title:
Discovery of an extra hard spectral component in the high-energy
  afterglow emission of GRB 130427A

abstract:
  The extended high-energy gamma-ray (>100 MeV) emission occurred after the
prompt gamma-ray bursts (GRBs) is usually characterized by a single power-law
spectrum, which has been explained as the afterglow synchrotron radiation. The
afterglow inverse-Compton emission has long been predicted to be able to
produce a high-energy component as well, but previous observations have not
revealed such a signature clearly, probably due to the small number of >10 GeV
photons even for the brightest GRBs known so far. In this Letter, we report on
the Fermi Large Area Telescope (LAT) observations of the >100 MeV emission from
the very bright and nearby GRB 130427A. We characterize the time-resolved
spectra of the GeV emission from the GRB onset to the afterglow phase. By
performing time-resolved spectral fits of GRB 130427A, we found a strong
evidence of an extra hard spectral component that exists in the extended
high-energy emission of this GRB. We argue that this hard component may arise
from the afterglow inverse Compton emission.


title: Computing Cliques is Intractable

abstract:
  The class P is in fact a proper sub-class of NP. We explore topological
properties of the Hamming space 2^[n] where [n]={1, 2,..., n}. With the
developed theory, we show: (i) a theorem that is closely related to Erdos and
Rado's sunflower lemma, and claims a stronger statement in most cases, (ii) a
new approach to prove the exponential monotone circuit complexity of the clique
problem, (iii) NC \ne NP through the impossibility of a Boolean circuit with
poly-log depth to compute cliques, based on the construction of (ii), and (iv)
P \ne NP through the exponential circuit complexity of the clique problem,
based on the construction of (iii). Item (i) leads to the existence of a
sunflower with a small core in certain families of sets, which is not an
obvious consequence of the sunflower lemma. In (iv), we show that any Boolean
circuit computing the clique function CLIQUE_{n,k} (k=n^{1/4}) has a size
exponential in n. Thus, we will separate P/poly from NP also. Razborov and
Rudich showed strong evidence that no natural proof can prove exponential
circuit complexity of a Boolean function. We confirm that the proofs for (iii)
and (iv) are not natural.


title: The CP-violating type-II 2HDM and Charged Higgs boson benchmarks

abstract:
  We review and update the interpretation of the 125 GeV scalar as the lightest
Higgs boson of the Two-Higgs-Doublet Model, allowing for CP violation in the
potential. The detection of a charged Higgs boson would exclude the Standard
Model. Proposed benchmarks for charged-Higgs searches in the channel pp\to
H^+W^-X\to W^+W^-H_1X are reviewed and updated.


title:
On the Identities Involving Special Polynomials Arising From Point of
  View of Fractional Calculus

abstract:
  In the present paper, we investigate some interesting properties including
several special polynomials arising from Caputo-fractional derivative. From our
investigation, we derive a lot of interesting identities of several special
polynomials.


title: Symmetry Improved CJT Effective Action

abstract:
  The formalism introduced by Cornwall, Jackiw and Tomboulis (CJT) provides a
systematic approach to consistently resumming non-perturbative effects in
Quantum Thermal Field Theory. One major limitation of the CJT effective action
is that its loopwise expansion introduces residual violations of possible
global symmetries, thus giving rise to massive Goldstone bosons in the
spontaneously broken phase of the theory. In this paper we develop a novel
symmetry-improved CJT formalism for consistently encoding global symmetries in
a loopwise expansion. In our formalism, the extremal solutions of the fields
and propagators to a loopwise truncated CJT effective action are subject to
additional constraints given by the Ward identities due to global symmetries.
By considering a simple O(2) scalar model, we show that, unlike other methods,
our approach satisfies a number of important field-theoretic properties. In
particular, we find that the Goldstone boson resulting from spontaneous
symmetry breaking of O(2) is massless and the phase transition is a second
order one, already in the Hartree-Fock approximation. After taking the sunset
diagrams into account, we show how our approach properly describes the
threshold properties of the massless Goldstone boson and the Higgs particle in
the loops. Finally, assuming minimal modifications to the Hartree-Fock
approximated CJT effective action, we calculate the corresponding
symmetry-improved CJT effective potential and discuss the conditions for its
uniqueness for scalar-field values away from its minimum.


title:
Minimum number of input states required for quantum gate
  characterization

abstract:
  We derive an algebraic framework which identifies the minimal information
required to assess how well a quantum device implements a desired quantum
operation. Our approach is based on characterizing only the unitary part of an
open system's evolution. We show that a reduced set of input states is
sufficient to estimate the average fidelity of a quantum gate, avoiding a
sampling over the full Liouville space. Surprisingly, the minimal set consists
of only two input states, independent of the Hilbert space dimension. The
minimal set is, however, impractical for device characterization since one of
the states is a totally mixed thermal state and extracting bounds for the
average fidelity is impossible. We therefore present two further reduced sets
of input states that allow, respectively, for numerical and analytical bounds
on the average fidelity.


title: More bang for your buck: Towards super-adiabatic quantum engines

abstract:
  The reversible nature of thermodynamical cycles is an idealisation based on
the assumption of perfect quasi-static dynamics. As a consequence of this
assumption, ideal engines operate at the maximum efficiency but have zero
power. Realistic engines, on the other hand, operate in finite-time and are
intrinsically irreversible, implying friction effects at short cycle times. The
engineering goal is to find the maximum efficiency allowed at the maximum
possible power. In the current technological age, with our ability to
manipulate devices at the nanoscale and beyond, one must understand the
consequences of engines which operate at the quantum mechanical level. In this
domain one cannot avoid the emergence of both quantum and thermal fluctuations
which drastically alter the energetics of the cycle. Very recently, it has been
shown that the Hamiltonian of a quantum system may be manipulated in such a way
as to mimic an adiabatic process via a non-adiabatic shortcut. A surge of
experimental progress has demonstrated several of these proposals in the
laboratory. In this paper we show that, by utilising shortcuts to adiabaticity
in a quantum engine cycle, one can engineer a thermodynamical cycle working at
finite power and zero friction. Our findings are elucidated using a harmonic
oscillator undergoing a quantum Otto cycle.


title:
Update-Efficiency and Local Repairability Limits for Capacity
  Approaching Codes

abstract:
  Motivated by distributed storage applications, we investigate the degree to
which capacity achieving encodings can be efficiently updated when a single
information bit changes, and the degree to which such encodings can be
efficiently (i.e., locally) repaired when single encoded bit is lost.
  Specifically, we first develop conditions under which optimum
error-correction and update-efficiency are possible, and establish that the
number of encoded bits that must change in response to a change in a single
information bit must scale logarithmically in the block-length of the code if
we are to achieve any nontrivial rate with vanishing probability of error over
the binary erasure or binary symmetric channels. Moreover, we show there exist
capacity-achieving codes with this scaling.
  With respect to local repairability, we develop tight upper and lower bounds
on the number of remaining encoded bits that are needed to recover a single
lost bit of the encoding. In particular, we show that if the code-rate is
$\epsilon$ less than the capacity, then for optimal codes, the maximum number
of codeword symbols required to recover one lost symbol must scale as
$\log1/\epsilon$.
  Several variations on---and extensions of---these results are also developed.


title: Normalizers inside amalgamated free product von Neumann algebras

abstract:
  Recently, Adrian Ioana proved that all crossed products by free ergodic
probability measure preserving actions of a nontrivial free product group
\Gamma_1 * \Gamma_2 have a unique Cartan subalgebra up to unitary conjugacy.
Ioana deduced this result from a more general dichotomy theorem on the
normalizer N_M(A)'' of an amenable subalgebra A of an amalgamated free product
von Neumann algebra M = M_1 *_B M_2. We improve this dichotomy theorem by
removing the spectral gap assumptions and obtain in particular a simpler proof
for the uniqueness of the Cartan subalgebra in crossed products by \Gamma_1 *
\Gamma_2.


title: An Explicit Cross Entropy Scheme for Mixtures

abstract:
  The key issue in importance sampling is the choice of the alternative
sampling distribution, which is often chosen from the exponential tilt family
of the underlying distribution. However, when the problem exhibits certain kind
of nonconvexity, it is very likely that a single exponential change of measure
will never attain asymptotic optimality and can lead to erroneous estimates. In
this paper we introduce an explicit iterative scheme which combines the
traditional cross-entropy method and the EM algorithm to find an efficient
alternative sampling distribution in the form of mixtures. We also study the
applications of this scheme to the estimation of rainbow option prices.


title: A study on ideal ward continuity

abstract:
  In this paper, we prove that any ideal ward continuous function is uniformly
continuous either on an interval or on an ideal ward compact subset of
$\textbf{R}$. A characterization of uniform continuity is also given via ideal
quasi-Cauchy sequences.


title:
An Understanding of the Shoulder of Giants: Jovian Planets around Late K
  Dwarf Stars and the Trend with Stellar Mass

abstract:
  Analyses of exoplanet statistics suggest a trend of giant planet occurrence
with host star mass, a clue to how planets like Jupiter form. One missing piece
of the puzzle is the occurrence around late K dwarf stars (masses of
0.5-0.75Msun and effective temperatures of 3900-4800K). We analyzed four years
of Doppler radial velocities data of 110 late K dwarfs, one of which hosts two
previously reported giant planets. We estimate that 4.0+/-2.3% of these stars
have Saturn-mass or larger planets with orbital periods <245d, depending on the
planet mass distribution and RV variability of stars without giant planets. We
also estimate that 0.7+/-0.5% of similar stars observed by Kepler have giant
planets. This Kepler rate is significantly (99% confidence) lower than that
derived from our Doppler survey, but the difference vanishes if only the single
Doppler system (HIP 57274) with completely resolved orbits is considered. The
difference could also be explained by the exclusion of close binaries (without
giant planets) from the Doppler but not Kepler surveys, the effect of
long-period companions and stellar noise on the Doppler data, or an intrinsic
difference between the two populations. Our estimates for late K dwarfs bridge
those for solar-type stars and M dwarfs and support a positive trend with
stellar mass. Small sample size precludes statements about finer structure,
e.g. a "shoulder" in the distribution of giant planets with stellar mass.
Future surveys such as the Next Generation Transit Survey and the Transiting
Exoplanet Satellite Survey will ameliorate this deficiency.


title: Thermoelectric Performance of various Benzo-difuran Wires

abstract:
  Using a first principles approach to electron transport, we calculate the
electrical and thermoelectrical transport properties of a series of molecular
wires containing benzo-difuran subunits. We demonstrate that the side groups
introduce Fano resonances, the energy of which is changing with the
electronegativity of selected atoms in it. We also study the relative effect of
single, double or triple bonds along the molecular backbone and find that
single bonds yield the highest thermopower, approximately 22$\mu$V/K at room
temperature, which is comparable with the highest measured values for
single-molecule thermopower reported to date.


title:
What is on Tap? The Role of Spin in Compact Objects and Relativistic
  Jets

abstract:
  We examine the role of spin in launching jets from compact objects across the
mass scale. Our work includes a total of 37 Seyferts, 11 stellar-mass black
holes, and 13 neutron stars. We find that when the Seyfert reflection lines are
modeled with Gaussian line features (a crude proxy for inner disk radius and
therefore spin), only a slight inverse correlation is found between the
Doppler-corrected radio luminosity at 5 GHz (a proxy for jet power) and line
width. When the Seyfert reflection features are fit with
relativistically-blurred disk reflection models that measure spin, there is a
tentative positive correlation between the Doppler-corrected radio luminosity
and the spin measurement. Further, when we include stellar-mass black holes in
the sample, to examine the effects across the mass scale, we find a slightly
stronger correlation with radio luminosity per unit mass and spin, at a
marginal significance (2.3 sigma confidence level). Finally, when we include
neutron stars, in order to probe lower spin values, we find a positive
correlation (3.3 sigma confidence level) between radio luminosity per unit mass
and spin. Although tentative, these results suggest that spin may have a role
in determining the jet luminosity. In addition, we find a slightly more
significant correlation (4.4 sigma confidence level) between radio luminosity
per Bolometric luminosity and spin, using our entire sample of black holes and
neutrons stars. Again, although tentative, these relations point to the
possibility that the mass accretion rate, i.e. Bolometric luminosity, is also
important in determining the jet luminosity, in addition to spin. Our analysis
suggests that mass accretion rate and disk or coronal magnetic field strength
may be the "throttle" in these compact systems, to which the Eddington limit
and spin may set the maximum jet luminosity that can be achieved.


title: Affine unfoldings of convex polyhedra

abstract:
  We show that every convex polyhedron admits a simple edge unfolding after an
affine transformation. In particular there exists no combinatorial obstruction
to a positive resolution of Durer's unfoldability problem, which answers a
question of Croft, Falconer, and Guy. Among other techniques, the proof employs
a topological characterization for embeddings among the planar immersions of
the disk.


title: Linear and nonlinear Anderson localization in a curved potential

abstract:
  We investigate disorder induced localization in the presence of nonlinearity
and curvature. We numerically analyze the time-resolved three-dimensional
expansion of a wave-packet in a bended cigar shaped potential with a focusing
Kerr-like interaction term and Gaussian disorder. We report on a
self-consistent analytical theory in which randomness, nonlinearity and
geometry are determined by a single scaling parameter, and show that curvature
enhances localization.


title: On Extensions of Polynomial Functors

abstract:
  A formula for calculating Extensions of (mainly integral) Polynomial Functors
is established, based upon projective resolutions. Sample computations are
performed, which, in particular, exhibit a surprising non-trivial extension of
Divided Cubes by Symmetric Cubes. An explicit description of the latter is
given.


title:
Characteristic classes of affine varieties and Plucker formulas for
  affine morphisms

abstract:
  An enumerative problem on a variety $V$ is usually solved by reduction to
intersection theory in the cohomology of a compactification of $V$. However, if
the problem is invariant under a "nice" group action on $V$ (so that $V$ is
spherical), then many authors suggested a better home for intersection theory:
the direct limit of the cohomology rings of all equivariant compactifications
of $V$. We call this limit the affine cohomology of $V$ and construct affine
characteristic classes of subvarieties of a complex torus, taking values in the
affine cohomology of the torus.
  This allows us to make the first steps in computing affine Thom polynomials.
Classical Thom polynomials count how many fibers of a generic proper map of a
smooth variety have a prescribed collection of singularities, and our affine
version addresses the same question for generic polynomial maps of affine
algebraic varieites. This notion is also motivated by developing an
intersection-theoretic approach to tropical correspondence theorems: they can
be reduced to the computation of affine Thom polynomials, because the
fundamental class of a variety in the affine cohomology is encoded by the
tropical fan of this variety.
  The first concrete answer that we obtain is the affine version of what were,
historically speaking, the first three Thom poylnomials -- the Plucker formulas
for the degree and the number of cusps and nodes of a projectively dual curve.
This, in particular, classifies toric varieties, whose projective dual is a
hypersurface, computes the tropical fan of the variety of double tangent
hyperplanes to a toric variety, and describes the Newton polytope of the
hypersurface of non-Morse polynomials of a given degree. We also make a
conjecture on the general form of affine Thom polynomials -- a key ingredient
is the $n$-ary fan, generalizing the secondary polytope.


title:
Optimal Estimation and Rank Detection for Sparse Spiked Covariance
  Matrices

abstract:
  This paper considers sparse spiked covariance matrix models in the
high-dimensional setting and studies the minimax estimation of the covariance
matrix and the principal subspace as well as the minimax rank detection. The
optimal rate of convergence for estimating the spiked covariance matrix under
the spectral norm is established, which requires significantly different
techniques from those for estimating other structured covariance matrices such
as bandable or sparse covariance matrices. We also establish the minimax rate
under the spectral norm for estimating the principal subspace, the primary
object of interest in principal component analysis. In addition, the optimal
rate for the rank detection boundary is obtained. This result also resolves the
gap in a recent paper by Berthet and Rigollet [1] where the special case of
rank one is considered.


title:
Evidence for New Relations between Gamma Ray Burst Prompt and X-ray
  Afterglow Emission from 9 Years of Swift

abstract:
  When a massive star explodes as a Gamma Ray Burst information about this
explosion is retained in the properties of the prompt and afterglow emission.
We report on new relationships between the prompt and X-ray afterglow emission
of Swift-detected Gamma Ray Bursts found from BAT and XRT data between 2004
December and 2013 August (754 GRBs). These relations suggest that the prompt
and afterglow emission are closely linked. In particular,we find very strong
correlations between the BAT 15-150keV $T_{90}$ and the break times before and
after the plateau phase in the X-ray 0.3-10keV afterglow light curves. We also
find a strong anti-correlation between the photon index of the GRB prompt
emission and the X-ray spectral slope of the afterglow. Further,
anti-correlations exist between the rest frame peak energy in the prompt
emission, E-peak,z, and the X-ray afterglow decay slope during the plateau
phase and the break times after the plateau phase. The rest-frame break times
before and after the plateau phase are also anti-correlated with the rest-frame
15-150keV luminosity and isotropic energy during the prompt emission. A
Principal Component Analysis suggests that GRB properties are primarily driven
by the luminosity/energy release in the 15-150 keV band. Luminosity functions
derived at various redshifts from logN-logS analysis, indicate that the density
of bright bursts is significantly lower in the local Universe compared with the
Universeat z$\approx$3, where the density of bright GRBs peaks. Using cluster
analysis, we find that the duration of Swift BAT-detected short-duration GRBs
is less than 1s. We also present the catalogue of all \swift-onboard detected
bursts.


title: Linear induction algebra and a normal form for linear operators

abstract:
  The set of natural integers is fundamental for at least two reasons: it is
the free induction algebra over the empty set (and at such allows definitions
of maps by primitive recursion) and it is the free monoid over a one-element
set, the latter structure being a consequence of the former. In this
contribution, we study the corresponding structure in the linear setting, i.e.,
in the category of modules over a commutative ring rather than in the category
of sets, namely the free module generated by the integers. It also provides
free structures of induction algebra and of monoid (in the category of
modules). Moreover we prove that each of its linear endomorphisms admits a
unique normal form, explicitly constructed, as a non-commutative formal power
series.


title:
Precise Definition And Analyticity of r-th order partial derivative of
  zeta(s,alpha)

abstract:
  S.Ramanujan[1] was aware of power series expression in alpha of
zeta(s,1-alpha)for complex s and for 0<=alpha<1,which he did not explore very
far.Author[2] had derived power series expression in alpha of
zeta(s,1+alpha)for complex {\alpha} with |alpha|<1 and had shown in author[3]
that the power series of zeta(-n,alpha) for integral n>=0,is a polynomial in
{\alpha} .On this backdrop, we give here the precise definition of r-th order
partial derivative w.r.t s of zeta(s,alpha) in terms of power series in alpha
for complex s and alpha . We also discuss the analyticity of r-th order partial
derivative w.r.t s of zeta(s,alpha) as functions of s and alpha and show that
partial derivatives w.r.t s and alpha commute.We compute partial derivative
w.r.t alpha of r-th order partial derivative w.r.t. s of zeta(s,alpha)for s=0
and s=1.We discuss the power series in s of zeta(s+1,alpha) for complex alpha.


title: A class of orthogonal functions given by a three term recurrence formula

abstract:
  The main goal in this manuscript is to present a class of functions
satisfying a certain orthogonality property for which there also exists a three
term recurrence formula. This class of functions, which can be considered as an
extension to the class of symmetric orthogonal polynomials on $[-1,1]$, has a
complete connection to the orthogonal polynomials on the unit circle.
Quadrature rules and other properties based on the zeros of these functions are
also considered.


title: Reaction-Diffusion Systems as Complex Networks

abstract:
  The spatially distributed reaction networks are indispensable for the
understanding of many important phenomena concerning the development of
organisms, coordinated cell behavior, and pattern formation. The purpose of
this brief discussion paper is to point out some open problems in the theory of
PDE and compartmental ODE models of balanced reaction-diffusion networks.


title:
An Incentive Compatible, Efficient Market for Air Traffic Flow
  Management

abstract:
  We present a market-based approach to the Air Traffic Flow Management (ATFM)
problem. The goods in our market are delays and buyers are airline companies;
the latter pay money to the FAA to buy away the desired amount of delay on a
per flight basis. We give a notion of equilibrium for this market and an LP
whose solution gives an equilibrium allocation of flights to landing slots as
well as equilibrium prices for the landing slots. Via a reduction to matching,
we show that this equilibrium can be computed combinatorially in strongly
polynomial time. Moreover, there is a special set of equilibrium prices, which
can be computed easily, that is identical to the VCG solution, and therefore
the market is incentive compatible in dominant strategy.


title: Neutron Star Masses and Radii from Quiescent Low-Mass X-ray Binaries

abstract:
  We perform a systematic analysis of neutron star radius constraints from five
quiescent low-mass X-ray binaries and examine how they depend on measurements
of their distances and amounts of intervening absorbing material, as well as
their assumed atmospheric compositions. We construct and calibrate to published
results a semi-analytic model of the neutron star atmosphere which approximates
these effects for the predicted masses and radii. Starting from mass and radius
probability distributions established from hydrogen-atmosphere spectral fits of
quiescent sources, we apply this model to compute alternate sets of probability
distributions. We perform Bayesian analyses to estimate neutron star
mass-radius curves and equation of state (EOS) parameters that best-fit each
set of distributions, assuming the existence of a known low-density neutron
star crustal EOS, a simple model for the high-density EOS, causality, and the
observation that the neutron star maximum mass exceeds $2~M_\odot$. We compute
the posterior probabilities for each set of distance measurements and
assumptions about absorption and composition. We find that, within the context
of our assumptions and our parameterized EOS models, some absorption models are
disfavored. We find that neutron stars composed of hadrons are favored relative
to those with exotic matter with strong phase transitions. In addition, models
in which all five stars have hydrogen atmospheres are found to be weakly
disfavored. Our most likely models predict neutron star radii that are
consistent with current experimental results concerning the nature of the
nucleon-nucleon interaction near the nuclear saturation density.


title: Scaling symmetry, renormalization, and time series modeling

abstract:
  We present and discuss a stochastic model of financial assets dynamics based
on the idea of an inverse renormalization group strategy. With this strategy we
construct the multivariate distributions of elementary returns based on the
scaling with time of the probability density of their aggregates. In its
simplest version the model is the product of an endogenous auto-regressive
component and a random rescaling factor designed to embody also exogenous
influences. Mathematical properties like increments' stationarity and
ergodicity can be proven. Thanks to the relatively low number of parameters,
model calibration can be conveniently based on a method of moments, as
exemplified in the case of historical data of the S&P500 index. The calibrated
model accounts very well for many stylized facts, like volatility clustering,
power law decay of the volatility autocorrelation function, and multiscaling
with time of the aggregated return distribution. In agreement with empirical
evidence in finance, the dynamics is not invariant under time reversal and,
with suitable generalizations, skewness of the return distribution and leverage
effects can be included. The analytical tractability of the model opens
interesting perspectives for applications, for instance in terms of obtaining
closed formulas for derivative pricing. Further important features are: The
possibility of making contact, in certain limits, with auto-regressive models
widely used in finance; The possibility of partially resolving the long-memory
and short-memory components of the volatility, with consistent results when
applied to historical series.


title: A Scoring System for Continuous Glucose Monitor Data

abstract:
  As continuous glucose monitors (CGMs) are used increasingly by diabetic
patients, new and intuitive tools are needed to help patients and their
physicians use these streams of data to improve blood glucose management. In
this paper, we propose a daily CGM Score which can be calculated from CGM data.
The calculation involves assigning grades and scores to 80-minute periods of
CGM data, and then aggregating the results. Scores for an individual patient,
or among a set of patients, can then be compared and contrasted, and
longitudinal studies of CGM data can also be accomplished.


title:
Waveform cross correlation for seismic monitoring of underground nuclear
  explosions. Part II: Synthetic master events

abstract:
  Waveform cross correlation is an efficient tool for detection and
characterization of seismic signals. The efficiency critically depends on the
availability of master events. For the purposes of the Comprehensive
Nuclear-Test-Ban Treaty, cross correlation can globally reduce the threshold
monitoring by 0.3 to 0.4 magnitude units. In seismically active regions, the
optimal choice of master events is straightforward. There are two approaches to
populate the global grid in aseismic areas: the replication of real masters and
synthetic seismograms calculated for seismic arrays of the International
Monitoring System. Synthetic templates depend on the accuracy of shape and
amplitude predictions controlled by focal depth and mechanism, source function,
velocity structure and attenuation along the master/station path. As in Part I,
we test three focal mechanisms (explosion, thrust fault, and actual Harvard CMT
solution for one of the April 11, 2012 Sumatera aftershocks) and two velocity
structures (ak135 and CRUST 2.0). Sixteen synthetic master events were
distributed over a 1ox1o grid. We built five cross correlation standard event
lists (XSEL) and compared detections and events with those built using the real
and grand master events as well as with the Reviewed Event Bulletin of the
International Data Centre. The XSELs built using the source of explosion and
ak135 and the reverse fault with isotropic radiation pattern demonstrate the
performance similar to that of the real and grand masters. Therefore, it is
possible to cover all aseismic areas with synthetic masters without significant
loss in seismic monitoring capabilities based on cross correlation.


title:
Parameterizing the Simplest Grassmann-Gaussian Relations for Pachner
  Move 3-3

abstract:
  We consider relations in Grassmann algebra corresponding to the
four-dimensional Pachner move 3-3, assuming that there is just one Grassmann
variable on each 3-face, and a 4-simplex weight is a Grassmann-Gaussian
exponent depending on these variables on its five 3-faces. We show that there
exists a large family of such relations; the problem is in finding their
algebraic-topologically meaningful parameterization. We solve this problem in
part, providing two nicely parameterized subfamilies of such relations. For the
second of them, we further investigate the nature of some of its parameters:
they turn out to correspond to an exotic analogue of middle homologies. In
passing, we also provide the 2-4 Pachner move relation for this second case.


title: Objectivity Through State Broadcasting: The Origins Of Quantum Darwinism

abstract:
  Quantum mechanics is one of the most successful theories, correctly
predicting huge class of physical phenomena. Ironically, in spite of all its
successes, there is a notorious problem: how does Nature create a ''bridge''
from fragile quanta to the robust, objective world of everyday experience? It
is now commonly accepted that the most promising approach is the Decoherence
Theory, based on the system-environment paradigm. To explain the observed
redundancy and objectivity of information in the classical realm, Zurek
proposed to divide the environment into independent fractions and argued that
each of them carries a nearly complete classical information about the system.
This Quantum Darwinism model has nevertheless some serious drawbacks: i) the
entropic information redundancy is motivated by a priori purely classical
reasoning; ii) there is no answer to the basic question: what physical process
makes the transition from quantum description to classical objectivity
possible? Here we prove that the necessary and sufficient condition for
objective existence of a state is the spectrum broadcasting process, which, in
particular, implies Quantum Darwinism. We first show it in general, using
multiple environments paradigm, a suitable definition of objectivity, and
Bohr's notion of non-disturbance, and then on the emblematic example for
Decoherence Theory: a dielectric sphere illuminated by photons. We also apply
Perron-Frobenius Theorem to show a faithful, ''decoherence-free'' form of
broadcasting. We suggest that the spectrum broadcasting might be one of the
foundational properties of Nature, which opens a ''window'' for life processes.


title:
Physical uncloneable function hardware keys utilizing
  Kirchhoff-law-Johnson-noise secure key exchange and noise-based logic

abstract:
  Weak physical uncloneable function (WPUF) encryption key means that the
manufacturer of the hardware can clone the key but anybody else is unable to so
that. Strong physical uncloneable function (SPUF) encryption key means that
even the manufacturer of the hardware is unable to clone the key. In this
paper, first we introduce a "ultra"-strong PUF with intrinsic dynamical
randomness, which is not only not cloneable but it also gets renewed to an
independent key (with fresh randomness) during each use via the unconditionally
secure key exchange. The solution utilizes the Kirchhoff-law-Johnson-noise
(KLJN) method for dynamical key renewal and a one-time-pad secure key for the
challenge/response process. The secure key is stored in a flash memory on the
chip to provide tamper-resistance and non-volatile storage with zero power
requirements in standby mode. Simplified PUF keys are shown: a strong PUF
utilizing KLJN protocol during the first run and noise-based logic (NBL)
hyperspace vector string verification method for the challenge/response during
the rest of its life or until it is re-initialized. Finally, the simplest PUF
utilizes NBL without KLJN thus it can be cloned by the manufacturer but not by
anybody else.


title:
Physical Modeling And Simulation Of Thermal Heating In Vertical
  Integrated Circuits

abstract:
  Interconnect is one of the main performance determinant of modern integrated
circuits (ICs). The new technology of vertical ICs places circuit blocks in the
vertical dimension in addition to the conventional horizontal plane. Compared
to the planar ICs, vertical ICs have shorter latencies as well as lower power
consumption due to shorter wires. This also increases speed, improves
performances and adds to ICs density. The benefits of vertical ICs increase as
we stack more dies, due to successive reductions in wire lengths. However, as
we stack more dies, the lattice self-heating becomes a challenging and critical
issue due to the difficulty in cooling down the layers away from the heat sink.
In this paper, we provide a quantitative electro-thermal analysis of the
temperature rise due to stacking. Mathematical models based on steady state
non-isothermal drift-diffusion transport equations coupled to heat flow
equation are used. These physically based models and the different heat sources
in semiconductor devices will be presented and discussed. Three dimensional
numerical results did show that, compared to the planar ICs, the vertical ICs
with 2-die technology increase the maximum temperature by 17 Kelvin in the die
away from the heat sink. These numerical results will also be presented and
analyzed for a typical 2-die structure of complementary metal oxide
semiconductor (CMOS) transistors.


title:
Bioacoustical Periodic Pulse Train Signal Detection and Classification
  using Spectrogram Intensity Binarization and Energy Projection

abstract:
  The following work outlines an approach for automatic detection and
recognition of periodic pulse train signals using a multi-stage process based
on spectrogram edge detection, energy projection and classification. The method
has been implemented to automatically detect and recognize pulse train songs of
minke whales. While the long term goal of this work is to properly identify and
detect minke songs from large multi-year datasets, this effort was developed
using sounds off the coast of Massachusetts, in the Stellwagen Bank National
Marine Sanctuary. The detection methodology is presented and evaluated on 232
continuous hours of acoustic recordings and a qualitative analysis of machine
learning classifiers and their performance is described. The trained automatic
detection and classification system is applied to 120 continuous hours,
comprised of various challenges such as broadband and narrowband noises, low
SNR, and other pulse train signatures. This automatic system achieves a TPR of
63% for FPR of 0.6% (or 0.87 FP/h), at a Precision (PPV) of 84% and an F1 score
of 71%.


title:
Field Programmable DSP Arrays - A Novel Reconfigurable Architecture for
  Efficient Realization of Digital Signal Processing Functions

abstract:
  Digital Signal Processing functions are widely used in real time high speed
applications. Those functions are generally implemented either on ASICs with
inflexibility, or on FPGAs with bottlenecks of relatively smaller utilization
factor or lower speed compared to ASIC. The proposed reconfigurable DSP
processor is redolent to FPGA, but with basic fixed Common Modules (CMs) (like
adders, subtractors, multipliers, scaling units, shifters) instead of CLBs.
This paper introduces the development of a reconfigurable DSP processor that
integrates different filter and transform functions. The switching between DSP
functions is occurred by reconfiguring the interconnection between CMs.
Validation of the proposed reconfigurable architecture has been achieved on
Virtex5 FPGA. The architecture provides sufficient amount of flexibility,
parallelism and scalability.


title:
Fault-tolerant control under controller-driven sampling using virtual
  actuator strategy

abstract:
  We present a new output feedback fault tolerant control strategy for
continuous-time linear systems. The strategy combines a digital nominal
controller under controller-driven (varying) sampling with virtual-actuator
(VA)-based controller reconfiguration to compensate for actuator faults. In the
proposed scheme, the controller controls both the plant and the sampling
period, and performs controller reconfiguration by engaging in the loop the VA
adapted to the diagnosed fault. The VA also operates under controller-driven
sampling. Two independent objectives are considered: (a) closed-loop stability
with setpoint tracking and (b) controller reconfiguration under faults. Our
main contribution is to extend an existing VA-based controller reconfiguration
strategy to systems under controller-driven sampling in such a way that if
objective (a) is possible under controller-driven sampling (without VA) and
objective (b) is possible under uniform sampling (without controller-driven
sampling), then closed-loop stability and setpoint tracking will be preserved
under both healthy and faulty operation for all possible sampling rate
evolutions that may be selected by the controller.


title: Social Network for Smart Devices using Embedded Ethernet

abstract:
  Embedded Ethernet is nothing but a microcontroller which is able to
communicate with the network. A design of AVR controller-based embedded
Ethernet interface is presented. In the design, an existing SPI serial device
can be converted into a network interface peripheral to obtain compatibility
with the network. By typing the IP-address of LAN on the web browser, the user
gets a web page on screen; this page contains all the information about the
status of the devices. The user can also control the devices interfaced to the
web server by pressing buttons provided in the web page. This creates a network
for easy communication among the devices.


title:
Classifying Topoi and Preservation of Higher Order Logic by Geometric
  Morphisms

abstract:
  Topoi are categories which have enough structure to interpret higher order
logic. They admit two notions of morphism: logical morphisms which preserve all
of the structure and therefore the interpretation of higher order logic, and
geometric morphisms which only preserve only some of the structure and
therefore only some of the interpretation of higher order logic. The question
then arises: what kinds of higher order theories are preserved by geometric
morphisms? It is known that certain first order theories called internal
geometric theories are preserved by geometric morphisms, and these admit what
are known as classifying topoi. Briefly, a classifying topos for an internal
geometric theory $\mathbb{T}$ in a topos $\mathcal{E}$ is a topos
$\mathcal{E}[\mathbb{T}]$ such that models of $\mathbb{T}$ in any topos
$\mathcal{F}$ with a geometric morphism to $\mathcal{E}$ are in one to one
correspondence with geometric morphisms from $\mathcal{F}$ to
$\mathcal{E}[\mathbb{T}]$ over $\mathcal{E}$. One useful technique for showing
that a higher order theory $\mathcal{T}$ is preserved by geometric morphisms is
to define an internal geometric theory $\mathbb{T}$ of "bad sets" for
$\mathcal{T}$ and show that $\mathcal{T}$ is equivalent to the higher order
theory which says "the classifying topos for $\mathbb{T}$ is degenerate". We
set up a deduction calculus for internal geometric theories and show that it
proves a contradiction if and only if the classifying topos of that theory is
degenerate. We use this result to study a variant of the higher order theory of
Dedekind finite objects and the higher order theory of field objects considered
as ring objects with no non-trivial ideals.


title:
Requirements Engineering of a Web Portal using Organizational Semiotics
  Artifacts and Participatory Practices

abstract:
  Software requirements are key elements that contribute to the quality and
users satisfaction of the final system. In this work, Requirements Engineering
(RE) of web sites is presented using an organizational semiotics perspective.
They are shown as being part of an organization, with particular practices,
rules and views considering stakeholders several differences and opinions. The
main contribution of this paper is to relate an experience, from elicitation to
validation, showing how organizational semiotics artifacts were exploited in a
collaborative and participatory way to RE of a web portal. A case study is
described in order to demonstrate the feasibility of using such artifacts to RE
when we think about the system as being part of a social organization.


title:
Ferrimagnetic Spin Wave Resonance and Superconductivity in Carbon
  Nanotubes

abstract:
  The phenomenon of ferrimagnetic spin wave resonance [uncompensated
antiferromagnetic spin wave resonance] has been detected for the first time. It
has been observed in carbon nanotubes, produced by high energy ion beam
modification of diamond single crystals in $\ <{100}\ >$ direction.
Peculiarities of spin wave resonance observed allow to insist on the formation
in given nanotubes of $s^+$ superconductivity at room temperature, coexisting
with uncompensated antiferromagnetic ordering.


title: An update on domineering on rectangular boards

abstract:
  Domineering is a combinatorial game played on a subset of a rectangular grid
between two players. Each board position can be put into one of four outcome
classes based on who the winner will be if both players play optimally. In this
note, we review previous work, establish the outcome classes for several
dimensions of rectangular board, and restrict the outcome class in several
more.


title: Holographic Special Relativity

abstract:
  We reinterpret special relativity, or more precisely its de Sitter
deformation, in terms of 3d conformal geometry, as opposed to (3+1)d spacetime
geometry. An inertial observer, usually described by a geodesic in spacetime,
becomes instead a choice of ways to reverse the conformal compactification of a
Euclidean vector space up to scale. The observer's "current time," usually
given by a point along the geodesic, corresponds to the choice of scale in the
decompactification. We also show how arbitrary conformal 3-geometries give rise
to "observer space geometries," as defined in recent work, from which spacetime
can be reconstructed under certain integrability conditions. We conjecture a
relationship between this kind of "holographic relativity" and the "shape
dynamics" proposal of Barbour and collaborators, in which conformal space takes
the place of spacetime in general relativity. We also briefly survey related
pictures of observer space, including the AdS analog and a representation
related to twistor theory.


title: The multisubset sum problem for finite abelian groups

abstract:
  In this note, we give the explicit formula for the number of multisubsets of
a finite abelian group $G$ with any given size such that the sum is equal to a
given element $g\in G$. This also gives the number of partitions of $g$ into a
given number of parts over a finite abelian group. An inclusion-exclusion
formula for the number of multisubsets of a subset of $G$ with a given size and
a given sum is also obtained.


title: Inflationary dark energy from a condensate of spinors in a 5D vacuum

abstract:
  What is the physical origin of dark energy? Could this energy be originated
by other fields than the inflaton? In this work we explore the possibility that
the expansion of the universe can be driven by a condensate of spinors. These
spinors are free of interactions on 5D relativistic vacuum in an extended de
Sitter spacetime. The extra coordinate is considered as noncompact. After
making a static foliation on the extra coordinate, we obtain an effective 4D
(inflationary) de Sitter expansion which describes an inflationary universe. In
view of our results we conclude that the condensate of spinors here studied
could be an interesting candidate to explain the presence of dark energy in the
early universe.


title: Optimal polarisation equations in FLRW universes

abstract:
  This paper presents the linearised Boltzmann equation for photons for scalar,
vector and tensor perturbations in flat, open and closed FLRW cosmologies. We
show that E- and B-mode polarisation for all types can be computed using only a
single hierarchy. This was previously shown explicitly for tensor modes in flat
cosmologies but not for vectors, and not for non-flat cosmologies.


title: Parametric seeding of a microresonator optical frequency comb

abstract:
  We have investigated parametric seeding of a microresonator frequency comb
(microcomb) by way of a pump laser with two electro-optic-modulation sidebands.
We show that the pump-sideband spacing is precisely replicated throughout the
microcomb's optical spectrum, and we demonstrate a record absolute line-spacing
stability for microcombs of $1.6\times10^{-13}$ at 1 s. The spectrum of a
parametric comb is complex, and often non-equidistant subcombs are observed.
Our results demonstrate that parametric seeding can not only control the
subcombs, but can lead to the generation of a strictly equidistant microcomb
spectrum.


title: Nonequilibrium transport through magnetic vibrating molecules

abstract:
  We calculate the nonequilibrium conductance through a molecule or a quantum
dot in which the occupation of the relevant electronic level is coupled with
intensity $\lambda$ to a phonon mode, and also to two conducting leads. The
system is described by the Anderson-Holstein Hamiltonian. We solve the problem
using the Keldysh formalism and the non-crossing approximation (NCA) for both,
the electron-electron and the electron-phonon interactions. We obtain a
moderate decrease of the Kondo temperature $T_K$ with $\lambda$ for fixed
renormalized energy of the localized level $\tilde{E_d}$. The meaning and value
of $\tilde{E_d}$ are discussed. The spectral density of localized electrons
shows in addition to the Kondo peak of width $2 T_K$, satellites of this peak
shifted by multiples of the phonon frequency $ \omega_0$. The nonequilibrium
conductance as a function of bias voltage $V_b$ at small temperatures, also
displays peaks at multiples of $\omega_0$ in addition to the central dominant
Kondo peak near $V_b=0$.


title: On indecomposable sets with applications

abstract:
  In this note we show the characteristic function of every indecomposable set
$F$ in the plane is $BV$ equivalent to the characteristic function a closed set
$\mathbb{F}$, i.e.
$||\mathbb{1}_{F}-\mathbb{1}_{\mathbb{F}}||_{BV(\mathbb{R}^2)}=0$. We show by
example this is false in dimension three and above. As a corollary to this
result we show that for every $\epsilon>0$ a set of finite perimeter $S$ can be
approximated by a closed subset $\mathbb{S}_{\epsilon}$ with finitely many
indecomposable components and with the property that $H^1(\partial^M
\mathbb{S}_{\epsilon}\backslash \partial^M S)=0$ and
$||\mathbb{1}_{S}-\mathbb{1}_{\mathbb{S}_{\epsilon}}||_{BV(\mathbb{R}^2)}<\epsilon$.
We apply this corollary to give a short proof that locally quasiminimizing sets
in the plane are $BV_l$ extension domains.


title: Interference Channel with Intermittent Feedback

abstract:
  We investigate how to exploit intermittent feedback for interference
management. Focusing on the two-user linear deterministic interference channel,
we completely characterize the capacity region. We find that the
characterization only depends on the forward channel parameters and the
marginal probability distribution of each feedback link. The scheme we propose
makes use of block Markov encoding and quantize-map-and-forward at the
transmitters, and backward decoding at the receivers. Matching outer bounds are
derived based on novel genie-aided techniques. As a consequence, the
perfect-feedback capacity can be achieved once the two feedback links are
active with large enough probabilities.


title:
The method of coupled fixed points and coupled quasisolutions when
  working with ODE's with arguments of bounded variation

abstract:
  The aim of this paper is to show the use of the coupled quasisolutions method
as a useful technique when treating with ordinary differential equations with
functional arguments of bounded variation. We will do this by looking for
solutions for a first-order ordinary differential equation with an advanced
argument of bounded variation. The main trick is to use the Jordan
decomposition of this argument in a nondecreasing part and a nonincreasing one.
As a necessary step, we will also talk about coupled fixed points of
multivalued operators.


title: Holographic Thermalization from Kerr-AdS

abstract:
  We study thermalization of a strongly coupled theory holographically dual to
a thin shell of null dust with non-zero angular momentum collapsing to
Kerr-AdS. We calculate thermalization time for two point correlation functions.
It happens that in the 3-dimensional case the thermalization time is just
proportional to the distance between points where the correlator is evaluated.
This is a very surprising and rather unexpected generalization of the same
relation in the case of zero momentum.


title:
On the existence of 0/1 polytopes with high semidefinite extension
  complexity

abstract:
  In Rothvo\ss{} it was shown that there exists a 0/1 polytope (a polytope
whose vertices are in \{0,1\}^{n}) such that any higher-dimensional polytope
projecting to it must have 2^{\Omega(n)} facets, i.e., its linear extension
complexity is exponential. The question whether there exists a 0/1 polytope
with high PSD extension complexity was left open. We answer this question in
the affirmative by showing that there is a 0/1 polytope such that any
spectrahedron projecting to it must be the intersection of a semidefinite cone
of dimension~2^{\Omega(n)} and an affine space. Our proof relies on a new
technique to rescale semidefinite factorizations.


title: Detection of X-rays from the jet-driving symbiotic star Hen 3-1341

abstract:
  Hen 3-1341 is a symbiotic binary system consisting of a white dwarf and a red
giant star that is one of about ten symbiotics that show hints of jets. The
bipolar jets have been detected through displaced components of emission lines
during its outburst from 1998 to 2004. These components disappeared when Hen
3-1341 reached quiescence. On February 23, 2012, Hen 3-1341 started a new
outburst with the emergence of new bipolar jets on March 3, 2012. We observed
Hen 3-1341 during quiescence with XMM-Newton in March 2010 with an effective
exposure time of 46.8 ks and with Swift on March 8-11, 2012 as ToO observations
with an effective exposure time of 10 ks in order to probe the interaction of
the jet with the ambient medium and also the accretion onto the white dwarf. We
fitted the XMM-Newton X-ray spectra with XSPEC and examined the X-ray and UV
light curves. We report the detection of X-ray emission during quiescence from
Hen 3-1341 with XMM-Newton. The spectrum can be fitted with an absorbed
one-temperature plasma or an absorbed blackbody. We did not detect Hen 3-1341
during our short Swift exposure. Neither periodic or aperiodic X-ray nor UV
variability were found. Our XMM-Newton data suggest that interaction of the
residual jet with the interstellar medium might survive for a long time after
outbursts and might be responsible for the observed X-ray emission during
quiescence. Additional data are strongly needed to confirm these suggestions.


title:
Infrared Parallaxes of Young Field Brown Dwarfs and Connections to
  Directly Imaged Gas-Giant Exoplanets

abstract:
  We have measured high-precision parallaxes for a large sample of candidate
young (~10-100 Myr) and intermediate-age (~100-600 Myr) ultracool dwarfs, with
spectral types ranging from M8 to T2.5. These objects are compelling benchmarks
for substellar evolution and ultracool atmospheres at lower surface gravities
(i.e., masses) than most of the field population. We find that the absolute
magnitudes of our young sample can be systematically offset from ordinary
(older) field dwarfs, with the young late-M objects being brighter and the
young/dusty mid-L (L3-L6.5) objects being fainter, especially at J band. Thus,
we conclude the "underluminosity" of the young planetary-mass companions HR
8799b and 2MASS J1207-39b compared to field dwarfs is also manifested in young
free-floating brown dwarfs, though the effect is not as extreme. At the same
time, some young objects over the full spectral type range of our sample are
similar to field objects, and thus a simple correspondence between youth and
magnitude offset relative to the field population appears to be lacking.
Comparing the kinematics of our sample to nearby stellar associations and
moving groups, we identify several new moving group members, including the
first free-floating L dwarf in the AB Dor moving group, 2MASS J0355+11.
Altogether, the effects of surface gravity (age) and dust content on the
magnitudes and colors of substellar objects appear to be degenerate.


title: Optical Phase Curves of Kepler Exoplanets

abstract:
  We have conducted a comprehensive search for optical phase variations of all
planet candidates with tight orbits in fifteen quarters of data from the Kepler
space telescope. After correcting for systematics, we found eight systems that
appear to show secondary eclipses as well as phase variations. Of these, five
(Kepler-5, Kepler-6, Kepler-8, KOI-64 and KOI-2133) are new and three (TrES-2,
HAT-P-7 and KOI-13) have previously published phase curves, albeit with many
fewer observations. We model the full phase curve of each planet candidate,
including the primary and secondary transits, and derive their albedos, day-
and night-side temperatures, ellipsoidal variations and Doppler beaming. We
find that KOI-64 and KOI-2133 have night-side temperatures well above their
equilibrium values (while KOI-2133 also has an albedo >1), so we conclude that
they are likely to be self-luminous objects rather than planets. The
characteristics of the six other candidates are consistent with their being
planets with low geometric albedos (<0.3). For TrES-2 and KOI-13, the Kepler
bandpass appears to probe atmospheric layers hotter than the planet's
equilibrium temperature. For KOI-13, we detect a never-before-seen third cosine
harmonic with an amplitude of 6.7+/-0.3 ppm and a phase shift of -1.1+/-0.1
radians in the phase curve residual, which could be due to its spin-orbit
misalignment. We report derived planetary parameters for all six planets,
including masses from ellipsoidal variations and Doppler beaming, and compare
our results to published values when available. Our results nearly double the
number of Kepler exoplanets with measured phase curve variations, thus
providing valuable new constraints on the properties of close-in hot Jupiters.


title:
Top-Quark Charge Asymmetry Goes Forward: Two New Observables for Hadron
  Colliders

abstract:
  We propose two new observables to measure the charge asymmetry in hadronic
top-quark pair production in association with a hard jet. The incline
asymmetry, based on the inclination between the planes of initial- and
final-state momenta, probes the charge asymmetry in the quark-antiquark
channel. Compared to the hitherto investigated rapidity asymmetries, the
incline asymmetry provides improved access to the partonic charge asymmetry at
both the Tevatron and the LHC. The energy asymmetry, based on the energy
difference between top and antitop quarks, for the first time allows us to
probe the charge asymmetry in the quark-gluon channel at the LHC. In quantum
chromodynamics, asymmetries of up to -12% at the leading order are achievable
with appropriate cuts. Top-pair plus jet production thus has the potential to
become the discovery channel of the charge asymmetry in proton-proton
collisions.


title: Are Narrow Line Seyfert 1s a special class of Active Galactic Nuclei?

abstract:
  No. Due to their apparently extreme optical to X-ray properties, Narrow Line
Seyfert 1s (NLSy1s) have been considered a special class of active galactic
nuclei (AGN). Here, we summarize observational results from different groups to
conclude that none of the characteristics that are typically used to define the
NLSy1s as a distinct group - from the, nowadays called, Broad Line Seyfert 1s
(BLSy1s) - is unique, nor ubiquitous of these particular sources, but shared by
the whole Type 1 AGN. Historically, the NLSy1s have been distinguished from the
BLSy1s by the narrow width of the broad Hbeta emission line. The upper limit on
the full width at half maximum of this line is 2000 km/s for NLSy1s, while in
BLSy1s it can be of several thousands of km/s. However, this border has been
arbitrarily set and does not correspond to the change of any physical property.
All observed parameters in Type 1 AGN cover continues ranges of values, which
does not allow to infer the existence of two different kind of populations with
FWHM(Hbeta,broad) = 2000 km/s as dividing point. We argue that the usage of
this velocity limit to define samples of NLSy1s galaxies - as it is usually
done in comparative studies -, together with the well known observational
biases, naturally favors the selection of sources with low black hole masses
and high Eddington ratios that are hosted by blue spiral galaxies. Therefore
selection biases might be responsible for the reported differences between
NLSy1 and BLSy1 sources.


title:
Implications of light charginos for Higgs observables, LHC searches and
  dark matter

abstract:
  A rather high Higgs mass, m_h = 126 GeV, suggests that at least a part of the
supersymmetric spectrum of the MSSM may live beyond O(1TeV) and hence
inaccessible to the LHC. However, there are theoretical and phenomenological
reasons supporting a possibility that charginos and neutralinos remain much
closer to the electroweak scale. In this paper, we explore such a scenario in
the light of recent Higgs measurements, mainly its di-photon decay rate, where
the data might indicate a slight excess over the SM prediction. That excess
could be fitted by the contribution of light charginos provided tan(beta) is
low to moderate, a possibility that is receiving much attention for other
theoretical reasons. We investigate the implications of this scenario for other
observables, such as dark matter constraints, electroweak observables and
experimental signals at the LHC, like di-lepton, tri-lepton and same-sign
dilepton. An important part of the models survive all the constraints and are
able to give positive signals at LHC-14TeV and/or XENON1T.


title: Modifying two-body relaxation in N-body systems by gas accretion

abstract:
  We consider the effects that accretion from the interstellar medium onto the
particles of an N-body system has on the rate of two-body relaxation. To this
end, we derive an accretion-modified relaxation time by adapting Spitzer's
two-component model to include the damping effects of accretion. We consider
several different mass-dependencies and efficiency factors for the accretion
rate, as well as different mass ratios for the two components of the model.
  The net effect of accretion is to accelerate mass segregation by increasing
the average mass $\bar{m}$, since the relaxation time is inversely proportional
to $\bar{m}$. Under the assumption that the accretion rate increases with the
accretor mass, there are two additional effects that accelerate mass
segregation. First, accretion acts to increase the range of any initial mass
spectrum, quickly driving the heaviest members to even higher masses. Second,
accretion acts to reduce the velocities of the accretors due to conservation of
momentum, and it is the heaviest members that are affected the most. Using our
two-component model, we quantify these effects as a function of the accretion
rate, the total cluster mass, and the component masses. We conclude by
discussing the implications of our results for the dynamical evolution of
primordial globular clusters, primarily in the context of black holes formed
from the most massive stellar progenitors.


title: Hybrid Cosmological Simulations with Stream Velocities

abstract:
  In the early universe, substantial relative "stream" velocities between the
gas and dark matter arise due to radiation pressure and persist after
recombination. To asses the impact of these velocities on high-redshift
structure formation, we carry out a suite of high-resolution Adaptive Mesh
Refinement (AMR) cosmological simulations, which use Smoothed Particle
Hydrodynamic datasets as initial conditions, converted using a new tool
developed for this work. These simulations resolve structures with masses as
small as a few 100 M$_\odot$, and we focus on the $10^6$ M$_\odot$ "mini-halos"
in which the first stars formed. At $z \approx 17,$ the presence of stream
velocities has only a minor effect on the number density of halos below $10^6$
M$_\odot$, but it greatly suppresses gas accretion onto all halos and the dark
matter structures around them. Stream velocities lead to significantly lower
halo gas fractions, especially for $\approx 10^5$ M$_\odot$ objects, an effect
that is likely to depend on the orientation of a halo's accretion lanes. This
reduction in gas density leads to colder, more compact radial profiles, and it
substantially delays the redshift of collapse of the largest halos, leading to
delayed star formation and possibly delayed reionization. These many
differences suggest that future simulations of early cosmological structure
formation should include stream velocities to properly predict gas evolution,
star-formation, and the epoch of reionization.


title:
Discovery of an Intermediate Mass Black Hole at the center of the
  starburst/Seyfert composite galaxy IRAS 01072+4954

abstract:
  The starburst/Seyfert composite galaxy IRAS 01072+4954 (z=0.0236) is an
enigmatic source that combines a Seyfert~1-like X-ray emission with a starburst
optical spectrum that lacks broad line emission. We performed high angular
resolution observations of the central kiloparsec of this galaxy in the
near-infrared. Combining our data with 2MASS images of the whole galaxy, we
obtain and model the surface brightness profile. We find indications for the
presence of an elongated bar-like structure in both data sets. We also model
the line of sight velocity distribution of the stars in the bulge. The derived
photometrical and kinematical parameters of the bulge are used to evaluate the
black hole mass through scaling relations. We find that all reliable
estimations of the black hole mass are consistent with the presence of an
intermediate mass black hole with a mass of ~10^5 solar masses (or less).


title:
New Methods for Characterizing Phases of 2D Supersymmetric Gauge
  Theories

abstract:
  We study the physics of two-dimensional N=(2,2) gauged linear sigma models
(GLSMs) via the two-sphere partition function. We show that the classical phase
boundaries separating distinct GLSM phases, which are described by the
secondary fan construction for abelian GLSMs, are completely encoded in the
analytic structure of the partition function. The partition function of a
non-abelian GLSM can be obtained as a limit from an abelian theory; we utilize
this fact to show that the phases of non-abelian GLSMs can be obtained from the
secondary fan of the associated abelian GLSM. We prove that the partition
function of any abelian GLSM satisfies a set of linear differential equations;
these reduce to the familiar A-hypergeometric system of Gel'fand, Kapranov, and
Zelevinski for GLSMs describing complete intersections in toric varieties. We
develop a set of conditions that are necessary for a GLSM phase to admit an
interpretation as the low-energy limit of a non-linear sigma model with a
Calabi-Yau threefold target space. Through the application of these criteria we
discover a class of GLSMs with novel geometric phases corresponding to
Calabi-Yau manifolds that are branched double-covers of Fano threefolds. These
criteria provide a promising approach for constructing new Calabi-Yau
geometries.


title: Higher derivative corrections to Lifshitz backgrounds

abstract:
  We explore the effect of curvature-square corrections on Lifshitz solutions
to the Einstein-Maxwell-dilaton system. After exhibiting the renormalized
Lifshitz scaling solution to the system with parameterized R^2 corrections, we
turn to a toy model with coupling g(\phi)C_{\mu\nu\rho\sigma}^2 and demonstrate
that such a term can both stabilize the dilaton and resolve the Lifshitz
horizon to AdS_2 x R^2. As an example, we construct numerical flows from AdS_4
in the UV to an intermediate Lifshitz region and then to AdS_2 x R^2 in the
deep IR.


title: MN Lup: X-rays from a weakly accreting T Tauri star

abstract:
  Young T Tauri stars (TTS) are surrounded by an accretion disk, which over
time disperses due to photoevaporation, accretion, and possibly planet
formation. The accretion shock on the central star produces an UV/optical
veiling continuum, line emission, and X-ray signatures. As the accretion rate
decreases, the impact on the central star must change. In this article we study
MN Lup, a young star where no indications of a disk are seen in IR
observations. We present XMM-Newton and VLT/UVES observations, some of them
taken simultaneously. The X-ray data show that MN Lup is an active star with
L_X/L_bol close to the saturation limit. However, we find high densities (n_e >
3e10 /cm^3) in the X-ray grating spectrum. This can be well fitted using an
accretion shock model with an accretion rate of 2e-11 M_sun/yr. Despite the
simple Halpha line profile which has a broad component, but no absorption
signatures as typically seen on accreting TTS, we find rotational modulation in
Ca II K and in photospheric absorption lines. In the Halpha line we see a
prominence in absorption about 2R_* above the stellar surface - the first of
its kind on a TTS. MN Lup is also the only TTS where accretion is seen, but no
dust disk is detected that could fuel it. We suggest that MN Lup presents a
unique and short-lived state in the disk evolution. It may have lost its dust
disk only recently and is now accreting the remaining gas at a very low rate.


title: Relative photometry of HAT-P-1b occultations

abstract:
  We present HST STIS observations of two occultations of the transiting
exoplanet HAT-P-1b. By measuring the planet to star flux ratio near opposition,
we constrain the geometric albedo of the planet, which is strongly linked to
its atmospheric temperature gradient. An advantage of HAT-P-1 as a target is
its binary companion ADS 16402 A, which provides an excellent photometric
reference, simplifying the usual steps in removing instrumental artifacts from
HST time-series photometry. We find that without this reference star, we would
need to detrend the lightcurve with the time of the exposures as well as the
first three powers of HST orbital phase, and this would introduce a strong bias
in the results for the albedo. However, with this reference star, we only need
to detrend the data with the time of the exposures to achieve the same
per-point scatter, therefore we can avoid most of the bias associated with
detrending. Our final result is a 2 sigma upper limit of 0.64 for the geometric
albedo of HAT-P-1b between 577 and 947 nm.


title: Emergence of hierarchy in cost driven growth of spatial networks

abstract:
  One of the most important features of spatial networks such as transportation
networks, power grids, Internet, neural networks, is the existence of a cost
associated with the length of links. Such a cost has a profound influence on
the global structure of these networks which usually display a hierarchical
spatial organization. The link between local constraints and large-scale
structure is however not elucidated and we introduce here a generic model for
the growth of spatial networks based on the general concept of cost benefit
analysis. This model depends essentially on one single scale and produces a
family of networks which range from the star-graph to the minimum spanning tree
and which are characterised by a continuously varying exponent. We show that
spatial hierarchy emerges naturally, with structures composed of various hubs
controlling geographically separated service areas, and appears as a
large-scale consequence of local cost-benefit considerations. Our model thus
provides the first building blocks for a better understanding of the evolution
of spatial networks and their properties. We also find that, surprisingly, the
average detour is minimal in the intermediate regime, as a result of a large
diversity in link lengths. Finally, we estimate the important parameters for
various world railway networks and find that --remarkably-- they all fall in
this intermediate regime, suggesting that spatial hierarchy is a crucial
feature for these systems and probably possesses an important evolutionary
advantage.


title: An approach to basic set theory and logic

abstract:
  The purpose of this paper is to outline a simple set of axioms for basic set
theory from which most fundamental facts can be derived. The key to the whole
project is a new axiom of set theory which I dubbed "The Law of Extremes". It
allows for quick proofs of basic set-theoretic identities and logical
tautologies, so it is also a good tool to aid one's memory.
  I do not assume any exposure to euclidean geometry via axioms. Only an
experience with transforming algebraic identities is required.
  The idea is to get students to do proofs right from the get-go. In
particular, I avoid entangling students in nuances of logic early on. Basic
facts of logic are derived from set theory, not the other way around.


title:
A high Eddington-ratio, true Seyfert 2 galaxy candidate: implications
  for broad-line-region models

abstract:
  A bright, soft X-ray source was detected on 2010 July 14 during an
XMM--Newton slew at a position consistent with the galaxy GSN 069 (z=0.018).
Previous ROSAT observations failed to detect the source and imply that GSN 069
is now >240 times brighter than it was in 1994 in the soft X-ray band. We
report here results from a ~1 yr monitoring with Swift and XMM-Newton, as well
as from optical spectroscopy. GSN 069 is an unabsorbed, ultra-soft source in
X-rays, with no flux detected above ~1 keV. The soft X-rays exhibit significant
variability down to timescales of hundreds of seconds. The UV-to-X-ray spectrum
of GSN 069 is consistent with a pure accretion disc model which implies an
Eddington ratio of ~0.5 and a black hole mass of ~ 1.2 million solar masses. A
new optical spectrum, obtained ~3.5 months after the XMM-Newton slew detection,
is consistent with earlier spectra and lacks any broad line component,
classifying the source as a Seyfert 2 galaxy. The lack of cold X-ray absorption
and the short timescale variability in the soft X-rays rule out a standard
Seyfert 2 interpretation of the X-ray data. We discuss our results within the
framework of two possible scenarios for the broad-line-region (BLR) in AGN,
namely the two-phase model (cold BLR clouds in pressure equilibrium with a
hotter medium), and models in which the BLR is part of an outflow, or
disc-wind. Finally, we point out that GSN 069 may be a member of a population
of super-soft AGN whose SED is completely dominated by accretion disc emission,
as it is the case in some black hole X-ray binary transients during their
outburst evolution. The disc emission for a typical AGN with larger black hole
mass than GSN 069 does not enters the soft X-ray band, so that GSN 069-like
objects would likely be missed by current X-ray surveys, or mis-classified as
Compton-thick candidates. (ABRIDGED)


title: On the Hermite problem for cubic irrationalities

abstract:
  In this paper, the Hermite problem has been approached finding a periodic
representation (by means of periodic rational or integer sequences) for any
cubic irrationality. In other words, the problem of writing cubic irrationals
as a periodic sequence of rational or integer numbers has been solved. In
particular, a periodic multidimensional continued fraction (with pre--period of
length 2 and period of length 3) is proved convergent to a given cubic
irrationality, by using the algebraic properties of cubic irrationalities and
linear recurrent sequences. This multidimensional continued fraction is derived
from a modification of the Jacobi algorithm, which is proved periodic if and
only if the inputs are cubic irrationals. Moreover, this representation
provides simultaneous rational approximations for cubic irrationals.


title: Scaling relations for galaxy clusters: properties and evolution

abstract:
  Well-calibrated scaling relations between the observable properties and the
total masses of clusters of galaxies are important for understanding the
physical processes that give rise to these relations. They are also a critical
ingredient for studies that aim to constrain cosmological parameters using
galaxy clusters. For this reason much effort has been spent during the last
decade to better understand and interpret relations of the properties of the
intra-cluster medium. Improved X-ray data have expanded the mass range down to
galaxy groups, whereas SZ surveys have openened a new observational window on
the intracluster medium. In addition,continued progress in the performance of
cosmological simulations has allowed a better understanding of the physical
processes and selection effects affecting the observed scaling relations. Here
we review the recent literature on various scaling relations, focussing on the
latest observational measurements and the progress in our understanding of the
deviations from self similarity.


title: Photospheric emission throughout GRB 100507 detected by Fermi

abstract:
  Gamma ray bursts with blackbody spectra are only a few and in most cases this
spectral component is accompanied by a dominating non-thermal one. Only four
bursts detected by Batse have a pure blackbody spectrum throughout their
duration. We present the new case of GRB 100507 detected by the Gamma Burst
Monitor on board the Fermi satellite. GRB 100507 has a blackbody spectrum for
the entire duration (~30 s) of the prompt emission. The blackbody temperature
varies between 25 and 40 keV. The flux varies between 1e-7 and 4e-7 erg/cm2 s.
There is no clear evidence of a correlation between the temperature and the
blackbody flux. If the thermal emission in GRB 100507 is due to the fireballs
becoming transparent, we can estimate the radius R_T and bulk Lorentz factor
Gamma_T corresponding to this transition and the radius R_0 where the fireballs
are created. We compare these parameters with those derived for the other four
bursts with a pure blackbody spectrum. In all but one burst, for fiducial
assumptions on the radiative efficiency and distance of the sources,
R_0~1e9-1e10 cm, i.e. much larger than the gravitational radius of a few solar
mass black hole. Possible solutions of this apparent inconsistency are
tentatively discussed considering the dependence of R_0 on the unknown
parameters. Alternatively, such a large R_0 could be where the fireball, still
opaque, converts most of its kinetic energy into internal energy (due to the
impact with some material left over by the progenitor star) and starts to
re-accelerate.


title: A Convex Analysis Approach to Computational Entropy

abstract:
  This paper studies the notion of computational entropy. Using techniques from
convex optimization, we investigate the following problems: (a) Can we
derandomize the computational entropy? More precisely, for the computational
entropy, what is the real difference in security defined using the three
important classes of circuits: deterministic boolean, deterministic real
valued, or (the most powerful) randomized ones? (b) How large the difference in
the computational entropy for an unbounded versus efficient adversary can be?
(c) Can we obtain useful, simpler characterizations for the computational
entropy?


title: Redundancy Allocation of Partitioned Linear Block Codes

abstract:
  Most memories suffer from both permanent defects and intermittent random
errors. The partitioned linear block codes (PLBC) were proposed by Heegard to
efficiently mask stuck-at defects and correct random errors. The PLBC have two
separate redundancy parts for defects and random errors. In this paper, we
investigate the allocation of redundancy between these two parts. The optimal
redundancy allocation will be investigated using simulations and the simulation
results show that the PLBC can significantly reduce the probability of decoding
failure in memory with defects. In addition, we will derive the upper bound on
the probability of decoding failure of PLBC and estimate the optimal redundancy
allocation using this upper bound. The estimated redundancy allocation matches
the optimal redundancy allocation well.


title: Feedback-cooling of an atomic spin ensemble

abstract:
  We describe a measurement-and-feedback technique to deterministically prepare
low-entropy states of atomic spin ensembles. Using quantum non-demolition
measurement and incoherent optical feedback, we drive arbitrary states in the
spin-orientation space toward the origin of the spin space. We observe 12 dB of
spin noise reduction, or a factor of 63 reduction in phase-space volume. We
find optimal feedback conditions and show that multi-stage feedback is
advantageous. An input-output calculation of quantum noise incorporating
realistic quantum noise sources and experimental limitations agrees well with
the observations. The method may have application to generation of exotic
phases of ultracold gases, for example macroscopic singlet states and
valence-bond solids.


title: Entanglement Temperature and Entanglement Entropy of Excited States

abstract:
  We derive a general relation between the ground state entanglement
Hamiltonian and the physical stress tensor within the path integral formalism.
For spherical entangling surfaces in a CFT, we reproduce the \emph{local}
ground state entanglement Hamiltonian derived by Casini, Huerta and Myers. The
resulting reduced density matrix can be characterized by a spatially varying
"entanglement temperature." Using the entanglement Hamiltonian, we calculate
the first order change in the entanglement entropy due to changes in conserved
charges of the ground state, and find a local first law-like relation for the
entanglement entropy. Our approach provides a field theory derivation and
generalization of recent results obtained by holographic techniques. However,
we note a discrepancy between our field theoretically derived results for the
entanglement entropy of excited states with a non-uniform energy density and
current holographic results in the literature. Finally, we give a CFT
derivation of a set of constraint equations obeyed by the entanglement entropy
of excited states in any dimension. Previously, these equations were derived in
the context of holography.


title: Discrete Quantum Theories

abstract:
  We explore finite-field frameworks for quantum theory and quantum
computation. The simplest theory, defined over unrestricted finite fields, is
unnaturally strong. A second framework employs only finite fields with no
solution to x^2+1=0, and thus permits an elegant complex representation of the
extended field by adjoining i=\sqrt{-1}. Quantum theories over these fields
recover much of the structure of conventional quantum theory except for the
condition that vanishing inner products arise only from null states;
unnaturally strong computational power may still occur. Finally, we are led to
consider one more framework, with further restrictions on the finite fields,
that recovers a local transitive order and a locally-consistent notion of inner
product with a new notion of cardinal probability. In this framework,
conventional quantum mechanics and quantum computation emerge locally (though
not globally) as the size of the underlying field increases. Interestingly, the
framework allows one to choose separate finite fields for system description
and for measurement: the size of the first field quantifies the resources
needed to describe the system and the size of the second quantifies the
resources used by the observer. This resource-based perspective potentially
provides insights into quantitative measures for actual computational power,
the complexity of quantum system definition and evolution, and the independent
question of the cost of the measurement process.


title:
On the asymptotics of the principal eigenvalue for a Robin problem with
  a large parameter in planar domains

abstract:
  Let $\Omega\subset \RR^2$ be a domain having a compact boundary $\Sigma$
which is Lipschitz and piecewise $C^4$ smooth, and let $\nu$ denote the inward
unit normal vector on $\Sigma$. We study the principal eigenvalue $E(\beta)$ of
the Laplacian in $\Omega$ with the Robin boundary conditions $\partial
f/\partial\nu +\beta f=0$ on $\Sigma$, where $\beta$ is a positive number.
Assuming that $\Sigma$ has no convex corners we show the estimate
$E(\beta)=-\beta^2- \gamma_\mx\beta + O\big(\beta^\{2}{3}\big)$ as
$\beta\to+\infty$, where $\gamma_\mx$ is the maximal curvature of the boundary.


title:
First Synoptic Maps of Photospheric Vector Magnetic Field from
  SOLIS/VSM: Non-Radial Magnetic Fields and Hemispheric Pattern of Helicity

abstract:
  We use daily full-disk vector magnetograms from Vector Spectromagnetograph
(VSM) on Synoptic Optical Long-term Investigations of the Sun (SOLIS) system to
synthesize the first Carrington maps of the photospheric vector magnetic field.
We describe these maps and make a comparison of observed radial field with the
radial field estimate from LOS magnetograms. Further, we employ these maps to
study the hemispheric pattern of current helicity density, Hc, during the
rising phase of the solar cycle 24. Longitudinal average over the 23
consecutive solar rotations shows a clear signature of the hemispheric helicity
rule, i.e. Hc is predominantly negative in the North and positive in South.
Although our data include the early phase of cycle 24, there appears no
evidence for a possible (systematic) reversal of the hemispheric helicity rule
at the beginning of cycle as predicted by some dynamo models. Further, we
compute the hemispheric pattern in active region latitudes (-30 deg \le \theta
\le 30 deg) separately for weak (100< |B_r| <500 G)and strong (|B_r|>1000 G)
radial magnetic fields. We find that while the current helicity of strong
fields follows the well-known hemispheric rule (i.e., \theta . Hc < 0), H_c of
weak fields exhibits an inverse hemispheric behavior (i.e., \theta . Hc > 0)
albeit with large statistical scatter. We discuss two plausible scenarios to
explain the opposite hemispheric trend of helicity in weak and strong field
region.


title:
Dynamically polarized target for the g2p and GEp experiments at
  Jefferson Lab

abstract:
  We describe a dynamically polarized target that has been utilized for two
electron scattering experiments in Hall A at Jefferson Lab. The primary
components of the target are a new, high cooling power 4He evaporation
refrigerator, and a re-purposed, superconducting split-coil magnet. It has been
used to polarize protons in irradiated NH3 at a temperature of 1 K and at
fields of 2.5 and 5.0 Tesla. The performance of the target material in the
electron beam under these conditions will be discussed. Maximum polarizations
of 28% and 95% were obtained at those fields, respectively. To satisfy the
requirements of both experiments, the magnet had to be routinely rotated
between angles of 0, 6, and 90 degrees with respect to the incident electron
beam. This was accomplished using a new rotating vacuum seal which permits
rotations to be performed in only a few minutes.


title:
Restoration of axial symmetry and its possible relation with restoration
  of chiral symmetry and deconfinement at finite temperature

abstract:
  The phase transitions characterized by deconfinement and restoration of
chiral symmetry as well as the restoration of axial symmetry, at finite
temperature, are investigated in the framework of SU(2)
Polyakov-Nambu-Jona-Lasinio (PNJL) models with the U$_A$(1) anomaly. The
thermodynamics of the phase transitions, the topological susceptibility, the
meson spectrum, and, in particular, the convergence of axial and chiral
partners are analyzed, in the framework of the ordinary PNJL model and in its
extension, the entangled Polyakov-Nambu-Jona-Lasinio (EPNJL) model. The latter
incorporates entanglement between restoration of chiral symmetry and
deconfinement.


title:
Sensitive Room-Temperature Terahertz Detection via Photothermoelectric
  Effect in Graphene

abstract:
  Terahertz (THz) radiation has uses from security to medicine; however,
sensitive room-temperature detection of THz is notoriously difficult. The
hot-electron photothermoelectric effect in graphene is a promising detection
mechanism: photoexcited carriers rapidly thermalize due to strong
electron-electron interactions, but lose energy to the lattice more slowly. The
electron temperature gradient drives electron diffusion, and asymmetry due to
local gating or dissimilar contact metals produces a net current via the
thermoelectric effect. Here we demonstrate a graphene thermoelectric THz
photodetector with sensitivity exceeding 10 V/W (700 V/W) at room temperature
and noise equivalent power less than 1100 pW/Hz^1/2 (20 pW/Hz^1/2), referenced
to the incident (absorbed) power. This implies a performance which is
competitive with the best room-temperature THz detectors for an optimally
coupled device, while time-resolved measurements indicate that our graphene
detector is eight to nine orders of magnitude faster than those. A simple model
of the response, including contact asymmetries (resistance, work function and
Fermi-energy pinning) reproduces the qualitative features of the data, and
indicates that orders-of-magnitude sensitivity improvements are possible.


title:
Enhanced atom interferometer readout through the application of phase
  shear

abstract:
  We present a method for determining the phase and contrast of a single shot
of an atom interferometer. The application of a phase shear across the atom
ensemble yields a spatially varying fringe pattern at each output port, which
can be imaged directly. This method is broadly relevant to atom interferometric
precision measurement, as we demonstrate in a 10 m Rb-87 atomic fountain by
implementing an atom interferometric gyrocompass with 10 millidegree precision.


title:
An ANOVA Test for Parameter Estimability using Data Cloning with
  Application to Statistical Inference for Dynamic Systems

abstract:
  Models for complex systems are often built with more parameters than can be
uniquely identified by available data. Because of the variety of causes,
identifying a lack of parameter identifiability typically requires mathematical
manipulation of models, monte carlo simulations, and examination of the Fisher
Information Matrix. A simple test for parameter estimability is introduced,
using Data Cloning, a Markov Chain Monte Carlo based algorithm. Together, Data
cloning and the ANOVA based test determine if the model parameters are
estimable and if so, determine their maximum likelihood estimates and provide
asymptotic standard errors. When not all model parameters are estimable, the
Data Cloning results and the ANOVA test can be used to determine estimable
parameter combinations or infer identifiability problems in the model
structure. The method is illustrated using three different real data systems
that are known to be difficult to analyze.


title: Towards conformally flat isothermic metrics

abstract:
  According to [8] if the stationary Schroedinger equation on n-dim. Riemann
space admits R-separation of variables (i.e. separation of variables with a
factor R), then the underlying metric is necessarily isothermic. An important
sub-class of isothermic metrics are the so called binary metrics. In this paper
we study conditions for vanishing of components C_ijkl of Weyl tensor of
arbitrary 4-binary metrics. In particular all 4-binary metrics for which C_ijij
are the only non-vanishing components are classified into four classes.
Finally, conformally flat metrics of the last class are isolated.


title:
Spatially Modulated Electronic Nematicity in the Three-Band Model of
  Cuprate Superconductors

abstract:
  Charge order in cuprate superconductors is a possible source of anomalous
electronic properties in the underdoped regime. Intra-unit cell charge ordering
tendencies point to electronic nematic order involving oxygen orbitals. In this
context we investigate charge instabilities in the Emery model and calculate
the charge susceptibility within diagrammatic perturbation theory. In this
approach, the onset of charge order is signalled by a divergence of the
susceptibility. Our calculations reveal three different kinds of order: a
commensurate ($q=0$) nematic order, and two incommensurate nematic phases with
modulation wavevectors that are either axial or oriented along the Brillouin
zone diagonal. We examine the nematic phase diagram as a function of the
filling, the interaction parameters, and the band structure. We also present
results for the excitation spectrum near the nematic instability, and show that
a soft nematic mode emerges from the particle-hole continuum at the transition.
The Fermi surface reconstructions that accompany the modulated nematic phases
are discussed with respect to their relevance for magneto-oscillation and
photoemission measurements. The modulated nematic phases that emerge from the
three-band Emery model are compared to those found previously in one-band
models.


title:
A New Multilevel Method for Electrostatic Problems through Hierarchical
  Loop Basis

abstract:
  We present a new multilevel method for calculating Poisson's equation, which
often arises form electrostatic problems, by using hierarchical loop bases.
This method, termed hierarchical Loop basis Poisson Solver (hieLPS), extends
previous Poisson solver through loop-tree basis to a multilevel mesh. In this
method, Poisson's equation is solved by a two-step procedure: First, the
electric flux is found by using loop-tree basis based on Helmholtz
decomposition of field; Second, the potential distribution is solved rapidly
with a fast solution of O(N) complexity. Among the solution procedures, finding
the loop part of electric flux is the most critical part and dominates the
computational effort. To expedite this part's convergent speed, we propose to
use hierarchical loop bases to construct a multilevel system. As a result, the
whole solution time has been noticeably reduced. Numerical examples are
presented to demonstrate the efficiency of the proposed method.


title: Modeling the processing of interstellar ices by energetic particles

abstract:
  Context. Interstellar ice is the main form of metal species in dark molecular
clouds. Experiments and observations have shown that the ice is significantly
processed after the freeze-out of molecules onto grains. The processing is
caused by cosmic-ray particles and cosmic-ray-induced UV photons. These
transformations are included in current astrochemical models only to a very
limited degree. Aims. We aim to establish a model of the "cold" chemistry in
interstellar ices and to evaluate its general impact on the composition of
interstellar ices. Methods. The ice was treated as consisting of two layers -
the surface and the mantle (or subsurface) layer. Subsurface chemical processes
are described with photodissociation of ice species and binary reactions on the
surfaces of cavities inside the mantle. Hydrogen atoms and molecules can
diffuse between the layers. We also included deuterium chemistry. Results. The
modeling results show that the content of chemically bound H is reduced in
subsurface molecules by about 30 % on average. This promotes the formation of
more hydrogen-poor species in the ice. The enrichment of ice molecules with
deuterium is significantly reduced by the subsurface processes. On average, it
follows the gas-phase atomic D-to-H abundance ratio, with a delay. The delay
produced by the model is on the order of several Myr. Conclusions. The
processing of ice may place new constraints on the production of deuterated
species on grains. In a mantle with a two-layer structure the upper layer (CO)
should be processed substantially more intensively than the lower layer (H2O).
Chemical explosions in interstellar ice might not be an important process. They
destroy the structure of the mantle, which forms over long timescales. Besides,
ices may lack the high radical content needed for the explosions.


title:
The effect of tow gaps on compression after impact strength of
  robotically laminated structures

abstract:
  When (robotic) Automated Fibre Placement (AFP) is used to manufacture
aerospace components with complex three dimensional geometries, gaps between
fibre tows can occur. This paper is the first to explore the interaction under
compressive load of these tow gaps with impact damage. Two coupons with
different distributions of tow-gaps were impacted. Results indicated that the
area of delamination is smaller for an impact directly over a tow gap where the
tow gap is situated close to the non-impact face. Subsequent Compression After
Impact (CAI) testing demonstrated that both the formation of sublaminate
buckles and subsequent growth of delaminations is inhibited by the presence of
a tow gap near the non-impact face. Non-destructive testing techniques and a
computationally efficient infinite Strip model are used to analyse the damage
resistance and damage tolerance of the coupons. A new validation of the Strip
model is also presented.


title: Self trapping transition for a nonlinear impurity within a linear chain

abstract:
  In the present work we revisit the issue of the self-trapping dynamical
transition at a nonlinear impurity embedded in an otherwise linear lattice. For
our Schr\"odinger chain example, we present rigorous arguments that establish
necessary conditions and corresponding parametric bounds for the transition
between linear decay and nonlinear persistence of a defect mode. The proofs
combine a contraction mapping approach applied in the fully dynamical problem
in the case of a 3D-lattice, together with variational arguments for the
derivation of parametric bounds for the creation of stationary states
associated with the expected fate of the self-trapping dynamical transition.
The results are relevant for both power law nonlinearities and saturable ones.
The analytical results are corroborated by numerical computations.


title: Recent Results in Neutrinoless Double Beta Decay

abstract:
  The search for neutrinoless double beta decay is a rich source for new
physics. The observation of this decay will lead to understanding of the
absolute mass scale of neutrinos, the Majorana nature of the neutrino (whether
the neutrino is its own anti-particle), and lepton number violation. Double
beta decay is being investigated around the world by several experiments using
different candidate isotopes. There has been much progress made in experimental
techniques recently such that achieving sensitivity to neutrino masses at 50
meV and below will be possible in the near future. A summary of recent results
in neutrinoless double beta decay is discussed with a look toward the
experimental goals for the future.


title:
Strain Gradient Elasticity Solution for Functionally Graded
  Micro-cylinders

abstract:
  In this paper, strain gradient elasticity formulation for analysis of FG
(Functionally Graded) micro-cylinders is presented. The material properties are
assumed to obey a power law in radial direction. The governing differential
equation is derived as a fourth order ODE. A power series solution for stresses
and displacements in FG micro-cylinders subjected to internal and external
pressures is obtained. Numerical examples are presented to study the effect of
the characteristic length parameter and FG power index on the displacement
field and stress distribution in FG cylinders. It is shown that the
characteristic length parameter has a considerable effect on the stress
distribution of FG micro-cylinders. Also, increasing material length parameter
leads to decrease of the maximum radial and tangential stresses in the
cylinder. Furthermore, it is shown that the FG power index has a significant
effect on the maximum radial and tangential stresses.