title:
A Brief Tutorial on Transformation Based Markov Chain Monte Carlo and
  Optimal Scaling of the Additive Transformation

abstract:
  We consider the recently introduced Transformation-based Markov Chain Monte
Carlo (TMCMC) (Dutta and Bhattacharya (2014)), a methodology that is designed
to update all the parameters simultaneously using some simple deterministic
transformation of a onedimensional random variable drawn from some arbitrary
distribution on a relevant support. The additive transformation based TMCMC is
similar in spirit to random walk Metropolis, except the fact that unlike the
latter, additive TMCMC uses a single draw from a onedimensional proposal
distribution to update the high-dimensional parameter. In this paper, we first
provide a brief tutorial on TMCMC, exploring its connections and contrasts with
various available MCMC methods. Then we study the diffusion limits of additive
TMCMC under various set-ups ranging from the product structure of the target
density to the case where the target is absolutely continuous with respect to a
Gaussian measure; we also consider the additive TMCMC within Gibbs approach for
all the above set-ups. These investigations lead to appropriate scaling of the
one-dimensional proposal density. We also show that the optimal acceptance rate
of additive TMCMC is 0.439 under all the aforementioned set-ups, in contrast
with the well-established 0.234 acceptance rate associated with optimal random
walk Metropolis algorithms under the same set-ups. We also elucidate the
ramifications of our results and clear advantages of additive TMCMC over random
walk Metropolis with ample simulation studies and Bayesian analysis of a real,
spatial dataset with which 160 unknowns are associated.


title:
Linear Time Computation of the Maximal Linear and Circular Sums of
  Multiple Independent Insertions into a Sequence

abstract:
  The maximal sum of a sequence "A" of "n" real numbers is the greatest sum of
all elements of any strictly contiguous and possibly empty subsequence of "A",
and it can be computed in "O(n)" time by means of Kadane's algorithm. Letting
"A^(x -> p)" denote the sequence which results from inserting a real number "x"
between elements "A[p-1]" and "A[p]", we show how the maximal sum of "A^(x ->
p)" can be computed in "O(1)" worst-case time for any given "x" and "p",
provided that an "O(n)" time preprocessing step has already been executed on
"A". In particular, this implies that, given "m" pairs "(x_0, p_0), ...,
(x_{m-1}, p_{m-1})", we can compute the maximal sums of sequences "A^(x_0 ->
p_0), ..., A^(x_{m-1} -> p_{m-1})" in "O(n+m)" time, which matches the lower
bound imposed by the problem input size, and also improves on the
straightforward strategy of applying Kadane's algorithm to each sequence
"A^(x_i -> p_i)", which takes a total of "Theta(n.m)" time. Our main
contribution, however, is to obtain the same time bound for the more
complicated problem of computing the greatest sum of all elements of any
strictly or circularly contiguous and possibly empty subsequence of "A^(x ->
p)". Our algorithms are easy to implement in practice, and they were motivated
by and find application in a buffer minimization problem on wireless mesh
networks.


title: Distributed Detection and Estimation in Wireless Sensor Networks

abstract:
  In this article we consider the problems of distributed detection and
estimation in wireless sensor networks. In the first part, we provide a general
framework aimed to show how an efficient design of a sensor network requires a
joint organization of in-network processing and communication. Then, we recall
the basic features of consensus algorithm, which is a basic tool to reach
globally optimal decisions through a distributed approach. The main part of the
paper starts addressing the distributed estimation problem. We show first an
entirely decentralized approach, where observations and estimations are
performed without the intervention of a fusion center. Then, we consider the
case where the estimation is performed at a fusion center, showing how to
allocate quantization bits and transmit powers in the links between the nodes
and the fusion center, in order to accommodate the requirement on the maximum
estimation variance, under a constraint on the global transmit power. We extend
the approach to the detection problem. Also in this case, we consider the
distributed approach, where every node can achieve a globally optimal decision,
and the case where the decision is taken at a central node. In the latter case,
we show how to allocate coding bits and transmit power in order to maximize the
detection probability, under constraints on the false alarm rate and the global
transmit power. Then, we generalize consensus algorithms illustrating a
distributed procedure that converges to the projection of the observation
vector onto a signal subspace. We then address the issue of energy consumption
in sensor networks, thus showing how to optimize the network topology in order
to minimize the energy necessary to achieve a global consensus. Finally, we
address the problem of matching the topology of the network to the graph
describing the statistical dependencies among the observed variables.


title: Toric Birational Geometry and Applications to Lattice Polytopes

abstract:
  Toric geometry provides a bridge between the theory of polytopes and
algebraic geometry: one can associate to each lattice polytope a polarized
toric variety. In this thesis we explore this correspondence to classify smooth
lattice polytopes having small degree, extending a classification provided by
Dickenstein, Di Rocco and Piene. Our approach consists in interpreting the
degree of a polytope as a geometric invariant of the corresponding polarized
variety, and then applying techniques from Adjunction Theory and Mori Theory.
In the opposite direction, we use the combinatorics of fans to describe the
extremal rays of several cones of cycles of a projective toric variety X. One
of these cones is the cone of moving curves, that is the closure of the cone
generated by classes of curves moving in a family that sweeps out X. This cone
plays an important role in the problem of birational classification of
projective varieties.


title:
TeV-PeV neutrinos over the atmospheric background: originating from two
  groups of sources?

abstract:
  In addition to the two ~1 PeV neutrinos, the IceCube Collaboration recently
reported a detection of 26 neutrino candidates at energies from 30 TeV to 250
TeV, implying a confidence level of 4.3\sigma over the atmospheric background.
We suggest that these TeV-PeV non-atmospheric neutrinos may originate from two
groups of sources, motivated by the non-detection of neutrinos in the energy
range 250 TeV- 1 PeV in current data. If intrinsic, the non-detection of 250
TeV-1 PeV neutrinos disfavors the single power-law spectrum model for the
TeV-PeV non-atmospheric neutrinos at a confidence level of ~ 2\sigma. We then
interpret the current neutrino data with a two-component spectrum model. One
has a flat spectrum with a cutoff at the energy ~ 250 TeV and the other has a
sharp peak at ~1 PeV. The former is likely via pp collision while the latter
may be generated by the photomeson interaction.


title: Generating functional of ChPT at one loop for non-minimal operators

abstract:
  The divergent part of the one-loop effective action in Chiral Perturbation
Theory with virtual photons has been evaluated in an arbitrary covariant gauge.
The differential operator, that emerges in the functional determinant, is of a
non-minimal type, for which the standard heat kernel methods are not directly
applicable. Both SU(2) and SU(3) cases have been worked out. A comparison with
existing results in the literature is given.


title:
Role of the orthogonal group in construction of osp(1|2n)
  representations

abstract:
  It is well known that the symmetric group has an important role (via Young
tableaux formalism) both in labelling of the representations of the unitary
group and in construction of the corresponding basis vectors (in the tensor
product of the defining representations). We show that orthogonal group has a
very similar role in the context of positive energy representations of
osp(1|2n,R). In the language of parabose algebra, we essentially solve the long
standing problem of reducibility of Green's ansatz representations.


title:
Equilibrium models of radially anisotropic spherical stellar systems
  with softened central potentials

abstract:
  We study a new class of equilibrium two-parametric distribution functions of
spherical stellar systems with radially anisotropic velocity distribution of
stars. The models are less singular counterparts of the so called generalized
polytropes, widely used in works on equilibrium and stability of gravitating
systems in the past. The offered models, unlike the generalized polytropes,
have finite density and potential in the center. The absence of the singularity
is necessary for proper consideration of the radial orbit instability, which is
the most important instability in spherical stellar systems. Comparison of the
main observed parameters (potential, density, anisotropy) predicted by the
present models and other popular equilibrium models is provided.


title: Relative volume of separable bipartite states

abstract:
  Every choice of an orthonormal frame in the d-dimensional Hilbert space of a
system corresponds to one set of all mutually commuting density matrices or,
equivalently, a classical statistical state space of the system; the quantum
state space itself can thus be profitably viewed as an SU(d) orbit of classical
state spaces, one for each orthonormal frame. We exploit this connection to
study the relative volume of separable states of a bipartite quantum system.
While the two-qubit case is studied in considerable analytic detail, for higher
dimensional systems we fall back on Monte Carlo. Several new insights seem to
emerge from our study.


title: A Note on Random Coverings of Tori

abstract:
  This note provides a generalisation of a recent result by J\"arvenp\"a\"a,
J\"arvenp\"a\"a, Koivusalo, Li, and Suomala, (to appear), on the dimension of
limsup-sets of random coverings of tori. The result in this note is stronger in
the sense that it provides also a large intersection property of the
limsup-sets, the assumptions are weaker, and it implies the result of
J\"arvenp\"a\"a, J\"arvenp\"a\"a, Koivusalo, Li, and Suomala as a special case.
The proof is based on a recent result by Persson and Reeve from 2013.


title:
Existence of blow-up solutions for a class of elliptic system with
  convection term

abstract:
  The present paper concerns with the existence of blow-up solution for a class
of elliptic system with convection term. Here, we prove a result involving sub
and supersolution for a class of elliptic system whose nonlinearity can depend
of the gradient of the solution. This result permits to study the existence of
blow-up solution for a large class of systems.


title:
Temperature Dependence of the Electrical Transport Properties of
  Multilayer Graphene

abstract:
  Multilayer graphene (MLG) thin films are deposited on silicon oxide
substrates by mechanical exfoliation (or 'scotch-tape method') from Kish
graphite. The thickness and number of layers are determined from both Atomic
Force Microscopy (AFM) and Raman Spectroscopy. Electrical terminals are
deposited on MLGs in a four-probe configuration by electron-beam lithography,
gold/titanium thermal evaporation, and lift-off. The electrical resistance is
measured from room temperature down to 2 K. The electrical resistance of the
MLGs shows an increase with decreasing temperature, and then decreases after
reaching a maximum value. These results are compared with recent experimental
and theoretical data from the literature.


title:
Modulation of the Optical Transmittance in Multilayer Graphene by an
  Electrical Signal

abstract:
  The modulation of the optical transmittance in multilayer graphene by means
of an electrical signal in the simple configuration of coplanar electrodes is
reported. Besides the fundamental frequency of modulation, higher harmonics
also appear in the transmitted signal. Modulation is also observed in the
optical reflectance. The modulation of the optical properties in multilayer
graphene by electrical signals may be useful for the transmission of
information by optical means.


title: The CLASSgal code for Relativistic Cosmological Large Scale Structure

abstract:
  We present some accurate and efficient computations of large scale structure
observables, obtained with a modified version of the CLASS code which is made
publicly available. This code includes all relativistic corrections and
computes both the power spectrum Cl(z1,z2) and the corresponding correlation
function xi(theta,z1,z2) in linear perturbation theory. For Gaussian initial
perturbations, these quantities contain the full information encoded in the
large scale matter distribution at the level of linear perturbation theory. We
illustrate the usefulness of our code for cosmological parameter estimation
through a few simple examples.


title:
Holographic Phase Transitions in (2+1)-dimensional black hole spacetimes
  in NMG

abstract:
  In this work we aim at the question of holographic phase transitions in two
dimensional systems with Lifshitz scaling. We consider the gravity side
candidate for a dual description as the black hole solution of New Massive
Gravity (NMG) with Lifshitz scaling. We discuss the effects due to the Lifshitz
scaling in the AGGH (Ayon-Beato-Garbarz-Giribet-Hassa\"i{\i}ne) solution in
comparison with the BTZ (Ba\~nados-Teitelboim-Zanelli) black hole. Likewise, we
compute the order parameter and it indicates a second order phase transition in
a (1+1) dimension Lifshitz boundary.


title:
Degrees of Freedom of the Rank-deficient Interference Channel with
  Feedback

abstract:
  We investigate the total degrees of freedom (DoF) of the K-user
rank-deficient interference channel with feedback. For the two-user case, we
characterize the total DoF by developing an achievable scheme and deriving a
matching upper bound. For the three-user case, we develop a new achievable
scheme which employs interference alignment to efficiently utilize the
dimension of the received signal space. In addition, we derive an upper bound
for the general K-user case and show the tightness of the bound when the number
of antennas at each node is sufficiently large. As a consequence of these
results, we show that feedback can increase the DoF when the number of antennas
at each node is large enough as compared to the ranks of channel matrices. This
finding is in contrast to the full-rank interference channel where feedback
provides no DoF gain. The gain comes from using feedback to provide alternative
signal paths, thereby effectively increasing the ranks of desired channel
matrices.


title: Time-delayed beam splitting with energy separation of x-ray channels

abstract:
  We introduce a time-delayed beam splitting method based on the energy
separation of x-ray photon beams. It is implemented and theoretically
substantiated on an example of an x-ray optical scheme similar to that of the
classical Michelson interferometer. The splitter/mixer uses Bragg-case
diffraction from a thin diamond crystal. Another two diamond crystals are used
as back-reflectors. For energy separation the back-reflectors are set at
slightly different temperatures and angular deviations from exact
backscattering. Because of energy separation and a minimal number (three) of
optical elements, the split-delay line has high efficiency and is simple to
operate. Due to the high transparency of diamond crystal, the split-delay line
can be used in a beam sharing mode at x-ray free-electron laser facilities. The
delay line can be made more compact by adding a fourth crystal.


title: Quantum Monte Carlo Study of High Pressure Solid Molecular Hydrogen

abstract:
  We use the diffusion quantum Monte Carlo (DMC) method to calculate the ground
state phase diagram of solid molecular hydrogen and examine the stability of
the most important insulating phases relative to metallic crystalline molecular
hydrogen. We develop a new method to account for finite-size errors by
combining the use of twist-averaged boundary conditions with corrections
obtained using the Kwee-Zhang-Krakauer (KZK) functional in density functional
theory. To study band-gap closure and find the metallization pressure, we
perform accurate quasi-particle many-body calculations using the $GW$ method.
In the static approximation, our DMC simulations indicate a transition from the
insulating Cmca-12 structure to the metallic Cmca structure at around 375 GPa.
The $GW$ band gap of Cmca-12 closes at roughly the same pressure. In the
dynamic DMC phase diagram, which includes the effects of zero-point energy, the
Cmca-12 structure remains stable up to 430 GPa, well above the pressure at
which the $GW$ band gap closes. Our results predict that the semimetallic state
observed experimentally at around 360 GPa [Phys. Rev. Lett. {\bf 108}, 146402
(2012)] may correspond to the Cmca-12 structure near the pressure at which the
band gap closes. The dynamic DMC phase diagram indicates that the hexagonal
close packed $P6_3/m$ structure, which has the largest band gap of the
insulating structures considered, is stable up to 220 GPa. This is consistent
with recent X-ray data taken at pressures up to 183 GPa [Phys. Rev. B {\bf 82},
060101(R) (2010)], which also reported a hexagonal close packed arrangement of
hydrogen molecules.


title: Global functional calculus for operators on compact Lie groups

abstract:
  In this paper we develop the functional calculus for elliptic operators on
compact Lie groups without the assumption that the operator is a classical
pseudo-differential operator. Consequently, we provide a symbolic descriptions
of complex powers of such operators. As an application, we give a constructive
symbolic proof of the G\r{a}rding inequality for operators in
$(\rho,\delta)$-classes in the setting of compact Lie groups.


title:
Three-particle Integrable Systems with Elliptic Dependence on Momenta
  and Theta Function Identities

abstract:
  We claim that some non-trivial theta-function identities at higher genus can
stand behind the Poisson commutativity of the Hamiltonians of elliptic
integrable systems, which are made from the theta-functions on Jacobians of the
Seiberg-Witten curves. For the case of three-particle systems the genus-2
identities are found and presented in the paper. The connection with the
Macdonald identities is established. The genus-2 theta-function identities
provide the direct way to construct the Poisson structure in terms of the
coordinates on the Jacobian of the spectral curve and the elements of its
period matrix. The Lax representations for the two-particle systems are also
obtained.


title: Detect adverse drug reactions for the drug Pravastatin

abstract:
  Adverse drug reaction (ADR) is widely concerned for public health issue. ADRs
are one of most common causes to withdraw some drugs from market. Prescription
event monitoring (PEM) is an important approach to detect the adverse drug
reactions. The main problem to deal with this method is how to automatically
extract the medical events or side effects from high-throughput medical data,
which are collected from day to day clinical practice. In this study we propose
an original approach to detect the ADRs using feature matrix and feature
selection. The experiments are carried out on the drug Pravastatin. Major side
effects for the drug are detected. The detected ADRs are based on computerized
method, further investigation is needed.


title: The origin of physical variations in the star formation law

abstract:
  Observations of external galaxies and of local star-forming clouds in the
Milky Way have suggested a variety of star formation laws, i.e., simple direct
relations between the column density of star formation (Sigma_SFR: the amount
of gas forming stars per unit area and time) and the column density of
available gas (Sigma_gas). Extending previous studies, we show that these
different, sometimes contradictory relations for Milky Way clouds, nearby
galaxies, and high-redshift discs and starbursts can be combined in one
universal star formation law in which Sigma_SFR is about 1% of the local gas
collapse rate, Sigma_gas/t_ff, but a significant scatter remains in this
relation. Using computer simulations and theoretical models, we find that the
observed scatter may be primarily controlled by physical variations in the Mach
number of the turbulence and by differences in the star formation efficiency.
Secondary variations can be induced by changes in the virial parameter,
turbulent driving and magnetic field. The predictions of our models are
testable with observations that constrain both the Mach number and the star
formation efficiency in Milky Way clouds, external disc and starburst galaxies
at low and high redshift. We also find that reduced telescope resolution does
not strongly affect such measurements when Sigma_SFR is plotted against
Sigma_gas/t_ff.


title: Stars on the run: escaping from stellar clusters

abstract:
  A significant proportion of Milky Way stars are born in stellar clusters,
which dissolve over time so that the members become part of the disc and halo
populations of the Galaxy. In the present work we will assume that these young
stellar clusters live mainly within the disc of the Galaxy and that they can
have primordial binary percentages ranging from 0% to as high as 70%. We have
evolved models of such clusters to an age of 4 Gyr through N-body simulations,
paying attention to the stars and binaries that escape in the process. We have
quantified the contribution of these escaping stars to the Galaxy population by
analysing their escape velocity and evolutionary stage at the moment of escape.
In this way we could analyse the mechanisms that produced these escapers,
whether evaporation through weak two- body encounters, energetic close
encounters or stellar evolution events, e.g. supernovae. In our models we found
that the percentage of primordial binaries in a star cluster does not produce
significant variations in the velocities of the stars that escape in the
velocity range of 0-20 km/s. However, in the high-velocity 20-100 km/s range
the number of escapers increased markedly as the primordial binary percentage
increased. We could also infer that dissolving stellar clusters such as those
that we have modelled can populate the Galactic halo with giant stars for which
the progenitors were stars of up to 2.4 Msun. Furthermore, choices made for the
velocity kicks of remnants do influence the production of hyper-velocity stars
- and to a lesser extent stars in the high-velocity range - but once again the
difference for the 99% of stars in the 0-20 km/s range is not significant.


title: Precision of a Low-Cost InGaAs Detector for Near Infrared Photometry

abstract:
  We have designed, constructed, and tested an InGaAs near-infrared camera to
explore whether low-cost detectors can make small (<1 m) telescopes capable of
precise (<1 mmag) infrared photometry of relatively bright targets. The camera
is constructed around the 640x512 pixel APS640C sensor built by FLIR
Electro-Optical Components. We designed custom analog-to-digital electronics
for maximum stability and minimum noise. The InGaAs dark current halves with
every 7 deg C of cooling, and we reduce it to 840 e-/s/pixel (with a
pixel-to-pixel variation of +/-200 e-/s/pixel) by cooling the array to -20 deg
C. Beyond this point, glow from the readout dominates. The single-sample read
noise of 149 e- is reduced to 54 e- through up-the-ramp sampling. Laboratory
testing with a star field generated by a lenslet array shows that 2-star
differential photometry is possible to a precision of 631 +/-205 ppm (0.68
mmag) hr^-0.5 at a flux of 2.4E4 e-/s. Employing three comparison stars and
de-correlating reference signals further improves the precision to 483 +/-161
ppm (0.52 mmag) hr^-0.5. Photometric observations of HD80606 and HD80607 (J=7.7
and 7.8) in the Y band shows that differential photometry to a precision of 415
ppm (0.45 mmag) hr^-0.5 is achieved with an effective telescope aperture of
0.25 m. Next-generation InGaAs detectors should indeed enable Poisson-limited
photometry of brighter dwarfs with particular advantage for late-M and L types.
In addition, one might acquire near-infrared photometry simultaneously with
optical photometry or radial velocity measurements to maximize the return of
exoplanet searches with small telescopes.


title:
Discovery, Progenitor & Early Evolution of a Stripped Envelope Supernova
  iPTF13bvn

abstract:
  The intermediate Palomar Transient Factory reports our discovery of a young
supernova, iPTF13bvn, in the nearby galaxy, NGC5806 (22.5Mpc). Our spectral
sequence in the optical and infrared suggests a likely Type Ib classification.
We identify a single, blue progenitor candidate in deep pre-explosion imaging
within a 2{\sigma} error circle of 80 mas (8.7 pc). The candidate has a MB
luminosity of -5.2 +/- 0.4 mag and a B-I color of 0.1+/-0.3 mag. If confirmed
by future observations, this would be the first direct detection for a
progenitor of a Type Ib. Fitting a power law to the early light curve, we find
an extrapolated explosion date around 1.1 days before our first detection. We
see no evidence of shock cooling. The pre-explosion detection limits constrain
the radius of the progenitor to be smaller than a few solar radii. iPTF13bvn is
also detected in cm and mm-wavelengths. Fitting a synchrotron self-absorption
model to our radio data, we find a mass loading parameter of 1.3*10^12 g/cm.
Assuming a wind velocity of 10^3km/s, we derive a progenitor mass loss rate of
3*10^-5Msun/yr. Our observations, taken as a whole, are consistent with a Wolf
Rayet progenitor of the supernova iPTF13bvn.


title:
The XMM-Newton deep survey in the CDF-S VI. Obscured AGN selected as
  infrared power-law galaxies

abstract:
  Accretion onto SMBH is believed to occur mostly in obscured AGN. Such objects
are proving rather elusive in surveys of distant galaxies, including those at
X-ray energies. Our main goal is to determine whether the revised IRAC criteria
of Donley et al. (2012) (objects with an IR power-law spectral shape), are
effective at selecting X-ray type-2 AGN. We present the results from the X-ray
spectral analysis of 147 AGN selected by cross-correlating the highest spectral
quality ultra-deep XMM-Newton and the Spitzer/IRAC catalogues in the CDF-S.
Consequently it is biased towards sources with high S/N X-ray spectra. In order
to measure the amount of intrinsic absorption in these sources, we adopt a
simple X-ray spectral model that includes a power-law modified by intrinsic
absorption and a possible soft X-ray component. We find 21/147 sources to be
heavily absorbed but the uncertainties in their obscuring column densities do
not allow us to confirm their Compton-Thick nature without resorting to
additional criteria. Although IR power-law galaxies are less numerous in our
sample than IR non-power-law galaxies (60 versus 87 respectively), we find that
the fraction of absorbed (N_{H} > 10^{22} cm^{-2}) AGN is significantly higher
(at about 3 sigma level) for IR-power-law sources ($\sim$2/3) than for those
sources that do not meet this IR selection criteria ($\sim$1/2). This behaviour
is particularly notable at low luminosities, but it appears to be present,
although with a marginal significance, at all luminosities. We therefore
conclude that the IR power-law method is efficient in finding X-ray-absorbed
sources. We would then expect that the long-sought dominant population of
absorbed AGN is abundant among IR power-law spectral shape sources not detected
in X-rays.


title: On the nature of sodium excess objects. I. Data and observed trends

abstract:
  Several studies have reported the presence of sodium excess objects that have
neutral atomic absorption lines at 5895A (NaD) and 8190A that are deeper than
expected based on stellar population models. van Dokkum & Conroy proposed that
low-mass stars are more prevalent in massive early-type galaxies, which may
lead to a strong NaI8190 line strength. It is, however, necessary to test this
prediction against other prominent line indices in optical wavelengths. We
newly identified roughly a thousand NaD excess objects (NEOs) based on the NaD
line strength in the redshift range 0.00<z<0.08 from the SDSS DR7. The novelty
of this work is that galaxies were carefully identified through direct visual
inspection of SDSS images, and we systematically compared the properties of
NEOs and those of a control sample of normal galaxies. Note that the majority
of galaxies with high velocity dispersion (>250km/s) show NaD excess. Most
late-type NEOs have strong Hb line strengths and significant emission lines.
This implies that the presence of ISM and/or dust contributes to the increase
in NaD line strengths observed for these galaxies. In contrast, the majority of
early-type NEOs are predominantly luminous and massive systems. However, we
find that models used to reproduce the NaI8190 line strengths that adopt a
bottom-heavy IMF are not able to reproduce the observed NaD line strengths. By
comparing the observed NaD, Mgb and Fe5270 line strengths with those of the
models, we identify a plausible range of parameters. In these models, the
majority of early-type NEOs are alpha-enhanced ([a/Fe]~0.3), metal-rich
([Z/H]~0.3) and especially Na-enhanced ([Na/Fe]~0.3). Enhanced Na abundance is
a particularly compelling hypothesis for the increase in the strength of the
NaD line index in our early-type NEOs that appear devoid of dust, both in their
SDSS images and spectra.


title: Electrons turn into anyons under an elastic membrane

abstract:
  We show that electrons acquire anyonic statistics if a two-dimensional
electron gas is placed in proximity to a charged magnetic membrane. In this
two-layered system, electrons become anyons through electromagnetic field
mediated interactions with a membrane phonon. The statistical parameter is
irrational and depends on the membrane tension and on the electric charge and
magnetic dipolar densities on the membrane. We propose a measurement that
yields the value of the statistical parameter.


title:
Distinct Chemical Regions in the "Prestellar" Infrared Dark Cloud (IRDC)
  G028.23-00.19

abstract:
  We have observed the IRDC G028.23-00.19 at 3.3 mm using CARMA. In its center,
the IRDC hosts one of the most massive (~1520 Msun) quiescent, cold (12 K)
clumps known (MM1). The low temperature, high NH_2D abundance, narrow molecular
line widths, and absence of embedded IR sources (from 3.6 to 70 mu) indicate
that the clump is likely prestellar. Strong SiO emission with broad line widths
(6-9 km s^-1) and high abundances (0.8-4 x 10^-9) is detected in the northern
and southern regions of the IRDC, unassociated with MM1. We suggest that SiO is
released to the gas phase from the dust grains through shocks produced by
outflows from undetected intermediate-mass stars or clusters of low-mass stars
deeply embedded in the IRDC. A weaker SiO component with narrow line widths (~2
km s^-1) and low abundances (4.3 x 10^-11) is detected in the center-west
region, consistent with either a "subcloud-subcloud" collision or an unresolved
population of a few low-mass stars. We report widespread CH_3OH emission
throughout the whole IRDC and the first detection of extended narrow methanol
emission (~2 km s^-1) in a cold, massive prestellar clump (MM1). We suggest
that the most likely mechanism releasing methanol into the gas phase in such a
cold region is the exothermicity of grain-surface reactions. HN^13C reveals
that the IRDC is actually composed of two distinct substructures ("subclouds")
separated in velocity space by ~1.4 km s^-1. The narrow SiO component arises
where the subclouds overlap. The spatial distribution of C_2H resembles that of
NH_2D, which suggests that C_2H also traces cold gas in this IRDC.


title: Quantum many-body interactions in digital oxide superlattices

abstract:
  Controlling the electronic properties of interfaces has enormous scientific
and technological implications and has been recently extended from
semiconductors to complex oxides which host emergent ground states not present
in the parent materials. These oxide interfaces present a fundamentally new
opportunity where, instead of conventional bandgap engineering, the electronic
and magnetic properties can be optimized by engineering quantum many-body
interactions. We utilize an integrated oxide molecular-beam epitaxy and
angle-resolved photoemission spectroscopy system to synthesize and investigate
the electronic structure of superlattices of the Mott insulator LaMnO3 and the
band insulator SrMnO3. By digitally varying the separation between interfaces
in (LaMnO3)2n/(SrMnO3)n superlattices with atomic-layer precision, we
demonstrate that quantum many-body interactions are enhanced, driving the
electronic states from a ferromagnetic polaronic metal to a pseudogapped
insulating ground state. This work demonstrates how many-body interactions can
be engineered at correlated oxide interfaces, an important prerequisite to
exploiting such effects in novel electronics.


title:
Evidence for Ubiquitous Collimated Galactic-Scale Outflows along the
  Star-Forming Sequence at z~0.5

abstract:
  We present an analysis of the MgII 2796, 2803 and FeII 2586, 2600 absorption
line profiles in individual spectra of 105 galaxies at 0.3<z<1.4. The galaxies,
drawn from redshift surveys of the GOODS fields and the Extended Groth Strip,
fully sample the range in star formation rates (SFRs) occupied by the
star-forming sequence with stellar masses log M_*/M_sun > 9.5 at 0.3<z<0.7.
Using the Doppler shifts of the MgII and FeII absorption lines as tracers of
cool gas kinematics, we detect large-scale winds in 66+/-5% of the galaxies.
HST/ACS imaging and our spectral analysis indicate that the outflow detection
rate depends primarily on galaxy orientation: winds are detected in ~89% of
galaxies having inclinations (i) <30 degrees (face-on), while the wind
detection rate is only ~45% in objects having i>50 degrees (edge-on). Combined
with the comparatively weak dependence of the wind detection rate on intrinsic
galaxy properties, this suggests that biconical outflows are ubiquitous in
normal, star-forming galaxies at z~0.5. We find that the wind velocity is
correlated with host galaxy M_* at 3.4-sigma significance, while the equivalent
width of the flow is correlated with host galaxy SFR at 3.5-sigma significance,
suggesting that hosts with higher SFR may launch more material into outflows
and/or generate a larger velocity spread for the absorbing clouds. Assuming
that the gas is launched into dark matter halos with simple, isothermal density
profiles, the wind velocities measured for the bulk of the cool material
(~200-400 km/s) are sufficient to enable escape from the halo potentials only
for the lowest-M_* systems in the sample. However, the outflows typically carry
sufficient energy to reach distances of >50 kpc, and may therefore be a viable
source of cool material for the massive circumgalactic medium observed around
bright galaxies at z~0. [abridged]


title:
Vevacious: A Tool For Finding The Global Minima Of One-Loop Effective
  Potentials With Many Scalars

abstract:
  Several extensions of the Standard Model of particle physics contain
additional scalars implying a more complex scalar potential compared to that of
the Standard Model. In general these potentials allow for charge and/or color
breaking minima besides the desired one with correctly broken SU(2)_L times
U(1)_Y . Even if one assumes that a metastable local minimum is realized, one
has to ensure that its lifetime exceeds that of our universe. We introduce a
new program called Vevacious which takes a generic expression for a one-loop
effective potential energy function and finds all the tree-level extrema, which
are then used as the starting points for gradient-based minimization of the
one-loop effective potential. The tunneling time from a given input vacuum to
the deepest minimum, if different from the input vacuum, can be calculated. The
parameter points are given as files in the SLHA format (though is not
restricted to supersymmetric models), and new model files can be easily
generated automatically by the Mathematica package SARAH. This code uses
HOM4PS2 to find all the minima of the tree-level potential, PyMinuit to follow
gradients to the minima of the one-loop potential, and CosmoTransitions to
calculate tunneling times.


title:
Non-Gaussian initial conditions in $\Lambda$CDM: Newtonian, relativistic
  and primordial contributions

abstract:
  The goal of the present paper is to set initial conditions for structure
formation at non-linear order, consistent with general relativity, while also
allowing for primordial non-Gaussianity. We use the non-linear continuity and
Raychauduri equations, which together with the non-linear energy constraint
determine the evolution of the matter density fluctuation in general
relativity. We solve this equations at first and second order in a perturbative
expansion, recovering and extending previous results derived in the
matter-dominated limit and in the Newtonian regime. We present a second-order
solution for the comoving density contrast in a $\Lambda$CDM universe,
identifying non-linear contributions coming from the Newtonian growing mode,
primordial non-Gaussianity and intrinsic non-Gaussianity, due to the essential
non-linearity of the relativistic constraint equations. We discuss the
application of these results to initial conditions in N-body simulations,
showing that relativistic corrections mimic a non-zero non-linear parameter
$f_{\rm NL}$.


title: Weakly commensurable groups, with applications to differential geometry

abstract:
  The article contains a survey of our results on weakly commensurable
arithmetic and general Zariski-dense subgroups, length-commensurable and
isospectral locally symmetric spaces and of related problems in the theory of
semi-simple agebraic groups. We have included a discussion of very recent
results and conjectures on absolutely almost simple algebraic groups having the
same maximal tori and finite-dimensional division algebras having the same
maximal subfields.


title: Lattices of regular closed subsets of closure spaces

abstract:
  For a closure space (P,f) with f(\emptyset)=\emptyset, the closures of open
subsets of P, called the regular closed subsets, form an ortholattice Reg(P,f),
extending the poset Clop(P,f) of all clopen subsets. If (P,f) is a finite
convex geometry, then Reg(P,f) is pseudocomplemented. The Dedekind-MacNeille
completion of the poset of regions of any central hyperplane arrangement can be
obtained in this way, hence it is pseudocomplemented. The lattice Reg(P,f)
carries a particularly interesting structure for special types of convex
geometries, that we call closure spaces of semilattice type. For finite such
closure spaces, (1) Reg(P,f) satisfies an infinite collection of stronger and
stronger quasi-identities, weaker than both meet- and join-semidistributivity.
Nevertheless it may fail semidistributivity. (2) If Reg(P,f) is
semidistributive, then it is a bounded homomorphic image of a free lattice. (3)
Clop(P,f) is a lattice iff every regular closed set is clopen. The extended
permutohedron R(G) on a graph G, and the extended permutohedron Reg(S) on a
join-semilattice S, are both defined as lattices of regular closed sets of
suitable closure spaces. While the lattice of regular closed sets is, in the
semilattice context, always the Dedekind Mac-Neille completion of the poset of
clopen sets, this does not always hold in the graph context, although it always
does so for finite block graphs and for cycles. Furthermore, both R(G) and
Reg(S) are bounded homomorphic images of free lattices.


title: Cosmic Censorship, Black Holes and Integer-spin Test Fields

abstract:
  It has been argued that, starting with a slightly sub-extremal Kerr black
hole instead of an extremal one, it is possible to overspin a black hole past
the extremal limit and turn it into a naked singularity by sending test bodies,
if one neglects radiative and self-force effects. In this work we show that (i)
an extremal Kerr black hole can not be overspun as a result of the interaction
with massless integer spin test fields (scalar, electromagnetic, or
gravitational), (ii) overspinning can be achieved if we start with a nearly
extremal black hole instead, and (iii) for the scalar field, the argument
applies to more general black holes, and also allows use of a more general
field configuration. Our analysis also neglects radiative and self-force
effects.


title: Towards Combining HTN Planning and Geometric Task Planning

abstract:
  In this paper we present an interface between a symbolic planner and a
geometric task planner, which is different to a standard trajectory planner in
that the former is able to perform geometric reasoning on abstract
entities---tasks. We believe that this approach facilitates a more principled
interface to symbolic planning, while also leaving more room for the geometric
planner to make independent decisions. We show how the two planners could be
interfaced, and how their planning and backtracking could be interleaved. We
also provide insights for a methodology for using the combined system, and
experimental results to use as a benchmark with future extensions to both the
combined system, as well as to the geometric task planner.


title:
Optimization Of Simulations And Activities For A New Introductory
  Quantum Mechanics Curriculum

abstract:
  The Institute of Physics New Quantum Curriculum (quantumphysics.iop.org)
consists of online texts and interactive simulations with accompanying
activities for an introductory course in quantum mechanics starting from
two-level systems. Observation sessions and analysis of homework and survey
responses from in-class trials were used to optimize the simulations and
activities in terms of clarity, ease-of-use, promoting exploration,
sense-making and linking of multiple representations. This work led to
revisions of simulations and activities and general design principles which
have been incorporated wherever applicable. This article describes the
optimization of one of the simulation controls and the refinement of activities
to help students make direct connections between multiple representations.


title: A new introductory quantum mechanics curriculum

abstract:
  The Institute of Physics New Quantum Curriculum consists of freely available
online learning and teaching materials (quantumphysics.iop.org) for a first
course in university quantum mechanics starting from two-level systems. This
approach immediately immerses students in inherently quantum mechanical aspects
by focusing on experiments that have no classical explanation. It allows from
the start a discussion of interpretive aspects of quantum mechanics and quantum
information theory. This article gives an overview of the resources available
at the IOP website. The core text is presented as around 80 articles
co-authored by leading experts that are arranged in themes and can be used
flexibly to provide a range of alternative approaches. Many of the articles
include interactive simulations with accompanying activities and problem sets
that can be explored by students to enhance their understanding. Much of the
linear algebra needed for this approach is part of the resource. Solutions to
activities are available to instructors. The resources can be used in a variety
of ways from supplements to existing courses to a complete programme.


title:
Quantum quench in a p + i p superfluid: Winding numbers and topological
  states far from equilibrium

abstract:
  We study the non-adiabatic dynamics of a 2D p+ip superfluid following a
quantum quench of the BCS coupling constant. The model describes a topological
superconductor with a non-trivial BCS (trivial BEC) phase appearing at weak
(strong) coupling strengths. We extract the exact long-time asymptotics of the
order parameter \Delta(t) by exploiting the integrability of the classical
p-wave Hamiltonian, which we establish via a Lax construction. Three different
types of behavior can occur depending upon the strength and direction of the
quench. In phase I, the order parameter asymptotes to zero. In phase II,
\Delta(t) goes to a non-zero constant. Phase III is characterized by persistent
oscillations of \Delta(t). For quenches within I and II, we determine the
topological character of the asymptotic states. We show that two different
formulations of the bulk topological winding number, although equivalent in the
ground state, must be regarded as independent out of equilibrium. The first
number Q characterizes the Anderson pseudospin texture of the initial state; we
show that it is conserved. For non-zero Q, this leads to the prediction of a
"gapless topological" state when \Delta(t) goes to zero. The presence or
absence of Majorana edge modes in a sample with a boundary is encoded in the
second winding number W, formulated in terms of the retarded Green's function.
We show that W can change following a quench across the quantum critical point.
We discuss the implications for the (dis)appearance of Majorana edge modes.
Finally, we show that the parity of zeros in the bulk out-of-equilibrium Cooper
pair distribution function constitutes a Z2-valued quantum number, which is
non-zero whenever W differs from Q. The pair distribution can in principle be
measured using RF spectroscopy in an ultracold atom realization, allowing
direct experimental detection of the bulk Z2 number.


title: Quantum Entanglement of Interacting Fermions in Monte Carlo

abstract:
  Given a specific interacting quantum Hamiltonian in a general spatial
dimension, can one access its entanglement properties, such as, the
entanglement entropy corresponding to the ground state wavefunction? Even
though progress has been made in addressing this question for interacting
bosons and quantum spins, as yet there exist no corresponding methods for
interacting fermions. Here we show that the entanglement structure of
interacting fermionic Hamiltonians has a particularly simple form -- the
interacting reduced density matrix can be written as a sum of operators that
describe free fermions. This decomposition allows one to calculate the Renyi
entropies for Hamiltonians which can be simulated via Determinantal Quantum
Monte Carlo, while employing the efficient techniques hitherto available only
for free fermion systems. The method presented works for the ground state, as
well as for the thermally averaged reduced density matrix.


title: Inhomogeneous Thermalization in Strongly Coupled Field Theories

abstract:
  To describe theoretically the creation and evolution of the quark-gluon
plasma, one typically employs three ingredients: a model for the initial state,
non-hydrodynamic early time evolution, and hydrodynamics. In this paper we
study the non-hydrodynamic early time evolution using the AdS/CFT
correspondence in the presence of inhomogeneities. We find that the AdS
description of the early time evolution is well-matched by free streaming. Near
the end of the early time interval where our analytic computations are
reliable, the stress tensor agrees with the second order hydrodynamic stress
tensor computed from the local energy density and fluid velocity. Our
techniques may also be useful for the study of far-from-equilibrium strongly
coupled systems in other areas of physics.


title: Axion searches with the EDELWEISS-II experiment

abstract:
  We present new constraints on the couplings of axions and more generic
axion-like particles using data from the EDELWEISS-II experiment. The EDELWEISS
experiment, located at the Underground Laboratory of Modane, primarily aims at
the direct detection of WIMPs using germanium bolometers. It is also sensitive
to the low-energy electron recoils that would be induced by solar or dark
matter axions. Using a total exposure of up to 448 kg.d, we searched for
axion-induced electron recoils down to 2.5 keV within four scenarios involving
different hypotheses on the origin and couplings of axions. We set a 95% CL
limit on the coupling to photons $g_{A\gamma}<2.13\times 10^{-9}$ GeV$^{-1}$ in
a mass range not fully covered by axion helioscopes. We also constrain the
coupling to electrons, $g_{Ae} < 2.56\times 10^{-11}$, similar to the more
indirect solar neutrino bound. Finally we place a limit on $g_{Ae}\times
g_{AN}^{\rm eff}<4.70 \times 10^{-17}$, where $g_{AN}^{\rm eff}$ is the
effective axion-nucleon coupling for $^{57}$Fe. Combining these results we
fully exclude the mass range $0.91\,{\rm eV}<m_A<80$ keV for DFSZ axions and
$5.73\,{\rm eV}<m_A<40$ keV for KSVZ axions.


title: Diophantine properties of nilpotent Lie groups

abstract:
  A finitely generated subgroup {\Gamma} of a real Lie group G is said to be
Diophantine if there is \beta > 0 such that non-trivial elements in the word
ball B_\Gamma(n) centered at the identity never approach the identity of G
closer than |B_{\Gamma} (n)|^{-\beta}. A Lie group G is said to be Diophantine
if for every k > 0, a random k-tuple in G generates a Diophantine subgroup.
Semi-simple Lie groups are conjectured to be Diophantine but very little is
proven in this direction. We give a characterization of Diophantine nilpotent
Lie groups in terms of the ideal of laws of their Lie algebra. In particular we
show that nilpotent Lie groups of class at most 5, or derived length at most 2,
as well as rational nilpotent Lie groups are Diophantine. We also find that
there are non Diophantine nilpotent and solvable (non nilpotent) Lie groups.


title: Zitterbewegung and the Magnetic Moment of the Electron

abstract:
  Zitterbewegung of a Dirac electron is an oscillation between positive and
negative energy states, and is thus distinct from the analogous phenomena
exhibited by spin half charged particles in electric and magnetic fields.
Quantum field theory offers an insight into the velocity operator and provides
an interpretation of zitterbewegung. Applying stationary perturbation theory to
these results the electron $g$ factor is obtained analytically up to the
Schwinger correction ($g = 2 + \alpha/\pi $).


title: Long time non-equilibrium dynamics of binary Bose condensates

abstract:
  We explore the out-of-equilibrium temporal dynamics of demixing and phase
separation in a two dimensional binary Bose fluid at zero temperature,
following a sudden quench across the miscible-immiscible phase boundary. On
short timescales, the system rapidly settles into a steady state characterized
by short-range correlations in the relative density. The subsequent dynamics is
extremely slow: domains of the relative density appear to grow with time,
however, the rate of growth is much slower than that predicted by conventional
theories of phase ordering kinetics. Moreover, we find that the growth dynamics
slows down with increasing time, and is consistent with logarithmic growth. Our
study sheds light on ongoing investigations of how isolated quantum systems
approach equilibrium, and indicates that studying the quantum phase diagram of
the binary Bose fluids following a quench, may be difficult due to
equilibration problems.


title: Higgs and W boson spectrum from lattice simulations

abstract:
  The spectrum of energy levels is computed for all available angular momentum
and parity quantum numbers in the SU(2)-Higgs model, with parameters chosen to
match experimental data from the Higgs-W boson sector of the standard model.
Several multi-boson states are observed, with and without linear momentum, and
all are consistent with weakly-interacting Higgs and W bosons. The creation
operators used in this study are gauge-invariant so, for example, the Higgs
operator is quadratic rather than linear in the Lagrangian's scalar field.


title: Dropout Training as Adaptive Regularization

abstract:
  Dropout and other feature noising schemes control overfitting by artificially
corrupting the training data. For generalized linear models, dropout performs a
form of adaptive regularization. Using this viewpoint, we show that the dropout
regularizer is first-order equivalent to an L2 regularizer applied after
scaling the features by an estimate of the inverse diagonal Fisher information
matrix. We also establish a connection to AdaGrad, an online learning
algorithm, and find that a close relative of AdaGrad operates by repeatedly
solving linear dropout-regularized problems. By casting dropout as
regularization, we develop a natural semi-supervised algorithm that uses
unlabeled data to create a better adaptive regularizer. We apply this idea to
document classification tasks, and show that it consistently boosts the
performance of dropout training, improving on state-of-the-art results on the
IMDB reviews dataset.


title:
Pseudogap in Cuprates and other Metals or How to Almost Elude Bloch's
  Theorem

abstract:
  The loop-current state discovered in under-doped cuprates is characterized by
a vector ${\bf \Omega}$ which has four possible orientations which correspond
to different domains of order in a perfect sample. Since translational symmetry
remains unchanged in the pure limit, no gap occurs at the chemical potential.
On the other hand Scanning tunneling microscopy (STM) has revealed that the
magnitude of the pseudo-gap in under-doped cuprates varies spatially and is
correlated with disorder. For disorder coupling also to the direction of ${\bf
\Omega}$, there can only be a finite temperature dependent static correlation
length for the loop-current state below the ordering temperature of the pure
problem. It is shown that, in this situation, singular forward scattering of
fermions for large correlation lengths induces an angle dependent pseudo-gap in
the single-particle spectral function near the chemical potential. The peaks in
the spectral function at the fermi-vectors are away from the chemical potential
proportionally to the square of the average loop order parameter measurable by
polarized neutron scattering. This result is tested. Due to the finite
correlation length there always exist low frequency excitations at long
wavelength at all temperatures in the "ordered" phase. Such fluctuations
motionally average over the shifts in frequencies of local probes such as NMR
and muon resonance expected for a truly static order.


title: A note on subfactor projections

abstract:
  We extend some results of [BF12] on subfactor projections to show that the
projection of a free factor B to the free factor complex of the free factor A
is well-defined with uniformly bound diameter, unless either A is contained in
B or A and B are vertex stabilizers of a single splitting of F_n, i.e. they are
disjoint. These projections are shown to satisfy properties analogous to
subsurface projections, and we give as an application a construction of fully
irreducible outer automorphisms using the Bounded Geodesic Image Theorem.


title:
Equivalence of quenched and annealed averaging in models of disordered
  polymers

abstract:
  Equivalence of the influence of quenched and annealed disorder on scaling
properties of long flexible polymer chains is proved by analyzing the
O(m)-symmetric field theory in polymer (de Gennes) limit m \to 0. Additional
symmetry properties of the model in this limit are discussed.


title: Curvature inequalities for Lagrangian submanifolds: the final solution

abstract:
  Let $M$ be an $n$-dimensional Lagrangian submanifold of a complex space form.
We prove a pointwise inequality $$\delta(n_1,\ldots,n_k) \leq
a(n,k,n_1,\ldots,n_k) \|H\|^2 + b(n,k,n_1,\ldots,n_k)c,$$ with on the left hand
side any delta-invariant of the Riemannian manifold $M$ and on the right hand
side a linear combination of the squared mean curvature of the immersion and
the constant holomorphic sectional curvature of the ambient space. The
coefficients on the right hand side are optimal in the sence that there exist
non-minimal examples satisfying equality at at least one point. We also
characterize those Lagrangian submanifolds satisfying equality at any of their
points. Our results correct and extend those given in [B.-Y. Chen and F.
Dillen, Optimal general inequalities for Lagrangian submanifolds in complex
space forms, J. Math. Anal. Appl. 379 (2011), 229--239].


title: Efficient Algorithms for Universal Quantum Simulation

abstract:
  A universal quantum simulator would enable efficient simulation of quantum
dynamics by implementing quantum-simulation algorithms on a quantum computer.
Specifically the quantum simulator would efficiently generate qubit-string
states that closely approximate physical states obtained from a broad class of
dynamical evolutions. I provide an overview of theoretical research into
universal quantum simulators and the strategies for minimizing computational
space and time costs. Applications to simulating many-body quantum simulation
and solving linear equations are discussed.


title:
Modular organization of cancer signaling networks is associated with
  patient survivability

abstract:
  Molecular signaling networks are believed to determine cancer robustness.
Although cancer patient survivability was reported to correlate with the
heterogeneous connectivity of the signaling networks inspired by theoretical
studies on the increase of network robustness due to the heterogeneous
connectivity, other theoretical and data analytic studies suggest an
alternative explanation: the impact of modular organization of networks on
biological robustness or adaptation to changing environments. In this study,
thus, we evaluate whether the modularity--robustness hypothesis is applicable
to cancer using network analysis. We focus on 14 specific cancer types whose
molecular signaling networks are available in databases, and show that modular
organization of cancer signaling networks is associated with the patient
survival rate. In particular, the cancers with less modular signaling networks
are more curable. This result is consistent with a prediction from the
modularity--robustness hypothesis. Furthermore, we show that the network
modularity is a better descriptor of the patient survival rate than the
heterogeneous connectivity. However, these results do not contradict the
importance of the heterogeneous connectivity. Rather, they provide new and
different insights into the relationship between cellular networks and cancer
behaviors. Despite several limitations of data analysis, these findings enhance
our understanding of adaptive and evolutionary mechanisms of cancer cells.


title: *-transforms of acyclic complexes

abstract:
  Let R be an n-dimensional Cohen-Macaulay local ring and Q a parameter ideal
of R. Suppose that an acyclic complex (F_{\bullet}, \varphi_{\bullet}) of
length n of finitely generated free R-modules is given. We put M = Im
\varphi_{1}, which is an R-submodule of F_{0}. Then F_{\bullet} is an R-free
resolution of F_{0}/M. In this paper, we describe a concrete procedure to get
an acyclic complex of length n that resolves F_{0}/(M : Q).


title: Heavy tailed time series with extremal independence

abstract:
  We consider strictly stationary heavy tailed time series whose
finite-dimensional exponent measures are concentrated on axes, and hence their
extremal properties cannot be tackled using classical multivariate regular
variation that is suitable for time series with extremal dependence. We recover
relevant information about limiting behavior of time series with extremal
independence by introducing a sequence of scaling functions and conditional
scaling exponent. Both quantities provide more information about joint extremes
than a widely used tail dependence coefficient. We calculate the scaling
functions and the scaling exponent for variety of models, including Markov
chains, exponential autoregressive model, stochastic volatility with heavy
tailed innovations or volatility.


title:
Spectral dualities in XXZ spin chains and five dimensional gauge
  theories

abstract:
  Motivated by recent progress in the study of supersymmetric gauge theories we
propose a very compact formulation of spectral duality between XXZ spin chains.
The action of the quantum duality is given by the Fourier transform in the
spectral parameter. We investigate the duality in various limits and, in
particular, prove it for q-->1, i.e. when it reduces to the XXX/Gaudin duality.
We also show that the universal difference operators are given by the normal
ordering of the classical spectral curves.


title: On Optimized Feedback Control and the Robustification of Opimal Controls

abstract:
  We consider a system that is exactly controllable. For given initial state,
terminal state and objective function, an optimal control is often
well-defined. Such an optimal control has the disadvantage that although it
works perfectly well for the given initial state, for a perturbed initial state
it often does not make sense. In this talk we present a concept to obtain
robust control schemes by the combination of the optimal control with a
stabilizing feedback law. In this way, also for perturbed initial states the
system is controlled in a reasonable way. In the talk we focus on the boundary
control of the wave equation. However, our concept is applicable to the control
of general time-dependent systems.


title: Bag vs. NJL models for color-flavor-locked strange quark matter

abstract:
  We compare the mass-radius relationship of strange stars obtained in two
theoretical frameworks describing the color-flavor-locking state of dense quark
matter: The semi-empirical MIT model and a self-consistent approach using the
Nambu-Jona-Lasinio (NJL) model. In the simplest MIT model extended to include
pairing, one can make the equation of state stiffer by increasing the gap
parameter so that larger maximum masses for these objects can be reached. In
the NJL model, however, such an effect is not possible. To increase the gap
parameter within the NJL model to values comparable to those considered in the
MIT case, a noticeably increase of the diquark-coupling-constant strength is
needed, but this in turn softens the equation of state producing a lower
maximum star mass. This behaviour is interpreted as signalling the system
crossover at high diquark coupling from a BCS regime to a BEC one, a process
that cannot be reproduced within the simple MIT prescription.


title: Equidistribution of digits in powers and Diophantine approximations

abstract:
  Given integers $a,b>1$ with $\log_b{a}$ irrational, we investigate the
connection between the conjectured asymptotic equidistribution of digits in the
base-$b$ expansion of $a^n$ and the (non-)Diophantine properties of the number
$\theta_{a,b}=\log_b{a}$.


title:
Generation of parabolic similaritons in tapered silicon photonic wires:
  comparison of pulse dynamics at telecom and mid-IR wavelengths

abstract:
  We study the generation of parabolic self-similar optical pulses in tapered
Si photonic nanowires (Si-PhNWs) both at telecom (\lambda=1.55 \mu m) and
mid-IR (\lambda=2.2 \mu m) wavelengths. Our computational study is based on a
rigorous theoretical model, which fully describes the influence of linear and
nonlinear optical effects on pulse propagation in Si-PhNWs with arbitrarily
varying width. Numerical simulations demonstrate that, in the normal dispersion
regime, optical pulses evolve naturally into parabolic pulses upon propagating
in millimeter-long tapered Si-PhNWs, with the efficiency of this pulse
reshaping process being strongly dependent on the spectral and pulse parameter
regime in which the device operates, as well as the particular shape of the
Si-PhNW.


title:
Uncoupled achromatic condition of a dog-leg system with the presence of
  RF cavities

abstract:
  To merge the beam from either of the two injectors to the main linac, a
dog-leg system will be employed in the second Medium Energy Beam Transport
(MEBT2) line of the China ADS driving accelerator. The achromatic condition has
to be guaranteed to avoid beam center excursion against energy jitter. RF
cavities were found indispensable to control the bunch length growth in the
dog-leg system of MEBT2. The full uncoupling between transverse and
longitudinal plane is desired to minimize the growth of projected rms
emittances. The uncoupled achromatic condition of this dogleg system with the
presence of RF bunching cavities will be deduced using the method of transfer
matrixes. It is found that to fulfil the uncoupling condition, the distance
between the bunching cavities is uniquely determined by the maximum energy gain
of the RF cavities. The theoretical analysis is verified by the simulation code
TraceWin. The space charge effect on the uncoupled achromatic condition and the
beam emittance growth will also be discussed.


title:
Multiple-Level Power Allocation Strategy for Secondary Users in
  Cognitive Radio Networks

abstract:
  In this paper, we propose a multiple-level power allocation strategy for the
secondary user (SU) in cognitive radio (CR) networks. Different from the
conventional strategies, where SU either stays silent or transmit with a
constant/binary power depending on the busy/idle status of the primary user
(PU), the proposed strategy allows SU to choose different power levels
according to a carefully designed function of the receiving energy. The way of
the power level selection is optimized to maximize the achievable rate of SU
under the constraints of average transmit power at SU and average interference
power at PU. Simulation results demonstrate that the proposed strategy can
significantly improve the performance of SU compared to the conventional
strategies.


title: Magnetic properties of the nucleon in a uniform background field

abstract:
  We present results for the magnetic moment and magnetic polarisability of the
neutron and the magnetic moment of the proton. These results are calculated
using the uniform background field method on 32^3 x 64 dynamical QCD lattices
provided by the PACS-CS collaboration as part of the ILDG. We use a uniform
background magnetic field quantised by the periodic spatial volume. We
investigate ways to improve the effective energy plots used to calculate
magnetic polarisabilities, including the use of correlation matrix techniques
with various source smearings.


title: A Reference for the Gravitational Hamiltonian Boundary Term

abstract:
  The Hamiltonian for physical systems and dynamic geometry generates the
evolution of a spatial region along a vector field. It includes a boundary term
which not only determines the value of the Hamiltonian, but also, via the
boundary term in the variation of the Hamiltonian, the boundary conditions. The
value of the Hamiltonian comes from its boundary term; it gives the quasi-local
quantities: energy-momentum and angular-momentum/center-of-mass. This boundary
term depends not only on the dynamical variables but also on their reference
values; these reference values determine the ground state---the state having
vanishing quasi-local quantities. Here our concern is how to select on the
two-boundary the reference values. To determine the "best matched" reference
metric and connection values for our preferred boundary term for Einstein's
general relativity, we propose on the boundary two-surface (i) \emph{four
dimensional} isometric matching, and (ii) extremizing the value of the energy.


title:
Weak convergence of a fully discrete approximation of a linear
  stochastic evolution equation with a positive-type memory term

abstract:
  In this paper we are interested in the numerical approximation of the
marginal distributions of the Hilbert space valued solution of a stochastic
Volterra equation driven by an additive Gaussian noise. This equation can be
written in the abstract It\^o form as $$ \dd X(t) + \left (\int_0^t b(t-s) A
X(s) \, \dd s \right) \, \dd t = \dd W^{_Q}(t), t\in (0,T]; ~ X(0) =X_0\in H,
$$ \noindent where $W^Q$ is a $Q$-Wiener process on the Hilbert space $H$ and
where the time kernel $b$ is the locally integrable potential $t^{\rho-2}$,
$\rho \in (1,2)$, or slightly more general. The operator $A$ is unbounded,
linear, self-adjoint, and positive on $H$. Our main assumption concerning the
noise term is that $A^{(\nu- 1/\rho)/2} Q^{1/2}$ is a Hilbert-Schmidt operator
on $H$ for some $\nu \in [0,1/\rho]$. The numerical approximation is achieved
via a standard continuous finite element method in space (parameter $h$) and an
implicit Euler scheme and a Laplace convolution quadrature in time (parameter
$\Delta t=T/N$). %Let $X_h^N$ be the discrete solution at time $T$. Eventually
let $\varphi : H\rightarrow \R$ is such that $D^2\varphi$ is bounded on $H$ but
not necessarily bounded and suppose in addition that either its first
derivative is bounded on $H$ and $X_0 \in L^1(\Omega)$ or $\varphi = \| \cdot
\|^2$ and $X_0 \in L^2(\Omega)$. We show that for $\varphi : H\rightarrow \R$
twice continuously differentiable test function with bounded second derivative,
$$ | \E \varphi(X^N_h) - \E \varphi(X(T)) | \leq C \ln
\left(\frac{T}{h^{2/\rho} + \Delta t} \right) (\Delta t^{\rho \nu} + h^{2\nu}),
$$ \noindent for any $0\leq \nu \leq 1/\rho$. This is essentially twice the
rate of strong convergence under the same regularity assumption on the noise.


title: A survey on Geometry of Slant Submanifolds

abstract:
  The present volume is the written version of the series of lectures the
author delivered at the Catholic University of Leuven, Belgium during the
period of June-July, 1990. The main purpose of these talks is to present some
of author's work and also his joint works with Professor T. Nagano and
Professor Y. Tazawa of Japan, Professor P. F. Leung of Singapore and Professor
J. M. Morvan of France on geometry of slant submanifolds and its related
subjects in a systematical way.


title: Symplectic Cohomology and the Stability of J-Anti-Invariant Cohomology

abstract:
  In this paper, we investigate the relationship between J-anti-invariant
cohomology of a closed symplectic 4-manifold introduced by T.-J. Li and W.
Zhang and new symplectic cohomologies introduced by L.-S. Tseng and S.-T. Yau.
We also prove that the dimension of J-anti-invariant cohomology is constant for
almost structures J which are compatible with a fixed symplectic form.


title: Network-Coded Multiple Access

abstract:
  This paper proposes and experimentally demonstrates a first wireless local
area network (WLAN) system that jointly exploits physical-layer network coding
(PNC) and multiuser decoding (MUD) to boost system throughput. We refer to this
multiple access mode as Network-Coded Multiple Access (NCMA). Prior studies on
PNC mostly focused on relay networks. NCMA is the first realized multiple
access scheme that establishes the usefulness of PNC in a non-relay setting.
NCMA allows multiple nodes to transmit simultaneously to the access point (AP)
to boost throughput. In the non-relay setting, when two nodes A and B transmit
to the AP simultaneously, the AP aims to obtain both packet A and packet B
rather than their network-coded packet. An interesting question is whether
network coding, specifically PNC which extracts packet (A XOR B), can still be
useful in such a setting. We provide an affirmative answer to this question
with a novel two-layer decoding approach amenable to real-time implementation.
Our USRP prototype indicates that NCMA can boost throughput by 100% in the
medium-high SNR regime (>=10dB). We believe further throughput enhancement is
possible by allowing more than two users to transmit together.


title: Laplace Transformations of Submanifolds

abstract:
  Let $x : M \to E^m$ be an isometric immersion of a Riemannian manifold $M$
into a Euclidean $m$-space. Denote by $\Delta$ the Laplace operator of $M$.
Then $\Delta$ gives rise to a differentiable map $L :M \to E^m$, called the
Laplace map, defined by $L(p)=(\Delta x)(p)$, $p\in M$. We call $L(M)$ the
Laplace image, and the transformation $L :M \to L(M)$ from $M$ onto its Laplace
image $L(M)$ the {\it Laplace transformation}. In this monograph, we provide a
fundamental study of the Laplace transformations of Euclidean submanifolds.


title:
Dynamic Decremental Approximate Distance Oracles with $(1+\epsilon, 2)$
  stretch

abstract:
  We provide a decremental approximate Distance Oracle that obtains stretch of
$1+\epsilon$ multiplicative and 2 additive and has $\hat{O}(n^{5/2})$ total
cost (where $\hat{O}$ notation suppresses polylogarithmic and
$n^{O(1)/\sqrt{n}}$ factors). The best previous results with $\hat{O}(n^{5/2})$
total cost obtained stretch $3+\epsilon$.


title:
Perform wordcount Map-Reduce Job in Single Node Apache Hadoop cluster
  and compress data using Lempel-Ziv-Oberhumer (LZO) algorithm

abstract:
  Applications like Yahoo, Facebook, Twitter have huge data which has to be
stored and retrieved as per client access. This huge data storage requires huge
database leading to increase in physical storage and becomes complex for
analysis required in business growth. This storage capacity can be reduced and
distributed processing of huge data can be done using Apache Hadoop which uses
Map-reduce algorithm and combines the repeating data so that entire data is
stored in reduced format. The paper describes performing a wordcount Map-Reduce
Job in Single Node Apache Hadoop cluster and compress data using
Lempel-Ziv-Oberhumer (LZO) algorithm.


title: Phase Separation in Soft Matter: Concept of Dynamic Asymmetry

abstract:
  Phase separation is a fundamental phenomenon that produces spatially
heterogeneous patterns in soft matter. In this Lecture Note we show that phase
separation in these materials generally belongs to what we call "viscoelastic
phase separation", where the morphology is determined by the mechanical balance
of not only the thermodynamic force (interface tension) but also the
viscoelastic force. The origin of the viscoelastic force is dynamic asymmetry
between the components of a mixture, which can be caused by either a size
disparity or a difference in the glass transition temperature between the
components. We stress that such dynamic asymmetry generally exists in soft
matter. The key is that dynamical asymmetry leads to a non-trivial coupling
between the concentration, velocity, and stress fields. Viscoelastic phase
separation can be explained by viscoelastic relaxation in pattern evolution and
the resulting switching of the relevant order parameter, which are induced by
the competition between the deformation rate of phase separation and the
slowest mechanical relaxation rate of a system. We also discuss an intimate
link of viscoelastic phase separation, where deformation fields are
spontaneously generated by phase separation itself, to mechanical instability
(or fracture) of glassy material, which is induced by externally imposed strain
fields. We propose that all these phenomena can be understood as
mechanically-driven inhomogeneization in a unified manner.

categories: cond-mat.soft cond-mat.mtrl-sci cond-mat.stat-mech physics.chem-ph


title: Negative magnetostrictive magnetoelectric coupling of BiFeO3

abstract:
  How the magnetoelectric coupling actually occurs on a microscopic level in
multiferroic BiFeO3 is not well known. By using the high-resolution single
crystal neutron diffraction techniques, we have determined the electric
polarization of each individual elements of BiFeO3, and concluded that the
magnetostrictive coupling suppresses the electric polarization at the Fe site
below TN. This negative magnetoelectric coupling appears to outweigh the spin
current contributions arising from the cycloid spin structure, which should
produce a positive magnetoelectric coupling.


title: Towards a characterization of fields leading to black hole hair

abstract:
  In the present work, it is shown that an asymptotically flat spherical black
hole can have a nontrivial signature of any field for an exterior observer if
the energy momentum tensor of the corresponding field is either tracefree or if
the trace falls off at least as rapidly as inverse cube of the radial distance.
In the absence of a general No Hair Theorem, this result can provide a
characterization of the fields leading to black hole hair.


title: The maximal order of Stern's diatomic sequence

abstract:
  We answer a question of Calkin and Wilf concerning the maximal order of
Stern's diatomic sequence. Specifically, we prove that
$$\limsup_{n\to\infty}\frac{a(n)}{\varphi^{\log_2 n}}=\frac{\varphi^{\log_2
3}}{\sqrt{5}},$$ where $\varphi=(\sqrt{5}+1)/2$ is the golden ratio. This
improves on previous results given by Berlekamp, Conway, and Guy, who showed
that the limit value was bounded above by 1.25, and by Calkin and Wilf, who
showed that the exact value was in the interval
$[({\varphi}/{\sqrt{5}})({3}/{2})^{\log_2\varphi},(\varphi+1)/{\sqrt{5}}].$


title:
Global symmetries in tensor network states: symmetric tensors versus
  minimal bond dimension

abstract:
  Tensor networks offer a variational formalism to efficiently represent
wave-functions of extended quantum many-body systems on a lattice. In a tensor
network N, the dimension \chi of the bond indices that connect its tensors
controls the number of variational parameters and associated computational
costs. In the absence of any symmetry, the minimal bond dimension \chi^{min}
required to represent a given many-body wave-function |\Psi> leads to the most
compact, computationally efficient tensor network description of |\Psi>. In the
presence of a global, on-site symmetry, one can use a tensor network N_{sym}
made of symmetric tensors. Symmetric tensors allow to exactly preserve the
symmetry and to target specific quantum numbers, while their sparse structure
leads to a compact description and lowers computational costs. In this paper we
explore the trade-off between using a tensor network N with minimal bond
dimension \chi^{min} and a tensor network N_{sym} made of symmetric tensors,
where the minimal bond dimension \chi^{min}_{sym} might be larger than
\chi^{min}. We present two technical results. First, we show that in a tree
tensor network, which is the most general tensor network without loops, the
minimal bond dimension can always be achieved with symmetric tensors, so that
\chi^{min}_{sym} = \chi^{min}. Second, we provide explicit examples of tensor
networks with loops where replacing tensors with symmetric ones necessarily
increases the bond dimension, so that \chi_{sym}^{min} > \chi^{min}. We further
argue, however, that in some situations there are important conceptual reasons
to prefer a tensor network representation with symmetric tensors (and possibly
larger bond dimension) over one with minimal bond dimension.


title: Optimal multi-photon phase sensing with a single interference fringe

abstract:
  Quantum entanglement can help to increase the precision of optical phase
measurements beyond the shot noise limit (SNL) to the ultimate Heisenberg
limit. However, the N-photon parity measurements required to achieve this
optimal sensitivity are extremely difficult to realize with current photon
detection technologies, requiring high-fidelity resolution of N+1 different
photon distributions between the output ports. Recent experimental
demonstrations of precision beyond the SNL have therefore used only one or two
photon-number detection patterns instead of parity measurements. Here we
investigate the achievable phase sensitivity of the simple and efficient single
interference fringe detection technique. We show that the maximally-entangled
"NOON" state does not achieve optimal phase sensitivity when N > 4, rather, we
show that the Holland-Burnett state is optimal. We experimentally demonstrate
this enhanced sensitivity using a single photon-counted fringe of the
six-photon Holland-Burnett state. Specifically, our single-fringe six-photon
measurement achieves a phase variance three times below the SNL.


title: Fundamentals of Heterogeneous Cellular Networks with Energy Harvesting

abstract:
  We develop a new tractable model for K-tier heterogeneous cellular networks
(HetNets), where each base station (BS) is powered solely by a self-contained
energy harvesting module. The BSs across tiers differ in terms of the energy
harvesting rate, energy storage capacity, transmit power and deployment
density. Since a BS may not always have enough energy, it may need to be kept
OFF and allowed to recharge while nearby users are served by neighboring BSs
that are ON. We show that the fraction of time a k^{th} tier BS can be kept ON,
termed availability \rho_k, is a fundamental metric of interest. Using tools
from random walk theory, fixed point analysis and stochastic geometry, we
characterize the set of K-tuples (\rho_1, \rho_2, ... \rho_K), termed the
availability region, that is achievable by general uncoordinated operational
strategies, where the decision to toggle the current ON/OFF state of a BS is
taken independently of the other BSs. If the availability vector corresponding
to the optimal system performance, e.g., in terms of rate, lies in this
availability region, there is no performance loss due to the presence of
unreliable energy sources. As a part of our analysis, we model the temporal
dynamics of the energy level at each BS as a birth-death process, derive the
energy utilization rate, and use hitting/stopping time analysis to prove that
there exists a fundamental limit on \rho_k that cannot be surpassed by any
uncoordinated strategy.


title:
Calculation of the bound states of power-law and logarithmic potentials
  through a generalized pseudospectral method

abstract:
  Bound states of the power-law and logarithmic potentials are calculated using
a generalized pseudospectral method. The solution of the single-particle
Schr\"odinger equation in a nonuniform and optimal spatial discretization
offers accurate eigenvalues, densities and expectation values. The calculations
are carried out for states with arbitrary $n$ and $\ell$ quantum numbers.
Comparisons are made with the available literature data and excellent agreement
is observed. In all the cases, the present method yields considerably improved
results over the other existing calculations. Some new states are reported.


title:
Initial carrier-envelope phase of few-cycle pulses determined by THz
  emission from air plasma

abstract:
  The evolution of THz waveform generated in air plasma provides a sensitive
probe to the variation of the carrier envelope phase (CEP) of propagating
intense few-cycle pulses. Our experimental observation and calculation reveal
that the number and positions of the inversion of THz waveform are dependent on
the initial CEP, which is near 0.5{\pi} constantly under varied input pulse
energies when two inversions of THz waveform in air plasma become one. This
provides a method of measuring the initial CEP in an accuracy that is only
limited by the stability of the driving few-cycle pulses.


title:
A survey of H$_2$O, CO$_2$ and CO ice features towards background stars
  and low mass YSOs using AKARI

abstract:
  We present near infrared spectroscopic observations of 19 molecular clouds
made using the AKARI satellite, and the data reduction pipeline written to
analyse those observations. The 2.5 --~5 $\mu$m spectra of 30 objects -- 22
field stars behind quiescent molecular clouds and eight low mass YSOs in cores
-- were successfully extracted using the pipeline. Those spectra are further
analysed to calculate the column densities of key solid phase molecular
species, including H$_2$O, CO$_2$, CO, and OCN$^-$. The profile of the H$_2$O
ice band is seen to vary across the objects observed and we suggest that the
extended red wing may be an evolutionary indicator of both dust and ice mantle
properties. The observation of 22 spectra with fluxes as low as $<$~5 mJy
towards background stars, including 15 where the column densities of H$_2$O, CO
and CO$_2$ were calculated, provides valuable data that could help to benchmark
the initial conditions in star-forming regions prior to the onset of star
formation.


title:
Proceedings 10th International Workshop On User Interfaces for Theorem
  Provers

abstract:
  This EPTCS volume collects the post-proceedings of the 10th International
Workshop On User Interfaces for Theorem Provers (UITP 2012), held as part of
the Conferences on Intelligent Computer Mathematics (CICM 2012) in Bremen on
July 11th 2012. The UITP workshop series aims at bringing together reasearchers
interested in designing, developing and evaluating interfaces for interactive
proof systems, such as theorem provers, formal method tools, and other tools
manipulating and presenting mathematical formulae. Started in 1995, it can look
back on seventeen years of history by now.
  The papers in the present volume give a good indication of the range of
questions currently addressed in the UITP community; this ranges from interface
design (Windsteiger; Dunchev et al) to using technologies such as machine
learning to assist the user (Komendantskaya et al). The web features
prominently (Tankink), and new technology necessitates changes right down to
the very basic modes of interaction (Wenzel) - the old REPL (read, evaluate,
print, loop) mode of interaction can not take advantage of modern technology,
such as the web and multi-core machines.


title: Covariograms generated by valuations

abstract:
  Let \phi be a real-valued valuation on the family of compact convex subsets
of \mathbb{R}^n and let K be a convex body in \mathbb{R}^n. We introduce the
\phi -covariogram g_{K,\phi} of K as the function associating to each x \in
\mathbb{R}^n the value \phi(K \cap (K+x)). If \phi is the volume, then
g_{K,\phi} is the covariogram, extensively studied in various sources. When
\phi is a quermassintegral (e.g., surface area or mean width) g_{K,\phi} has
been introduced by Nagel.
  We study various properties of \phi -covariograms, mostly in the case n=2 and
under the assumption that \phi is translation invariant, monotone and even. We
also consider the generalization of Matheron's covariogram problem to the case
of \phi -covariograms, that is, the problem of determining an unknown convex
body K, up to translations and point reflections, by the knowledge of
g_{K,\phi}. A positive solution to this problem is provided under different
assumptions, including the case that K is a polygon and \phi is either strictly
monotone or \phi is the width in a given direction. We prove that there are
examples in every dimension n\geq3 where K is determined by its covariogram but
it is not determined by its width-covariogram. We also present some consequence
of this study in stochastic geometry.


title: Nonclassicality in two-mode BEC

abstract:
  An analytic operator solution of a generalized quantum mechanical Hamiltonian
of two-mode Bose Einstein condensates (BECs) is obtained and the same is used
to investigate the nonclassical properties of the modes present in the system.
Nonclassical characters are observed by means of single mode and intermodal
squeezing, single mode and intermodal sub-Poissonian boson statistics and
intermodal entanglement. In addition to the traditionally studied lower order
nonclassical properties, signatures of higher order nonclassical characters of
two-mode BEC systems are also obtained by investigating the possibility of
higher order antibunching and higher order entanglement. The mutual relation
among the observed nonclassicalities and their evolution (variation) with
rescaled time and the ratio of the single boson tunneling amplitude
($\varepsilon$) and the coupling constant for the intra-modal interaction
($\kappa$) are also reported.


title: Three-dimensional symmetry breaking topological matters

abstract:
  We discuss topological electronic states described by the Dirac Hamiltonian
plus an additional one in three-dimension. When the additional Hamiltonian is
an element of an Abelian group, electronic states become topologically
nontrivial even in the absence of fundamental symmetries such as the
time-reversal and the particle-hole symmety. The symmetry-breaking topological
states are charercterized by the Chern number defined in the two-dimensional
partial Brillouin zone. The topological insulators under Zeeman field are an
example of the symmetry-breaking topological matters. We show the transision
from the topological insulating phase to the topological semimetal one under
the strong Zeeman field.


title: Delay performance in random-access grid networks

abstract:
  We examine the impact of torpid mixing and meta-stability issues on the delay
performance in wireless random-access networks. Focusing on regular meshes as
prototypical scenarios, we show that the mean delays in an $L\times L$ toric
grid with normalized load $\rho$ are of the order $(\frac{1}{1-\rho})^L$. This
superlinear delay scaling is to be contrasted with the usual linear growth of
the order $\frac{1}{1-\rho}$ in conventional queueing networks. The intuitive
explanation for the poor delay characteristics is that (i) high load requires a
high activity factor, (ii) a high activity factor implies extremely slow
transitions between dominant activity states, and (iii) slow transitions cause
starvation and hence excessively long queues and delays. Our proof method
combines both renewal and conductance arguments. A critical ingredient in
quantifying the long transition times is the derivation of the communication
height of the uniformized Markov chain associated with the activity process. We
also discuss connections with Glauber dynamics, conductance and mixing times.
Our proof framework can be applied to other topologies as well, and is also
relevant for the hard-core model in statistical physics and the sampling from
independent sets using single-site update Markov chains.


title:
Control of high power pulse extracted from the maximally compressed
  pulse in a nonlinear optical fiber

abstract:
  We address the possibility to control high power pulses extracted from the
maximally compressed pulse in a nonlinear optical fiber by adjusting the
initial excitation parameters. The numerical results show that the power,
location and splitting order number of the maximally compressed pulse and the
transmission features of high power pulses extracted from the maximally
compressed pulse can be manipulated through adjusting the modulation amplitude,
width, and phase of the initial Gaussian-type perturbation pulse on a
continuous wave background.


title: High power pulses extracted from the Peregrine rogue wave

abstract:
  We address the various initial excitations of the Peregrine rogue wave and
establish a robust transmission scheme of high power pulses extracted from the
Peregrine rogue wave in a standard telecommunications fiber. The results show
that the Peregrine rogue wave can be excited by using a weak pulse atop a
continuous wave background and that the high power pulses extracted from the
Peregrine rogue wave exhibit the typical characteristics of breathing solitons.
The influence of higher-order effects, such as the third-order dispersion, the
self-steepening and the Raman effect, on the propagation of the pulse extracted
from the peak position and the interaction between neighboring high power
pulses induced by initial perturbations are also investigated.


title:
Spin liquid phase due to competing classical orders in the semiclassical
  theory of the Heisenberg model with ring exchange on an anisotropic
  triangular lattice

abstract:
  Linear spin wave theory shows that ring exchange induces a quantum disordered
region in the phase diagram of the title model. Spin wave spectra show that
this is a direct manifestation of competing classical orders. A spin liquid is
found in the `Goldilocks zone' of frustration, where the quantum fluctuations
are large enough to cause strong competition between different classical
orderings but not strong enough to stabilize spiral order. We note that the
spin liquid phases of $\kappa$-(BEDT-TTF)${_2}X$ and $Y$[Pd(dmit)$_2$]$_2$ are
found in this Goldilocks zone.


title:
Validity of rotating wave approximation in non-adiabatic holonomic
  quantum computation

abstract:
  We examine the validity of the rotating wave approximation (RWA) in
non-adiabatic holonomic single-qubit gates [New J. Phys. {\bf 14}, 103035
(2012)]. We demonstrate that the adoption of RWA may lead to a sharp decline in
fidelity for rapid gate implementation and small energy separation between the
excited and computational states. The validity of the RWA in the recent
experimental realization [Nature (London) {\bf 496}, 482 (2013)] of
non-adiabatic holonomic quantum computation for a superconducting qubit is
examined.


title:
Optimal Power Allocation and User Loading for Multiuser MISO Channels
  with Regularized Channel Inversion

abstract:
  We consider a multiuser system where a single transmitter equipped with
multiple antennas (the base station) communicates with multiple users each with
a single antenna. Regularized channel inversion is employed as the precoding
strategy at the base station. Within this scenario we are interested in the
problems of power allocation and user admission control so as to maximize the
system throughput, i.e., which users should we communicate with and what power
should we use for each of the admitted users so as to get the highest sum rate.
This is in general a very difficult problem but we do two things to allow some
progress to be made. Firstly we consider the large system regime where the
number of antennas at the base station is large along with the number of users.
Secondly we cluster the downlink path gains of users into a finite number of
groups. By doing this we are able to show that the optimal power allocation
under an average transmit power constraint follows the well-known water filling
scheme. We also investigate the user admission problem which reduces in the
large system regime to optimization of the user loading in the system.


title: Decay and fragmentation in an open Bose-Hubbard chain

abstract:
  We analyze the decay of ultracold atoms from an optical lattice with loss
form a single lattice site. If the initial state is dynamically stable a
suitable amount of dissipation can stabilize a Bose-Einstein condensate, such
that it remains coherent even in the presence of strong interactions. A
transition between two different dynamical phases is observed if the initial
state is dynamically unstable. This transition is analyzed here in detail. For
strong interactions, the system relaxes to an entangled quantum state with
remarkable statistical properties: The atoms bunch in a few "breathers" forming
at random positions. Breathers at different positions are coherent, such that
they can be used in precision quantum interferometry and other applications.


title:
Inverse problems and invisibility cloaking for FEM models and resistor
  networks

abstract:
  In this paper we consider inverse problems for resistor networks and for
models obtained via the Finite Element Method (FEM) for the conductivity
equation. These correspond to discrete versions of the inverse conductivity
problem of Calder\'on. We characterize FEM models corresponding to a given
triangulation of the domain that are equivalent to certain resistor networks,
and apply the results to study nonuniqueness of the discrete inverse problem.
It turns out that the degree of nonuniqueness for the discrete problem is
larger than the one for the partial differential equation. We also study
invisibility cloaking for FEM models, and show how an arbitrary body can be
surrounded with a layer so that the cloaked body has the same boundary
measurements as a given background medium.


title: On a new Bell test with photons seemingly violating quantum predictions

abstract:
  A disagreement of the empirical results with quantum mechanical predictions
is pointed out in the experiment by B. G. Christensen et al. The anomaly is
quite similar to one present in the analogous experiment by M. Giustina et al.
[arXiv:1306.5772].


title: Particle-hole entanglement of ultracold atoms in an optical lattice

abstract:
  We study the ground state of two-component bosonic atoms in a one-dimensional
optical lattice. By applying an external field to the atoms at one end of
lattice, the atoms are transported and becomes localized at that site. The
holes are then created in the remaining sites. The particle-hole superpositions
are produced in this process. We investigate the entanglement entropy between
the atoms in the two different parts of a lattice. A large degree of
particle-hole entanglement is generated in the ground state. The particle-hole
quantum correlations can be probed by the two-site parity correlation
functions. The transport properties of the low-lying excited states are also
discussed.


title:
DOBBS: Towards a Comprehensive Dataset to Study the Browsing Behavior of
  Online Users

abstract:
  The investigation of the browsing behavior of users provides useful
information to optimize web site design, web browser design, search engines
offerings, and online advertisement. This has been a topic of active research
since the Web started and a large body of work exists. However, new online
services as well as advances in Web and mobile technologies clearly changed the
meaning behind "browsing the Web" and require a fresh look at the problem and
research, specifically in respect to whether the used models are still
appropriate. Platforms such as YouTube, Netflix or last.fm have started to
replace the traditional media channels (cinema, television, radio) and media
distribution formats (CD, DVD, Blu-ray). Social networks (e.g., Facebook) and
platforms for browser games attracted whole new, particularly less tech-savvy
audiences. Furthermore, advances in mobile technologies and devices made
browsing "on-the-move" the norm and changed the user behavior as in the mobile
case browsing is often being influenced by the user's location and context in
the physical world. Commonly used datasets, such as web server access logs or
search engines transaction logs, are inherently not capable of capturing the
browsing behavior of users in all these facets. DOBBS (DERI Online Behavior
Study) is an effort to create such a dataset in a non-intrusive, completely
anonymous and privacy-preserving way. To this end, DOBBS provides a browser
add-on that users can install, which keeps track of their browsing behavior
(e.g., how much time they spent on the Web, how long they stay on a website,
how often they visit a website, how they use their browser, etc.). In this
paper, we outline the motivation behind DOBBS, describe the add-on and captured
data in detail, and present some first results to highlight the strengths of
DOBBS.