title:
On representation and regularity of viscosity solutions to degenerate
  Isaacs equations and certain nonconvex Hessian equations

abstract:
  We study the smoothness of the upper and lower value functions of stochastic
differential games in the framework of time-homogeneous (possibly degenerate)
diffusion processes in a domain, under the assumption that the diffusion, drift
and discount coefficients are all independent of the spatial variables. Under
suitable conditions (see Assumptions 2.1 and 2.2), we obtain the optimal local
Lipschitz continuity of the value functions, provided that the running and
terminal payoffs are globally Lipschitz. As applications, we obtain the
stochastic representation and optimal interior $C^{0,1}$-regularity of the
unique viscosity solution to the Dirichlet problem for certain degenerate
elliptic, nonconvex Hessian equations in suitable domains, with Lipschitz
boundary data.


title:
Herschel and IRAM-30m Observations of Comet C/2012 S1 (ISON) at 4.5 AU
  from the Sun

abstract:
  Our goal was to characterize the distant gaseous and dust activity of comet
C\2012 S1 (ISON), inbound, from observations of H2O, CO and the dust coma in
the far-infrared and submillimeter domains. In this paper, we report
observations undertaken with the Herschel Space Observatory on 8 & 13 March
2013 (rh = 4.54 - 4.47AU) and with the 30m telescope of Institut de
Radioastronomie Millim\'etrique (IRAM) in March and April 2013 (rh = 4.45 -
4.18 AU). The HIFI instrument aboard Herschel was used to observe the H$_{2}$O
$1_{10}-1_{01}$ line at 557 GHz, whereas images of the dust coma at 70 and 160
{\mu}m were acquired with the PACS instrument. Spectra acquired at the IRAM 30m
telescope cover the CO J(2-1) line at 230.5 GHz. The spectral observations were
analysed with excitation and radiative transfer models. A model of dust thermal
emission taking into account a range of dust sizes is used to analyse the PACS
maps. While H$_{2}$O was not detected in our 8 March 2013 observation, we
derive a sensitive 3 $\sigma$ upper limit of QH$_{2}$O < 3.5 x 10$^{26}$
molecules/s for this date. A marginal 3.2 $\sigma$ detection of CO is found,
corresponding to a CO production rate of QCO = 3.5 x 10$^{27}$ molecules/s. The
Herschel PACS measurements show a clear detection of the coma and tail in both
the 70 {\mu}m and 160 {\mu}m maps. Under the assumption of a 2 km radius
nucleus, we infer dust production rates in the range 10 - 13 kg/s or 40 - 70
kg/s depending on whether a low or high gaseous activity from the nucleus
surface is assumed. We constrain the size distribution of the emitted dust by
comparing PACS 70 and 160 {\mu}m data, and considering optical data. Size
indices between -4 and -3.6 are suggested. The morphology of the tail observed
on 70 {\mu}m images can be explained by the presence of grains with ages older
than 60 days.


title:
Rate Adaptation and Admission Control for Video Transmission with
  Subjective Quality Constraints

abstract:
  Adapting video data rate during streaming can effectively reduce the risk of
playback interruptions caused by channel throughput fluctuations. The
variations in rate, however, also introduce video quality fluctuations and thus
potentially affects viewers' Quality of Experience (QoE). We show how the QoE
of video users can be improved by rate adaptation and admission control. We
conducted a subjective study wherein we found that viewers' QoE was strongly
correlated with the empirical cumulative distribution function (eCDF) of the
predicted video quality. Based on this observation, we propose a
rate-adaptation algorithm that can incorporate QoE constraints on the empirical
cumulative quality distribution per user. We then propose a threshold-based
admission control policy to block users whose empirical cumulative quality
distribution is not likely to satisfy their QoE constraint. We further devise
an online adaptation algorithm to automatically optimize the threshold.
Extensive simulation results show that the proposed scheme can reduce network
resource consumption by $40\%$ over conventional average-quality maximized
rate-adaptation algorithms.


title:
Moment based Spectrum Sensing Algorithm for Cognitive Radio Networks
  with Noise Variance Uncertainty

abstract:
  This paper proposes simple moment based spectrum sensing algorithm for
cognitive radio networks in a flat fading channel. It is assumed that the
transmitted signal samples are binary (quadrature) phase-shift keying BPSK
(QPSK), Mary quadrature amplitude modulation (QAM) or continuous uniformly
distributed random variables and the noise samples are independent and
identically distributed circularly symmetric complex Gaussian random variables
all with unknown (imperfect) variance. Under these assumptions, we propose a
simple test statistics employing a ratio of fourth and second moments. For this
statistics, we provide analytical expressions for both probability of false
alarm (Pf) and probability of detection (Pd) in an additive white Gaussian
noise (AWGN) channel.We confirm the theoretical expressions by computer
simulation. Furthermore, under noise variance uncertainty, simulation results
demonstrate that the proposed moment based detector gives better detection
performance compared to that of energy detector in AWGN and Rayleigh fading
channels.


title:
On certain multivariate Vandermonde determinants whose variables
  separate

abstract:
  We prove that for almost square tensor product grids and certain sets of
bivariate polynomials the Vandermonde determinant can be factored into a
product of univariate Vandermonde determinants. This result generalizes the
conjecture [Lemma 1, L. Bos et al. (2009), Dolomites Research Notes on
Approximation, 2:1-15]. As a special case, we apply the result to Padua and
Padua-like points.


title:
Initial data for general relativistic SPH with Centroidal Voronoi
  Tessellations

abstract:
  In this work we present an alternative method to obtain a distribution of
particles over an hyper surface, such that they obey a rest-mass density
distribution $\rho(x^i)$. We use density profiles that can be written as
$\rho(x^1,x^2,x^3)=\rho(x^1) \rho(x^2) \rho(x^3)$ in order to be able to use
them as a probability density functions. We can find the relation between the
chart $x^j$ and a uniform random variable $\bar{x}^j \in (0,1)$, say
$F(x^j)=\bar{x}^j$. Using the inverse of this function we relate a set of $N$
arbitrary number of points inside a cube with coordinates $\{ x^j
=F^{-1}(\bar{x}^j)\}$ giving the position in order to get the density
distribution $\rho(x^j)$. We get some noise due to the random distribution and
we can notice that each time we relax the configuration on the cube we also get
a better distribution of the desired physical configuration described with
$\rho(x^j)$. This relaxation of the position of the particles in the cube has
been performed a Lloyd's algorithm in 3D and we have used {\it Voro++} library
in order to get the Voronoi tessellations.


title:
Axisymmetric Dirac-Nambu-Goto branes on Myers-Perry black hole
  backgrounds

abstract:
  Stationary, D-dimensional test branes, interacting with N-dimensional
Myers-Perry bulk black holes, are investigated in arbitrary brane and bulk
dimensions. The branes are asymptotically flat and axisymmetric around the
rotation axis of the black hole with a single angular momentum. They are also
spherically symmetric in all other dimensions allowing a total of O(1)xO(D-2)
group of symmetry. It is shown that even though this setup is the most natural
extension of the spherical symmetric problem to the simplest rotating case in
higher dimensions, the obtained solutions are not compatible with the spherical
solutions in the sense that the latter ones are not recovered in the
non-rotating limit. The brane configurations are qualitatively different from
the spherical problem, except in the special case of a 3-dimensional brane.
Furthermore, a quasi-static phase transition between the topologically
different solutions cannot be studied here, due to the lack of a general,
stationary, equatorial solution.


title: Superconducting series nanowire detector counting up to twelve photons

abstract:
  We demonstrate a superconducting photon-number-resolving detector capable of
resolving up to twelve photons at telecommunication wavelengths. It is based on
a series array of twelve superconducting NbN nanowire elements, each connected
in parallel with an integrated resistor. The photon-induced voltage signals
from the twelve elements are summed up into a single readout pulse with a
height proportional to the detected photon number. Thirteen distinct output
levels corresponding to the detection of n=0-12 photons are observed
experimentally. A detailed analysis of the excess noise shows the potential of
scaling to an even larger dynamic range.

categories: quant-ph cond-mat.supr-con physics.ins-det physics.optics


title:
The Meissner and Mesoscopic Superconducting States in 1-4 Unit-Cell
  FeSe-Films up to 80 K

abstract:
  Recent reports of interface-induced superconductivity in the unit-cell films
of FeSe on SrTiO3 with a Tc up to ~ 65+-5 K, highest among the Fe-based
superconductors and second only to that of the cuprates, have generated great
excitement. Here we show results of the first magnetic and resistive
investigation on the 1-4 unit-cell FeSe-films on SrTiO3. The samples display
the Meissner state below ~ 20 K with a penetration field as low as 0.1 Oe due
to large edge effect at 2 K, a mesoscopic superconducting state comprising
patches of dimension < 1 micrometer up to 45~55 K and an unusual relaxation of
the diamagnetic signal up to 80 K, suggesting possible superconductivity at
this high temperature. The observations demonstrate the heterogeneous nature of
the superconducting state in these films and offer new insights into the role
of interfaces in high temperature superconductivity proposed and future
superconducting electronics fabricated.


title: Wavelet Transform-Based Analysis of QRS complex in ECG Signals

abstract:
  In the present paper we have reported a wavelet based time-frequency
multiresolution analysis of an ECG signal. The ECG (electrocardiogram), which
records hearts electrical activity, is able to provide with useful information
about the type of Cardiac disorders suffered by the patient depending upon the
deviations from normal ECG signal pattern. We have plotted the coefficients of
continuous wavelet transform using Morlet wavelet. We used different ECG signal
available at MIT-BIH database and performed a comparative study. We
demonstrated that the coefficient at a particular scale represents the presence
of QRS signal very efficiently irrespective of the type or intensity of noise,
presence of unusually high amplitude of peaks other than QRS peaks and Base
line drift errors. We believe that the current studies can enlighten the path
towards development of very lucid and time efficient algorithms for identifying
and representing the QRS complexes that can be done with normal computers and
processors.


title: Non viability of hyperbolic quantum mechanics as a theory of Nature

abstract:
  Quantum and classical mechanics share a common algebraic formalism which is
expressed naturally in the language of category theory. A third realization of
this formalism is the so-called hyperbolic quantum mechanics where
split-complex numbers replace the usual complex numbers. We introduce and
explore the corresponding generalization of C*-algebras and prove that
hyperbolic quantum mechanics is not a viable candidate for describing Nature.
Quantum and classical mechanics are the only acceptable theories of Nature
which are invariant under tensorial composition.


title: The Inverse Iteration Method for Julia Sets in the 3-Dimensional Space

abstract:
  In this article, we introduce the adapted inverse iteration method to
generate bicomplex Julia sets associated to the polynomial map $w^2+c$. The
result is based on a full characterization of bicomplex Julia sets as the
boundary of a particular bicomplex cartesian set and the study of the fixed
points of $w^2+c$. The inverse iteration method is used in particular to
generate and display in the usual 3-dimensional space bicomplex Julia sets that
are dendrites.


title:
Constraints of $\Delta\mu/\mu$ based on H$_2$ observations in QSO
  spectra at high redshifts

abstract:
  This article summarizes the latest results on the proton-to-electron mass
ratio $\mu$ derived from H$_2$ observations at high redshift in the light of
possible variations of fundamental physical constants. The focus lies on UVES
observations of the past years as enormous progress was achieved since the
first positive results on $\Delta\mu/\mu$ were published. With the better
understanding of systematics, dedicated observation runs, and numerous
approaches to improve wavelength calibration accuracy, all current findings are
in reasonable good agreement with no variation and provide an upper limit of
$\Delta\mu/\mu < 1\times 10^{-5}$ for the redshift range of $2 <$ z $< 3$.


title: Non-planarity through unitarity in ABJM

abstract:
  We use unitarity techniques to compute the two-loop non-planar corrections to
the Sudakov form factor and the four-point amplitude in ABJM theory. We start
by reconstructing non-planar integrals from two-particle cuts in three
dimensions. This causes ambiguities, due to the one-loop four-point amplitude
being subleading in dimensional regularization. We provide a prescription to
circumvent them and show that it leads to the correct results, as checked
against the recent Feynman diagram computation. For the amplitude we point out
an alternative basis of integrals, including a non-planar double-box with a
numerator inspired by color-kinematics duality. We reproduce the result using a
combination thereof with the coefficients fixed by generalized unitarity. For
BLG theory we propose that this gives the form of the amplitude satisfying
color-kinematics duality. Finally, we compute the complete two-loop amplitude
of three-dimensional N = 8 SYM, and the corresponding four-point amplitude in N
= 16 supergravity as a double copy.


title: A New Method for the Spin Determination of Dark Matter

abstract:
  We construct a new kinematical variable that is able to fully reconstruct the
absolute value, and partially reconstruct the sign, of the angular distribution
in the center of momentum system of a decaying particle in certain cases where
the center of momentum system is only known up to a two-fold ambiguity. After
making contact with Drell-Yan production at the Large Hadron Collider, we apply
this method to the pair-production of dark matter in association with two
charged leptons at the International Linear Collider and show that for a small
intermediate width, perfect agreement is found with the true angular
distribution in the absence of initial state radiation. In the presence of
initial state radiation, we find that the modification to the angular
distributions is small for most angles and that the different spin combinations
should still be distinguishable. This enables us to determine the spin of the
mother particle and the dark matter particle in certain cases.


title: Spatially-resolved dust properties of the GRB 980425 host galaxy

abstract:
  Gamma-ray bursts (GRBs) have been proposed as a tool for studying star
formation in the Universe, so it is crucial to investigate whether their host
galaxies and immediate environments are in any way special compared with other
star-forming galaxies. Here we present spatially resolved maps of dust emission
of the host galaxy of the closest known GRB 980425 at z=0.0085 using our new
high-resolution observations from Herschel, Atacama Pathfinder Experiment
(APEX), Atacama Large Millimeter Array (ALMA) and Australia Telescope Compact
Array (ATCA). We modelled the spectral energy distributions of the host and of
the star-forming region displaying the Wolf-Rayet signatures in the spectrum
(WR region), located 800 pc from the GRB position. The host is characterised by
low dust content and a high fraction of UV-visible star formation, similar to
other dwarf galaxies. These galaxies are abundant in the local universe, so it
is not surprising to find a GRB in one of them, assuming the correspondence
between the GRB rate and star formation. The WR region contributes
substantially to the host emission at the far-infrared, millimetre, and radio
wavelengths and we propose that this is a consequence of its high gas density.
If dense environments are also found close to the positions of other GRBs, then
the ISM density should also be considered, along with metallicity, an important
factor influencing whether a given stellar population can produce a GRB.


title:
Removal of systematics in photometric measurements: static and rotating
  illumination corrections in FORS2@VLT data

abstract:
  Images taken with modern detectors require calibration via flat fielding to
obtain the same flux scale across the whole image. One method for obtaining the
best possible flat fielding accuracy is to derive a photometric model from
dithered stellar observations. A large variety of effects have been taken into
account in such modelling. Recently, Moehler et al. (2010) discovered
systematic variations in available flat frames for the European Southern
Observatory's FORS instrument that change with the orientation of the projected
image on the sky. The effect on photometry is large compared to other
systematic effects that have already been taken into account. In this paper, we
present a correction method for this effect: a generalization of the fitting
procedure of Bramich & Freudling (2012) to include a polynomial representation
of rotating flat fields. We then applied the method to the specific case of
FORS2 photometric observations of a series of standard star fields, and provide
parametrised solutions that can be applied by the users. We found polynomial
coefficients to describe the static and rotating large-scale systematic
flat-field variations across the FORS2 field of view. Applying these
coefficients to FORS2 data, the systematic changes in the flux scale across
FORS2 images can be improved by ~1% to ~2% of the total flux. This represents a
significant improvement in the era of large-scale surveys, which require
homogeneous photometry at the 1% level or better.


title: Scattering properties of dark atoms and molecules

abstract:
  There has been renewed interest in the possibility that dark matter exists in
the form of atoms, analogous to those of the visible world. An important input
for understanding the cosmological consequences of dark atoms is their
self-scattering. Making use of results from atomic physics for the potentials
between hydrogen atoms, we compute the low-energy elastic scattering cross
sections for dark atoms. We find an intricate dependence upon the ratio of the
dark proton to electron mass, allowing for the possibility to "design"
low-energy features in the cross section. Dependences upon other parameters,
namely the gauge coupling and reduced mass, scale out of the problem by using
atomic units. We derive constraints on the parameter space of dark atoms by
demanding that their scattering cross section does not exceed bounds from dark
matter halo shapes. We discuss the formation of molecular dark hydrogen in the
universe, and determine the analogous constraints on the model when the dark
matter is predominantly in molecular form.


title: NGC1266 as a Local Candidate for Rapid Cessation of Star Formation

abstract:
  We present new Spectrographic Areal Unit for Research on Optical Nebulae
(SAURON) integral-field spectroscopy and Swift Ultraviolet Optical Telescope
(UVOT) observations of molecular outflow host galaxy NGC 1266 that indicate NGC
1266 has experienced a rapid cessation of star formation. Both the SAURON maps
of stellar population age and the Swift UVOT observations demonstrate the
presence of young ($< 1$ Gyr) stellar populations within the central 1 kpc,
while existing Combined Array for Research in Millimeter-wave Astronomy (CARMA)
CO(1--0) maps indicate that the sites of current star formation are constrained
to the inner few hundred parsecs of the galaxy only. The optical spectrum of
NGC 1266 from Moustakas & Kennicutt (2006) reveal a characteristic
post-starburst (K+A) stellar population and Davis et al. (2012) confirm that
ionized gas emission in the system originate from a shock. Galaxies with K+A
spectra and shock-like ionized gas line ratios may comprise an important,
overlooked segment of the post-starburst population, containing exactly those
objects in which the AGN is actively expelling the star-forming material. While
AGN activity is not the likely driver of the post-starburst event that occurred
500 Myr ago, the faint spiral structure seen in the Hubble Space Telescope
(HST) Wide-field Camera 3 (WFC3) Y-, J- and H-band imaging seems to point to
the possibility of gravitational torques being the culprit. If the molecular
gas were driven into the center at the same time as the larger scale galaxy
disk underwent quenching, the AGN might be able to sustain the presence of
molecular gas for $\gtrsim 1$ Gyr by cyclically injecting turbulent kinetic
energy into the dense molecular gas via a radio jet, inhibiting star formation.


title: A note on smeared branes in flux vacua and gauged supergravity

abstract:
  In the known examples of flux vacua with calibrated spacetime-filling sources
(branes or orientifold planes), one can smear the source in order to perform a
standard KK reduction and obtain a lower-dimensional supergravity description.
Furthermore, it is expected that the smeared and localized solution preserve
equal amounts of supersymmetry. In this note we point out that the
$\mathrm{AdS}_7$ solution discussed in arXiv:1111.2605 and arXiv:1309.2949 is a
counterexample to this common lore. The solution is supersymmetric when the
spacetime-filling D6-branes are localized but breaks supersymmetry in the
smeared limit. By using the embedding tensor formalism we demonstrate that
there is no gauged supergravity description for the solution, regardless of the
source being smeared or not. We conjecture that for flux solutions with
separation between the KK scale and the AdS radius this cannot occur.


title:
Boundary Stress-Energy Tensor and Newton-Cartan Geometry in Lifshitz
  Holography

abstract:
  For a specific action supporting z=2 Lifshitz geometries we identify the
Lifshitz UV completion by solving for the most general solution near the
Lifshitz boundary. We identify all the sources as leading components of bulk
fields which requires a vielbein formalism. This includes two linear
combinations of the bulk gauge field and timelike vielbein where one asymptotes
to the boundary timelike vielbein and the other to the boundary gauge field.
The geometry induced from the bulk onto the boundary is a novel extension of
Newton-Cartan geometry that we call torsional Newton-Cartan (TNC) geometry.
There is a constraint on the sources but its pairing with a Ward identity
allows one to reduce the variation of the on-shell action to unconstrained
sources. We compute all the vevs along with their Ward identities and derive
conditions for the boundary theory to admit conserved currents obtained by
contracting the boundary stress-energy tensor with a TNC analogue of a
conformal Killing vector. We also obtain the anisotropic Weyl anomaly that
takes the form of a Horava-Lifshitz action defined on a TNC geometry. The
Fefferman-Graham expansion contains a free function that does not appear in the
variation of the on-shell action. We show that this is related to an irrelevant
deformation that selects between two different UV completions.


title: Baryon Asymmetry, Dark Matter and Local Baryon Number

abstract:
  We propose a new mechanism to understand the relation between the baryon and
dark matter asymmetries in the universe in theories where the baryon number is
a local symmetry. In these scenarios the B-L asymmetry generated through a
mechanism such as leptogenesis is transferred to the dark matter and baryonic
sectors through sphalerons processes which conserve total baryon number. We
show that it is possible to have a consistent relation between the dark matter
relic density and the baryon asymmetry in the universe even if the baryon
number is broken at the low scale through the Higgs mechanism. We also discuss
the case where one uses the Stueckelberg mechanism to understand the
conservation of baryon number in nature.


title:
Central galaxies in different environments: Do they have similar
  properties?

abstract:
  We perform an exhaustive comparison among central galaxies from SDSS catalogs
in different local environments at 0.01<=z<=0.08. The central galaxies are
separated into two categories: group centrals (host halos containing
satellites) and field centrals (host halos without satellites). From the
latter, we select other two subsamples: isolated centrals and bright field
centrals, both with the same magnitude limit. The stellar mass (Ms)
distributions of the field and group central galaxies are different, which
explains why in general the field central galaxies are mainly located in the
blue cloud/star forming regions, whereas the group central galaxies are
strongly biased to the red sequence/passive regions. The isolated centrals
occupy the same regions as the bright field centrals since both populations
have similar Ms distributions. At parity of Ms, the color and specific star
formation rate (sSFR) distributions of the samples are similar, specially
between field and group centrals. Furthermore, we find that the stellar-to-halo
mass (Ms-Mh) relation of isolated galaxies does not depend on the color, sSFR
and morphological type. For systems without satellites, the Ms-Mh relation
steepens at high halo masses compared to group centrals, which is a consequence
of assuming a one-to-one relation between group total stellar mass and halo
mass. Under the same assumption, the scatter around the Ms-Mh relation of
centrals with satellites increases with halo mass. Our results suggest that the
mass growth of central galaxies is mostly driven by the halo mass, with
environment and mergers playing a secondary role.


title:
An Information-Theoretic Proof of the Constructive Commutative Quantum
  Lov\'asz Local Lemma

abstract:
  The Quantum Lov\'asz Local Lemma (QLLL) [AKS12] establishes
non-constructively that any quantum system constrained by a local Hamiltonian
has a zero-energy ground state, if the local Hamiltonian terms overlap only in
a certain restricted way. In this paper, we present an efficient quantum
algorithm to prepare this ground state for the special case of commuting
projector terms. The related classical problem has been open for more than 34
years. Our algorithm follows the breakthrough ideas of Moser's [Moser09]
classical algorithm and lifts his information theoretic argument to the quantum
setting. A similar result has been independently published by Arad and Sattath
[AS13] recently.


title:
Modeling reverberation mapping data II: dynamical modeling of the Lick
  AGN Monitoring Project 2008 dataset

abstract:
  We present dynamical modeling of the broad line region (BLR) for a sample of
five Seyfert 1 galaxies using reverberation mapping data taken by the Lick AGN
Monitoring Project in 2008. By modeling the AGN continuum light curve and
H$\beta$ line profiles directly we are able to constrain the geometry and
kinematics of the BLR and make a measurement of the black hole mass that does
not depend upon the virial factor, $f$, needed in traditional reverberation
mapping analysis. We find that the geometry of the BLR is generally a thick
disk viewed close to face-on. While the H$\beta$ emission is found to come
preferentially from the far side of the BLR, the mean size of the BLR is
consistent with the lags measured with cross-correlation analysis. The BLR
kinematics are found to be consistent with either inflowing motions or
elliptical orbits, often with some combination of the two. We measure black
hole masses of $\log_{10}(M_{\rm\,BH}/M_\odot)=6.62^{+0.10}_{-0.13}$ for Arp
151, $7.42^{+0.26}_{-0.27}$ for Mrk 1310, $7.51^{+0.23}_{-0.14}$ for NGC 5548,
$6.42^{+0.24}_{-0.18}$ for NGC 6814, and $6.99^{+0.32}_{-0.25}$ for SBS
1116+583A. The $f$ factors measured individually for each AGN are found to
correlate with inclination angle, although not with $M_{\rm\,BH}$, $L_{5100}$,
or FWHM/$\sigma$ of the emission line profile.


title: Two-loop applications of the program SecDec

abstract:
  SecDec is a program which can be used for the factorisation of poles and
subsequent numerical evaluation of multi-loop integrals, in particular massive
two-loop integrals. We show applications to two-loop master integrals entering
the calculation of top quark pair production at NNLO, and to the dominant
momentum dependent two-loop corrections to the neutral Higgs boson masses in
the MSSM.


title: Building Blocks for Generalized Heterotic/F-theory Duality

abstract:
  In this note we propose a generalization of heterotic/F-theory duality. We
introduce a set of non-compact building blocks which we glue together to reach
compact examples of generalized duality pairs. The F-theory building blocks
consist of non-compact elliptically fibered Calabi-Yau fourfolds which also
admit a K3 fibration. The compact elliptic model obtained by gluing need not
have a globally defined K3 fibration. By replacing the K3 fiber of each
F-theory building block with a T^2, we reach building blocks in a heterotic
dual vacuum which includes a position dependent dilaton and three-form flux.
These building blocks are glued together to reach a heterotic flux background.
We argue that in these vacua, the gauge fields of the heterotic string become
localized, and remain dynamical even when gravity decouples. This enables a
heterotic dual for the hyperflux GUT breaking mechanism which has recently
figured prominently in F-theory GUT models. We illustrate our general proposal
with some explicit examples.


title: Monotop phenomenology at the Large Hadron Collider

abstract:
  We investigate new physics scenarios where systems comprised of a single top
quark accompanied by missing transverse energy, dubbed monotops, can be
produced at the LHC. Following a simplified model approach, we describe all
possible monotop production modes via an effective theory and estimate the
sensitivity of the LHC, assuming 20 fb$^{-1}$ of collisions at a center-of-mass
energy of 8 TeV, to the observation of a monotop state. Considering both
leptonic and hadronic top quark decays, we show that large fractions of the
parameter space are reachable and that new physics particles with masses
ranging up to 1.5 TeV can leave hints within the 2012 LHC dataset, assuming
moderate new physics coupling strengths.


title: Lattice understanding of the Delta I=1/2 rule & some implications

abstract:
  After decades of intensive efforts, lattice methods finally revealed one
clear source of the large enhancement of the ratio $Re A_0/Re A_2$
\cite{RBC_UKQCD_PRL13}, which has been a puzzle in particle physics for about
sixty years. Lattice studies of direct $K \to \pi \pi$ in the $I=2$ channel
show that in fact this channel clearly suffers from a severe suppression due to
a significant cancellation between the two amplitudes for the original, charged
current (tree) operator. % [($\bar s_\alpha \gamma_mu (1 - \gamma_5)
u_\alpha)(\bar u_\beta \gamma_mu(1-gamma_5)d_\beta$)], One of these amplitudes
goes as N and the other one goes as $N^2$, where $N=3$ for QCD. For physical
pion masses the cancellation between the two contributions towards $Re A_2$ is
about $70\%$. This appreciable cancellation suggests that expectations from
large N for QCD may be amenable to receiving significant corrections. The
penguin operators seem to make a small contribution to $ReA_0$ at a scale
$\gsim 1.5 GeV$. Possible repercussions of the lattice observation for other
decays are briefly discussed.


title: SUSY Simplified Models at 14, 33, and 100 TeV Proton Colliders

abstract:
  Results are presented for a variety of SUSY Simplified Models at the 14 TeV
LHC as well as a 33 and 100 TeV proton collider. Our focus is on models whose
signals are driven by colored production. We present projections of the upper
limit and discovery reach in the gluino-neutralino (for both light and heavy
flavor decays), squark-neutralino, and gluino-squark Simplified Model planes.
Depending on the model a jets + MET, mono-jet, or same-sign di-lepton search is
applied. The impact of pileup is explored. This study utilizes the Snowmass
backgrounds and combined detector. Assuming 3000 fb^{-1} of integrated
luminosity, a gluino that decays to light flavor quarks can be discovered below
2.3 TeV at the 14 TeV LHC and below 11 TeV at a 100 TeV machine.


title: Symmetry-induced anyon "breeding" in fractional quantum Hall states

abstract:
  An exotic feature of the fractional quantum Hall effect is the emergence of
anyons, which are quasiparticle excitations with fractional statistics. In the
presence of a symmetry, such as $U(1)$ charge conservation, it is well known
that anyons can carry fractional symmetry quantum numbers. In this work we
reveal a different class of symmetry realizations: i.e. anyons can "breed" in
multiples under symmetry operation. We focus on the global Ising ($Z_2$)
symmetry and show examples of these unconventional symmetry realizations in
Laughlin-type fractional quantum Hall states. One remarkable consequence of
such an Ising symmetry is the emergence of anyons on the Ising symmetry domain
walls. We also provide a mathematical framework which generalizes this
phenomenon to any Abelian topological orders.


title:
Q^2-evolution of the electric and magnetic polarizabilities of the
  proton

abstract:
  The generalized Baldin sum rule at finite four-momentum transfer Q^2 is
evaluated utilizing a structure function parameterization fit to recent
experimental data. The most recent measurements on F_1 from Hall C at Jlab, as
well as the F_2 structure function data from Hall B at Jlab and SLAC, were used
in constructing our parameterization. We find that at Q^2 below 1 GeV^2 the
dominant contribution to the electric and magnetic polarizabilities of the
nucleon comes from the resonance region.


title: Collisions of oppositely charged black holes

abstract:
  The first fully non-linear numerical simulations of colliding charged black
holes in D=4 Einstein-Maxwell theory were recently reported arXiv:1205.1063.
These collisions were performed for black holes with equal charge-to-mass
ratio, for which initial data can be found in closed analytic form. Here we
generalize the study of collisions of charged black holes to the case of
unequal charge-to-mass ratios. We focus on oppositely charged black holes, as
to maximize acceleration-dependent effects. As |Q|/M increases from 0 to 0.99,
we observe that the gravitational radiation emitted increases by a factor of ~
2.7; the electromagnetic radiation emission becomes dominant for |Q|/M >~ 0.37
and at |Q|/M=0.99 is larger, by a factor of ~ 5.8, than its gravitational
counterpart. We observe that these numerical results exhibit a precise and
simple scaling with the charge. Furthermore, we show that the results from the
numerical simulations are qualitatively captured by a simple analytic model
that computes the electromagnetic dipolar radiation and the gravitational
quadrupolar radiation of two non-relativistic interacting particles in
Minkowski spacetime.


title:
The sum of the squares of p positive integers which are consecutive
  terms of an arithmetic progression: Always a non-perfect square when p(a
  prime)=3 or p is congruent to 5 or 7 modulo 12

abstract:
  In a paper published by this author in www.academia.edu(see reference[3]), it
was established that there exist no three positive integers which are
consecutive terms of an arithmetic progression; and whose sum of squares is a
perfect or integer square. In that paper, we made use of the 3-parameter
formulas which describe the entire set of positive integer solutions of the
4-variable equation, $x^2+y^2+z^2= t^2$ (See reference [1]) In this work, we
offer an alternative proof to the above result; a proof that uses only powers
of 3 divisibility arguments. This is done in Theorem1, Section2. After that, in
Proposition3(Section4) we use the Quadratic Reciprocity Law for odd primes, to
establish that if p is a prime congruent to 5 or 7 modulo12; then 3 is
quadratic non-residue of p. This then, plays a key role in proving Theorem 2,
which postulates that if p is an odd prime congruent to 5 or 2 mod12; then, the
sum of the squares any p natural numbers which are consecutive terms of an
arithmetic progression; is a non-perfect square. Theorem3 is an immediate
corollary of Theorem2 : for primes p congruent to 5 or 7 mod12; the sum of the
squares of p natural numbers, consecutive terms of an arithmetic progression;
cannot be a perfect square.


title: New Kinetic Interactions for Massive Gravity?

abstract:
  We show that there can be no new Lorentz invariant kinetic interactions free
from the Boulware-Deser ghost in four dimensions in the metric formulation of
gravity, beyond the standard Einstein-Hilbert, up to total derivatives. We use
dimensional deconstruction as a way to motivate a non-linear ansatz for
potential new ghost free kinetic interactions for massive gravity, bi-gravity
and multi-gravity in four and higher dimensions. These interactions descend
from Lovelock terms, and so naively one might expect the interactions to be
ghost free. However we show that these new interactions inevitably lead to more
than five propagating degrees of freedom. We then perform a general
perturbative analysis in four dimensions, and show that the only term with two
derivatives that does not introduce a ghost is the Einstein-Hilbert term. This
result extends to all orders in perturbations.


title:
Online inference in Markov modulated nonlinear dynamic systems: a
  Rao-Blackwellized particle filtering approach

abstract:
  The Markov modulated (switching) state space is an important model paradigm
in applied statistics. In this article, we specifically consider Markov
modulated nonlinear state-space models and address the online Bayesian
inference problem for such models. In particular, we propose a new
Rao-Blackwellized particle filter for the inference task which is our main
contribution here. The detailed descriptions including an algorithmic summary
are subsequently presented.


title: Quadratic Palatini gravity and stable black hole remnants

abstract:
  We present a four-dimensional Planck-scale corrected quadratic extension of
General Relativity (GR) where no a priori relation between metric and
connection is imposed (Palatini formalism). Static spherically symmetric
electrovacuum solutions are obtained in exact analytical form. The macroscopic
properties of these solutions are in excellent agreement with GR, though the
region around the central singularity is modified. In fact, the singularity is
generically replaced by a wormhole supported by the electric field, which
provides a non-trivial topology to the space-time. Moreover, for a certain
charge-to-mass ratio the geometry is completely regular everywhere. For such
regular solutions, the horizon disappears in the microscopic regime below a
critical number of charges ($N<17$), yielding a set of massive objects that
could be naturally identified as black hole remnants.


title: Exploring the dark side of the top Yukawa

abstract:
  We investigate simple extensions of the Standard Model that could lead to the
negative values of the top Yukawa coupling still allowed by the ATLAS Higgs
results. Integrating out tree-level new physics generates dimension six
operators that can lead to large changes to the top Yukawa couplings. If the
top Yukawa coupling is negative, there is new physics beneath the TeV scale. We
illustrate the simplest models still allowed by current searches.


title: Smooth Manifolds vs Differential triads

abstract:
  We consider differentiable maps in the setting of Abstract Differential
Geometry and we study the conditions that ensure the uniqueness of
differentials in this setting. In particular, we prove that smooth maps between
smooth manifolds admit a unique differential, coinciding with the usual one.
Thus smooth manifolds form a full subcategory of the category of differential
triads, a result with physical implications.


title:
Nanoscale Imaging of Lithium Ion Distribution During In Situ Operation
  of Battery Electrode and Electrolyte

abstract:
  A major challenge in the development of new battery materials is
understanding their fundamental mechanisms of operation and degradation. Their
microscopically inhomogeneous nature calls for characterization tools that
provide operando and localized information from individual grains and
particles. Here we describe an approach that images the nanoscale distribution
of ions during electrochemical charging of a battery in a transmission electron
microscope liquid flow cell. We use valence energy-loss spectroscopy to track
both solvated and intercalated ions, with electronic structure fingerprints of
the solvated ions identified using an ab initio non-linear response theory.
Equipped with the new electrochemical cell holder, nanoscale spectroscopy and
theory, we have been able to determine the lithiation state of a LiFePO4
electrode and surrounding aqueous electrolyte in real time with nanoscale
resolution during electrochemical charge and discharge. We follow lithium
transfer between electrode and electrolyte and observe charging dynamics in the
cathode that differ among individual particles. This technique represents a
general approach for the operando nanoscale imaging of electrochemically active
ions in a wide range of electrical energy storage systems.


title: UV completion without symmetry restoration

abstract:
  We show that it is not possible to UV-complete certain low-energy effective
theories with spontaneously broken space-time symmetries by embedding them into
linear sigma models, that is, by adding "radial" modes and restoring the broken
symmetries. When such a UV completion is not possible, one can still raise the
cutoff up to arbitrarily higher energies by adding fields that transform
non-linearly under the broken symmetries, that is, new Goldstone bosons.
However, this (partial) UV completion does not necessarily restore any of the
broken symmetries. We illustrate this point by considering a concrete example
in which a combination of space-time and internal symmetries is broken down to
a diagonal subgroup. Along the way, we clarify a recently proposed
interpretation of inverse Higgs constraints as gauge-fixing conditions.


title:
Performance Evaluation of Multiterminal Backhaul Compression for Cloud
  Radio Access Networks

abstract:
  In cloud radio access networks (C-RANs), the baseband processing of the
available macro- or pico/femto-base stations (BSs) is migrated to control
units, each of which manages a subset of BS antennas. The centralized
information processing at the control units enables effective interference
management. The main roadblock to the implementation of C-RANs hinges on the
effective integration of the radio units, i.e., the BSs, with the backhaul
network. This work first reviews in a unified way recent results on the
application of advanced multiterminal, as opposed to standard point-to-point,
backhaul compression techniques. The gains provided by multiterminal backhaul
compression are then confirmed via extensive simulations based on standard
cellular models. As an example, it is observed that multiterminal compression
strategies provide performance gains of more than 60% for both the uplink and
the downlink in terms of the cell-edge throughput.


title: Monomial Valuations, Cusp Singularities, and Continued Fractions

abstract:
  This paper explores the relationship between real valued monomial valuations
on $k(x,y)$, the resolution of cusp singularities, and continued fractions. It
is shown that up to equivalence there is a one to one correspondence between
real valued monomial valuations on $k(x,y)$ and continued fraction expansions
of real numbers between zero and one. This relationship with continued
fractions is then used to provide a characterization of the valuation rings for
real valued monomial valuations on $k(x,y)$. In the case when the monomial
valuation is equivalent to an integral monomial valuation, we exhibit explicit
generators of the valuation rings. Finally, we demonstrate that if $\nu$ is a
monomial valuation such that $\nu(x)=a$ and $\nu(y)=b$, where $a$ and $b$ are
relatively prime positive integers larger than one, then $\nu$ governs a
resolution of the singularities of the plane curve $x^{b}=y^{a}$ in a way we
make explicit. Further, we provide an exact bound on the number of blow ups
needed to resolve singularities in terms of the continued fraction of $a/b$


title:
A new way for the extension of quantum theory: Non-Bohmian quantum
  potentials

abstract:
  Quantum Mechanics is a good example of a successful theory. Most of atomic
phenomena are described well by quantum mechanics and cases such as Lamb Shift
that are not described by quantum mechanics, are described by quantum
electrodynamics. Of course, at the nuclear level, because of some
complications, it is not clear that we can claim the same confidence. One way
of taking these complications and corrections into account seems to be a
modification of the standard quantum theory. In this paper and its follow ups
we consider a straightforward way of extending quantum theory. Our method is
based on a Bohmian approach. We show that this approach has the essential
ability for extending quantum theory, and we do this by introducing
"non-Bohmian" forms for the quantum potential.


title:
Multiple State Representation Scheme for Organic Bulk Heterojunction
  Solar Cells: A Novel Analysis Perspective

abstract:
  The physics of organic bulk heterojunction solar cells is studied within a
six state model, which is used to analyze the factors that affect
current-voltage characteristics, power-voltage properties and efficiency, and
their dependence on nonradiative losses, reorganization of the nuclear
environment, and environmental polarization. Both environmental reorganization
and polarity is explicitly taken into account by incorporating Marcus
heterogeneous and homogeneous electron transfer rates. The environmental
polarity is found to have a nonnegligible influence both on the stationary
current and on the overall solar cell performance. For our organic bulk
heterojunction solar cell operating under steady-state open circuit condition,
we also find that the open circuit voltage logarithmically decreases with
increasing nonradiative electron-hole recombination processes.


title: Chemical Compositions of RV Tauri Stars and Related Objects

abstract:
  We have undertaken a comprehensive abundance analysis for a sample of
relatively unexplored RV Tauri and RV Tauri like stars to further our
understanding of post-Asymptotic Giant Branch (post-AGB) evolution. From our
study based on high resolution spectra and grid of model atmospheres, we find
indications of mild s-processing for V820 Cen and IRAS 06165+3158. On the other
hand, SU Gem and BT Lac exhibit the effects of mild dust-gas winnowing. We have
also compiled the existing abundance data on RV Tauri objects and find that a
large fraction of them are afflicted by dust-gas winnowing and now added by the
present work, we find a small group of two RV Tauris showing mild s-process
enhancement in our Galaxy. With two out of three reported s-process enhanced
objects belonging to RV Tauri spectroscopic class C, these intrinsically
metal-poor objects appear to be promising candidates to analyse the possible
s-processing in RV Tauri stars.


title: A Quasi-Newtonian Approach to Bohmian Mechanics I: Quantum Potential

abstract:
  In this article, we investigate Bohm's view of quantum theory, especially
Bohm's quantum potential, from a new perspective. We develop a quasi-Newtonian
approach to Bohmian mechanics. We show that to arrive at Bohmian formulation of
quantum mechanics, there is no necessity to start from the Schr\"odinger
equation. We also obtain an equation that restricts the possible forms of
quantum potential and determines the functional form of it without appealing to
the wave function and the Schr\"odinger equation. Finally, we discuss about the
significance of quantum potential in the conceptual structure of quantum
theory.


title:
A Quasi-Newtonian Approach to Bohmian Mechanics II: Inherent
  Quantization

abstract:
  In a previous paper, we obtained the functional form of quantum potential by
a quasi-Newtonian approach and without appealing to the wave function. We also
described briefly the characteristics of this approach to the Bohmian
mechanics. In this article, we consider the quantization problem and we show
that the 'eigenvalue postulate' is a natural consequence of continuity
condition and there is no need for postulating that the spectrum of energy and
angular momentum are eigenvalues of their relevant operators. In other words,
the Bohmian mechanics predicts the 'eigenvalue postulate'.


title:
Dynamic Contraction of the Positive Column of a Self-Sustained Glow
  Discharge in Air Flow

abstract:
  We study the dynamic contraction a self-sustained glow discharge in air in a
rectangular duct with convective cooling. A two dimensional numerical model of
the plasma contraction was developed in a cylindrical frame. The process is
described by a set of time-dependent continuity equations for the electrons,
positive and negative ions; gas and vibrational temperature; and equations
which account for the convective heat and plasma losses by the transverse flux.
Transition from the uniform to contracted state was analyzed. It was shown that
such transition experiences a hysteresis, and that the critical current of the
transition increases when the gas density drops. Possible coexistence of the
contracted and uniform state of the plasma in the discharge, where the current
flows along the density gradient of the background gas, is discussed.


title: Stitched Panoramas from Toy Airborne Video Cameras

abstract:
  Effective panoramic photographs are taken from vantage points that are high.
High vantage points have recently become easier to reach as the cost of
quadrotor helicopters has dropped to nearly disposable levels. Although cameras
carried by such aircraft weigh only a few grams, their low-quality video can be
converted into panoramas of high quality and high resolution. Also, the small
size of these aircraft vastly reduces the risks inherent to flight.


title:
Existence of infinitely many minimal hypersurfaces in positive Ricci
  curvature

abstract:
  In the early 1980s, S. T. Yau conjectured that any compact Riemannian
three-manifold admits an infinite number of closed immersed minimal surfaces.
We use min-max theory for the area functional to prove this conjecture in the
positive Ricci curvature setting. More precisely, we show that every compact
Riemannian manifold with positive Ricci curvature and dimension at most seven
contains infinitely many smooth, closed, embedded minimal hypersurfaces.
  In the last section we mention some open problems related with the geometry
of these minimal hypersurfaces.


title: A simplified model of collision-driven dynamo action in small bodies

abstract:
  We investigate numerically the self-sustained dynamo action in a spinning
sphere whose sense of rotation reverses periodically. This system serves as a
simple model of a dynamo in small bodies powered by frequent collisions. It is
found that dynamo action is possible in some intervals of collision rates. At
high Ekman numbers the laminar spin-up flow is helical in the boundary layers
and the Ekman circulation together with the azimuthal shear powers the dynamo
action. At low Ekman number a non-axisymmetric instability helps the dynamo
action. The intermittency of magnetic field occurs at low Ekman number.


title:
PopCORN: Hunting down the differences between binary population
  synthesis codes

abstract:
  Binary population synthesis (BPS) modelling is a very effective tool to study
the evolution and properties of close binary systems. The uncertainty in the
parameters of the model and their effect on a population can be tested in a
statistical way, which then leads to a deeper understanding of the underlying
physical processes involved. To understand the predictive power of BPS codes,
we study the similarities and differences in the predicted populations of four
different BPS codes for low- and intermediate-mass binaries. We investigate
whether the differences are caused by different assumptions made in the BPS
codes or by numerical effects. To simplify the complex problem of comparing BPS
codes, we equalise the inherent assumptions as much as possible. We find that
the simulated populations are similar between the codes. Regarding the
population of binaries with one WD, there is very good agreement between the
physical characteristics, the evolutionary channels that lead to the birth of
these systems, and their birthrates. Regarding the double WD population, there
is a good agreement on which evolutionary channels exist to create double WDs
and a rough agreement on the characteristics of the double WD population.
Regarding which progenitor systems lead to a single and double WD system and
which systems do not, the four codes agree well. Most importantly, we find that
for these two populations, the differences in the predictions from the four
codes are not due to numerical differences, but because of different inherent
assumptions. We identify critical assumptions for BPS studies that need to be
studied in more detail.


title:
Phase diagram of the square lattice bilayer Hubbard model: a variational
  Monte Carlo study

abstract:
  We investigate the phase diagram of the square lattice bilayer Hubbard model
at half filling with the variational Monte Carlo method for both the magnetic
and the paramagnetic case as a function of interlayer hopping t_perp and
on-site Coulomb repulsion U. With this study we resolve some discrepancies in
previous calculations based on the dynamical mean field theory, and we are able
to determine the nature of the phase transitions between metal, Mott insulator
and band insulator. In the magnetic case we find only two phases: An
antiferromagnetic Mott insulator at small t_perp for any value of U and a band
insulator at large t_perp. At large U values we approach the Heisenberg limit.
The paramagnetic phase diagram shows at small t_perp a metal to Mott insulator
transition at moderate U values and a Mott to band insulator transition at
larger U values. We also observe a reentrant Mott insulator to metal transition
and metal to band insulator transition for increasing t_perp in the range of
5.5t < U < 7.5t. Finally, we discuss the obtained phase diagrams in relation to
previous studies based on different many-body approaches.


title: Evaluating the Impact of SDC on the GMRES Iterative Solver

abstract:
  Increasing parallelism and transistor density, along with increasingly
tighter energy and peak power constraints, may force exposure of occasionally
incorrect computation or storage to application codes. Silent data corruption
(SDC) will likely be infrequent, yet one SDC suffices to make numerical
algorithms like iterative linear solvers cease progress towards the correct
answer. Thus, we focus on resilience of the iterative linear solver GMRES to a
single transient SDC. We derive inexpensive checks to detect the effects of an
SDC in GMRES that work for a more general SDC model than presuming a bit flip.
Our experiments show that when GMRES is used as the inner solver of an
inner-outer iteration, it can "run through" SDC of almost any magnitude in the
computationally intensive orthogonalization phase. That is, it gets the right
answer using faulty data without any required roll back. Those SDCs which it
cannot run through, get caught by our detection scheme.


title:
Electronic and atomic structure of complex defects in highly n-type
  doped ZnO films

abstract:
  Point defects in Ga- and Al-doped ZnO thin films are studied by means of
first principles electronic structure calculations. Candidate defects are
identified to explain recently observed differences in electrical and
spectroscopical behavior of both systems. Substitutional doping in Ga-ZnO
explain the metallic behavior of the electrical properties. Complexes of
interstitial oxygen with substitutional Ga can behave as acceptor and cause
partial compensation, as well as gap states below the conduction band minimum
as observed in photoemission experiments. Zn vacancies can also act as
compensating acceptors. On the other hand, the semiconducting behavior of
Al-ZnO and the small variation in the optical gap compared with pure ZnO, can
be explained by almost complete compensation between acceptor Zn vacancies and
substitutional Al donors. Interstitial Al can also be donor levels and can be
the origin of the small band observed in photoemission experiments below the
Fermi level. Combinations of substitutional Al with interstitial oxygen can act
simultaneously as compensating acceptor and generator o the mentioned
photoemission band. The theoretical calculations have been done using density
functional theory (DFT) within the generalized gradient approximation with
on-site Coulomb interaction. In selected cases, DFT calculations with
semilocal-exact exchange hybrid functionals have been performed. Results are
compared with photoelectron spectra for Ga-ZnO and Al-ZnO at the corresponding
doping levels.


title:
Interacting and fractional topological insulators via the $\mathbb{Z}_2$
  chiral anomaly

abstract:
  Recently it was shown that the topological properties of $2D$ and $3D$
topological insulators are captured by a $\mathbb{Z}_2$ chiral anomaly in the
boundary field theory. It remained, however, unclear whether the anomaly
survives electron-electron interactions. We show that this is indeed the case,
thereby providing an alternative formalism for treating topological insulators
in the interacting regime. We apply this formalism to fractional topological
insulators (FTI) via projective/parton constructions and use it to test the
robustness of all fractional topological insulators which can be described in
this way. The stability criterion we develop is easy to check and based on the
pairswitching behaviour of the noninteracting partons. In particular, we find
that FTIs based on bosonic Laughlin states and the $M=0$ bosonic Read-Rezayi
states are fragile and may have a completely gapped and non-degenerate edge
spectrum in each topological sector. In contrast, the $\mathbb{Z}_{k}$
Read-Rezayi states with $M=1$ and odd $k$ and the bosonic $3D$ topological
insulator with a $\pi/4$ fractional theta-term are topologically stable.


title: Existence of pulses in excitable media with nonlocal coupling

abstract:
  We prove the existence of fast traveling pulse solutions in excitable media
with non-local coupling. Existence results had been known, until now, in the
case of local, diffusive coupling and in the case of a discrete medium, with
finite-range, non-local coupling. Our approach replaces methods from geometric
singular perturbation theory, that had been crucial in previous existence
proofs, by a PDE oriented approach, relying on exponential weights, Fredholm
theory, and commutator estimates.


title: I-Q relation for rapidly rotating neutron stars

abstract:
  We consider a universal relation between moment of inertia and quadrupole
moment of arbitrarily fast rotating neutron stars. Recent studies suggest that
this relation breaks down for fast rotation. We find that it is still universal
among various suggested equations of state for constant values of certain
dimensionless parameters characterizing the magnitude of rotation. One of these
parameters includes the neutron star radius, leading to a new universal
relation expressing the radius through the mass, frequency, and spin parameter.
This can become a powerful tool for radius measurements.


title: Are all training examples equally valuable?

abstract:
  When learning a new concept, not all training examples may prove equally
useful for training: some may have higher or lower training value than others.
The goal of this paper is to bring to the attention of the vision community the
following considerations: (1) some examples are better than others for training
detectors or classifiers, and (2) in the presence of better examples, some
examples may negatively impact performance and removing them may be beneficial.
In this paper, we propose an approach for measuring the training value of an
example, and use it for ranking and greedily sorting examples. We test our
methods on different vision tasks, models, datasets and classifiers. Our
experiments show that the performance of current state-of-the-art detectors and
classifiers can be improved when training on a subset, rather than the whole
training set.


title: Intransitive Dice

abstract:
  We consider $n$-sided dice whose face values lie between $1$ and $n$ and
whose faces sum to $n(n+1)/2$. For two dice $A$ and $B$, define $A \succ B$ if
it is more likely for $A$ to show a higher face than $B$. Suppose $k$ such dice
$A_1,\dots,A_k$ are randomly selected. We conjecture that the probability of
ties goes to 0 as $n$ grows. We conjecture and provide some supporting evidence
that---contrary to intuition---each of the $2^{k \choose 2}$ assignments of
$\succ$ or $\prec$ to each pair is equally likely asymptotically. For a
specific example, suppose we randomly select $k$ dice $A_1,\dots,A_k$ and
observe that $A_1 \succ A_2 \succ \ldots \succ A_k$. Then our conjecture
asserts that the outcomes $A_k \succ A_1$ and $A_1 \prec A_k$ both have
probability approaching $1/2$ as $n \rightarrow \infty$.


title: Nuclear structure contribution to the Lamb shift in muonic deuterium

abstract:
  We consider the two-photon exchange contribution to the $2P-2S$ Lamb shift in
muonic deuterium in the framework of forward dispersion relations. The
dispersion integrals are evaluated using experimental data on elastic deuteron
form factors and inelastic electron-deuteron scattering, both in the
quasielastic and hadronic range. The subtraction constant that is required to
ensure convergence of the dispersion relation for the forward Compton amplitude
$T_1(\nu,Q^2)$ is related to the deuteron magnetic polarizability $\beta(Q^2)$.
Based on phenomenological information, we obtain for the Lamb shift $\Delta
E_{2P-2S}=2.01\pm0.74$ meV. The main source of the uncertainty of the
dispersion analysis is due to lack of quasielastic data at low energies and
forward angles. We show that a targeted measurement of the deuteron
electrodesintegration in the kinematics of upcoming experiments A1 and MESA at
Mainz can help quenching this uncertainty significantly.


title:
The Yield Condition in the Mobilization of Yield-Stress Materials in
  Distensible Tubes

abstract:
  In this paper we investigate the yield condition in the mobilization of
yield-stress materials in distensible tubes. We discuss the two possibilities
for modeling the yield-stress materials prior to yield: solid-like materials
and highly-viscous fluids and identify the logical consequences of these two
approaches on the yield condition. As part of this investigation we derive an
analytical expression for the pressure field inside a distensible tube with a
Newtonian flow using a one-dimensional Navier-Stokes flow model in conjunction
with a pressure-area constitutive relation based on elastic tube wall
characteristics.


title: QCD calculations for jet substructure

abstract:
  We present results on novel analytic calculations to describe invariant mass
distributions of QCD jets with three substructure algorithms: trimming, pruning
and the mass-drop taggers. These results not only lead to considerable insight
into the behaviour of these tools, but also show how they can be improved. As
an example, we discuss the remarkable properties of the modified mass-drop
tagger.


title:
Chandra and XMM-Newton imaging and spectroscopic study of the supernova
  remnant Kes 73 hosting the magnetar 1E 1841-045

abstract:
  We present a Chandra and XMM-Newton study of the supernova remnant (SNR) Kes
73 hosting the anomalous X-ray pulsar 1E 1841-045. The Chandra image reveals
clumpy structures across the remnant with enhanced emission along the western
rim. The X-ray emission fills the radio shell and spatially correlates with the
infrared image. The global X-ray spectrum is described by a two-component
thermal model with a column density N_H ~ 2.6e22 cm^{-2} and a total luminosity
of L_X ~ 3.3e37 ergs/s (0.5-10 keV, at an assumed distance of 8.5 kpc). The
soft component is characterized by a temperature kT_s ~ 0.5 keV, a high
ionization timescale, and enhanced Si and S abundances suggesting emission that
is dominated by shocked ejecta. The hard component has a temperature kT_h ~ 1.6
keV, a relatively low ionization timescale, and mostly solar abundances
suggesting emission that is dominated by interstellar/circumstellar shocked
material. A spatially resolved spectroscopy study reveals no significant
variations in the spectral properties. We infer an SNR age ranging between 750
yr and 2100 yr, an explosion energy of ~0.3e51 ergs and a shock velocity of
1200 km/s (under the Sedov phase assumption). We also discuss the possible
scenario for Kes 73 expanding into the late red supergiant wind phase of its
massive progenitor. Comparing the inferred metal abundances to core-collapse
nucleosynthesis model yields, we estimate a progenitor mass >20 solar masses,
adding a candidate to the growing list of highly magnetized neutron stars
proposed to be associated with very massive progenitors.


title: Inverse Edelstein Effect

abstract:
  We provide a precise microscopic definition of the recently observed "Inverse
Edelstein Effect" (IEE), in which a non-equilibrium spin accumulation in the
plane of a two-dimensional (interfacial) electron gas drives an electric
current perpendicular to its own direction. The drift-diffusion equations that
govern the effect are presented and applied to the interpretation of the
experiments.


title: Collision Strengths for [O III] Optical and Infrared Lines

abstract:
  We present electron collision strengths and their thermally averaged values
for the forbidden lines of the astronomically abundant doubly-ionized oxygen
ion, O^{2+}, in an intermediate coupling scheme using the Breit-Pauli
relativistic terms as implemented in an R-matrix atomic scattering code. We use
several atomic targets for the R-matrix scattering calculations including one
with 72 atomic terms. We also compare with new results obtained using the
intermediate coupling frame transformation method. We find spectroscopically
significant differences against a recent Breit-Pauli calculation for the
excitation of the [O III] lambda 4363 transition but confirm the results of
earlier calculations.


title: Standard Examples as Subposets of Posets

abstract:
  We prove that a poset with no induced subposet $S_k$ (for fixed $k\geq 3$)
must have dimension that is sublinear in terms of the number of elements.


title: Recent Highlights from IceCube

abstract:
  The $\sim$1 km$^3$ IceCube neutrino observatory was completed in December,
2010 and is taking data on cosmic-ray muons and neutrinos, extra-terrestrial
neutrinos, and setting limits on a variety of exotic phenomena. This proceeding
will cover recent IceCube results, with an emphasis on cosmic-rays and on
searches for extra-terrestrial neutrinos, with a stress on results that were
presented at the 2013 International Cosmic Ray Conference.


title:
Absolute calibration of the refractive index in photo-induced photonic
  lattices

abstract:
  We demonstrate a method to experimentally calibrate the refractive index
modulation in photorefractive lattices, a task rarely addressed that is crucial
for quantitative comparisons of theories with experiments. We consider the
linear propagation of a normally incident plane wave through simple lattices
and its modulation amplitude at crystal output face. Finding no evidence of
longitudinal (Talbot-like) oscillations, we discard an ideal propagation theory
and construct a simple effective model that includes longitudinal relaxation.
We obtain calibrations of 1D and 2D lattices consistent with standard theory in
a high saturation regime. For 2D lattices, we find anisotropies $\chi=1.5-
2.5$, stronger for smaller lattice period, and refractive indexes larger than
for 1D lattices, also with more noise.


title: Protected Josephson Rhombi Chains

abstract:
  We have studied the low-energy excitations in a minimalistic protected
Josephson circuit which contains two basic elements (rhombi) characterized by
the $\pi$ periodicity of the Josephson energy. Novel design of these elements,
which reduces their sensitivity to the offset charge fluctuations, has been
employed. We have observed that the life time $T_{1}$ of the first excited
state of this quantum circuit in the protected regime is increased up to $70\mu
s$, a factor of $\sim100$ longer than that in the unprotected state. The
quality factor $\omega_{01}T_{1}$ of this qubit exceeds $10^{6}$ . Our results
are in agreement with theoretical expectations; they demonstrate the
feasibility of symmetry protection in the rhombi-based qubits fabricated with
existing technology.


title: V1309 SCO - Understanding a merger

abstract:
  One of the two outcomes of a common envelope event is a merger of the two
stars. To date, the best known case of a binary merger is the V1309 Sco
outburst, where the orbital period was known and observed to decay up to the
outburst. Using the hydrodynamical code StarSmasher, we study in detail which
characteristics of the progenitor binary affect the outburst and produce the
best match with observations. We have developed a set of tools in order to
quantify any common envelope event. We consider binaries consisting of a
1.52$M_\odot$ giant and a 0.16$M_\odot$ companion with $P_{\rm orb}\sim1.4$
days, varying the nature of the companion and its synchronization. We show that
all considered progenitor binaries evolve towards the merger primarily due to
the Darwin instability. The merger is accompanied by mass ejection that
proceeds in several separate mass outbursts and takes away a few percent of the
donor mass. This very small mass, nonetheless, is important as it is not only
sufficient to explain the observed light-curve, but it also carries away up to
1/3 of the both initial total angular momentum and initial orbital energy. We
find that all synchronized systems experience $L_2$ mass loss that operates
during just a few days prior to merger and produces ring-shaped ejecta. The
formed star is always a strongly heated radiative star that differentially
rotates. We conclude that the case of a synchronized binary with a
main-sequence companion gives the best match with observations of V1309 Sco.


title:
First Galaxy-Galaxy Lensing Measurement of Satellite Halo Mass in the
  CFHT Stripe-82 Survey

abstract:
  We select satellite galaxies from the galaxy group catalog constructed with
the SDSS spectroscopic galaxies and measure the tangential shear around these
galaxies with source catalog extracted from CFHT/MegaCam Stripe-82 Survey to
constrain the mass of subhalos associated with them. The lensing signal is
measured around satellites in groups with masses in the range [10^{13},
5x10^{14}]h^{-1}M_{sun}, and is found to agree well with theoretical
expectation. Fitting the data with a truncated NFW profile, we obtain an
average subhalo mass of log M_{sub}= 11.68 \pm 0.67 for satellites whose
projected distances to central galaxies are in the range [0.1, 0.3] h^{-1}Mpc,
and log M_{sub}= 11.68 \pm 0.76 for satellites with projected halo-centric
distance in [0.3, 0.5] h^{-1}Mpc. The best-fit subhalo masses are comparable to
the truncated subhalo masses assigned to satellite galaxies using abundance
matching and about 5 to 10 times higher than the average stellar mass of the
lensing satellite galaxies.


title: Tying Dark Matter to Baryons with Self-interactions

abstract:
  Self-interacting dark matter (SIDM) models have been proposed to solve the
small-scale issues with the collisionless cold dark matter (CDM) paradigm. We
derive equilibrium solutions in these SIDM models for the dark matter halo
density profile including the gravitational potential of both baryons and dark
matter. Self-interactions drive dark matter to be isothermal and this ties the
core sizes and shapes of dark matter halos to the spatial distribution of the
stars, a radical departure from previous expectations and from CDM predictions.
Compared to predictions of SIDM-only simulations, the core sizes are smaller
and the core densities are higher, with the largest effects in baryon-dominated
galaxies. As an example, we find a core size around 0.5 kpc for dark matter in
the Milky Way, more than an order of magnitude smaller than the core size from
SIDM-only simulations, which has important implications for indirect searches
of SIDM candidates.


title:
The spectrum of a family of fourth-order equations near the global
  attractor

abstract:
  The thin-film and quantum drift diffusion equations belong to a fourth-order
family of evolution equations proposed in ref. 16 to be analogous to the
(second-order) porous medium family. They are $2$-Wasserstein gradient ($W_2$)
flows of the generalized Fisher information $I(u)$ just as the porous medium
family was shown to be the $W_2$ gradient flow of the generalized entropy
$E(u)$ by Otto. The identity $I(u) = |\nabla_{W_2} E(u)|^2/2$ (formally)
becomes $\Hess_{W_2} I(u_*) =\Hess_{W_2}^2 E(u_*)$ when linearizing the
equation around its self-similar solution $u_*$. We couple this relation with
the diagonalization of $\Hess_{W_2} E(u_*)$ for the porous medium flow computed
in ref. 38. This yields information about the leading- and higher-order
asymptotics of the equation on $\R^N$ which --- outside of special cases ---
was inaccessible previously.


title:
The Untold Story of the Clones: Content-agnostic Factors that Impact
  YouTube Video Popularity

abstract:
  Video dissemination through sites such as YouTube can have widespread impacts
on opinions, thoughts, and cultures. Not all videos will reach the same
popularity and have the same impact. Popularity differences arise not only
because of differences in video content, but also because of other
"content-agnostic" factors. The latter factors are of considerable interest but
it has been difficult to accurately study them. For example, videos uploaded by
users with large social networks may tend to be more popular because they tend
to have more interesting content, not because social network size has a
substantial direct impact on popularity. In this paper, we develop and apply a
methodology that is able to accurately assess, both qualitatively and
quantitatively, the impacts of various content-agnostic factors on video
popularity. When controlling for video content, we observe a strong linear
"rich-get-richer" behavior, with the total number of previous views as the most
important factor except for very young videos. The second most important factor
is found to be video age. We analyze a number of phenomena that may contribute
to rich-get-richer, including the first-mover advantage, and search bias
towards popular videos. For young videos we find that factors other than the
total number of previous views, such as uploader characteristics and number of
keywords, become relatively more important. Our findings also confirm that
inaccurate conclusions can be reached when not controlling for content.


title:
Experimental evidence for collisional shock formation via two obliquely
  merging supersonic plasma jets

abstract:
  We report spatially resolved measurements of the oblique merging of two
supersonic laboratory plasma jets. The jets are formed and launched by
pulsed-power-driven railguns using injected argon, and have electron density
$\sim 10^{14}$ cm$^{-3}$, electron temperature $\approx 1.4$ eV, ionization
fraction near unity, and velocity $\approx 40$ km/s just prior to merging. The
jet merging produces a few-cm-thick stagnation layer, as observed in both
fast-framing camera images and multi-chord interferometer data, consistent with
collisional shock formation [E. C. Merritt et al., Phys. Rev. Lett. {\bf 111},
085003 (2013)].


title: Measurement of Higgs couplings and self-coupling at the ILC

abstract:
  In the Standard Model (SM) the couplings of the Higgs boson to SM particles
and itself (self-couplings) are uniquely specified once the masses of the
particles in question as well as the Higgs boson mass are given. Precision
measurements of these couplings in the future collider experiments are the key
to either verifying the mechanism of the electroweak symmetry breaking in the
SM or uncovering physics beyond the SM. This article gives an overview of how
various Higgs couplings will be measured at the ILC. Emphasis is put on the
ILC's capability of performing fully model independent determination of
absolute $HZZ$ and $HWW$ couplings, the Higgs total width, and hence various
other Higgs couplings, which cover essentially all the crucial ones including
the top-Yukawa coupling $Htt$ and the trilinear Higgs self-coupling
$\lambda_{HHH}$. The strategy to get the best precision measurements at the ILC
is through staged running, which provides many independent
$\sigma\times\mathrm{Br}$ measurements for different production channels and at
different energies. A method of global fitting is discussed to utilize all of
the available information and to derive combined precisions.


title:
A Blockwise Descent Algorithm for Group-penalized Multiresponse and
  Multinomial Regression

abstract:
  In this paper we purpose a blockwise descent algorithm for group-penalized
multiresponse regression. Using a quasi-newton framework we extend this to
group-penalized multinomial regression. We give a publicly available
implementation for these in R, and compare the speed of this algorithm to a
competing algorithm --- we show that our implementation is an order of
magnitude faster than its competitor, and can solve gene-expression-sized
problems in real time.


title: A Mixture of Generalized Hyperbolic Factor Analyzers

abstract:
  Model-based clustering imposes a finite mixture modelling structure on data
for clustering. Finite mixture models assume that the population is a convex
combination of a finite number of densities, the distribution within each
population is a basic assumption of each particular model. Among all
distributions that have been tried, the generalized hyperbolic distribution has
the advantage that is a generalization of several other methods, such as the
Gaussian distribution, the skew t-distribution, etc. With specific parameters,
it can represent either a symmetric or a skewed distribution. While its
inherent flexibility is an advantage in many ways, it means the estimation of
more parameters than its special and limiting cases. The aim of this work is to
propose a mixture of generalized hyperbolic factor analyzers to introduce
parsimony and extend the method to high dimensional data. This work can be seen
as an extension of the mixture of factor analyzers model to generalized
hyperbolic mixtures. The performance of our generalized hyperbolic factor
analyzers is illustrated on real data, where it performs favourably compared to
its Gaussian analogue.


title: Brains and pseudorandom generators

abstract:
  In a pioneering classic, Warren McCulloch and Walter Pitts proposed a model
of the central nervous system; motivated by EEG recordings of normal brain
activity, Chv\' atal and Goldsmith asked whether or not this model can be
engineered to provide pseudorandom number generators. We supply evidence
suggesting that the answer is negative.


title:
Epitaxial Growth and Electronic Structure of a Layered Zinc Pnictide
  Semiconductor, beta-BaZn2As2

abstract:
  BaZn2As2 is expected for a good p-type semiconductor and has two crystalline
phases of an orthorhombic alpha phase and a higher-symmetry tetragonal beta
phase. Here, we report high-quality epitaxial films of the tetragonal
beta-BaZn2As2 were grown on single-crystal MgO (001) substrates by a reactive
solid-phase epitaxy technique. Out-of-plane and in-plane epitaxial
relationships between the film and the substrate were BaZn2As2 (00l)//MgO (001)
and BaZn2As2 [200]//MgO [200], respectively. The full-widths at half maximum
were 0.082o for a 008 out-of-plane rocking curve and 0.342o for a 200 in-plane
rocking curve. A step-and-terrace structure was observed by atomic force
microscopy. The band gap of beta-BaZn2As2 was evaluated to be around 0.2 eV,
which is much smaller than that of a family compound LaZnOAs (1.5 eV). Density
functional theory calculation using the Heyd-Scuseria-Ernzerhof hybrid
functionals supports the small band gap.


title: A review of beam tomography research at Daresbury Laboratory

abstract:
  This is a review on beam tomography research at Daresbury. The research has
focussed on development of normalised phase space techniques. It starts with
the idea of sampling tomographic projections at equal phase advances and shows
that this would give the optimal reconstruction results. This idea has
influenced the design, construction and operation of the tomography sections at
the Photo Injector Test Facility at Zeuthen (PITZ) and at the Accelerator and
Laser in Combined Experiments (ALICE) at Daresbury. The theoretical
justification of this idea is later developed through simulations and analysis
of the measurements results at ALICE. The mathematical formalism is constructed
around the normalised phase space and the idea of equal phase advances become
the basis of this. This formalism is applied to a variety of experimental and
simulated situations and shown to be useful in improving resolution, increasing
reliability and providing diagnostic information. In this review, we also
present the simplifying concepts, formalisms and simulation tools that we have
developed.


title: The behavior of Chern scalar curvature under Chern-Ricci flow

abstract:
  In this note we study finite-time singularities in the Chern-Ricci flow. We
show that finite-time singularities are characterized by the blow-up of the
scalar curvature of the Chern connection.


title:
Lattice Boltzmann method for bosons and fermions and the fourth order
  Hermite polynomial expansion

abstract:
  The Boltzmann equation with the Bhatnagar-Gross-Krook collision operator is
considered for the Bose-Einstein and Fermi-Dirac equilibrium distribution
functions. We show that the expansion of the microscopic velocity in terms of
Hermite polynomials must be carried until the fourth order to correctly
describe the energy equation. The viscosity and thermal coefficients,
previously obtained by J.Y. Yang et al through the Uehling-Uhlenbeck approach,
are also derived here. Thus the construction of a lattice Boltzmann method for
the quantum fluid is possible provided that the Bose-Einstein and Fermi-Dirac
equilibrium distribution functions are expanded until fourth order in the
Hermite polynomials.


title: Universal Codes from Switching Strategies

abstract:
  We discuss algorithms for combining sequential prediction strategies, a task
which can be viewed as a natural generalisation of the concept of universal
coding. We describe a graphical language based on Hidden Markov Models for
defining prediction strategies, and we provide both existing and new models as
examples. The models include efficient, parameterless models for switching
between the input strategies over time, including a model for the case where
switches tend to occur in clusters, and finally a new model for the scenario
where the prediction strategies have a known relationship, and where jumps are
typically between strongly related ones. This last model is relevant for coding
time series data where parameter drift is expected. As theoretical ontributions
we introduce an interpolation construction that is useful in the development
and analysis of new algorithms, and we establish a new sophisticated lemma for
analysing the individual sequence regret of parameterised models.


title:
Calculation of glueball spectra in supersymmetric theories via
  holography

abstract:
  Lattice simulations currently present the only way to access nonperturbative
data in strongly coupled theories from a first principle calculation. However,
in supersymmetric theories this valuable tool is not available due to the
technical sign problem. We are going to demonstrate that in the case of
glueball spectra a good quantitative estimate for the lightest states of low
spin can be obtained by means of the holographic approach. We will review the
results of the calculation in the singlet glueball sector of the N=1
supersymmetric Klebanov-Strassler model. We come up with a prediction of the
spectrum of lightest glueballs in (large Nc) N=1 supersymmetric Yang-Mills
theory.


title: Lattice and orbital fluctuations in TiPO4

abstract:
  In the s = 1/2 antiferromagnetic spin chain material TiPO4 the formation of a
spin gap takes place in a two step process with two characteristic
temperatures, T*=111 K and TSP=74 K. We observe an unusual lattice dynamics
over a large temperature regime as well as evidence for an orbital instability
preceding the spin-Peierls transition. We relate different intrachain exchange
interactions of the high temperature compared to the spin-Peierls phase to a
modification of the orbital ordering pattern. In particular, our observation of
a high energy excitation of mixed electronic and lattice origin suggests an
exotic dimerization process different from other spin-Peierls materials.


title: Quantum Raychaudhuri equation

abstract:
  We compute quantum corrections to the Raychaudhuri equation, by replacing
classical geodesics with quantal (Bohmian) trajectories, and show that they
prevent focusing of geodesics, and the formation of conjugate points. We
discuss implications for the Hawking-Penrose singularity theorems, and for
curvature singularities.


title: Warm p-soup and near extremal black holes

abstract:
  We consider a model of D-dimensional supergravity coupled to elementary
p-branes. We use gravitational arguments to deduce the low energy effective
theory of N nearly parallel branes. This is a (p+1)-dimensional scalar field
theory, where the scalars represent the positions of the branes in their
transverse space. We propose that the same theory in a certain temperature
regime describes a `soup' of strongly interacting branes, giving a microscopic
description of near extremal black p-branes. We use natural approximations to
estimate the energy density of this soup as a function of the physical
parameters; N, temperature, brane tension and gravitational coupling. We also
characterise the horizon radius, measured in the metric natural to the branes,
with the thermal vev of the scalars. For both quantities we find agreement with
the corresponding supergravity black brane results. Surprisingly, beyond the
physical parameters, we are naturally able to reproduce certain irrational
factors such as pi's. We comment on how these ideas may explain why black hole
thermodynamics arises in gauge theories with holographic duals at finite
temperature.


title: Classical Machian Resolution of the Spacetime Reconstruction Problem

abstract:
  Following from a question of Wheeler, why does the Hamiltonian constraint
${\cal H}$ of GR have the particular form it does? A first answer, by Hojman,
Kucha\v{r} and Teitelboim, is that using embeddability into spacetime as a
principle gives the form of ${\cal H}$. The present paper culminates a second
Machian answer - initially by Barbour, Foster and \'{o} Murchadha - in which
space but not spacetime are assumed. Thus this answer is additionally a
classical-level resolution of the spacetime reconstruction problem. In this
approach, mere consistency imposed by the Dirac procedure whittles down a
general ansatz to one of four alternatives: Lorentzian, Galilean, or Carrollian
relativity, or constant mean curvature slicing. These arise together as the
different ways to kill off a 4-factor obstruction term. It is novel for such an
alternative to arise from principles of dynamics considerations (in contrast
with the historical form of the dichotomy between universal local Galilean or
Lorentzian relativity). It is furthermore intriguing that it gives constant
mean curvature slicing - familiar from York's work on the initial value problem
-- as a further option on a similar footing. That is related to a number of
recent alternative theories/formulations of GR known collectively as `shape
dynamics'. The original work did not treat this with Poisson brackets and a
proper systematic Dirac-type analysis; we rectify this in this paper. It is
also the first demonstration of how this approach solves the classical
spacetime reconstruction problem via `hypersurface tensor dual nationality' and
what can be interpreted as embedding equations arising.


title: Implementing program extraction from CL1-proofs

abstract:
  Computability logic (CoL) is a formal theory of interactive computation. It
understands computational problems as games played by two players: a machine
and its environment, uses logical formalism to describe valid principles of
computability and formulas to represent computational problems. Logic CL1 is a
deductive system for a fragment of CoL. The logical vocabulary contains all of
the operators of classical logic and choice operators, the atoms represent
elementary games i.e. predicates of classical logic. In this paper, we present
a program that takes a CL1-proof of an arbitrary formula $F$, and extract a
winning strategy for $F$ from that proof then play $F$ using that strategy. We
hope this paper would provide a starting point for further work in program
extraction of the CoL-based arithmetic and other CoL-based applied systems.


title:
ReputationPro: The Efficient Approaches to Contextual Transaction Trust
  Computation in E-Commerce Environments

abstract:
  In e-commerce environments, the trustworthiness of a seller is utterly
important to potential buyers, especially when the seller is unknown to them.
Most existing trust evaluation models compute a single value to reflect the
general trust level of a seller without taking any transaction context
information into account. In this paper, we first present a trust vector
consisting of three values for Contextual Transaction Trust (CTT). In the
computation of three CTT values, the identified three important context
dimensions, including product category, transaction amount and transaction
time, are taken into account. In particular, with different parameters
regarding context dimensions that are specified by a buyer, different sets of
CTT values can be calculated. As a result, all these values can outline the
reputation profile of a seller that indicates the dynamic trust levels of a
seller in different product categories, price ranges, time periods, and any
necessary combination of them. We term this new model as ReputationPro.
However, in ReputationPro, the computation of reputation profile requires novel
algorithms for the precomputation of aggregates over large-scale ratings and
transaction data of three context dimensions as well as new data structures for
appropriately indexing aggregation results to promptly answer buyers' CTT
requests. To solve these challenging problems, we then propose a new index
scheme CMK-tree. After that, we further extend CMK-tree and propose a
CMK-treeRS approach to reducing the storage space allocated to each seller.
Finally, the experimental results illustrate that the CMK-tree is superior in
efficiency for computing CTT values to all three existing approaches in the
literature. In addition, though with reduced storage space, the CMK-treeRS
approach can further improve the performance in answering buyers' CTT queries.


title: The non-Urysohn number of a topological space

abstract:
  We call a nonempty subset $A$ of a topological space $X$ finitely non-Urysohn
if for every nonempty finite subset $F$ of $A$ and every family $\{U_x:x\in
F\}$ of open neighborhoods $U_x$ of $x\in F$, $\cap\{\mathrm{cl}(U_x):x\in
F\}\ne\emptyset$ and we define the non-Urysohn number of $X$ as follows:
$nu(X):=1+\sup\{|A|:A$ is a finitely non-Urysohn subset of $X\}$.
  Then for any topological space $X$ and any subset $A$ of $X$ we prove the
following inequalities: (1) $|\mathrm{cl}_\theta(A)|\le |A|^{\kappa(X)}\cdot
nu(X)$, (2) $|[A]_\theta|\le (|A|\cdot nu(X))^{\kappa(X)}$, (3) $|X|\le
nu(X)^{\kappa(X)sL_\theta(X)}$, and (4) $|X|\le nu(X)^{\kappa(X)aL(X)}$.
  In 1979, A. V. Arhangelskii asked if the inequality $|X|\le
2^{\chi(X)wL_c(X)}$ was true for every Hausdorff space $X$. It follows from the
third inequality that the answer of this question is in the affirmative for all
spaces with $nu(X)$ not greater than the cardinality of the continuum.
  We also give a simple example of a Hausdorff space $X$ such that
$|\mathrm{cl}_\theta(A)|>|A|^{\chi(X)}U(X)$ and
$|\mathrm{cl}_\theta(A)|>(|A|\cdot U(X))^{\chi(X)}$, where $U(X)$ is the
Urysohn number of $X$, recently introduced by Bonanzinga, Cammaroto and
Matveev. This example shows that in (1) and (2) above, $nu(X)$ cannot be
replaced by $U(X)$ and answers some questions posed by Bella and Cammaroto
(1988), Bonanzinga, Cammaroto and Matveev (2011), and Bonanzinga and Pansera
(2012).


title: On Quantum Markov Chains on Cayley tree III: Ising model

abstract:
  In this paper, we consider the classical Ising model on the Cayley tree of
order k and show the existence of the phase transition in the following sense:
there exists two quantum Markov states which are not quasi-equivalent. It turns
out that the found critical temperature coincides with usual critical
temperature.


title: The Compactness of Presupernova Stellar Cores

abstract:
  The success or failure of the neutrino-transport mechanism for producing a
supernova in an evolved massive star is known to be sensitive not only to the
mass of the iron core that collapses, but also to the density gradient in the
silicon and oxygen shells surrounding that core. Here we study the systematics
of a presupernova core's "compactness" (O'Connor & Ott 2011) as a function of
the mass of the star and the physics used in its calculation. Fine-meshed
surveys of presupernova evolution are calculated for stars from 15 to 65 Msun.
The metallicity and the efficiency of semiconvection and overshoot mixing are
both varied and bare carbon-oxygen cores are explored as well as full
hydrogenic stars. Two different codes, KEPLER and MESA, are used for the study.
A complex interplay of carbon and oxygen burning, especially in shells, can
cause rapid variations in the compactness for stars of very nearly the same
mass. On larger scales, the distribution of compactness with main sequence mass
is found to be robustly non-monotonic, implying islands of "explodability",
particularly around 8 to 20 Msun and 25 to 30 Msun. The carbon-oxygen (CO) core
mass of a presupernova star is a better, though still ambiguous discriminant of
its core structure than the main sequence mass.


title:
Practical Inexact Proximal Quasi-Newton Method with Global Complexity
  Analysis

abstract:
  Recently several methods were proposed for sparse optimization which make
careful use of second-order information [10, 28, 16, 3] to improve local
convergence rates. These methods construct a composite quadratic approximation
using Hessian information, optimize this approximation using a first-order
method, such as coordinate descent and employ a line search to ensure
sufficient descent. Here we propose a general framework, which includes
slightly modified versions of existing algorithms and also a new algorithm,
which uses limited memory BFGS Hessian approximations, and provide a novel
global convergence rate analysis, which covers methods that solve subproblems
via coordinate descent.


title: Low-Bias-Anomaly and Tunnel Fluctuoscopy

abstract:
  Electron tunneling spectroscopy pioneered by Esaki and Giaever offered a
powerful tool for studying electronic spectra and density of states (DOS) in
superconductors. This led to important discoveries that revealed, in
particular, the pseudogap in the tunneling spectrum of superconductors above
their critical temperatures. However, the phenomenological approach is
insufficient for describing the does not resolve the fine structure of low-bias
behavior carrying significant information about electron scattering,
interactions, and decoherence effects. Here we construct a complete microscopic
theory of electron tunneling into a superconductor in the fluctuation regime.
We reveal a non-trivial low-energy anomaly in tunneling conductivity due to
Andreev-like reflection of injected electrons from superconducting
fluctuations. Our findings enable real-time observation of fluctuating Cooper
pairs dynamics by time-resolved scanning tunneling microscopy measurements and
open new horizons for quantitative analysis of the fluctuation electronic
spectra of superconductors.


title: Multi-lepton signatures at LHC from sneutrino dark matter

abstract:
  We investigate multi-lepton LHC signals arising from an extension at the
grand unification scale of the standard minimal supersymmetric model (MSSM)
involving right-handed neutrino superfields. In this framework neutrinos have
Dirac masses and the mixed sneutrinos are the lightest supersymmetric particles
and hence the dark matter candidates. We analyze the model parameter space in
which the sneutrino is a good dark matter particle and has a direct detection
cross-section compatible with the LUX bound. Studying the supersymmetric mass
spectrum of this region, we find several signatures relevant for LHC, which are
distinct from the predictions of the MSSM with neutralino dark matter. For
instance two opposite sign and different flavor leptons, three uncorrelated
leptons and long-lived staus are the most representative. Simulating both the
signal and expected background, we find that the multi-lepton signatures and
the long-lived stau are in the reach of the future run of LHC with a luminosity
of 100/fb. We point out that if one of these signatures is detected, it might
be an indication of sneutrino dark matter.