title: Applications of incidence bounds in point covering problems

abstract:
  In the Line Cover problem a set of n points is given and the task is to cover
the points using either the minimum number of lines or at most k lines. In
Curve Cover, a generalization of Line Cover, the task is to cover the points
using curves with d degrees of freedom. Another generalization is the
Hyperplane Cover problem where points in d-dimensional space are to be covered
by hyperplanes. All these problems have kernels of polynomial size, where the
parameter is the minimum number of lines, curves, or hyperplanes needed. First
we give a non-parameterized algorithm for both problems in O*(2^n) (where the
O*(.) notation hides polynomial factors of n) time and polynomial space,
beating a previous exponential-space result. Combining this with incidence
bounds similar to the famous Szemeredi-Trotter bound, we present a Curve Cover
algorithm with running time O*((Ck/log k)^((d-1)k)), where C is some constant.
Our result improves the previous best times O*((k/1.35)^k) for Line Cover
(where d=2), O*(k^(dk)) for general Curve Cover, as well as a few other bounds
for covering points by parabolas or conics. We also present an algorithm for
Hyperplane Cover in R^3 with running time O*((Ck^2/log^(1/5) k)^k), improving
on the previous time of O*((k^2/1.3)^k).


title:
Large Magnetoresistance at Room Temperature in Ferromagnet/Topological
  Insulator Contacts

abstract:
  We report magnetoresistance for current flow through iron/topological
insulator (Fe/TI) and Fe/evaporated-oxide/TI contacts when a magnetic field is
used to initially orient the magnetic alignment of the incorporated
ferromagnetic Fe bar, at temperatures ranging from 100 K to room temperature.
This magnetoresistance is associated with the relative orientation of the Fe
bar magnetization and spin-polarization of electrons moving on the surface of
the TI with helical spin-momentum locking. The magnitude of the observed
magnetoresistance is relatively large compared to that observed in prior work.


title: GR 290 (Romano's Star): 2. Light history and evolutionary state

abstract:
  We have built the historical light curve of the luminous variable GR 290 back
to 1901, from old observations of the star found in several archival plates of
M 33. These old recordings together with published and new data show that for
at least half a century the star was in a low luminosity state, with B ~18.
After 1960, five large variability cycles of visual luminosity were recorded.
The amplitude of the oscillations was seen increasing towards the 1992-1994
maximum, then decreasing during the last maxima. The recent light curve
indicates that the photometric variations have been quite similar in all the
bands, and that the B-V color index has been constant within +/-0.1 m despite
the 1.5m change of the visual luminosity. The spectrum of GR 290 at the large
maximum of 1992-94, was equivalent to late-B type, while, during 2002-2014, it
has varied between WN10h-11h near the visual maxima to WN8h-9h at the
luminosity minima. We have detected, during this same period, a clear
anti-correlation between the visual luminosity, the strength of the HeII 4686 A
emission line, the strength of the 4600-4700 A lines blend and the spectral
type. From a model analysis of the spectra collected during the whole 2002-2014
period we find that the Rosseland radius R_{2/3}, changed between the minimum
and maximum luminosity phases by a factor of 3, while T_eff varied between
about 33,000 K and 23,000 K. The bolometric luminosity of the star was not
constant, but increased by a factor of ~1.5 between minimum and maximum
luminosity, in phase with the apparent luminosity variations. In the light of
current evolutionary models of very massive stars, we find that GR 290 has
evolved from a ~60 M_Sun progenitor star and should have an age of about 4
million years. We argue that it has left the LBV stage and is moving to a
Wolf-Rayet stage of late nitrogen spectral type.


title: A guide to convolution arithmetic for deep learning

abstract:
  We introduce a guide to help deep learning practitioners understand and
manipulate convolutional neural network architectures. The guide clarifies the
relationship between various properties (input shape, kernel shape, zero
padding, strides and output shape) of convolutional, pooling and transposed
convolutional layers, as well as the relationship between convolutional and
transposed convolutional layers. Relationships are derived for various cases,
and are illustrated in order to make them intuitive.


title:
VERITAS and Multiwavelength Observations of the BL Lacertae Object 1ES
  1741+196

abstract:
  We present results from multiwavelength observations of the BL Lacertae
object 1ES 1741+196, including results in the very-high-energy $\gamma$-ray
regime using the Very Energetic Radiation Imaging Telescope Array System
(VERITAS). The VERITAS time-averaged spectrum, measured above 180 GeV, is
well-modelled by a power law with a spectral index of
$2.7\pm0.7_{\mathrm{stat}}\pm0.2_{\mathrm{syst}}$. The integral flux above 180
GeV is $(3.9\pm0.8_{\mathrm{stat}}\pm1.0_{\mathrm{syst}})\times 10^{-8}$
m$^{-2}$ s$^{-1}$, corresponding to 1.6% of the Crab Nebula flux on average.
The multiwavelength spectral energy distribution of the source suggests that
1ES 1741+196 is an extreme-high-frequency-peaked BL Lacertae object. The
observations analysed in this paper extend over a period of six years, during
which time no strong flares were observed in any band. This analysis is
therefore one of the few characterizations of a blazar in a non-flaring state.


title:
Dynamical control of quantum systems in the context of mean ergodic
  theorems

abstract:
  Equidistant and non-equidistant single pulse "bang-bang" dynamical controls
are investigated in the context of mean ergodic theorems. We show the
requirements in which the limit of infinite pulse control for both the
equidistant and the non-equidistant dynamical control converges to the same
unitary evolution. It is demonstrated that the generator of this evolution can
be obtained by projecting the generator of the free evolution onto the
commutant of the unitary operator representing the pulse. Inequalities are
derived to prove this statement and in the case of non-equidistant approach
these inequalities are optimised as a function of the time intervals.


title: IGR J17451--3022: constraints on the nature of the donor star

abstract:
  We constrain the binary parameters of the eclipsing accreting X-ray binary
IGR J17451--3022 and the nature of its donor star. The donor mass, its radius,
and the system inclination angle are computed based on the system orbital
period and eclipse duration recently reported by Bozzo et al.\ (2016). We find
that the donor is most likely a main-sequence star with the mass comprised
within the range $\sim$(0.5--$0.8){\rm M}_{\odot}$ and the radius of $\sim\!
0.7{\rm R}_{\odot}$. Assuming that the accreting compact object in IGR
J17451--3022 is a neutron star, the duration of the nearly total rectangular
eclipses yields the inclination angle of the system of $71^\circ\lesssim
i\lesssim 76^\circ$, compatible with the presence of dips in this system. We
rule out the presence of either brown or white dwarf. However, we find an
alternative possibility that the donor star in IGR J17451--3022 could be a
partially stripped giant with a very low mass, $\sim\! 0.2{\rm M}_{\odot}$.
This case requires a substantial mass loss prior to the formation of the
giant-star He core. According to that solution, the radius would be $\sim\!
0.4{\rm R}_{\odot}$, at $i\sim 80^\circ$. We additionally show that the
well-known approximate dependence of the giant-star radius exclusively on its
core mass breaks down below $\sim\!0.3{\rm M}_{\odot}$.


title: Percolation in Finite Matching Lattices

abstract:
  We derive an exact, simple relation between the average number of clusters
and the wrapping probabilities for two-dimensional percolation. The relation
holds for periodic lattices of any size. It generalizes a classical result of
Sykes and Essam and it can be used to find exact or very accurate
approximations of the critical density. The criterion that follows is related
to the criterion Scullard and Jacobsen use to find precise approximate
thresholds, and our work provides a new perspective on their approach.

categories: cond-mat.stat-mech cond-mat.dis-nn math-ph math.MP


title: Empirical residual neutron-proton interaction in odd-odd nuclei

abstract:
  Two types of average neutron-proton interaction formulas are compared: In the
first type, neutron-proton interactions for even-even and odd-$A$ nuclei
extracted from experimental binding energies show a smooth behavior as a
function of mass number $A$ and are dominated by the contribution from the
symmetry energy. Whereas in the second type large systematic staggering is seen
between even-$A$ and odd-$A$ nuclei. This deviation is understood in term of
the additional neutron-proton interaction in odd-odd nuclei relative to the
neighboring even-even and odd-$A$ systems. We explore three possible ways to
extract this additional interaction from the binding energy difference of
neighboring nuclei. The extracted interactions are positive in nearly all cases
and show weak dependence on the mass number. The empirical interactions are
also compared with theoretical values extracted from recent nuclear mass models
where large unexpected fluctuations are seen in certain nuclei. The
reproduction of the residual neutron-proton interaction and the correction of
those irregular fluctuations can be a good criterion for the refinement of
those mass models.


title:
Symmetrized Bingham Distribution for Representing Texture: Parameter
  estimation with respect to crystal and sample symmetries

abstract:
  The quaternion Bingham distribution has been used to model preferred
crystallographic orientation, or crystallographic texture, in polycrystalline
materials in the materials science and geological communities. A primary
difficulty in applying the Bingham distribution has been the lack of an
efficient method for fitting the distribution parameters with respect to the
materials underlying crystallographic symmetry or any statistical sample
symmetry due to processing. In this paper we present a symmetrized
distribution, based on the quaternion Bingham, which can account for any
general combination of crystallographic or sample symmetries. We also introduce
a numerical scheme for estimating the parameters of the symmetrized
distribution based on the well known expectation maximization algorithm.


title: Debugging Machine Learning Tasks

abstract:
  Unlike traditional programs (such as operating systems or word processors)
which have large amounts of code, machine learning tasks use programs with
relatively small amounts of code (written in machine learning libraries), but
voluminous amounts of data. Just like developers of traditional programs debug
errors in their code, developers of machine learning tasks debug and fix errors
in their data. However, algorithms and tools for debugging and fixing errors in
data are less common, when compared to their counterparts for detecting and
fixing errors in code. In this paper, we consider classification tasks where
errors in training data lead to misclassifications in test points, and propose
an automated method to find the root causes of such misclassifications. Our
root cause analysis is based on Pearl's theory of causation, and uses Pearl's
PS (Probability of Sufficiency) as a scoring metric. Our implementation, Psi,
encodes the computation of PS as a probabilistic program, and uses recent work
on probabilistic programs and transformations on probabilistic programs (along
with gray-box models of machine learning algorithms) to efficiently compute PS.
Psi is able to identify root causes of data errors in interesting data sets.


title: The largest fragment of a homogeneous fragmentation process

abstract:
  We show that in homogeneous fragmentation processes the largest fragment at
time $t$ has size $e^{-t \Phi'(\bar{p})}t^{-\frac32 (\log
\Phi)'(\bar{p})+o(1)},$ where $\Phi$ is the L\'evy exponent of the
fragmentation process, and $\bar{p}$ is the unique solution of the equation
$(\log \Phi)'(\bar{p})=\frac1{1+\bar{p}}$. We argue that this result is in line
with predictions arising from the classification of homogeneous fragmentation
processes as logarithmically correlated random fields.


title: On the Theory and Practice of Privacy-Preserving Bayesian Data Analysis

abstract:
  Bayesian inference has great promise for the privacy-preserving analysis of
sensitive data, as posterior sampling automatically preserves differential
privacy, an algorithmic notion of data privacy, under certain conditions
(Dimitrakakis et al., 2014; Wang et al., 2015). While this one posterior sample
(OPS) approach elegantly provides privacy "for free," it is data inefficient in
the sense of asymptotic relative efficiency (ARE). We show that a simple
alternative based on the Laplace mechanism, the workhorse of differential
privacy, is as asymptotically efficient as non-private posterior inference,
under general assumptions. This technique also has practical advantages
including efficient use of the privacy budget for MCMC. We demonstrate the
practicality of our approach on a time-series analysis of sensitive military
records from the Afghanistan and Iraq wars disclosed by the Wikileaks
organization.


title: From four- to two-channel Kondo effect in junctions of XY spin chains

abstract:
  We consider the Kondo effect in Y-junctions of anisotropic XY models in an
applied magnetic field along the critical lines characterized by a gapless
excitation spectrum. We find that, while the boundary interaction Hamiltonian
describing the junction can be recasted in the form of a four-channel, spin-1/2
antiferromagnetic Kondo Hamiltonian, the number of channels effectively
participating in the Kondo effect depends on the chain parameters, as well as
on the boundary couplings at the junction. The system evolves from an effective
four-channel topological Kondo effect for a junction of XX-chains with
symmetric boundary couplings into a two-channel one at a junction of three
quantum critical Ising chains. The effective number of Kondo channels depends
on the properties of the boundary and of the bulk. The XX-line is a "critical"
line, where a four-channel topological Kondo effect can be recovered by
fine-tuning the boundary parameter, while along the line in parameter space
connecting the extreme regimes, XX-line and the critical Ising point the
junction is effectively equivalent to a two-channel topological Kondo
Hamiltonian. Using a renormalization group approach, we determine the flow of
the boundary couplings, which allows us to define and estimate the critical
couplings and Kondo temperatures of the different Kondo (pair) channels.
Finally, we study the local transverse magnetization in the center of the
Y-junction, eventually arguing that it provides an effective tool to monitor
the onset of the two-channel Kondo effect.


title: $N=Z$ nuclei: A laboratory for neutron-proton collective mode

abstract:
  The neutron-neutron and proton-proton pairing correlations have long been
recognised to be the dominant many-body correlation beyond the nuclear mean
field since the introduction of pairing mechanism by Bohr, Mottelson and Pines
nearly 60 year ago. Nevertheless, few conclusion has been reached concerning
the existence of analogous neutron-proton (np) pair correlated state. One can
see a renaissance in np correlation studies in relation to the significant
progress in radioactive ion beam facilities and detection techniques. The np
pairs can couple isospin T = 1 (isovector) or 0 (isoscalar). In the isovector
channel, the angular momentum zero component is expected to be the most
importance one. On the other hand, as one may infer from the general properties
of the np two-body interaction, in the isoscalar channel, both the np pairs
with minimum (J=1) and maximum (J=2j) spin values can be important. In this
contribution, we will discuss the possible evidence for np pair coupling from
different perspective and analyze its influence on interesting phenomena
including the Wigner effect and mass correlations in odd-odd nuclei. In
particular, we will explain the spin-aligned pair coupling scheme and quartet
coupling involving pairs with maximum (J=2j) spin values.


title: Complex superconductivity in the noncentrosymmetric compound Re$_{6}$Zr

abstract:
  We report the electronic structure, synthesis, and measurements of the
magnetic, transport, and thermal properties of the polycrystalline
noncentrosymmetric compound Re$_{6}$Zr. We observed a bulk superconducting
transition at temperature $T_{c}$ $\sim$ 6.7 K, and measured the resistivity,
heat capacity, thermal conductivity, and the London penetration depth below the
transition, as well as performed doping and pressure studies. From these
measurements we extracted the critical field, and the superconducting
parameters of Re$_{6}$Zr. Our measurements indicate a relatively weak to
moderate contribution from a triplet component to the order parameter, and
favor a full superconducting gap, although we cannot exclude the existence of
point nodes based on our data.


title: Effective approximation of the solutions of algebraic equations

abstract:
  Let F be a holomorphic map whose components satisfy some polynomial
relations. We present an algorithm for constructing Nash maps locally
approximating F, whose components satisfy the same relations.


title:
$K$-corrections: an Examination of their Contribution to the Uncertainty
  of Luminosity Measurements

abstract:
  In this paper we provide formulae that can be used to determine the
uncertainty contributed to a measurement by a $K$-correction and, thus,
valuable information about which flux measurement will provide the most
accurate $K$-corrected luminosity. All of this is done at the level of a
Gaussian approximation of the statistics involved, that is, where the galaxies
in question can be characterized by a mean spectral energy distribution (SED)
and a covariance function (spectral 2-point function). This paper also includes
approximations of the SED mean and covariance for galaxies, and the three
common subclasses thereof, based on applying the templates from Assef et al.
(2010) to the objects in zCOSMOS bright 10k (Lilly et al. 2009) and photometry
of the same field from Capak et al. (2007), Sanders et al. (2007), and the
AllWISE source catalog.


title:
A study of VLF signals variations associated with the changes of
  ionization level in the D-region in consequence of solar conditions

abstract:
  In this paper we confine our attention to the analysis of amplitude and phase
data acquired by monitoring VLF/LF radio signals emitted by four European
transmitters during a seven-year period (2008-2014). All the data were recorded
at a Belgrade site (44.85$^{0}$ N, 20.38$^{0}$ E) by the Stanford University
ELF/VLF receiver AWESOME. Propagation of VLF/LF radio signal takes place in the
Earth-ionosphere waveguide and strongly depends on ionization level of the
D-region, which means that it is mainly controlled by solar conditions. Some
results of amplitude and phase variations on GQD/22.10 kHz, DHO/23.40 kHz,
ICV/20.27 kHz and NSC/45.90 kHz radio signals measurements at short distances
($D < 2$ Mm) over Central Europe and their interpretation are summarized in
this paper. Attention is restricted to regular diurnal, seasonal and solar
variations including sunrise and sunset effects on propagation characteristics
of four VLF/LF radio signals. We study VLF/LF propagation over short path as a
superposition of different number of discrete modes which depends on the
variations of the path parameters. Although the solar X-ray flare effects on
propagation of VLF/LF radio signals are well recognized on all paths,
similarities and differences between them are defined under existing conditions
over the paths. Statistical results show that the size of amplitude and phase
perturbations on VLF/LF radio signal is in correlation with the intensity of
X-ray flux. We present the calculations of electron density enhancements in the
D-region caused by different classes of solar X-ray flares during the period of
ascending phase and maximum of the solar cycle 24.


title:
Convergence Rate Analysis of the Majorize-Minimize Subspace Algorithm --
  Extended Version

abstract:
  State-of-the-art methods for solving smooth optimization problems are
nonlinear conjugate gradient, low memory BFGS, and Majorize-Minimize (MM)
subspace algorithms. The MM subspace algorithm which has been introduced more
recently has shown good practical performance when compared with other methods
on various optimization problems arising in signal and image processing.
However, to the best of our knowledge, no general result exists concerning the
theoretical convergence rate of the MM subspace algorithm. This paper aims at
deriving such convergence rates both for batch and online versions of the
algorithm and, in particular, discusses the influence of the choice of the
subspace.


title: Optimization of an exchange-correlation density functional for water

abstract:
  We describe a method, that we call data projection onto parameter space
(DPPS), to optimize an energy functional of the electron density, so that it
reproduces a dataset of experimental magnitudes. Our scheme, based on Bayes
theorem, constrains the optimized functional not to depart unphysically from
existing ab initio functionals. The resulting functional maximizes the
probability of being the \correct" parametrization of a given functional form,
in the sense of Bayes theory. The application of DPPS to water sheds new light
on why density functional theory has performed rather poorly for liquid water,
on what improvements are needed, and on the intrinsic limitations of the
generalized gradient approximation to electron exchange and correlation.
Finally, we present tests of our water-optimized functional, that we call
vdW-DF-w, showing that it performs very well for a variety of condensed water
systems.


title: A Diphoton Resonance from Bulk RS

abstract:
  Recent LHC data hinted at a 750 GeV mass resonance that decays into two
photons. A significant feature of this resonance is that its decays to any
other Standard Model particles would be too low to be detected so far. Such a
state has a compelling explanation in terms of a scalar or a pseudoscalar that
is strongly coupled to vector states charged under the Standard Model gauge
groups. Such a scenario is readily accommodated in bulk RS with a scalar
localized in the bulk away from but close to the Higgs. Turning this around, we
argue that a good way to find the elusive bulk RS model might be the search for
a resonance with prominent couplings to gauge bosons.


title: Mobile Icosapods

abstract:
  Pods are mechanical devices constituted of two rigid bodies, the base and the
platform, connected by a number of other rigid bodies, called legs, that are
anchored via spherical joints. It is possible to prove that the maximal number
of legs of a mobile pod, when finite, is 20. In 1904, Borel designed a
technique to construct examples of such 20-pods, but could not constrain the
legs to have base and platform points with real coordinates. We show that
Borel's construction yields all mobile 20-pods, and that it is possible to
construct examples with all real coordinates.


title:
Mid-Infrared ultra-high-Q resonators based on fluoride crystalline
  materials

abstract:
  Decades ago, the losses of glasses in the near infrared (near-IR) were
investigated in views of developments for optical telecommunications. Today,
properties in the mid-infrared (mid-IR) are of interest for molecular
spectroscopy applications. In particular, high-sensitivity spectroscopic
techniques based on high-finesse mid-IR cavities hold high promise for medical
applications. Due to exceptional purity and low losses, whispering gallery mode
microresonators based on polished alkaline earth metal fluoride crystals (i.e
the $\mathrm{XF_2}$ family, where X $=$ Ca, Mg, Ba, Sr,...) have attained
ultra-high quality (Q) factor resonances (Q$>$10$^{8}$) in the near-IR and
visible spectral ranges. Here we report for the first time ultra-high Q factors
in the mid-IR using crystalline microresonators. Using an uncoated chalcogenide
(ChG) tapered fiber, light from a continuous wave quantum cascade laser (QCL)
is efficiently coupled to several crystalline microresonators at 4.4 $\mu$m
wavelength. We measure the optical Q factor of fluoride crystals in the mid-IR
using cavity ringdown technique. We observe that $\mathrm{MgF_2}$
microresonators feature quality factors that are very close to the fundamental
absorption limit, as caused by the crystal's multiphonon absorption
(Q$\sim$10$^{7}$), in contrast to near-IR measurements far away from these
fundamental limits. Due to lower multiphonon absorption in $\mathrm{BaF_2}$ and
$\mathrm{SrF_2}$, we show that ultra-high quality factors of Q $\geqslant$ 1.4
$\times 10^{8}$ can be reached at 4.4 $\mu$m. This corresponds to an optical
finesse of $\mathcal{F}>$4$\cdot$ 10$^{4}$, the highest value achieved for any
type of mid-IR resonator to date, and a more than 10-fold improvement over the
state-of-the-art. Such compact ultra-high Q crystalline microresonators provide
a route for narrow linewidth frequency-stabilized QCL or mid-IR Kerr comb
generation.


title: Dynamics and Transit Variations of Resonant Exoplanets

abstract:
  The Transit Timing Variations (TTVs) are deviations of the measured
mid-transit times from the exact periodicity. One of the most interesting
causes of TTVs is the gravitational interaction between planets. Here we
consider a case of two planets in a mean motion resonance (orbital periods in a
ratio of small integers). This case is important because the resonant
interaction can amplify the TTV effect and allow planets to be detected more
easily. We develop an analytic model of the resonant dynamics valid for small
orbital eccentricities and use it to derive the principal TTV terms. We find
that a resonant system should show TTV terms with two basic periods (and their
harmonics). The resonant TTV period is proportional (m/M_*)^(-2/3), where m and
M_* are the planetary and stellar masses. For m=10^(-4) M_*, for example, the
TTV period exceeds the orbital period by ~2 orders of magnitude. The amplitude
of the resonant TTV terms scales linearly with the libration amplitude. The
ratio of the TTV amplitudes of two resonant planets is inversely proportional
to the ratio of their masses. These and other relationships discussed in the
main text can be used to aid the interpretation of TTV observations.


title: $C_T$ for Non-unitary CFTs in Higher Dimensions

abstract:
  The coefficient $C_T$ of the conformal energy-momentum tensor two-point
function is determined for the non-unitary scalar CFTs with four- and
six-derivative kinetic terms. The results match those expected from large-$N$
calculations for the CFTs arising from the $O(N)$ non-linear sigma and
Gross-Neveu models in specific even dimensions. $C_T$ is also calculated for
the CFT arising from $(n-1)$-form gauge fields with derivatives in $2n+2$
dimensions. Results for $(n-1)$-form theory extended to general dimensions as a
non-gauge-invariant CFT are also obtained; the resulting $C_T$ differs from
that for the gauge-invariant theory. The construction of conformal primaries by
subtracting descendants of lower-dimension primaries is also discussed. For
free theories this also leads to an alternative construction of the
energy-momentum tensor, which can be quite involved for higher-derivative
theories.


title: Multi-Wavelength Observations of the Blazar 1ES 1011+496 in Spring 2008

abstract:
  The BL Lac object 1ES 1011+496 was discovered at Very High Energy gamma-rays
by MAGIC in spring 2007. Before that the source was little studied in different
wavelengths. Therefore a multi-wavelength (MWL) campaign was organized in
spring 2008. Along MAGIC, the MWL campaign included the Metsahovi radio
observatory, Bell and KVA optical telescopes and the Swift and AGILE
satellites. MAGIC observations span from March to May, 2008 for a total of 27.9
hours, of which 19.4 hours remained after quality cuts. The light curve showed
no significant variability. The differential VHE spectrum could be described
with a power-law function. Both results were similar to those obtained during
the discovery. Swift XRT observations revealed an X-ray flare, characterized by
a harder when brighter trend, as is typical for high synchrotron peak BL Lac
objects (HBL). Strong optical variability was found during the campaign, but no
conclusion on the connection between the optical and VHE gamma-ray bands could
be drawn. The contemporaneous SED shows a synchrotron dominated source, unlike
concluded in previous work based on nonsimultaneous data, and is well described
by a standard one zone synchrotron self Compton model. We also performed a
study on the source classification. While the optical and X-ray data taken
during our campaign show typical characteristics of an HBL, we suggest, based
on archival data, that 1ES 1011+496 is actually a borderline case between
intermediate and high synchrotron peak frequency BL Lac objects.


title: From $\Xi_b \to \Lambda_b \pi$ to $\Xi_c \to \Lambda_c \pi$

abstract:
  Using a successful framework for describing S-wave hadronic decays of light
hyperons induced by a subprocess $s \to u (\bar u d)$, we presented recently a
model-independent calculation of the amplitude and branching ratio for $\Xi^-_b
\to \Lambda_b \pi^-$ in agreement with a LHCb measurement. The same quark
process contributes to $\Xi^0_c \to \Lambda_c \pi^-$, while a second term from
the subprocess $cs \to cd$ has been related by Voloshin to differences among
total decay rates of charmed baryons. We calculate this term and find it to
have a magnitude approximately equal to the $s \to u (\bar u d)$ term. We argue
for a negligible relative phase between these two contributions, potentially
due to final state interactions. However, we do not know whether they interfere
destructively or constructively. For constructive interference one predicts
${\cal B}(\Xi_c^0 \to \Lambda_c \pi^-) = (1.94 \pm 0.70)\times 10^{-3}$ and
${\cal B}(\Xi_c^+ \to \Lambda_c \pi^0) = (3.86 \pm 1.35)\times 10^{-3}$. For
destructive interference, the respective branching fractions are expected to be
less than about $10^{-4}$ and $2 \times 10^{-4}$.


title:
Densities non-realizable as the Jacobian of a 2-dimensional bi-Lipschitz
  map are generic

abstract:
  It is shown that, generically, a positive continuous functions cannot be
written as the derivative of a bi-Lipschitz plane homeomorphism. The same is
proved for generic bounded functions.


title: The entropy of an acoustic black hole in neo-Newtonian theory

abstract:
  In this paper we consider the metric of a 2+1-dimensional rotating acoustic
black hole in the neo-Newtonian theory to compute the Hawking temperature and
applying the quantum statistical method, we calculate the statistical entropy
using a corrected state density due to the generalized uncertainty principle
(GUP). In our calculations we have shown that the obtained entropy is finite
and correction terms are generated. Moreover, the computation of the entropy
for this method does not present logarithmic corrections.


title: Constructive Tensor Field Theory

abstract:
  We provide an up-to-date review of the recent constructive program for field
theories of the vector, matrix and tensor type, focusing not on the models
themselves but on the mathematical tools used.


title:
CONDITOR1: Topic Maps and DITA labelling tool for textual documents with
  historical information

abstract:
  Conditor is a software tool which works with textual documents containing
historical information. The purpose of this work two-fold: firstly to show the
validity of the developed engine to correctly identify and label the entities
of the universe of discourse with a labelled-combined XTM-DITA model. Secondly
to explain the improvements achieved in the information retrieval process
thanks to the use of a object-oriented database (JPOX) as well as its
integration into the Lucene-type database search process to not only accomplish
more accurate searches, but to also help the future development of a
recommender system. We finish with a brief demo in a 3D-graph of the results of
the aforementioned search.


title:
Central limit theorem for a class of globally correlated random
  variables

abstract:
  The standard central limit theorem with a Gaussian attractor for the sum of
independent random variables may lose its validity in presence of strong
correlations between the added random contributions. Here, we study this
problem for similar interchangeable globally correlated random variables. Under
these conditions, a hierarchical set of equations is derived for the
conditional transition probabilities. This result allows us to define different
classes of memory mechanisms that depend on a symmetric way on all involved
variables. Depending on the correlation mechanisms and single statistics, the
corresponding sums are characterized by distinct statistical probability
densities. For a class of urn models it is also possible to characterize their
domain of attraction which, as in the standard case, is parametrized by the
probability density of each random variable. Symmetric and asymmetric
$q$-Gaussian attractors $(q<1)$ are a particular case of these models.


title:
Majorana Zero Modes in Superconducting Proximity-coupled Magnetic Domain
  Wall

abstract:
  We propose a simple model consisting of a magnetic domain wall
proximity-coupled to an $s$-wave superconductor for realization of Majorana
zero-energy modes. A spin-dependent gauge transformation translates the
rotating magnetic profile through the domain wall to effective spin-orbit and
Zeeman terms. The Hamiltonian breaks time reversal and chiral symmetries, while
preserving particle-hole symmetry, placing itself into topological D class
characterized by the $\mathbb{Z}_{2}$ topological invariant for quasi
one-dimensional system. The low-energy sector of the model maps to the one
isomorphic with Kitaev Hamiltonian. The existence and localization of Majorana
zero modes in the nontrivial phase are demonstrated explicitly and we obtain
the topological phase diagram with extended regime of nontrivial phase and
surprising occurrence of a re-entrance phase transition. Our calculation shows
that the system can be easily tuned between trivial and topological ground
states and can be implemented experimentally to realize non-Abelian statistics.


title:
Optimal Injectivity Conditions for Bilinear Inverse Problems with
  Applications to Identifiability of Deconvolution Problems

abstract:
  We study identifiability for bilinear inverse problems under sparsity and
subspace constraints. We show that, up to a global scaling ambiguity, almost
all such maps are injective on the set of pairs of sparse vectors if the number
of measurements $m$ exceeds $2(s_1+s_2)-2$, where $s_1$ and $s_2$ denote the
sparsity of the two input vectors, and injective on the set of pairs of vectors
lying in known subspaces of dimensions $n_1$ and $n_2$ if $m\geq 2(n_1+n_2)-4$.
We also prove that both these bounds are tight in the sense that one cannot
have injectivity for a smaller number of measurements. Our proof technique
draws from algebraic geometry. As an application we derive optimal
identifiability conditions for the deconvolution problem, thus improving on
recent work of Li et al. [1].


title: Holographic conformal blocks from interacting Wilson lines

abstract:
  We present a simple prescription for computing conformal blocks and
correlation functions holographically in AdS$_3$ in terms of Wilson lines
merging at a bulk vertex. This is shown to reproduce global conformal blocks
and heavy-light Virasoro blocks. In the case of higher spin theories the space
of vertices is in one-to-one correspondence with the space of ${\cal W}_N$
conformal blocks, and we show how the latter are obtained by explicit
computations.


title:
Discovery of Lorentz-violating Weyl fermion semimetal state in LaAlGe
  materials

abstract:
  We report theoretical and experimental discovery of Lorentz-violating Weyl
fermion semimetal type-II state in the LaAlGe class of materials. Previously
type-II Weyl state was predicted in WTe2 materials which remains unrealized in
surface experiments. We show theoretically and experimentally that LaAlGe class
of materials are the robust platforms for the study of type-II Weyl physics.


title:
Putting Peer Prediction Under the Micro(economic)scope and Making
  Truth-telling Focal

abstract:
  Peer-prediction is a (meta-)mechanism which, given any proper scoring rule,
produces a mechanism to elicit privately-held, non-verifiable information from
self-interested agents. Formally, truth-telling is a strict Nash equilibrium of
the mechanism. Unfortunately, there may be other equilibria as well (including
uninformative equilibria where all players simply report the same fixed signal,
regardless of their true signal) and, typically, the truth-telling equilibrium
does not have the highest expected payoff. The main result of this paper is to
show that, in the symmetric binary setting, by tweaking peer-prediction, in
part by carefully selecting the proper scoring rule it is based on, we can make
the truth-telling equilibrium focal---that is, truth-telling has higher
expected payoff than any other equilibrium.
  Along the way, we prove the following: in the setting where agents receive
binary signals we 1) classify all equilibria of the peer-prediction mechanism;
2) introduce a new technical tool for understanding scoring rules, which allows
us to make truth-telling pay better than any other informative equilibrium; 3)
leverage this tool to provide an optimal version of the previous result; that
is, we optimize the gap between the expected payoff of truth-telling and other
informative equilibria; and 4) show that with a slight modification to the peer
prediction framework, we can, in general, make the truth-telling equilibrium
focal---that is, truth-telling pays more than any other equilibrium (including
the uninformative equilibria).


title: Uniform Spanning Forests of Planar Graphs

abstract:
  We prove that the free uniform spanning forest of any bounded degree proper
plane graph is connected almost surely, answering a question of Benjamini,
Lyons, Peres and Schramm.
  We provide a quantitative form of this result, calculating the critical
exponents governing the geometry of the uniform spanning forests of transient
proper plane graphs with bounded degrees and codegrees. We find that the same
exponents hold universally over this entire class of graphs provided that
measurements are made using the hyperbolic geometry of their circle packings
rather than their usual combinatorial geometry.


title: Ultra-Light Dark Matter in Ultra-Faint Dwarf Galaxies

abstract:
  Cold Dark Matter (CDM) models struggle to match the observations at galactic
scales. The tension can be reduced either by dramatic baryonic feedback effects
or by modifying the particle physics of CDM. Here, we consider an ultra-light
scalar field DM particle manifesting a wave nature below a DM particle
mass-dependent Jeans scale. For DM mass $m\sim10^{-22}{\rm eV}$, this scenario
delays galaxy formation and avoids cusps in the center of the dark matter
haloes. We use new measurements of half-light mass in ultra-faint dwarf
galaxies Draco II and Triangulum II to estimate the mass of the DM particle in
this model. We find that if the stellar populations are within the core of the
density profile then the data are in agreement with a wave dark matter model
having a DM particle with $m\sim 3.7-5.6\times 10^{-22}{\rm eV}$. The presence
of this extremely light particle will contribute to the formation of a central
solitonic core replacing the cusp of a Navarro-Frenk-White profile and bringing
predictions closer to observations of cored central density in dwarf galaxies.


title: On Delay-Optimal Scheduling in Queueing Systems with Replications

abstract:
  In modern computer systems, jobs are divided into short tasks and executed in
parallel. Empirical observations in practical systems suggest that the task
service times are highly random and the job service time is bottlenecked by the
slowest straggling task. One common solution for straggler mitigation is to
replicate a task on multiple servers and wait for one replica of the task to
finish early. The delay performance of replications depends heavily on the
scheduling decisions of when to replicate, which servers to replicate on, and
which job to serve first. So far, little is understood on how to optimize these
scheduling decisions for minimizing the delay to complete the jobs. In this
paper, we present a comprehensive study on delay-optimal scheduling of
replications in both centralized and distributed multi-server systems.
Low-complexity scheduling policies are designed and are proven to be
delay-optimal or near delay-optimal in stochastic ordering among all causal and
non-preemptive policies. These theoretical results are established for general
system settings and delay metrics that allow for arbitrary arrival processes,
arbitrary job sizes, arbitrary due times, and heterogeneous servers with data
locality constraints. Novel sample-path tools are developed to prove these
results.


title: Learning Mixtures of Plackett-Luce Models

abstract:
  In this paper we address the identifiability and efficient learning problems
of finite mixtures of Plackett-Luce models for rank data. We prove that for any
$k\geq 2$, the mixture of $k$ Plackett-Luce models for no more than $2k-1$
alternatives is non-identifiable and this bound is tight for $k=2$. For generic
identifiability, we prove that the mixture of $k$ Plackett-Luce models over $m$
alternatives is generically identifiable if $k\leq\lfloor\frac {m-2}
2\rfloor!$. We also propose an efficient generalized method of moments (GMM)
algorithm to learn the mixture of two Plackett-Luce models and show that the
algorithm is consistent. Our experiments show that our GMM algorithm is
significantly faster than the EMM algorithm by Gormley and Murphy (2008), while
achieving competitive statistical efficiency.


title: Simulations of Galaxy Cluster Collisions with a Dark Plasma Component

abstract:
  Dark plasma is an intriguing form of self-interacting dark matter with an
effective fluid-like behavior, which is well motivated by various theoretical
particle physics models. We aim to find an explanation for an isolated mass
clump in the Abell 520 system, which cannot be explained by traditional models
of dark matter, but has been detected in weak lensing observations. We
performed N-body smoothed particle hydrodynamics simulations of galaxy cluster
collisions with a two component model of dark matter, which is assumed to
consist of a predominant non-interacting dark matter component and a 10-40
percent mass fraction of dark plasma. The mass of a possible dark clump was
calculated for each simulation in a parameter scan over the underlying model
parameters. In two higher resolution simulations shock-waves and Mach cones
were observed to form in the dark plasma halos. By choosing suitable simulation
parameters, the observed distributions of dark matter in both the Bullet
Cluster (1E 0657-558) and Abell 520 (MS 0451.5+0250) can be qualitatively
reproduced.


title: Sensitive Radio Survey of Obscured Quasar Candidates

abstract:
  We study the radio properties of moderately obscured quasars over a range of
redshifts to understand the role of radio activity in accretion using the
Jansky Very Large Array (JVLA) at 6.0GHz and 1.4GHz. Our z~2.5 sample consists
of optically-selected obscured quasar candidates, all of which are radio-quiet,
with typical radio luminosities of $\nu L_{\nu}$[1.4 GHz] < $10^{40}$ erg
s$^{-1}$. Only a single source is individually detected in our deep (rms~10
$\mu$Jy) exposures. This population would not be identified by radio-based
selection methods used for distinguishing dusty star-forming galaxies and
obscured active nuclei. In our pilot A-array study of z~0.5 radio-quiet
quasars, we spatially resolve four of five objects on scales ~ 5 kpc and find
they have steep spectral indices. Therefore, radio emission in these sources
could be due to jet-driven or radiatively driven bubbles interacting with
interstellar material on the scale of the host galaxy. Finally, we also study
the population of ~ 200 faint (~40 $\mu$Jy - 40 mJy) radio sources observed
over ~ 120 arcmin$^2$ of our data. 60% of these detections are matched in the
SDSS and/or WISE and are, in roughly equal shares, active nuclei at a broad
range of redshifts, passive galaxies with no other signs of nuclear activity
and IR-bright but optically faint sources. Spectroscopically or photometrically
confirmed star-forming galaxies constitute only a small minority of the
matches. Such sensitive radio surveys allow us to address important questions
of AGN evolution and evaluate the AGN contribution to the radio-quiet sky.


title: Acceleration of Universe by Nonlinear Electromagnetic Fields

abstract:
  A new model of nonlinear electromagnetic fields possessing a dimensional
parameter $\beta$ is proposed. Electromagnetic fields are considered as the
source of the gravitation field and accelerated expansion of the universe is
driven by nonlinear electromagnetic fields. We consider the magnetic universe
and the stochastic magnetic field is a source of the universe acceleration.
After the universe inflation and the accelerated expansion the universe
decelerates. We show the causality of the model and a classical stability at
the deceleration phase. The spectral index, the tensor-to-scalar ratio, and the
running of the spectral index were estimated that approximately fulfil the
PLANK, WMAP, and BICEP2 data.


title:
Constellation Shaping for WDM systems using 256QAM/1024QAM with
  Probabilistic Optimization

abstract:
  In this paper, probabilistic shaping is numerically and experimentally
investigated for increasing the transmission reach of wavelength division
multiplexed (WDM) optical communication system employing quadrature amplitude
modulation (QAM). An optimized probability mass function (PMF) of the QAM
symbols is first found from a modified Blahut-Arimoto algorithm for the optical
channel. A turbo coded bit interleaved coded modulation system is then applied,
which relies on many-to-one labeling to achieve the desired PMF, thereby
achieving shaping gain. Pilot symbols at rate at most 2% are used for
synchronization and equalization, making it possible to receive input
constellations as large as 1024QAM. The system is evaluated experimentally on a
10 GBaud, 5 channels WDM setup. The maximum system reach is increased w.r.t.
standard 1024QAM by 20% at input data rate of 4.65 bits/symbol and up to 75% at
5.46 bits/symbol. It is shown that rate adaptation does not require changing of
the modulation format. The performance of the proposed 1024QAM shaped system is
validated on all 5 channels of the WDM signal for selected distances and rates.
Finally, it was shown via EXIT charts and BER analysis that iterative
demapping, while generally beneficial to the system, is not a requirement for
achieving the shaping gain.


title: On the Fundamental Theorem of the Theory of Relativity

abstract:
  A new formulation of what may be called the "fundamental theorem of the
theory of relativity" is presented and proved in (3+1)-space-time, based on the
full classification of special transformations and the corresponding velocity
addition laws. A system of axioms is introduced and discussed leading to the
result, and a study is made of several variants of that system. In particular
the status of the group axiom is investigated with respect to the condition of
the two-way isotropy of light. Several issues which are ignored or
misunderstood in the literature are emphasized.


title: On the Capillarity Equation in Two Dimensions

abstract:
  We study the capillarity equation from the global point of view of behavior
of its solutions without explicit regard to boundary conditions. We show its
solutions to be constrained in ways, that have till now not been characterized
in literature known to us.


title: 3D String Theory and Umbral Moonshine

abstract:
  The simplest string theory compactifications to 3D with 16 supercharges --
the heterotic string on $T^7$, and type II strings on $K3 \times T^3$ -- are
related by U-duality, and share a moduli space of vacua parametrized by
$O(8,24; \mathbb{Z}) \backslash O(8,24) / (O(8) \times O(24))$. One can think
of this as the moduli space of even, self-dual 32-dimensional lattices with
signature (8,24). At 24 special points in moduli space, the lattice splits as
$\Gamma^{8,0} \oplus \Gamma^{0,24}$. $\Gamma^{0,24}$ can be the Leech lattice
or any of 23 Niemeier lattices, while $\Gamma^{8,0}$ is the $E_8$ root lattice.
We show that starting from this observation, one can find a precise connection
between the Umbral groups and type IIA string theory on $K3$. This provides a
natural physical starting point for understanding Mathieu and Umbral moonshine.
The maximal unbroken subgroups of Umbral groups in 6D (or any other limit) are
those obtained by starting at the associated Niemeier point and moving in
moduli space while preserving the largest possible subgroup of the Umbral
group. To illustrate the action of these symmetries on BPS states, we discuss
the computation of certain protected four-derivative terms in the effective
field theory, and recover facts about the spectrum and symmetry representations
of 1/2-BPS states.


title:
Post-maximum near infrared spectra of SN 2014J: A search for interaction
  signatures

abstract:
  We present near infrared (NIR) spectroscopic and photometric observations of
the nearby Type Ia SN 2014J. The seventeen NIR spectra span epochs from +15.3
to +92.5 days after $B$-band maximum light, while the $JHK_s$ photometry
include epochs from $-$10 to +71 days. This data is used to constrain the
progenitor system of SN 2014J utilizing the Pa$\beta$ line, following recent
suggestions that this phase period and the NIR in particular are excellent for
constraining the amount of swept up hydrogen-rich material associated with a
non-degenerate companion star. We find no evidence for Pa$\beta$ emission lines
in our post-maximum spectra, with a rough hydrogen mass limit of $\lesssim$0.1
$M_{\odot}$, which is consistent with previous limits in SN 2014J from
late-time optical spectra of the H$\alpha$ line. Nonetheless, the growing
dataset of high-quality NIR spectra holds the promise of very useful hydrogen
constraints.


title:
Physical Properties of Local Star-Forming Analogues to z~5 Lyman Break
  Galaxies

abstract:
  Intense, compact, star-forming galaxies are rare in the local Universe but
ubiquitous at high redshift. We interpret the 0.1-22 um spectral energy
distributions (SED) of a sample of 180 galaxies at 0.05<z<0.25 selected for
extremely high surface densities of inferred star formation in the ultraviolet.
By comparison with well-established stellar population synthesis models we find
that our sample comprises young (~ 60 - 400 Myrs), moderate mass (~ $6\times
10^9$ Msun) star-forming galaxies with little dust extinction (mean stellar
continuum extinction $E_\mathrm{cont}$(B-V) ~ 0.1) and find star formation
rates of a few tens of Solar masses per year. We use our inferred masses to
determine a mean specific star formation rate for this sample of ~ $10^{-9}$
yr$^{-1}$, and compare this to the specific star formation rates in distant
Lyman break galaxies (LBGs), and in other low redshift populations. We conclude
that our sample's characteristics overlap significantly with those of the z~5
LBG population, making ours the first local analogue population well tuned to
match those high redshift galaxies. We consider implications for the origin and
evolution of early galaxies.


title:
Going the Distance: Mapping Host Galaxies of LIGO and Virgo Sources in
  Three Dimensions Using Local Cosmography and Targeted Follow-up

abstract:
  The Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)
discovered gravitational waves (GWs) from a binary black hole merger in 2015
September and may soon observe signals from neutron star mergers. There is
considerable interest in searching for their faint and rapidly fading
electromagnetic (EM) counterparts, though GW position uncertainties are as
coarse as hundreds of square degrees. Because LIGO's sensitivity to binary
neutron stars is limited to the local universe, the area on the sky that must
be searched could be reduced by weighting positions by mass, luminosity, or
star formation in nearby galaxies. Since GW observations provide information
about luminosity distance, combining the reconstructed volume with positions
and redshifts of galaxies could reduce the area even more dramatically. A key
missing ingredient has been a rapid GW parameter estimation algorithm that
reconstructs the full distribution of sky location and distance. We demonstrate
the first such algorithm, which takes under a minute, fast enough to enable
immediate EM follow-up. By combining the three-dimensional posterior with a
galaxy catalog, we can reduce the number of galaxies that could conceivably
host the event by a factor of 1.4, the total exposure time for the Swift X-ray
Telescope by a factor of 2, the total exposure time for a synoptic optical
survey by a factor of 2, and the total exposure time for a narrow-field optical
telescope by a factor of 3. This encourages us to suggest a new role for small
field of view optical instruments in performing targeted searches of the most
massive galaxies within the reconstructed volumes.


title:
Time dependent models of accretion disks with nuclear burning following
  the tidal disruption of a white dwarf by a neutron star

abstract:
  We construct time-dependent one-dimensional (vertically averaged) models of
accretion disks produced by the tidal disruption of a white dwarf (WD) by a
binary neutron star (NS) companion. Nuclear reactions in the disk midplane burn
the WD matter to increasingly heavier elements at sequentially smaller radii,
releasing substantial energy which can impact the disk dynamics. A model for
disk outflows is employed, by which cooling from the outflow balances other
sources of heating (viscous, nuclear) in regulating the Bernoulli parameter of
the midplane to a fixed value $\lesssim 0$. We perform a comprehensive
parameter study of the compositional yields and velocity distributions of the
disk outflows for WDs of different initial compositions. For C/O WDs, the
radial composition profile of the disk evolves self-similarly in a
quasi-steady-state manner, and is remarkably robust to model parameters. The
nucleosynthesis in helium WD disks does not exhibit this behavior, which
instead depends sensitively on factors controlling the disk midplane density
(e.g. the strength of the viscosity, $\alpha$). By the end of the simulation, a
substantial fraction of the WD mass is unbound in outflows at characteristic
velocities of $\sim 10^9~{\rm cm~s}^{-1}$. The outflows from WD-NS merger disks
contain $10^{-4}-3 \times 10^{-3} M_\odot$ of radioactive $^{56}$Ni, resulting
in fast ($\sim$ week long) dim ($\sim10^{40}~{\rm erg~s}^{-1}$) optical
transients; shock heating of the ejecta by late time outflows may increase the
peak luminosity to $\sim 10^{43}~{\rm erg~s}^{-1}$. The accreted mass onto the
neutron star is probably not sufficient to induce gravitational collapse, but
may be capable of spinning up the NS to periods of $\sim 10~{\rm ms}$. This is
a new possible channel for forming isolated recycled pulsars.


title: Superbumps

abstract:
  For a wide range of supersymmetric models, there is a chiral superfield whose
scalar and pseudo-scalar have approximately degenerate masses and couplings to
Standard Model particles. At colliders, they may show up as "superbumps": a
pair of resonances with similar masses and production cross-sections. Observing
the superbumps may provide evidence of supersymmetry even without seeing
superpartners with a different spin. We present two models which realize the
superbump scenario. The first one contains an elementary superfield, 24, under
SU(5)_GUT, while the second one is based on the supersymmetric QCD model with
N_f = N_c +1 and identifying SU(N_f=5) as SU(5)_GUT. Both models have rich
phenomenology including nearly mass-degenerate scalar and pseudo-scalar color
octets that appear as three body resonances of two photons and one gluon. We
also show that the recent 750 GeV diphoton excess at the LHC could be the first
hint of a superbump signature.


title: Auxiliary-field quantum Monte Carlo calculations of the molybdenum dimer

abstract:
  Chemical accuracy is difficult to achieve for systems with transition metal
atoms. Third row transition metal atoms are particularly challenging due to
strong electron-electron correlation in localized d-orbitals. The Cr2 molecule
is an outstanding example, which we previously treated with highly accurate
auxiliary-field quantum Monte Carlo (AFQMC) calculations [Purwanto et al., J.
Chem. Phys. 142, 064302 (2015)]. Somewhat surprisingly, computational
description of the isoelectronic Mo2 dimer has also, to date, been scattered
and less than satisfactory. We present high-level theoretical benchmarks of the
Mo2 singlet ground state ($X ^1\Sigma_g^+$) and first triplet excited state ($a
^3\Sigma_u^+$), using the phaseless AFQMC calculations. Extrapolation to the
complete basis set limit is performed. Excellent agreement with experimental
spectroscopic constants is obtained. We also present a comparison of the
correlation effects in Cr2 and Mo2.


title:
Testing DARKexp against energy and density distributions of
  Millennium-II halos

abstract:
  We test the DARKexp model for relaxed, self-gravitating, collisionless
systems against equilibrium dark matter halos from the Millennium-II
simulation. While limited tests of DARKexp against simulations and observations
have been carried out elsewhere, this is the first time the testing is done
with a large sample of simulated halos spanning a factor of ~ 50 in mass, and
using independent fits to density and energy distributions. We show that
DARKexp, a one shape parameter family, provides very good fits to the shapes of
density profiles, \rho(r), and differential energy distributions, N(E), of
individual simulated halos. The best fit shape parameter $\phi_{0}$ obtained
from the two types of fits are correlated, though with scatter. Our most
important conclusions come from \rho(r) and N(E) that have been averaged over
many halos. These show that the bulk of the deviations between DARKexp and
individual Millennium-II halos come from halo-to-halo fluctuations, likely
driven by substructure, and other density perturbations. The average \rho(r)
and N(E) are quite smooth and follow DARKexp very closely. The only deviation
that remains after averaging is small, and located at most bound energies for
N(E) and smallest radii for \rho(r). Since the deviation is confined to 3-4
smoothing lengths, and is larger for low mass halos, it is likely due to
numerical resolution effects.


title:
Mode-sum construction of the covariant graviton two-point function in
  the Poincar\'e patch of de Sitter space

abstract:
  We construct the graviton two-point function for a two-parameter family of
linear covariant gauges in n-dimensional de Sitter space. The construction is
performed via the mode-sum method in the Bunch-Davies vacuum in the Poincar\'e
patch, and a Fierz-Pauli mass term is introduced to regularize the infrared
(IR) divergences. The resulting two-point function is de Sitter-invariant, and
free of IR divergences in the massless limit (for a certain range of
parameters) though analytic continuation with respect to the mass for the
pure-gauge sector of the two-point function is necessary for this result. This
general result agrees with the propagator obtained by analytic continuation
from the sphere [Phys. Rev. D 34, 3670 (1986); Class. Quant. Grav. 18, 4317
(2001)]. However, if one starts with strictly zero mass theory, the IR
divergences are absent only for a specific value of one of the two parameters,
with the other parameter left generic. These findings agree with recent
calculations in the Landau (exact) gauge [J. Math. Phys. 53, 122502 (2012)],
where IR divergences do appear in the spin-two (tensor) part of the two-point
function. However, we find the strength (including the sign) of the IR
divergence to be different from the one found in this reference.


title:
Mass of intermediate black hole in the source M82 X-1 restricted by
  models of twin high-frequency quasi-periodic oscillations

abstract:
  We apply the relativistic precession (RP) model with its variants and the
resonance epicyclic model with its variants, based on the frequencies of the
geodesic epicyclic motion in the field of a Kerr black hole, to put limits on
the mass of the black hole in the ultraluminous X-ray source M82 X-1
demonstrating twin high-frequency quasi-periodic oscillations (HF QPOs) with
the frequency ratio near 3:2. The mass limits implied by the geodesic HF QPO
models are compared to those obtained due to the model of string loop
oscillations around a stable equilibrium position. Assuming the whole range of
the black hole dimensionless spin, 0 < a < 1, the restrictions on the black
hole mass related to the twin HF QPOs are widely extended and strongly model
dependent; nevertheless, they give the lower limit M_{M82 X-1} > 130 M_{sun}
confirming existence of an intermediate black hole in the M82 X-1 source. The
upper limit given by one of the variants of the geodesic twin HF QPO models
goes up to M_{M82 X-1}<1500 M_{sun}. The range 37-210 mHz of the low-frequency
QPOs observed in the M82 X-1 source introduces additional restrictive limits on
the black hole mass, if we model the low-frequency QPOs by nodal precession of
the epicyclic motion. The nodal precession model restrictions combined with
those implied by the geodesic models of the twin HF QPOs give allowed ranges of
the M82 X-1 black hole parameters, namely 140 M_{sun}<M_{M82 X-1}<660 M_{sun}
for the mass parameter and 0.05<a_{M82 X-1}<0.6 for the spin parameter.


title:
Peeling and Nibbling the Cactus: Subexponential-Time Algorithms for
  Counting Triangulations and Related Problems

abstract:
  Given a set of $n$ points $S$ in the plane, a triangulation $T$ of $S$ is a
maximal set of non-crossing segments with endpoints in $S$. We present an
algorithm that computes the number of triangulations on a given set of $n$
points in time $n^{(11+ o(1))\sqrt{n} }$, significantly improving the previous
best running time of $O(2^n n^2)$ by Alvarez and Seidel [SoCG 2013]. Our main
tool is identifying separators of size $O(\sqrt{n})$ of a triangulation in a
canonical way. The definition of the separators are based on the decomposition
of the triangulation into nested layers ("cactus graphs"). Based on the above
algorithm, we develop a simple and formal framework to count other non-crossing
straight-line graphs in $n^{O(\sqrt{n})}$ time. We demonstrate the usefulness
of the framework by applying it to counting non-crossing Hamilton cycles,
spanning trees, perfect matchings, $3$-colorable triangulations, connected
graphs, cycle decompositions, quadrangulations, $3$-regular graphs, and more.


title:
Acceleration of Deep Neural Network Training with Resistive Cross-Point
  Devices

abstract:
  In recent years, deep neural networks (DNN) have demonstrated significant
business impact in large scale analysis and classification tasks such as speech
recognition, visual object detection, pattern extraction, etc. Training of
large DNNs, however, is universally considered as time consuming and
computationally intensive task that demands datacenter-scale computational
resources recruited for many days. Here we propose a concept of resistive
processing unit (RPU) devices that can potentially accelerate DNN training by
orders of magnitude while using much less power. The proposed RPU device can
store and update the weight values locally thus minimizing data movement during
training and allowing to fully exploit the locality and the parallelism of the
training algorithm. We identify the RPU device and system specifications for
implementation of an accelerator chip for DNN training in a realistic
CMOS-compatible technology. For large DNNs with about 1 billion weights this
massively parallel RPU architecture can achieve acceleration factors of 30,000X
compared to state-of-the-art microprocessors while providing power efficiency
of 84,000 GigaOps/s/W. Problems that currently require days of training on a
datacenter-size cluster with thousands of machines can be addressed within
hours on a single RPU accelerator. A system consisted of a cluster of RPU
accelerators will be able to tackle Big Data problems with trillions of
parameters that is impossible to address today like, for example, natural
speech recognition and translation between all world languages, real-time
analytics on large streams of business and scientific data, integration and
analysis of multimodal sensory data flows from massive number of IoT (Internet
of Things) sensors.


title: BEANS - a software package for distributed Big Data analysis

abstract:
  BEANS software is a web based, easy to install and maintain, new tool to
store and analyse data in a distributed way for a massive amount of data. It
provides a clear interface for querying, filtering, aggregating, and plotting
data from an arbitrary number of datasets. Its main purpose is to simplify the
process of storing, examining and finding new relations in the so-called Big
Data.
  Creation of BEANS software is an answer to the growing needs of the
astronomical community to have a versatile tool to store, analyse and compare
the complex astrophysical numerical simulations with observations (e.g.
simulations of the Galaxy or star clusters with the Gaia archive). However,
this software was built in a general form and it is ready to use in any other
research field or open source software.


title:
A simple and rapid method for detecting living microorganisms in food
  using laser speckle decorrelation

abstract:
  Measuring microorganisms in food products is a critical issue for food safety
and human health. Although various approaches for detecting low-levels of
microorganisms in food have been developed, they require high-cost, complex
equipment, invasive procedures, and skilled technicians which limit their
widespread use in the food industry. Here, we present a simple,
non-destructive, non-contact, and rapid optical method for measuring living
microorganisms in meat products using laser speckle decorrelation. By simply
measuring dynamic speckle intensity patterns reflected from samples and
analyzing the temporal correlation time, the presence of living microorganisms
can be non-invasively detected with high sensitivity. We present
proof-of-principle demonstrations for detecting E. coli and B. cereus in
chicken breast tissues.


title:
Asymptotic stability for odd perturbations of the the stationary kink in
  the variable-speed $\phi^4$ model

abstract:
  We consider the $\phi^4$ model in one space dimension with propagation speeds
that are small deviations from a constant function. In the constant-speed case,
a stationary solution called the kink is known explicitly, and the recent work
of Kowalczyk, Martel, and Mu\~noz established the asymptotic stability of the
kink with respect to odd perturbations in the natural energy space. We show
that a stationary kink solution exists also for our class of non-constant
propagation speeds, and extend the asymptotic stability result by taking a
perturbative approach to the method of Kowalczyk, Martel, and Mu\~noz. This
requires an understanding of the spectrum of the linearization around the
variable-speed kink.


title:
Simulating the Formation of Massive Protostars: I. Radiative Feedback
  and Accretion Disks

abstract:
  We present radiation hydrodynamic simulations of collapsing protostellar
cores with initial masses of 30, 100, and 200 M$_{\odot}$. We follow their
gravitational collapse and the formation of a massive protostar and
protostellar accretion disk. We employ a new hybrid radiative feedback method
blending raytracing techniques with flux-limited diffusion for a more accurate
treatment of the temperature and radiative force. In each case, the disk that
forms becomes Toomre-unstable and develops spiral arms. This occurs between
0.35 and 0.55 freefall times and is accompanied by an increase in the accretion
rate by a factor of 2-10. Although the disk becomes unstable, no other stars
are formed. In the case of our 100 and 200 M$_{\odot}$ simulation, the star
becomes highly super-Eddington and begins to drive bipolar outflow cavities
that expand outwards. These radiatively-driven bubbles appear stable, and
appear to be channeling gas back onto the protostellar accretion disk.
Accretion proceeds strongly through the disk. After 81.4 kyr of evolution, our
30 M$_{\odot}$ simulation shows a star with a mass of 5.48 M$_{\odot}$ and a
disk of mass 3.3 M$_{\odot}$, while our 100 M$_{\odot}$ simulation forms a 28.8
M$_{\odot}$ mass star with a 15.8 M$_{\odot}$ disk over the course of 41.6 kyr,
and our 200 M$_{\odot}$ simulation forms a 43.7 M$_{\odot}$ star with an 18
M$_{\odot}$ disk in 21.9 kyr. In the absence of magnetic fields or other forms
of feedback, the masses of the stars in our simulation do not appear limited by
their own luminosities.


title: Black Phosphorus Mid-Infrared Photodetectors with High Gain

abstract:
  Recently, black phosphorus (BP) has joined the two dimensional material
family as a promising candidate for photonic applications, due to its moderate
bandgap, high carrier mobility, and compatibility with a diverse range of
substrates. Photodetectors are probably the most explored BP photonic devices,
however, their unique potential compared with other layered materials in the
mid-infrared wavelength range has not been revealed. Here, we demonstrate BP
mid infrared detectors at 3.39 um with high internal gain, resulting in an
external responsivity of 82 A/W. Noise measurements show that such BP
photodetectors are capable of sensing low intensity mid-infrared light in the
picowatt range. Moreover, the high photoresponse remains effective at kilohertz
modulation frequencies, because of the fast carrier dynamics arising from BPs
moderate bandgap. The high photoresponse at mid infrared wavelengths and the
large dynamic bandwidth, together with its unique polarization dependent
response induced by low crystalline symmetry, can be coalesced to promise
photonic applications such as chip-scale mid-infrared sensing and imaging at
low light levels.


title: Gaia archive

abstract:
  The Gaia archive is being designed and implemented by the DPAC Consortium.
The purpose of the archive is to maximize the scientific exploitation of the
Gaia data by the astronomical community. Thus, it is crucial to gather and
discuss with the community the features of the Gaia archive as much as
possible. It is especially important from the point of view of the GENIUS
project to gather the feedback and potential use cases for the archive. This
paper presents very briefly the general ideas behind the Gaia archive and
presents which tools are already provided to the community.


title: Exact solution of the pairing problem for spherical and deformed systems

abstract:
  There has been increasing interest in studying the Richardson model from
which one can derive the exact solution for certain pairing Hamiltonians.
However, it is still a numerical challenge to solve the nonlinear equations
involved. In this paper we tackle this problem by employing a simple hybrid
polynomial approach. The method is found to be robust and is valid for both
deformed and nearly spherical nuclei. It also provides important and convenient
initial guesses for spherical systems with large degeneracy. As an example, we
apply the method to study the shape coexistence in neutron-rich Ni isotopes.


title: On volumes of quasi-arithmetic hyperbolic lattices

abstract:
  We prove that the covolume of any quasi-arithmetic hyperbolic lattice (a
notion that generalizes the definition of arithmetic subgroups) is a rational
multiple of the covolume of an arithmetic subgroup. As a corollary, we obtain a
good description for the shape of the volumes of most of the known hyperbolic
n-manifolds with n>3.


title:
Computing Eigenvalues of Large Scale Sparse Tensors Arising from a
  Hypergraph

abstract:
  The spectral theory of higher-order symmetric tensors is an important tool to
reveal some important properties of a hypergraph via its adjacency tensor,
Laplacian tensor, and signless Laplacian tensor. Owing to the sparsity of these
tensors, we propose an efficient approach to calculate products of these
tensors and any vectors. Using the state-of-the-art L-BFGS approach, we develop
a first-order optimization algorithm for computing H- and Z-eigenvalues of
these large scale sparse tensors (CEST). With the aid of the
Kurdyka-{\L}ojasiewicz property, we prove that the sequence of iterates
generated by CEST converges to an eigenvector of the tensor.When CEST is
started from multiple randomly initial points, the resulting best eigenvalue
could touch the extreme eigenvalue with a high probability. Finally, numerical
experiments on small hypergraphs show that CEST is efficient and promising.
Moreover, CEST is capable of computing eigenvalues of tensors corresponding to
a hypergraph with millions of vertices.


title: Non-determinism in Byzantine Fault-Tolerant Replication

abstract:
  Service replication distributes an application over many processes for
tolerating faults, attacks, and misbehavior among a subset of the processes.
The established state-machine replication paradigm inherently requires the
application to be deterministic. This paper distinguishes three models for
dealing with non-determinism in replicated services, where some processes are
subject to faults and arbitrary behavior (so-called Byzantine faults): first, a
modular approach that does not require any changes to the potentially
non-deterministic application (and neither access to its internal data);
second, a master-slave approach, in which ties are broken by a leader and the
other processes validate the choices of the leader; and finally, a treatment of
applications that use cryptography and secret keys. Cryptographic operations
and secrets must be treated specially because they require strong randomness to
satisfy their goals.
  The paper also introduces two new protocols. The first uses the modular
approach for filtering out non-de\-ter\-min\-istic operations in an
application. It ensures that all correct processes produce the same outputs and
that their internal states do not diverge. The second protocol implements
cryptographically secure randomness generation with a verifiable random
function and is appropriate for certain security models. All protocols are
described in a generic way and do not assume a particular implementation of the
underlying consensus primitive.


title: Parton Distribution Function from the Hadronic Tensor on the Lattice

abstract:
  The path-integral formulation of the hadronic tensor W_{\mu\nu} of deep
inelastic scattering is reviewed. It is shown that there are 3 gauge invariant
and topologically distinct contributions. The separation of the connected sea
partons from those of the disconnected sea can be achieved with a combination
of the global fit of the parton distribution function (PDF), the semi-inclusive
DIS data on the strange PDF and the lattice calculation of the ratio of the
strange to $u/d$ momentum fraction in the disconnected insertion. We shall
discuss numerical issues associated with lattice calculation of the hadronic
tensor involving a four-point function, such as large hadron momenta and
improved maximum entropy method to obtain the spectral density from the
hadronic tensor in Euclidean time. We also draw a comparison between the large
momentum approach to the parton distribution function (PDF) and the hadronic
tensor approach.


title: Streaming patterns in Faraday waves

abstract:
  Waves patterns in the Faraday instability have been studied for decades.
Besides the rich dynamics that can be observed on the waves at the interface,
Faraday waves hide beneath them an elusive range of flow patterns --or
streaming patterns-- which have not been studied in detail until now. The
streaming patterns are responsible for a net circulation in the flow which are
reminiscent of convection cells. In this article, we analyse these streaming
flows by conducting experiments in a Faraday-wave setup. To visualize the
flows, tracers are used to generate both trajectory maps and to probe the
streaming velocity field via Particle Image Velocimetry (PIV). We identify
three types of patterns and experimentally show that identical Faraday waves
can mask streaming patterns that are qualitatively very different. Next we
propose a three-dimensional model that explains streaming flows in
quasi-inviscid fluids. We show that the streaming inside the fluid arises from
a complex coupling between the bulk and the boundary layers. This coupling can
be taken into account by applying modified boundary conditions in a
three-dimensional Navier-Stokes formulation for the streaming in the bulk.
Numerical simulations based on this theoretical framework show good qualitative
and quantitative agreement with experimental results. They also highlight the
relevance of three-dimensional effects in the streaming patterns. Our
simulations reveal that the variety of experimental patterns is deeply linked
to the boundary condition at the top interface, which may be strongly affected
by the presence of contaminants along the surface.


title: Photon-jet ridge at RHIC and the LHC

abstract:
  We investigate long range rapidity correlations of pairs of prompt photon and
jet in the Color Glass Condensate (CGC) framework in proton-proton and
proton-nucleus collisions at RHIC and the LHC. We show that photon-jet
correlations exhibit long-range azimuthal collimation at near-side for low
transverse momenta of the produced photon and jet in high-multiplicity events.
These ridge-like features are strikingly similar to the observed ridge effect
for di-hadron correlations at RHIC and the LHC. We show that correlations in
the relative rapidity and the relative azimuthal angle between pairs of prompt
photon and jet strongly depend on the gluon saturation dynamics at small-x
kinematics and such measurements can help to understand the true origin of the
observed di-hadron ridge in p+A collisions, and address whether the ridge is a
universal phenomenon for all two particle correlations at high energy and high
multiplicity events. We also investigate if there is a ridge-like structure for
photon-hadron pair correlations at RHIC and the LHC. We found that the
hadronization of jet has non-trivial effects on the photon-jet correlations.


title:
Clinical Informatics: Recursive Concurrence Intravenous Medication
  Administration Systems Protocols for Addressing the Potential Problem of
  Recessive Lethal Autonomy in Smart Infusion Systems

abstract:
  Smart Infusion Pumps are vital tools for use in administering a broad range
of parenteral/intravenous medications. Safe and effective use of smart infusion
pumps depends upon their integration with Pump Servers, Computerized Physician
Order Entry Systems, Pharmacy Information Systems, DERS/MERS Dose/Medication
Error Reduction Systems( and the digital Drug Libraries that they use),
eMARS/electronic Medication Administration Records Systems, etc. More computer
systems result in more computer network connections, with systems that run on
ever more lines of computer software code. Resulting in more chaos and more
complexity, and inevitably a greater likelihood for systems failure and/or
malfunction - this in effect runs contrary to the objective of deploying
clinical informatics solutions such as smart infusion systems, due to their
inherent technical and chronic performance problems as well as error prone
usage that may occasion Recessive(unintended but underlying) Lethal Autonomy.
The Recursive Concurrence protocols suggested in this paper are a means for
reducing if not eliminating the challenging phenomenon of Recessive Lethal
Autonomy in clinical informatics devices and/or systems.


title: An elementary introduction to quantum graphs

abstract:
  We describe some basic tools in the spectral theory of Schr\"odinger operator
on metric graphs (also known as "quantum graph") by studying in detail some
basic examples. The exposition is kept as elementary and accessible as
possible. In the later sections we apply these tools to prove some results on
the count of zeros of the eigenfunctions of quantum graphs.


title: DocLite: A Docker-Based Lightweight Cloud Benchmarking Tool

abstract:
  Existing benchmarking methods are time consuming processes as they typically
benchmark the entire Virtual Machine (VM) in order to generate accurate
performance data, making them less suitable for real-time analytics. The
research in this paper is aimed to surmount the above challenge by presenting
DocLite - Docker Container-based Lightweight benchmarking tool. DocLite
explores lightweight cloud benchmarking methods for rapidly executing
benchmarks in near real-time. DocLite is built on the Docker container
technology, which allows a user-defined memory size and number of CPU cores of
the VM to be benchmarked. The tool incorporates two benchmarking methods - the
first referred to as the native method employs containers to benchmark a small
portion of the VM and generate performance ranks, and the second uses historic
benchmark data along with the native method as a hybrid to generate VM ranks.
The proposed methods are evaluated on three use-cases and are observed to be up
to 91 times faster than benchmarking the entire VM. In both methods, small
containers provide the same quality of rankings as a large container. The
native method generates ranks with over 90% and 86% accuracy for sequential and
parallel execution of an application compared against benchmarking the whole
VM. The hybrid method did not improve the quality of the rankings
significantly.


title:
Error Bounds for the Krylov Subspace Methods for Computations of Matrix
  Exponentials

abstract:
  In this paper, we present new a posteriori and a priori error bounds for the
Krylov subspace methods for computing $e^{-\tau A}v$ for a given $\tau>0$ and
$v \in C^n$, where $A$ is a large sparse non-Hermitian matrix. The {\em a
priori} error bounds relate the convergence to
$\lambda_{\min}\left(\frac{A+A^*}{2}\right)$,
$\lambda_{\max}\left(\frac{A+A^*}{2}\right)$ (the smallest and the largest
eigenvalue of the Hermitian part of $A$) and
$|\lambda_{\max}\left(\frac{A-A^*}{2}\right)|$ (the largest eigenvalue in
absolute value of the skew-Hermitian part of $A$), which define a rectangular
region enclosing the field of values of $A$. In particular, our bounds explain
an observed superlinear convergence behavior where the error may first stagnate
for certain iterations before it starts to converge. The special case that $A$
is skew-Hermitian is also considered. Numerical examples are given to
demonstrate the theoretical bounds.


title:
Regular black holes: Guilfoyle's electrically charged solutions with a
  perfect fluid phantom core

abstract:
  Regular black hole solutions are found among the Guilfoyle exact solutions.
These are spherically symmetric solutions of general relativity coupled to
Maxwell's electromagnetism and charged matter where the metric potentials and
electromagnetic fields are related in some particularly simple form. We show
that, for certain ranges of the parameters, there are objects which correspond
to regular charged black holes, whose interior region is filled by an
electrically charged phantom-like fluid, or, in the limiting case, a de Sitter
false vacuum fluid, and whose exterior region is Reissner-Nordstr\"om. The
boundary between both regions is a smooth boundary surface, except in the
limiting case where the boundary is made of a massless electrically charged
spherically symmetric coat. The main physical and geometrical properties of
such charged regular solutions are analyzed.


title: Newtonian hydrodynamic equations with relativistic pressure and velocity

abstract:
  We present a new approximation to include fully general relativistic pressure
and velocity in Newtonian hydrodynamics. The energy conservation, momentum
conservation and two Poisson's equations are consistently derived from
Einstein's gravity in the zero-shear gauge assuming weak gravity and
action-at-a-distance limit. The equations show proper special relativity limit
in the absence of gravity. Our approximation is complementary to the
post-Newtonian approximation and the equations are valid in fully nonlinear
situations.


title: The Force Singularity for Partially Immersed Parallel Plates

abstract:
  In earlier work, we provided a general description of the forces of
attraction and repulsion, encountered by two parallel vertical plates of
infinite extent and of possibly differing materials, when partially immersed in
an infinite liquid bath and subject to surface tension forces. In the present
study, we examine some unusual details of the exotic behavior that can occur at
the singular configuration separating infinite rise from infinite descent of
the fluid between the plates, as the plates approach each other. In connection
with this singular behavior, we present also some new estimates on meniscus
height details.


title: Chern-Simons Actions and Their Gaugings in 4D, N=1 Superspace

abstract:
  We gauge the abelian hierarchy of tensor fields in 4D by a Lie algebra. The
resulting non-abelian tensor hierarchy can be interpreted via an equivariant
chain complex. We lift this structure to N=1 superspace by constructing
superfield analogs for the tensor fields, along with covariant superfield
strengths. Next we construct Chern-Simons actions, for both the bosonic and N=1
cases, and note that the condition of gauge invariance can be presented
cohomologically. Finally, we provide an explicit realization of these
structures by dimensional reduction, for example by reducing the three-form of
eleven-dimensional supergravity into a superspace with manifest 4D, N=1
supersymmetry.


title: Deviation of viscous drops at chemical steps

abstract:
  We present systematic wetting experiments and numerical simulations of
gravity driven liquid drops sliding on a plane substrate decorated with a
linear chemical step. Surprisingly, the optimal direction to observe crossing
is not the one perpendicular to the step, but a finite angle that depends on
the material parameters. We computed the landscapes of the force acting on the
drop by means of a contact line mobility model showing that contact angle
hysteresis dominates the dynamics at the step and determines whether the drop
passes onto the lower substrate. This analysis is very well supported by the
experimental dynamic phase diagram in terms of pinning, crossing, sliding and
sliding followed by pinning.


title: Special divisors on marked chains of cycles

abstract:
  We completely describe all Brill-Noether loci on metric graphs consisting of
a chain of g cycles with arbitrary edge lengths, generalizing work of Cools,
Draisma, Payne, and Robeva. The structure of these loci is determined by
displacement tableaux on rectangular partitions, which we define. More
generally, we fix a marked point on the rightmost cycle, and completely analyze
the loci of divisor classes with specified ramification at the marked point,
classifying them using displacement tableaux. Our results give a tropical proof
of the generalized Brill-Noether theorem for general marked curves, and serve
as a foundation for the analysis of general algebraic curves of fixed gonality.


title:
Positive-part moments via the characteristic functions, and more general
  expressions

abstract:
  A unifying and generalizing approach to representations of the positive-part
and absolute moments $\mathsf{E} X_+^p$ and $\mathsf{E}|X|^p$ of a random
variable $X$ for real $p$ in terms of the characteristic function (c.f.) of
$X$, as well as to related representations of the c.f.\ of $X_+$, generalized
moments $\mathsf{E} X_+^p e^{iuX}$, truncated moments, and the distribution
function is provided. Existing and new representations of these kinds are all
shown to stem from a single basic representation. Computational aspects of
these representations are addressed.


title:
Models of quasi-periodic oscillations related to mass and spin of the
  GRO J1655-40 black hole

abstract:
  Frequencies of the three quasi-periodic oscillation (QPO) modes observed
simultaneously in the accreting black hole GRO J1655-40 are compared with the
predictions of models. Models in which all three QPO signals are produced at
the same radius are considered: these include different versions of
relativistic precession, epicyclic resonance, tidal disruption, and warped disc
models. Models that were originally proposed to interpret only the twin
high-frequency QPOs are generalized here to interpret also the low-frequency
QPO in terms of relativistic nodal precession. Inferred values of the black
hole mass and spin from each QPO model are compared with the mass measured from
optical observations and the spin inferred from X-ray spectroscopy techniques.
We find that along with the relativistic precession model predicting
$M=(5.3\pm0.1)~M_{\odot}, a=0.286\pm0.004$, the so-called total precession
model ($M=(5.5\pm0.1)~M_{\odot}, a=0.276\pm0.003$), and the resonance epicyclic
model with beat frequency ($M=(5.1\pm0.1)~M_{\odot}, a=0.274\pm0.003$) also
satisfy the optical mass test. We compare our results with those inferred from
X-ray spectral measurements.


title: Renormalized Volume

abstract:
  We develop a universal distributional calculus for regulated volumes of
metrics that are singular along hypersurfaces. When the hypersurface is a
conformal infinity we give simple integrated distribution expressions for the
divergences and anomaly of the regulated volume functional valid for any choice
of regulator. For closed hypersurfaces or conformally compact geometries,
methods from a previously developed boundary calculus for conformally compact
manifolds can be applied to give explicit holographic formulae for the
divergences and anomaly expressed as hypersurface integrals over local
quantities (the method also extends to non-closed hypersurfaces). The resulting
anomaly does not depend on any particular choice of regulator, while the
regulator dependence of the divergences is precisely captured by these
formulae. Conformal hypersurface invariants can be studied by demanding that
the singular metric obey, smoothly and formally to a suitable order, a Yamabe
type problem with boundary data along the conformal infinity. We prove that the
volume anomaly for these singular Yamabe solutions is a conformally invariant
integral of a local Q-curvature that generalizes the Branson Q-curvature by
including data of the embedding. In each dimension this canonically defines a
higher dimensional generalization of the Willmore energy/rigid string action.
Recently Graham proved that the first variation of the volume anomaly recovers
the density obstructing smooth solutions to this singular Yamabe problem; we
give a new proof of this result employing our boundary calculus. Physical
applications of our results include studies of quantum corrections to
entanglement entropies.


title:
Nonexistence in Thomas-Fermi-Dirac-von Weizs\"acker theory with small
  nuclear charges

abstract:
  We study the ionization problem in the Thomas-Fermi-Dirac-von Weizs\"acker
theory for atoms and molecules. We prove the nonexistence of minimizers for the
energy functional when the number of electrons is large and the total nuclear
charge is small. This nonexistence result also applies to external potentials
decaying faster than the Coulomb potential. In the case of arbitrary nuclear
charges, we obtain the nonexistence of stable minimizers and radial minimizers.


title: Modeling multi-particle complexes in stochastic chemical systems

abstract:
  Large complexes of classical particles play central roles in biology, in
polymer physics, and in other disciplines. However, physics currently lacks
mathematical methods for describing such complexes in terms of component
particles, interaction energies, and assembly rules. Here we describe a Fock
space structure that addresses this need, as well as diagrammatic methods that
facilitate the use of this formalism. These methods can dramatically simplify
the equations governing both equilibrium and non-equilibrium stochastic
chemical systems. A mathematical relationship between the set of all complexes
and a list of rules for complex assembly is also identified.

categories: q-bio.QM cond-mat.stat-mech physics.bio-ph physics.chem-ph q-bio.MN


title: Digital IP Protection Using Threshold Voltage Control

abstract:
  This paper proposes a method to completely hide the functionality of a
digital standard cell. This is accomplished by a differential threshold logic
gate (TLG). A TLG with $n$ inputs implements a subset of Boolean functions of
$n$ variables that are linear threshold functions. The output of such a gate is
one if and only if an integer weighted linear arithmetic sum of the inputs
equals or exceeds a given integer threshold. We present a novel architecture of
a TLG that not only allows a single TLG to implement a large number of complex
logic functions, which would require multiple levels of logic when implemented
using conventional logic primitives, but also allows the selection of that
subset of functions by assignment of the transistor threshold voltages to the
input transistors. To obfuscate the functionality of the TLG, weights of some
inputs are set to zero by setting their device threshold to be a high $V_t$.
The threshold voltage of the remaining transistors is set to low $V_t$ to
increase their transconductance. The function of a TLG is not determined by the
cell itself but rather the signals that are connected to its inputs. This makes
it possible to hide the support set of the function by essentially removing
some variable from the support set of the function by selective assignment of
high and low $V_t$ to the input transistors. We describe how a standard cell
library of TLGs can be mixed with conventional standard cells to realize
complex logic circuits, whose function can never be discovered by reverse
engineering. A 32-bit Wallace tree multiplier and a 28-bit 4-tap filter were
synthesized on an ST 65nm process, placed and routed, then simulated including
extracted parastics with and without obfuscation. Both obfuscated designs had
much lower area (25%) and much lower dynamic power (30%) than their
nonobfuscated CMOS counterparts, operating at the same frequency.


title:
Efficient Enumeration of Unidirectional Cuts for Technology Mapping of
  Boolean Networks

abstract:
  In technology mapping, enumeration of subcircuits or cuts to be replaced by a
standard cell is an important step that decides both the quality of the
solution and execution speed. In this work, we view cuts as set of edges
instead of as set of nodes and based on it, provide a classification of cuts.
It is shown that if enumeration is restricted to a subclass of cuts called
unidirectional cuts, the quality of solution does not degrade. We also show
that such cuts are equivalent to a known class of cuts called strong line cuts
first proposed in [14]. We propose an efficient enumeration method based on a
novel graph pruning algorithm that utilizes network flow to approximate minimum
strong line cut. The runtimes for the proposed enumeration method are shown to
be quite practical for enumeration of a large number of cuts.


title: Dynamics Resonances in Atomic States of Astrophysical Relevance

abstract:
  Ionized geocosmic media parameters in a thermal and a subthermal range of
energy have a number of unique features. The photoresonance plasma that is
formed by optical excitation of the lowest excited (resonance) atomic states is
one example of conversion of radiation energy into electrical one. Since
spontaneous fluorescence of excited atoms is probabilistic, the description of
the radiating quantized system evolution along with photons energy transfer in
a cold atoms medium, should include elements of stochastic dynamics. Finally,
the chaotic dynamics of a weakly bound Rydberg electron over a grid of the
energy levels diagram of a quasi-molecular Rydberg complex provides an
excitation migration of the electron forward to the ionization continuum. This
work aims at discussing the specific features of the dynamic resonances
formalism in the description of processes involving Rydberg states of an
excited atom, including features in the fluorescence spectrum partially caused
by the quantum defect control due to the presence of statistic electromagnetic
fields.


title:
Analysis of experimental series of plutonium nitrate in aqueous solution
  and their correlation coefficients

abstract:
  In this work we performed a detailed analysis on the calculation of 43
critical experiments from 6 experimental series all describing plutonium
nitrate in aqueous solution contained in metal spheres. The underlying
experimental data is taken from the handbook of the International Criticality
Safety Benchmark Evaluation Project (ICSBEP) Working Group. We present our
modeling assumptions which were derived from the interpretation of the
experimental data and discuss the resulting sensitivity analysis. Although the
experiments share some components, the derived correlation coefficients are for
many cases statistically not significant. Comparing our findings for the
correlation coefficients with available data from the DICE Database we find an
agreement for the correlation coefficients due to nuclear data. We also compare
our results for the correlation coefficients due to experimental uncertainty.
Our findings indicate that for the reliable Determination of correlation
coefficients a detailed study of the underlying experimental data, the modeling
approach and assumptions, and the resulting sensitivity analysis seems to be
inevitable.