases even in the ultra-low-temperature limit.
Umklapp scattering is required to relax the total momentum of the quasiparticle
distribution function. We investigate the transport properties of a
two-dimensional system of quasiparticles with repulsive on-site interactions
and nonmagnetic impurity scattering on a square lattice with a single-orbital
tight-binding model of the dispersion. We demonstrate that unconventional
scaling properties of the electrical resistivity, which are often interpreted
as indication of a non-Fermi-liquid state, can arise due to special geometric
conditions of the Fermi surface. The appearance of robust deviations from the
predictions of Fermi-liquid theory within our simple model presents a novel
viewpoint in order to interpret unconventional transport properties in
electron-electron scattering dominated metallic systems.


title:
Fine structures in the spectrum of the open-boundary Heisenberg chain at
  large anisotropies

abstract:
  At large anisotropies, the spectrum of the Heisenberg XXZ spin chain
separates into `bands' with energies largely determined by the number of domain
walls. The band structure is richer with open boundary conditions: there are
more bands and the bands develop intricate fine structures. We characterize and
explain these structures and substructures in the open-boundary chain. The fine
structures are explained using degenerate perturbation theory. We also present
some dynamical consequences of these sub-band structures, through explicit time
evolution of the wavefunction from initial states motivated by the fine
structure analysis.


title: Quantum discord determines the interferometric power of quantum states

abstract:
  Quantum metrology exploits quantum mechanical laws to improve the precision
in estimating technologically relevant parameters such as phase, frequency, or
magnetic fields. Probe states are usually tailored on the particular dynamics
whose parameters are being estimated. Here we consider a novel framework where
quantum estimation is performed in an interferometric configuration, using
bipartite probe states prepared when only the spectrum of the generating
Hamiltonian is known. We introduce a figure of merit for the scheme, given by
the worst case precision over all suitable Hamiltonians, and prove that it
amounts exactly to a computable measure of discord-type quantum correlations
for the input probe. We complement our theoretical results with a metrology
experiment, realized in a highly controllable room-temperature nuclear magnetic
resonance setup, which provides a proof-of-concept demonstration for the
usefulness of discord in sensing applications. Discordant probes are shown to
guarantee a nonzero precision in the estimation procedure for different
generating Hamiltonians, while classically correlated probes are unable to
accomplish the estimation in a worst case setting. This work establishes a
rigorous and direct operational interpretation for general quantum
correlations, shedding light on their potential for quantum technology.

categories: quant-ph cond-mat.stat-mech math-ph math.MP nucl-ex physics.data-an


title:
On the observed duration distribution of gamma-ray bursts from
  collapsars

abstract:
  The duration of the prompt emission of long gamma-ray bursts is generally
considered to be fairly similar to the duration of the activity of the engine
in the center of the progenitor star. Here, we investigate the relation between
the duration of the engine activity and that of the observed light curve, using
inputs from both numerical simulations and observations. We find that the
observed burst duration is a good proxy for the engine duration after the time
necessary for the jet to break out the star's surface is subtracted. However,
the observed duration is a function of the viewing angle and can be
significantly shorter than the duration of the engine activity. We also show
that the observed, redshift-corrected burst duration evolves only moderately
with redshift for both observations and synthetic light curves. We conclude
that the broad distribution of the observed duration of long BATSE gamma-ray
bursts is mostly accounted for by an engine lasting ~20 s, the dispersion being
due to viewing and redshift effects. Our results do not rule out the existence
of engines with very long duration. However, we find that they are constrained
to be a small minority of the BATSE detected bursts.


title:
Role of Solution Conductivity in Reaction Induced Charge
  Auto-Electrophoresis

abstract:
  Catalytic bimetallic Janus particles swim by a bipolar electrochemical
propulsion mechanism that results from electroosmotic fluid slip around the
particle surface. The flow is driven by electrical body forces which are
generated from a coupling of a reaction-induced electric field and net charge
in the diffuse layer surrounding the particle. This paper presents simulations,
scaling, and physical descriptions of the experimentally observed trend that
the swimming speed decays rapidly with increasing solution conductivity. The
simulations solve the full Poisson-Nernst-Planck-Stokes equations with multiple
ionic species, a cylindrical particle in an infinite fluid, and nonlinear
Butler-Volmer boundary conditions to represent the electrochemical surface
reactions. The speed of bimetallic particles is reduced in high-conductivity
solutions because of reductions in the induced electric field in the diffuse
layer near the rod, the total reaction rate, and the magnitude of the rod zeta
potential. The results in this work suggest that the auto-electrophoretic
mechanism is inherently susceptible to speed reductions in higher ionic
strength solutions.


title: The evolution of triples with a Roche-lobe filling outer star

abstract:
  The evolution of triples has not attracted much attention in the literature,
although their evolution can be dramatically different from binaries and single
stars. Triples are quite common, and we find that for about 1% of the triples
in the Tokovinin catalogue of multiple stellar systems in the solar
neighbourhood, the tertiary star will overflow its Roche lobe at some time in
its evolution, before any of the inner stars leave the main sequence. For two
of these systems, Xi Tauri and HD97131 we simulate in detail this phase of mass
transfer, during which stellar evolution, gravitational dynamics and
hydrodynamics all play an important role. We have used the Astrophysical
Multi-purpose Software Environment (AMUSE) to solve these physical processes in
a self-consistent way. The resulting evolution, mass transfer and the effects
on the inner as well as on the outer orbit are profound, although it is not
trivial to predict the eventual consequence of the phase of mass transfer and
the appearance of the resulting system.


title: Supersymmetry Breaking by Higher Dimension Operators

abstract:
  We discuss a supersymmetry breaking mechanism for N = 1 theories triggered by
higher dimensional op- erators. We consider such operators for real linear and
chiral spinor superfields that break superymmetry and reduce to the
Volkov-Akulov action. We also consider supersymmetry breaking induced by a
higher dimensional operator of a nonminimal scalar (complex linear) multiplet.
The latter differs from the stan- dard chiral multiplet in its auxiliary
sector, which contains, in addition to the complex scalar auxiliary of a chiral
superfield, a complex vector and two spinors auxiliaries. By adding an
appropriate higher di- mension operator, the scalar auxiliary may acquire a
nonzero vev triggering spontaneous supersymmetry breaking. We find that the
spectrum of the theory in the supersymmetry breaking vacuum consists of a free
chiral multiplet and a constraint chiral superfield describing the goldstino.
Interestingly, the latter turns out to be one of the auxiliary fermions, which
becomes dynamical in the supersymmetry breaking vacuum. In all cases we are
considering here, there is no sgoldstino mode and thus the goldstino does not
have a superpartner. The sgoldstino is decoupled since the goldstino is one of
the auxiliaries, which is propagating only in the supersymmetry breaking
vacuum. We also point out how higher dimension operators introduce a potential
for the propagating scalar of the theory.


title:
Observational Requirements for Lyman-alpha Forest Tomographic Mapping of
  Large-Scale Structure at z ~ 2

abstract:
  The z > 2 Lyman-alpha (Lya) forest traces the underlying dark-matter
distribution on large scales and, given sufficient sightlines, can be used to
create 3D maps of large-scale structure. We examine the observational
requirements to construct such maps and estimate the signal-to-noise as a
function of exposure time and sightline density. Sightline densities at z =
2.25 are n_los = [360, 1200,3300] deg^{-2} at limiting magnitudes of g =[24.0,
24.5,25.0], resulting in transverse sightline separations of d_perp = [3.6,
1.9, 1.2] h^{-1} Mpc, which roughly sets the reconstruction scale. We simulate
these reconstructions using mock spectra with realistic noise properties, and
find that spectra with S/N = 4 per angstrom can be used to generate maps that
clearly trace the underlying dark-matter at overdensities of rho/<rho> ~ 1. For
the VLT/VIMOS spectrograph, exposure times t_exp = [4, 6, 10] hrs are
sufficient for maps with spatial resolution epsilon_3d = [5.0, 3.2, 2.3] h^{-1}
Mpc. Assuming ~ 250 h^{-1} Mpc is probed along the line-of-sight, 1 deg^2 of
survey area would cover a comoving volume of ~ 10^6 h^{-3} Mpc^3 at <z>=2.3,
enabling efficient mapping of large volumes with 8-10m telescopes. These maps
could be used to study galaxy environments, detect proto-clusters, and study
the topology of large-scale structure at high-z.


title:
Thermodynamics, entropy, and stability of thin shells in 2+1 flat
  spacetimes

abstract:
  The thermodynamic equilibrium states of a static thin ring shell in a
(2+1)-dimensional flat spacetime is analyzed. Inside the ring the spacetime is
flat, whereas outside it is conical flat. The first law of thermodynamics
applied to the thin shell leads to a shell's entropy which is a function of its
mass alone. Two simple forms for this mass function are given leading to two
different expressions for the entropy. The equations of thermodynamic stability
are analyzed resulting in certain allowed regions for the free parameters.
Contrary to the usual (3+1)-dimensional case this shell's entropy is purely
classic, as the only fundamental constant that enters into the problem is the
(2+1)-dimensional gravitational constant $G_3$, which has units of inverse
mass.


title:
Paramagnetic Collective Electronic Mode and Low Temperature Hybrid Modes
  in the Far Infrared Dynamics of Orthorhombic NdMnO3

abstract:
  We report on far- and mid-infrared reflectivity of NdMnO3 from 4 K to 300K.
Two main features are distinguished in the infrared spectra: active phonons in
agreement with the expected for orthorhombic D2h 16-Pbnm (Z=4) space group
remaining constant down to 4 K and a well-defined collective excitation in the
THz region due to eg electrons in a d-orbital fluctuating environment. We trace
its origin to the NdMnO3 high temperature orbital disordered intermediate phase
not being totally dynamically quenched at lower temperatures. This results in
minute orbital misalignments that translate in randomize non-static eg
electrons within orbitals yielding a room temperature collective excitation.
Below TN~78 K, electrons gradually localize inducing long-range magnetic order
as the THz band condenses into two modes that emerge pinned to the A-type
antiferromagmetic order. They harden simultaneously down to 4 K obeying power
laws with TN as the critical temperature and exponents {\beta}~0.25 and
{\beta}~0.53, as for a tri-critical point and Landau magnetic ordering,
respectively. At 4K they match known zone center spin wave modes. The power law
dependence is concomitant with a second order transition in which spin modes
modulate orbital instabilities in a magnetoelectric hybridized
orbital/charge/spin/lattice scenario. We also found that phonon profiles also
undergo strong changes at TN~78 K due to magnetoelasticity.


title: Remarks on Combinatorial Aspects of the KP Equation

abstract:
  We survey several results connecting combinatorics and Wronskian solutions of
the KP equation, contextualizing the successes of a recent approach introduced
by Kodama, et. al. We include the necessary combinatorial and analytical
background to present a formula for generalized KP solitons, compute several
explicit examples, and indicate how such a perspective could be used to extend
previous research relating line-soliton solutions of the KP equation with
Grassmannians.


title:
Rayleigh scattering boosted multi-GHz displacement sensitivity in
  whispering gallery opto-mechanical resonators

abstract:
  Finite photon lifetimes for light fields in an opto-mechanical cavity impose
a bandwidth limit on displacement sensing at mechanical resonance frequencies
beyond the loaded cavity photon decay rate. Opto-mechanical modulation
efficiency can be enhanced via multi-GHz transduction techniques such as
piezo-opto-mechanics at the cost of on-chip integration. In this paper, we
present a novel high bandwidth displacement sense scheme employing Rayleigh
scattering in photonic resonators. Using this technique in conjunction with
on-chip electrostatic drive in silicon enables efficient modulation at
frequencies up to 9.1GHz. Being independent of the drive mechanism, this scheme
could readily be extended to piezo-opto-mechanical and all optical transduced
systems.


title:
High Temperature Far Infrared Dynamics of Orthorhombic NdMnO3:
  Emissivity and Reflectivity

abstract:
  We report on near normal far- and mid-infrared emission and reflectivity of
NdMnO3 perovskite from room temperature to sample decomposition above 1800 K.
At 300 K the number infrared active phonons is in close agreement with the 25
calculated for the orthorhombic D2h16-Pbnm (Z=4) space group. Their number
gradually decreases as we approach the temperature of orbital disorder at ~1023
K where the orthorhombic O' lower temperature cooperative phase coexists with
the cubic orthorhombic O. At above ~1200 K, the three infrared active phonons
coincide with the expected for cubic Pm-3m (Z=1) in the high temperature
insulating regime. Heating samples in dry air triggers double exchange
conductivity by Mn3+ and Mn4+ ions and a small polaron mid-infrared band. Fits
to the optical conductivity single out the octahedral antisymmetric and
symmetric vibrational modes as main phonons in the electron-phonon interactions
at 875 K. For 1745 K, it is enough to consider the symmetric stretching
internal mode. An overdamped defect induced Drude component is clearly outlined
at the highest temperatures. We conclude that Rare Earth manganites eg
electrons are prone to spin, charge, orbital, and lattice couplings in an
intrinsic orbital distorted perovskite lattice favoring embryonic low energy
collective excitations.


title: Scaling laws for near barrier Coulomb and Nuclear Breakup

abstract:
  We investigate the nuclear and the Coulomb contributions to the breakup cross
sections of $^6$Li in collisions with targets in different mass ranges.
Comparing cross sections for different targets at collision energies
corresponding to the same $E/V_{\mathrm{\scriptscriptstyle B}}$, we obtain
interesting scaling laws. First, we derive an approximate linear expression for
the nuclear breakup cross section as a function of $A_{\mathrm{%
\scriptscriptstyle T}}^{1/3}$. We then confirm the validity of this expression
performing CDCC calculations. Scaling laws for the Coulomb breakup cross
section are also investigated. In this case, our CDCC calculations indicate
that this cross section has a linear dependence on the atomic number of the
target. This behavior is explained by qualitative arguments. Our findings,
which are consistent with previously obtained results for higher energies, are
important when planning for experiments involving exotic weakly bound nuclei.


title: $\Lambda\Lambda$ interaction and hypernuclei

abstract:
  Data on $\Lambda\Lambda$ hypernuclei provide a unique method to learn details
about the strangeness S =- 2 sector of the baryon-baryon interaction. From the
free space Bonn-J\"ulich potentials, determined from data on baryon-baryon
scattering in the S = 0, -1 channels, we construct an interaction in the S =-2
sector to describe the experimentally known LL hypernuclei. After including
short-range (Jastrow) and RPA correlations, we find masses for these LL
hypernuclei in a reasonable agreement with data, taking into account
theoretical and experimental uncertainties. Thus, we provide a natural
extension, at low energies, of the Bonn-J\"ulich one-boson exchange potentials
to the S =-2 channel.


title:
Formally expressing the semantics of observer-based fault detection
  software

abstract:
  The aim is to create reliable and verifiable fault detection software to
detect abrupt changes in safety-critical dynamic systems. Fault detection
methods are implemented as software on digital computers that monitor and
control the system. We implement three observer-based fault detection methods
on a 3 degrees of freedom (3DOF) laboratory helicopter, in the form of
software. We examine the performance of those methods to detect different
faults during flight in a closed-loop setup. All selected methods show
acceptable detection performance. However, it is not possible to repeat the
test for every possible conditions, inputs and fault scenarios. In this paper,
we translate fault detection properties and mathematical proofs into a formal
language, previously used in software validation and verification. We include
the translated properties in software in the form of non-executable annotations
that can be read by machine. Consequently, some high level functional
properties of the code can be verified by automatic software verification
tools. This certifies fault detection software for a set of bounded data and
increases the reliability in practice.


title: Acoustic Black Holes and Universal Aspects of Area Products

abstract:
  In this paper we derive acoustic metrics in the (3+1)-dimensional Abelian
Higgs model with higher derivative terms. We have found acoustic metrics that
are conformally related to the Reissner-Nordstr\"om and Kerr-Newman metrics.
The universal aspects of area products which depend only on quantized
quantities such as conserved electric charge and angular momentum are also
addressed. We relate these areas with entanglement entropy of acoustic black
holes in BEC systems. We also have shown there is an equivalence between
microscopic descriptions of axisymmetric acoustic black hole entropy in a BEC
system in four and two dimensions. Particularly, the system seems to develop an
analogue of the Kerr/CFT correspondence.


title: Out of the White Hole: A Holographic Origin for the Big Bang

abstract:
  While most of the singularities of General Relativity are expected to be
safely hidden behind event horizons by the cosmic censorship conjecture, we
happen to live in the causal future of the classical big bang singularity,
whose resolution constitutes the active field of early universe cosmology.
Could the big bang be also hidden behind a causal horizon, making us immune to
the decadent impacts of a naked singularity? We describe a braneworld
description of cosmology with both 4d induced and 5d bulk gravity (otherwise
known as Dvali-Gabadadze-Porati, or DGP model), which exhibits this feature:
The universe emerges as a spherical 3-brane out of the formation of a 5d
Schwarzschild black hole. In particular, we show that a pressure singularity of
the holographic fluid, discovered earlier, happens inside the white hole
horizon, and thus need not be real or imply any pathology. Furthermore, we
outline a novel mechanism through which any thermal atmosphere for the brane,
with comoving temperature of 20% of the 5D Planck mass can induce
scale-invariant primordial curvature perturbations on the brane, circumventing
the need for a separate process (such as cosmic inflation) to explain current
cosmological observations. Finally, we note that 5D space-time is
asymptotically flat, and thus potentially allows an S-matrix or (after minor
modifications) AdS/CFT description of the cosmological big bang.


title:
Stellar granulation as seen in disk-integrated intensity. II.
  Theoretical scaling relations compared with observations

abstract:
  A large set of stars observed by CoRoT and Kepler shows clear evidence for
the presence of a stellar background, which is interpreted to arise from
surface convection, i.e., granulation. These observations show that the
characteristic time-scale (tau_eff) and the root-mean-square (rms) brightness
fluctuations (sigma) associated with the granulation scale as a function of the
peak frequency (nu_max) of the solar-like oscillations. We aim at providing a
theoretical background to the observed scaling relations based on a model
developed in the companion paper. We computed for each 3D model the theoretical
power density spectrum (PDS) associated with the granulation as seen in
disk-integrated intensity on the basis of the theoretical model. For each PDS
we derived tau_eff and sigma and compared these theoretical values with the
theoretical scaling relations derived from the theoretical model and the Kepler
measurements. We derive theoretical scaling relations for tau_eff and sigma,
which show the same dependence on nu_max as the observed scaling relations. In
addition, we show that these quantities also scale as a function of the
turbulent Mach number (Ma) estimated at the photosphere. The theoretical
scaling relations for tau_eff and sigma match the observations well on a global
scale. Our modelling provides additional theoretical support for the observed
variations of sigma and tau_eff with nu_m max. It also highlights the important
role of Ma in controlling the properties of the stellar granulation. However,
the observations made with Kepler on a wide variety of stars cannot confirm the
dependence of our scaling relations on Ma. Measurements of the granulation
background and detections of solar-like oscillations in a statistically
sufficient number of cool dwarf stars will be required for confirming the
dependence of the theoretical scaling relations with Ma.


title:
Electric-Magnetic Duality of Topological Gauge Theories from
  Compactification

abstract:
  In this note, we discuss electric-magnetic duality between a pair of 4d
topological field theories (TQFTs) by considering their compactifications to 2
dimensions. These TQFTs control the long-distance behavior of loop and surface
operators in 4d gauge theories with gapped phases. These were recently used in
work by S. Gukov and A. Kapustin in detecting phases not distinguishable by the
Wilson-'t Hooft criterion and by A. Kapustin and the author to construct
discrete theta-angles for lattice Yang-Mills theories. The strong-weak duality
is manifested in an exchange of dynamical and background degrees of freedom in
the compactified TQFTs.


title:
Velocity dependence of the quantum friction force on an atom near a
  dielectric surface

abstract:
  Different approaches to the problem of the "quantum friction" force F acting
on an atom moving with velocity v<<c parallel to a dielectric surface have
resulted in different predictions for the way in which F depends on v. For
instance, Scheel and Buhmann [Phys. Rev. A 80, 042902 (2009)] and Barton [New
J. Phys. 12, 113045 (2010)] and others find a force linear in v, while
Intravaia, Behunin, and Dalvit [arXiv:1308.0712, 2013] and others find that the
force varies as v^3 to lowest order in v. We argue that the F proportional to
v^3 prediction results from an oversimplified treatment of the atom as a linear
oscillator, and that F depends on v in just the way predicted by Scheel and
Buhmann and Barton.


title: Observing Dirac's classical phase space analog to the quantum state

abstract:
  In 1945, Dirac attempted to develop a "formal probability" distribution to
describe quantum operators in terms of two non-commuting variables, such as
position x and momentum p [Rev. Mod. Phys. 17, 195 (1945)]. The resulting
quasi-probability distribution is a complete representation of the quantum
state and can be observed directly in experiments. We measure Dirac's
distribution for the quantum state of the transverse degree of freedom of a
photon by weakly measuring transverse x so as to not randomize the subsequent p
measurement. Further, we show that the distribution has the classical-like
feature that it transforms (e.g., propagates) according to Bayes' law.


title: Commodity futures and market efficiency

abstract:
  We analyze the market efficiency of 25 commodity futures across various
groups -- metals, energies, softs, grains and other agricultural commodities.
To do so, we utilize recently proposed Efficiency Index to find that the most
efficient of all the analyzed commodities is heating oil, closely followed by
WTI crude oil, cotton, wheat and coffee. On the other end of the ranking, we
detect live cattle and feeder cattle. The efficiency is also found to be
characteristic for specific groups of commodities -- energy commodities being
the most efficient and the other agricultural commodities (formed mainly of
livestock) the least efficient groups. We also discuss contributions of the
long-term memory, fractal dimension and approximate entropy to the total
inefficiency. Last but not least, we come across the nonstandard relationship
between the fractal dimension and Hurst exponent. For the analyzed dataset, the
relationship between these two is positive meaning that local persistence
(trending) is connected to global anti-persistence. We attribute this to
specifics of commodity futures which might be predictable in a short term and
locally but in a long term, they return to their fundamental price.


title:
Shake-Rattle-and-Roll: A Model of Dynamic Structural Disorder in
  Supported Nanoscale Catalysts

abstract:
  We investigate the effects of "dynamic structural disorder" (DSD) on the
behavior of supported nano-scale catalysts. DSD refers to the intrinsic
fluctuating, inhomogeneous structure of such nano-scale systems. In contrast to
bulk materials, nano-scale systems exhibit substantial fluctuations in energy,
charge, and other extensive quantities as well as large surface effects. The
DSD is driven by the stochastic librational motion of the center of mass and
fluxional bonding at the nanoparticle surface due to thermal coupling with the
substrate. Our approach for calculating DSD is based on a combination of
statistical mechanics, transient coupled-oscillator models, and real-time
DFT/MD simulations. This approach treats thermal and dynamic effects over
multiple time-scales, including bond-stretching and -bending vibrations, DSD,
and transient tethering to the substrate at longer ps time-scales. Model
calculations of molecule-cluster interactions and molecular dissociation
reaction paths are presented in which the reactant molecules are adsorbed on
the surface of dynamically sampled clusters. This model suggests that DSD
affects both the prefactors and distribution of energy barriers in reaction
rates, and thus can strongly affect catalytic activity at the nano-scale.


title:
Universal Conductance Fluctuations in Electrolyte-Gated SrTiO3
  Nanostructures

abstract:
  We report low-temperature magnetoconductance measurements of a patterned
two-dimensional electron system (2DES) at the surface of strontium titanate,
gated by an ionic liquid electrolyte. We observe universal conductance
fluctuations, a signature of phase-coherent transport in mesoscopic devices.
From the universal conductance fluctuations we extract an electron dephasing
rate linear in temperature, characteristic of electron-electron interaction in
a disordered conductor. Furthermore, the dephasing rate has a
temperature-independent offset, suggestive of unscreened local magnetic moments
in the sample.


title:
Results on the Erd\H os-Falconer distance problem in $\mathbb{Z}_q^d$
  for odd $q$

abstract:
  The Erd\H os-Falconer distance problem in $\mathbb{Z}_q^d$ asks one to show
that if $E \subset \mathbb{Z}_q^d$ is of sufficiently large cardinality, then
$\Delta(E) := \{(x_1 - y_1)^2 + \dots + (x_d - y_d)^2 : x, y \in E\}$ satisfies
$\Delta(E) = \mathbb{Z}_q$. Here, $\mathbb{Z}_q$ is the set of integers modulo
$q$, and $\mathbb{Z}_q^d$ is the free module of rank $d$ over $\mathbb{Z}_q$.
We extend known results in two directions. Previous results were known only in
the setting $q = p^{\ell}$, where $p$ is an odd prime, and as such only showed
that all units were obtained in the distance set. We remove the constriction
that $q$ is a power of a prime, and despite this, shows that the distance set
of $E$ contains \emph{all} of $\mathbb{Z}_q$ whenever $E$ is sufficiently
large.


title: Methods for Large Scale Hydraulic Fracture Monitoring

abstract:
  In this paper we propose computationally efficient and robust methods for
estimating the moment tensor and location of micro-seismic event(s) for large
search volumes. Our contribution is two-fold. First, we propose a novel
joint-complexity measure, namely the sum of nuclear norms which while imposing
sparsity on the number of fractures (locations) over a large spatial volume,
also captures the rank-1 nature of the induced wavefield pattern. This
wavefield pattern is modeled as the outer-product of the source signature with
the amplitude pattern across the receivers from a seismic source. A rank-1
factorization of the estimated wavefield pattern at each location can therefore
be used to estimate the seismic moment tensor using the knowledge of the array
geometry. In contrast to existing work this approach allows us to drop any
other assumption on the source signature. Second, we exploit the recently
proposed first-order incremental projection algorithms for a fast and efficient
implementation of the resulting optimization problem and develop a hybrid
stochastic & deterministic algorithm which results in significant computational
savings.


title: A note on star-like configurations in finite settings

abstract:
  Given $E \subset \mathbb{F}_q^d$, we show that certain configurations occur
frequently when $E$ is of sufficiently large cardinality. Specifically, we show
that we achieve the statistically number of $k$-stars
$\displaystyle\left|\left\{(x, x^1, \dots, x^k) \in E^{k+1} : \| x - x^i \| =
t_i \right\}\right|$ when is $|E| \gg_k q^{\frac{d+1}{2}}$. This result can be
thought of as a natural generalization of the Erd\H os-Falconer distance
problem. Our result improves on a pinned-version of our theorem which implied
the above result, but only in the range $|E| \gg q^{\frac{d+k}{2}}$. As an
immediate corollary, this demonstrates that when $|E| \gg c_k
q^{\frac{d+1}{2}}$, then $E$ determines a positive proportion of all $k$-stars.
Our results also extend to the setting of integers mod $q$.


title: Quantum derivation of Manley Rowe type relations

abstract:
  The Ermakov Lewis quantum invariant for the time dependent harmonic
oscillator is expressed in terms of number and phase operators. The
identification of these variables is made in accordance with the correspondence
principle and the amplitude and phase representation of the classical
orthogonal functions invariant. The relationship between the number and phase
operators is established through this invariant as the system evolves from one
frequency to another. In the specific case where the excitations represent the
photon number, these relations are equivalent to the power density transport
equations derived in nonlinear optical processes.


title: Looking for Very Short-Period Planets with Re-Purposed Kepler

abstract:
  A re-purposed Kepler mission could continue the search for nearly Earth-sized
planets in very short-period (< 1 day) orbits. Recent surveys of the Kepler
data already available have revealed at least a dozen such planetary
candidates, and a more complete and focused survey is likely to reveal more.
Given the planets' short orbital periods, building the requisite
signal-to-noise to detect the candidates by stacking multiple transits requires
a much shorter observational baseline than for longer-period planets, and the
transits are likely more robust against the much larger instrumental variations
anticipated for the modified Kepler pointing capabilities. Searching for these
unusual planets will also leverage the Kepler mission's already considerable
expertise in planetary transit detection and analysis. These candidates may
represent an entirely new class of planet. They may also provide unprecedented
insights into planet formation and evolution and sensitive probes for
planet-star interactions and the stellar wind. Whatever their origins and
natures, such planets would be particularly amenable to discovery by the
planned TESS mission, and a preliminary survey by Kepler could pave the way for
such TESS discoveries.


title: The Exemplar T8 Subdwarf Companion of Wolf 1130

abstract:
  We have discovered a wide separation (188.5") T8 subdwarf companion to the
sdM1.5+WD binary Wolf 1130. Companionship of WISE J200520.38+542433.9 is
verified through common proper motion over a ~3 year baseline. Wolf 1130 is
located 15.83 +/- 0.96 parsecs from the Sun, placing the brown dwarf at a
projected separation of ~3000 AU. Near-infrared colors and medium resolution
(R~2000-4000) spectroscopy establish the uniqueness of this system as a
high-gravity, low-metallicity benchmark. Although there are a number of
low-metallicity T dwarfs in the literature, WISE J200520.38+542433.9 has the
most extreme inferred metallicity to date with [Fe/H] = -0.64 +/- 0.17 based on
Wolf 1130. Model comparisons to this exemplar late-type subdwarf support it
having an old age, a low metallicity, and a small radius. However, the
spectroscopic peculiarities of WISE J200520.38+542433.9 underscore the
importance of developing the low-metallicity parameter space of the most
current atmospheric models.


title: Improvements to deep convolutional neural networks for LVCSR

abstract:
  Deep Convolutional Neural Networks (CNNs) are more powerful than Deep Neural
Networks (DNN), as they are able to better reduce spectral variation in the
input signal. This has also been confirmed experimentally, with CNNs showing
improvements in word error rate (WER) between 4-12% relative compared to DNNs
across a variety of LVCSR tasks. In this paper, we describe different methods
to further improve CNN performance. First, we conduct a deep analysis comparing
limited weight sharing and full weight sharing with state-of-the-art features.
Second, we apply various pooling strategies that have shown improvements in
computer vision to an LVCSR speech task. Third, we introduce a method to
effectively incorporate speaker adaptation, namely fMLLR, into log-mel
features. Fourth, we introduce an effective strategy to use dropout during
Hessian-free sequence training. We find that with these improvements,
particularly with fMLLR and dropout, we are able to achieve an additional 2-3%
relative improvement in WER on a 50-hour Broadcast News task over our previous
best CNN baseline. On a larger 400-hour BN task, we find an additional 4-5%
relative improvement over our previous best CNN baseline.


title:
Long-term Spatial and Temporal Variations of Aurora Borealis Events in
  the Period 1700--1905

abstract:
  Catalogues and other records of aurora-borealis events were used to study the
long-term spatial and temporal variation of these phenomena in the period from
1700 to 1905 in the Northern Hemisphere. For this purpose, geographic and
geomagnetic coordinates were assigned to approximately 27 000 auroral events
with more than 80 000 observations. They were analysed separately in three
large-scale areas: i) Europe and North Africa, ii) North America, and iii)
Asia. There was a clear need to fill some gaps existing in the records so as to
have a reliable proxy of solar activity, especially during the 18th century. In
order to enhance the long-term variability, an 11-year smoothing window was
applied to the data. Variations in the cumulative numbers of auroral events
with latitude (in both geographic and geomagnetic coordinates) were used to
discriminate between the two main solar sources: coronal mass ejections and
high-speed streams from coronal holes. The characteristics of the associated
aurorae correlate differently with the solar-activity cycle.


title:
Strength of the $E_{\text{cm}} = 1113$ keV resonance in $^{20}${Ne}$(p,
  \gamma)^{21}${Na}

abstract:
  The $^{20}$Ne$(p, \gamma)^{21}$Na reaction is the starting point of the NeNa
cycle, which is an important process for the production of intermediate mass
elements. The $E_{\text{cm}} = 1113$ keV resonance plays an important role in
the determination of stellar rates for this reaction since it is used to
normalize experimental direct capture yields at lower energies. The commonly
accepted strength of this resonance, $\omega \gamma = 1.13 \pm 0.07$ eV, has
been misinterpreted as the strength in the center-of-mass frame when it is
actually the strength in the laboratory frame. This has motivated a new
measurement of the $E_{\text{cm}} = 1113$ keV resonance strength in
$^{20}$Ne$(p, \gamma)^{21}$Na using the DRAGON recoil mass spectrometer. The
DRAGON result, $0.972 \pm 0.11$ eV, is in good agreement with the accepted
value when both are calculated in the same frame of reference.


title:
Detecting projectivity in sheaves associated to representations of
  infinitesimal groups

abstract:
  Let G be an infinitesimal group scheme of finite height r and V(G) the scheme
which represents 1-parameter subgroups of G. We consider sheaves over the
projectivization P(G) of V(G) constructed from a G-module M. We show that if
P(G) is regular then the sheaf H^[1](M) is zero if and only if M is projective.
In general, H^[1] defines a functor from the stable module category and we
prove that its kernel is a thick triangulated subcategory. Finally, we give
examples of G such that P(G) is regular and indicate, in characteristic 2, the
connection to the BGG correspondence. Along the way we will provide new proofs
of some known results and correct some errors in the literature.


title: Computations of sheaves associated to the representation theory of sl_2

abstract:
  We explicitly compute examples of sheaves over the projectivization of the
spectrum of the cohomology of sl_2. In particular, we compute \ker\Theta_M for
every indecomposable M and we compute F_i(M) when M is an indecomposable Weyl
module and i \neq p. We also give a brief review of the classification of
sl_2-modules and of the general theory of such sheaves in the case of a
restricted Lie algebra.


title: Sums of products of fractional parts

abstract:
  We prove upper and lower bounds for certain sums of products of fractional
parts by using majoring and minorizing functions from Fourier analysis. In
special cases the upper bounds are sharp if there exist counterexamples to the
Littlewood conjecture in Diophantine approximation. We introduce a
generalization of such counterexamples which we call strongly badly
approximable matrices. And we prove a transference principle for strongly badly
approximable matrices.


title: A Quantized Johnson Lindenstrauss Lemma: The Finding of Buffon's Needle

abstract:
  In 1733, Georges-Louis Leclerc, Comte de Buffon in France, set the ground of
geometric probability theory by defining an enlightening problem: What is the
probability that a needle thrown randomly on a ground made of equispaced
parallel strips lies on two of them? In this work, we show that the solution to
this problem, and its generalization to $N$ dimensions, allows us to discover a
quantized form of the Johnson-Lindenstrauss (JL) Lemma, i.e., one that combines
a linear dimensionality reduction procedure with a uniform quantization of
precision $\delta>0$. In particular, given a finite set $\mathcal S \subset
\mathbb R^N$ of $S$ points and a distortion level $\epsilon>0$, as soon as $M >
M_0 = O(\epsilon^{-2} \log S)$, we can (randomly) construct a mapping from
$(\mathcal S, \ell_2)$ to $(\delta\mathbb Z^M, \ell_1)$ that approximately
preserves the pairwise distances between the points of $\mathcal S$.
Interestingly, compared to the common JL Lemma, the mapping is quasi-isometric
and we observe both an additive and a multiplicative distortions on the
embedded distances. These two distortions, however, decay as $O(\sqrt{(\log
S)/M})$ when $M$ increases. Moreover, for coarse quantization, i.e., for high
$\delta$ compared to the set radius, the distortion is mainly additive, while
for small $\delta$ we tend to a Lipschitz isometric embedding. Finally, we
prove the existence of a "nearly" quasi-isometric embedding of $(\mathcal S,
\ell_2)$ into $(\delta\mathbb Z^M, \ell_2)$. This one involves a non-linear
distortion of the $\ell_2$-distance in $\mathcal S$ that vanishes for distant
points in this set. Noticeably, the additive distortion in this case is slower,
and decays as $O(\sqrt[4]{(\log S)/M})$.


title:
Accelerating Hessian-free optimization for deep neural networks by
  implicit preconditioning and sampling

abstract:
  Hessian-free training has become a popular parallel second or- der
optimization technique for Deep Neural Network training. This study aims at
speeding up Hessian-free training, both by means of decreasing the amount of
data used for training, as well as through reduction of the number of Krylov
subspace solver iterations used for implicit estimation of the Hessian. In this
paper, we develop an L-BFGS based preconditioning scheme that avoids the need
to access the Hessian explicitly. Since L-BFGS cannot be regarded as a
fixed-point iteration, we further propose the employment of flexible Krylov
subspace solvers that retain the desired theoretical convergence guarantees of
their conventional counterparts. Second, we propose a new sampling algorithm,
which geometrically increases the amount of data utilized for gradient and
Krylov subspace iteration calculations. On a 50-hr English Broadcast News task,
we find that these methodologies provide roughly a 1.5x speed-up, whereas, on a
300-hr Switchboard task, these techniques provide over a 2.3x speedup, with no
loss in WER. These results suggest that even further speed-up is expected, as
problems scale and complexity grows.


title:
Understanding inelastically scattered neutrons from water on a
  time-of-flight small-angle neutron scattering (SANS) instrument

abstract:
  It is generally assumed by most of the small-angle neutron scattering (SANS)
user community that a neutrons energy is unchanged during SANS measurements.
Here, the scattering from water, specifically light water, was measured on the
EQ-SANS instrument, a time-of-flight SANS instrument located at the Spallation
Neutron Source of Oak Ridge National Laboratory. A significant inelastic
process was observed in the TOF spectra of neutrons scattered from water.
Analysis of the TOF spectra from the sample showed that the scattered neutrons
have energies consistent with room-temperature thermal energies (~20 meV)
regardless of the incident neutron energy. With the aid of Monte Carlo particle
transport simulations, we conclude that the thermalization process within the
sample results in faster neutrons that arrive at the detector earlier than
expected based on the incident neutron energies. This thermalization process
impacts the measured SANS intensities in a manner that will ultimately be
sample- and temperature-dependent, necessitating careful processing of the raw
data into the SANS cross-section.


title: Hahn, Jacobi, and Krawtchouck polynomials of several variables

abstract:
  Hahn polynomials of several variables can be defined by using the Jacobi
polynomials on the simplex as a generating function. Starting from this
connection, a number of properties for these two families of orthogonal
polynomials are derived. It is shown that the Hahn polynomials appear as
connecting coefficients between several families of orthogonal polynomials on
the simplex. Closed-form formulas are derived for the reproducing kernels of
the Hahn polynomials and Krawtchouck polynomials. As an application, the
Poisson kernels for the Hahn polynomials and the Krawtchouck polynomials are
shown to be nonnegative.


title: Virtual Homological Torsion of Closed Hyperbolic 3-manifolds

abstract:
  In this paper, we will use Kahn-Markovic's almost totally geodesic surfaces
to construct certain $\pi_1$-injective 2-complexes in closed hyperbolic
3-manifolds. Such 2-complexes are locally almost totally geodesic except along
a 1-dimensional subcomplex. Using Agol and Wise's result that fundamental
groups of hyperbolic 3-manifolds are LERF and quasi-convex subgroups are
virtual retract, we will show that closed hyperbolic 3-manifolds virtually
contain any prescribed homological torsion: For any finite abelian group $A$,
and any closed hyperbolic 3-manifold $M$, there exists a finite cover $N$ of
$M$, such that $A$ is a direct summand of $Tor(H_1(N;\mathbb{Z}))$.


title: Lipshitz matchbox manifolds

abstract:
  A matchbox manifold is a connected, compact foliated space with totally
disconnected transversals; or in other notation, a generalized lamination. It
is said to be Lipschitz if there exists a metric on its transversals for which
the holonomy maps are Lipschitz. Examples of Lipschitz matchbox manifolds
include the exceptional minimal sets for $C^1$-foliations of compact manifolds,
tiling spaces, the classical solenoids, and the weak solenoids of McCord and
Schori, among others. We address the question: When does a Lipschitz matchbox
manifold admit an embedding as a minimal set for a smooth dynamical system, or
more generally for as an exceptional minimal set for a $C^1$-foliation of a
smooth manifold? We gives examples which do embed, and develop criteria for
showing when they do not embed, and give examples. We also discuss the
classification theory for Lipschitz weak solenoids.


title: Sharpening surface of magnetic paranematic droplets

abstract:
  In a non-uniform magnetic field, the droplets of colloids of nickel nanorods
and nanoparticles aggregate to form a cusp at the droplet surface not deforming
the entire droplet shape. When the field is removed, nanorods diffuse away and
cusp disappears. Spherical particles can form cusps in a similar way, but they
stay aggregated after release of the field; finally, the aggregates settle down
to the bottom of the drop. X-ray phase contrast imaging reveals that nanorods
in the cusps stay parallel to each other without visible spatial order of their
centers of mass. Formation of cusps can be explained with a model that includes
magnetostatic and surface tension forces. The discovered possibility of
controlled assembly and quenching of nanorod orientation under the cusped
liquid surface offers vast opportunities for alignment of carbon nanotubes,
nanowires and nanoscrolls, prior to spinning them into superstrong and
multifunctional fibers. Magneto and electrostatic analogy suggests that similar
ideal alignment can be achieved with the rod-like dipoles subject to a strong
electric filed.


title: Reach in All Hadronic Stop Decays: A Snowmass White Paper

abstract:
  We study the discovery prospects for stops which decay to a top and a light
neutralino. We consider fully hadronic decays of the tops and present an
estimate for the reach at various future collider runs. Our results are
summarized in Table 1.


title: Semantic-driven Configuration of Internet of Things Middleware

abstract:
  We are currently observing emerging solutions to enable the Internet of
Things (IoT). Efficient and feature rich IoT middeware platforms are key
enablers for IoT. However, due to complexity, most of these middleware
platforms are designed to be used by IT experts. In this paper, we propose a
semantics-driven model that allows non-IT experts (e.g. plant scientist, city
planner) to configure IoT middleware components easier and faster. Such tools
allow them to retrieve the data they want without knowing the underlying
technical details of the sensors and the data processing components. We propose
a Context Aware Sensor Configuration Model (CASCoM) to address the challenge of
automated context-aware configuration of filtering, fusion, and reasoning
mechanisms in IoT middleware according to the problems at hand. We incorporate
semantic technologies in solving the above challenges. We demonstrate the
feasibility and the scalability of our approach through a prototype
implementation based on an IoT middleware called Global Sensor Networks (GSN),
though our model can be generalized into any other middleware platform. We
evaluate CASCoM in agriculture domain and measure both performance in terms of
usability and computational complexity.


title:
On Secrecy Capacity of Fast Fading MIMOME Wiretap Channels With
  Statistical CSIT

abstract:
  In this paper, we consider secure transmissions in ergodic Rayleigh
fast-faded multiple-input multiple-output multiple-antenna-eavesdropper
(MIMOME) wiretap channels with only statistical channel state information at
the transmitter (CSIT). When the legitimate receiver has more (or equal)
antennas than the eavesdropper, we prove the first MIMOME secrecy capacity with
partial CSIT by establishing a new secrecy capacity upper-bound. The key step
is to form an MIMOME degraded channel by dividing the legitimate receiver's
channel matrix into two submatrices, and setting one of the submatrices to be
the same as the eavesdropper's channel matrix. Next, under the total power
constraint over all transmit antennas, we analytically solve the channel-input
covariance matrix optimization problem to fully characterize the MIMOME secrecy
capacity. Typically, the MIMOME optimization problems are non-concave. However,
thank to the proposed degraded channel, we can transform the stochastic MIMOME
optimization problem to be a Schur-concave one and then find its solution.
Besides total power constraint, we also investigate the secrecy capacity when
the transmitter is subject to the practical per-antenna power constraint. The
corresponding optimization problem is even more difficult since it is not
Schuar-concave. Under the two power constraints considered, the corresponding
MIMOME secrecy capacities can both scale with the signal-to-noise ratios (SNR)
when the difference between numbers of antennas at legitimate receiver and
eavesdropper are large enough. However, when the legitimate receiver and
eavesdropper have a single antenna each, such SNR scalings do not exist for
both cases.


title: On the Capacity of Networks with Correlated Sources

abstract:
  Characterizing the capacity region for a network can be extremely difficult.
Even with independent sources, determining the capacity region can be as hard
as the open problem of characterizing all information inequalities. The
majority of computable outer bounds in the literature are relaxations of the
Linear Programming bound which involves entropy functions of random variables
related to the sources and link messages. When sources are not independent, the
problem is even more complicated. Extension of linear programming bounds to
networks with correlated sources is largely open. Source dependence is usually
specified via a joint probability distribution, and one of the main challenges
in extending linear programming bounds is the difficulty (or impossibility) of
characterizing arbitrary dependencies via entropy functions. This paper tackles
the problem by answering the question of how well entropy functions can
characterize correlation among sources. We show that by using carefully chosen
auxiliary random variables, the characterization can be fairly "accurate".


title:
Modeling, Analysis and Optimization of Multicast Device-to-Device
  Transmission

abstract:
  Multicast device-to-device (D2D) transmission is important for applications
like local file transfer in commercial networks and is also a required feature
in public safety networks. In this paper we propose a tractable baseline
multicast D2D model, and use it to analyze important multicast metrics like the
coverage probability, mean number of covered receivers and throughput. In
addition, we examine how the multicast performance would be affected by certain
factors like mobility and network assistance. Take the mean number of covered
receivers as an example. We find that simple repetitive transmissions help but
the gain quickly diminishes as the repetition time increases. Meanwhile,
mobility and network assistance (i.e. allowing the network to relay the
multicast signals) can help cover more receivers. We also explore how to
optimize multicasting, e.g. by choosing the optimal multicast rate and the
optimal number of retransmission times.


title:
Investigation of the Puzzling Abundance Pattern in the Stars of the
  Fornax Dwarf Spheroidal Galaxy

abstract:
  Many works have found unusual characteristics of elemental abundances in
nearby dwarf galaxies. This implies that there is a key factor of galactic
evolution that is different from that of the Milky Way (MW). The chemical
abundances of the stars in the Fornax dwarf spheroidal galaxy (Fornax dSph)
provide excellent information for setting constraints on the models of the
galactic chemical evolution. In this work, adopting the five-component
approach, we fit the abundances of the Fornax dSph stars, including $\alpha$
elements, iron group elements and neutron-capture elements. For most sample
stars, the relative contributions from the various processes to the elemental
abundances are not usually in the MW proportions. We find that the
contributions from massive stars to the primary $\alpha$ elements and iron
group elements increase monotonously with increasing [Fe/H]. This means that
the effect of the galactic wind is not strong enough to halt star formation and
the contributions from massive stars to $\alpha$ elements did not halted for
[Fe/H]$\lesssim$-0.5. The average contributed ratios of various processes
between the dSph stars and the MW stars monotonously decrease with increasing
progenitor mass. This is important evidence of a bottom-heavy initial mass
function (IMF) for the Fonax dSph, compared to the MW. Considering a
bottom-heavy IMF for the dSph, the observed relations of [$\alpha$/Fe] versus
[Fe/H], [iron group/Fe] versus [Fe/H] and [neutron-capture/Fe] versus [Fe/H]
for the dSph stars can be explained.


title:
Targeting Young Stars with Kepler: Planet Formation, Migration
  Mechanisms and the Early History of Planetary Systems

abstract:
  This white paper discusses a repurposed mission for the Kepler spacecraft
that focusses on solving outstanding problems in planet formation and evolution
by targeting the study of the hot Jupiter population of young stars. This
mission can solve the question of the mode of migration of hot Jupiters,
address the problem of whether Jupiters form by hot-start (gravitational
instability) or cold-start (core accretion) mechanisms, and provide a wealth of
data on the early stages of planetary system evolution during the active phases
of stars which impact planetary habitability. In one year of observations of
three weeks dwell time per field, Kepler would increase by more than an order
of magnitude the number of known hot Jupiters, which can be followed up with
fast cadence observations to to search for transit timing variations and to
perform asteroseismological characterization of the host stars. This mission
scenario continues to operate Kepler in the photometric monitoring mode for
which it was designed, and is generally flexible with regards to field
selection enabling prioritization of fuel usage and attitude control
constraints.


title: Nano-scale reservoir computing

abstract:
  This work describes preliminary steps towards nano-scale reservoir computing
using quantum dots. Our research has focused on the development of an
accumulator-based sensing system that reacts to changes in the environment, as
well as the development of a software simulation. The investigated systems
generate nonlinear responses to inputs that make them suitable for a physical
implementation of a neural network. This development will enable
miniaturisation of the neurons to the molecular level, leading to a range of
applications including monitoring of changes in materials or structures. The
system is based around the optical properties of quantum dots. The paper will
report on experimental work on systems using Cadmium Selenide (CdSe) quantum
dots and on the various methods to render the systems sensitive to pH, redox
potential or specific ion concentration. Once the quantum dot-based systems are
rendered sensitive to these triggers they can provide a distributed array that
can monitor and transmit information on changes within the material.


title:
Long distance coherent tunneling effect on the charge and heat currents
  in serially coupled triple quantum dots

abstract:
  The effect of long distance coherent tunneling (LDCT) on the charge and heat
currents in serially coupled triple quantum dots (TQDs) connected to electrodes
is illustrated by using a combination of the extended Hurbbard model and
Anderson model. The charge and heat currents are calculated with a closed-form
Landauer expression for the transmission coefficient suitable for the Coulomb
blockade regime. The physical parameters including bias-dependent quantum dot
energy levels, electron Coulomb interactions, and electron hopping strengths
are calculated in the framework of effective mass theory for semiconductor
TQDs. We demonstrate that the effect of LDCT on the charge and heat currents
can be robust. In addition, it is shown that prominent heat rectification
behavior can exist in the TQD system with asymmetrical energy levels.


title:
Relativistic symmetry in deformed nuclei by similarity renormalization
  group

abstract:
  The similarity renormalization group is used to transform a general Dirac
Hamiltonian into diagonal form. The diagonal Dirac operator consists of the
nonrelativistic term, the spin-orbit term, the dynamical term, and the
relativistic modification of kinetic energy, which are very useful to explore
the symmetries hidden in the Dirac Hamiltonian for any deformed system. As an
example, the relativistic symmetries in an axially deformed nucleus are
investigated by comparing the contributions of every term to the single
particle energies and their correlations with the deformation. The result shows
that the deformation considerably influences the spin-orbit interaction and
dynamical effect, which play a critical role in the relativistic symmetries and
its breaking.

categories: nucl-th cond-mat.mes-hall cond-mat.mtrl-sci nucl-ex quant-ph


title: Guided Self-Organization of Input-Driven Recurrent Neural Networks

abstract:
  We review attempts that have been made towards understanding the
computational properties and mechanisms of input-driven dynamical systems like
RNNs, and reservoir computing networks in particular. We provide details on
methods that have been developed to give quantitative answers to the questions
above. Following this, we show how self-organization may be used to improve
reservoirs for better performance, in some cases guided by the measures
presented before. We also present a possible way to quantify task performance
using an information-theoretic approach, and finally discuss promising future
directions aimed at a better understanding of how these systems perform their
computations and how to best guide self-organized processes for their
optimization.