title:
The statistical mechanics of random set packing and a generalization of
  the Karp-Sipser algorithm

abstract:
  We analyse the asymptotic behaviour of random instances of the Maximum Set
Packing (MSP) optimization problem, also known as Maximum Matching or Maximum
Strong Independent Set on Hypergraphs. We give an analytical prediction of the
MSPs size using the 1RSB cavity method from statistical mechanics of disordered
systems. We also propose a heuristic algorithm, a generalization of the
celebrated Karp-Sipser one, which allows us to rigorously prove that the
replica symmetric cavity method prediction is exact for certain problem
ensembles and breaks down when a core survives the leaf removal process. The
$e$-phenomena threshold discovered by Karp and Sipser, marking the onset of
core emergence and of replica symmetry breaking, is elegantly generalized to
$c_s = \frac{e}{d-1}$ for one of the ensembles considered, where $d$ is the
size of the sets.


title:
Lower Bounds on the Sizes of Integer Programs Without Additional
  Variables

abstract:
  Let X be the set of integer points in some polyhedron. We investigate the
smallest number of facets of any polyhedron whose set of integer points is X.
This quantity, which we call the relaxation complexity of X, corresponds to the
smallest number of linear inequalities of any integer program having X as the
set of feasible solutions that does not use auxiliary variables. We show that
the use of auxiliary variables is essential for constructing polynomial size
integer programming formulations in many relevant cases. In particular, we
provide asymptotically tight exponential lower bounds on the relaxation
complexity of the integer points of several well-known combinatorial polytopes,
including the traveling salesman polytope and the spanning tree polytope.


title: Scaling laws and the rate of convergence in thin magnetic films

abstract:
  We study static 180 degree domain walls in thin infinite magnetic films. We
establish the scaling of the minimal energy by {\Gamma}-convergence and the
energy minimizer pro-file, which turns out to be the so called transverse wall
as predicted in earlier numerical and experimental work. Surprisingly, the
minimal energy decays faster than the area of the film cross section at an
infinitesimal cross section diameter. We establish a rate of convergence of the
rescaled energies as well.


title: Compressive Nonparametric Graphical Model Selection For Time Series

abstract:
  We propose a method for inferring the conditional indepen- dence graph (CIG)
of a high-dimensional discrete-time Gaus- sian vector random process from
finite-length observations. Our approach does not rely on a parametric model
(such as, e.g., an autoregressive model) for the vector random process; rather,
it only assumes certain spectral smoothness proper- ties. The proposed
inference scheme is compressive in that it works for sample sizes that are
(much) smaller than the number of scalar process components. We provide
analytical conditions for our method to correctly identify the CIG with high
probability.


title:
Generalized Kac-Moody Lie algebras, free Lie algebras and the structure
  of the Monster Lie algebra

abstract:
  It is shown that any generalized Kac-Moody Lie algebra g that has no mutually
orthogonal imaginary simple roots can be written as the vector space direct sum
of a Kac-Moody subalgebra and subalgebras isomorphic to free Lie algebras over
certain modules for the Kac-Moody subalgebra. Also included is a detailed
discussion of Borcherds' construction of the Monster Lie algebra from a vertex
algebra and an elementary proof of Borcherds' theorem relating Lie algebras
with `an almost positive definite bilinear form' to generalized Kac-Moody
algebras. (Preprint version 1996)


title: Parafermions in Interacting Nanowire Bundle

abstract:
  We propose a scheme to induce $\mathbb{Z}_3$ parafermion modes, exotic
zero-energy bound states that possess non-Abelian statistics. We consider a
minimal setup consisting of a bundle of four tunnel coupled nanowires hosting
spinless electrons that interact strongly with each other. The hallmark of our
setup is that it relies only on simple one-dimensional wires, uniform magnetic
fields, and strong interactions, but does not require the presence of
superconductivity or exotic quantum Hall phases.


title:
Black hole mass estimates and emission-line properties of a sample of
  redshift z>6.5 quasars

abstract:
  We present the analysis of optical and near-infrared spectra of the only four
$z>6.5$ quasars known to date, discovered in the UKIDSS-LAS and VISTA-VIKING
surveys. Our data-set consists of new VLT/X-Shooter and Magellan/FIRE
observations. These are the best optical/NIR spectroscopic data that are likely
to be obtained for the $z>6.5$ sample using current $6$ - $10$ m facilities. We
estimate the black hole mass, the Eddington ratio, and the SiIV/CIV, CIII]/CIV,
and FeII/MgII emission-line flux ratios. We perform spectral modeling using a
procedure that allows us to derive a probability distribution for the continuum
components and to obtain the quasar properties weighted upon the underlying
distribution of continuum models. The $z>6.5$ quasars show the same emission
properties as their counterparts at lower redshifts. The $z>6.5$ quasars host
black holes with masses of $\sim 10^9$ M$_{\odot}$ that are accreting close to
the Eddington luminosity ($\langle{\rm log} (L_{\rm Bol}/L_{\rm Edd})\rangle=
-0.4\pm0.2$), in agreement with what has been observed for a sample of
$4.0<z<6.5$ quasars. By comparing the SiIV/CIV and CIII]/CIV flux ratios with
the results obtained from luminosity-matched samples at $z\sim6$ and $2\leq
z\leq4.5$, we find no evidence of evolution of the line ratios with cosmic
time. We compare the measured FeII/MgII flux ratios with those obtained for a
sample of $4.0<z<6.4$ sources. The two samples are analyzed using a consistent
procedure. There is no evidence that the FeII/MgII flux ratio evolves between
$z=7$ and $z=4$. Under the assumption that the FeII/MgII traces the Fe/Mg
abundance ratio, this implies the presence of major episodes of chemical
enrichment in the quasar hosts in the first $\sim0.8$ Gyr after the Big Bang.


title: Experimental Design for Dynamics Identification of Cellular Processes

abstract:
  We address the problem of using nonlinear models to design experiments to
characterize the dynamics of cellular processes by using the approach of the
Maximally Informative Next Experiment (MINE), which was introduced in [W. Dong,
et al. Systems biology of the clock in neurospora crassa. {\em PLoS ONE}, page
e3105, 2008] and independently in [M. M. Donahue, et al. Experiment design
through dynamical characterization of non-linear systems biology models
utilising sparse grids. {\em IET System Biology}, 4:249--262, 2010]. In this
approach, existing data is used to define a probability distribution on the
parameters; the next measurement point is the one that yields the largest model
output variance with this distribution. Building upon this approach, we
introduce the Expected Dynamics Estimator (EDE), which is the expected value
using this distribution of the output as a function of time. We prove the
consistency of this estimator (uniform convergence to true dynamics) even when
the chosen experiments cluster in a finite set of points. We extend this proof
of consistency to various practical assumptions on noisy data and moderate
levels of model mismatch. Through the derivation and proof, we develop a
relaxed version of MINE that is more computationally tractable and robust than
the original formulation. The results are illustrated with numerical examples
on two nonlinear ordinary differential equation models of biomolecular and
cellular processes.


title:
$\Lambda$CDM model with a scalar perturbation vs. preferred direction of
  the universe

abstract:
  We present a scalar perturbation for the $\Lambda$CDM model, which breaks the
isotropic symmetry of the universe. Based on the Union2 data, the
least-$\chi^2$ fit of the scalar perturbed $\Lambda$CDM model shows that the
universe has a preferred direction
$(l,b)=(287^\circ\pm25^\circ,11^\circ\pm22^\circ)$. The magnitude of scalar
perturbation is about $-2.3\times10^{-5}$. The scalar perturbation for the
$\Lambda$CDM model implies a peculiar velocity, which is perpendicular to the
radial direction. We show that the maximum peculiar velocities at redshift
$z=0.15$ and $z=0.015$ equal to $73\pm28 \rm km\cdot s^{-1}$ and $1099\pm427
\rm km\cdot s^{-1}$, respectively. They are compatible with the constraints on
peculiar velocity given by Planck Collaboration.


title:
Cosmic expansion driven by real scalar field for different forms of
  potential

abstract:
  We discuss the expansion of the universe in the FRLW model assuming that the
source of dark energy is either tachyonic scalar field or quintessence. The
tachyonic scalar field with exponential and power-law potential (function of
homogeneous scalar field $\phi$) both gives exponential expansion of the
universe. It is found that this behaviour is not distinguishable from the
quintessence with respect to these potentials.


title:
Deterministic particle method approximation of a contact inhibition
  cross-diffusion problem

abstract:
  We use a deterministic particle method to produce numerical approximations to
the solutions of an evolution cross-diffusion problem for two populations.
  According to the values of the diffusion parameters related to the intra and
inter-population repulsion intensities, the system may be classified in terms
of an associated matrix. When the matrix is definite positive, the problem is
well posed and the Finite Element approximation produces convergent
approximations to the exact solution.
  A particularly important case arises when the matrix is only positive
semi-definite and the initial data are segregated: the contact inhibition
problem. In this case, the solutions may be discontinuous and hence the
(conforming) Finite Element approximation may exhibit instabilities in the
neighborhood of the discontinuity.
  In this article we deduce the particle method approximation to the general
cross-diffusion problem and apply it to the contact inhibition problem. We then
provide some numerical experiments comparing the results produced by the Finite
Element and the particle method discretizations.


title:
Current Sensing Noise Thermometry: A fast practical solution to low
  temperature measurement

abstract:
  We describe the design and performance of a series of fast, precise current
sensing noise thermometers. The thermometers have been fabricated with a range
of resistances from 1.290 $\Omega$ down to 0.2 m$\mathrm{\Omega}$. This results
in either a thermometer that has been optimised for speed, taking advantage of
the improvements in superconducting quantum interference device (SQUID) noise
and bandwidth, or a thermometer optimised for ultra-low temperature
measurement, minimising the system noise temperature. By using a single
temperature calibration point, we show that noise thermometers can be used for
accurate measurements over a wide range of temperatures below 4 K. Comparisons
with a melting curve thermometer, a calibrated germanium thermometer and a
pulsed platinum nuclear magnetic resonance thermometer are presented. For the
1.290 $\mathrm{\Omega}$ resistance we measure a 1 % precision in just 100 ms,
and have shown this to be independent of temperature.


title: Subdiagrams of Bratteli diagrams supporting finite invariant measures

abstract:
  We study finite measures on Bratteli diagrams invariant with respect to the
tail equivalence relation. Amongst the proved results on finiteness of measure
extension, we characterize the vertices of a Bratteli diagram that support an
ergodic finite invariant measure.


title:
Harmonic measures and the foliated geodesic flow for foliations with
  negatively curved leaves

abstract:
  In this paper we define a notion of Gibbs measure for the geodesic flow
tangent to a foliation with negatively curved leaves and associated to a
particular potential H. We prove that there is a canonical bijective
correspondence between these measures and Garnett's harmonic measures.


title: On the Expansion of Group-Based Lifts

abstract:
  A $k$-lift of an $n$-vertex base graph $G$ is a graph $H$ on $n\times k$
vertices, where each vertex $v$ of $G$ is replaced by $k$ vertices
$v_1,\cdots{},v_k$ and each edge $(u,v)$ in $G$ is replaced by a matching
representing a bijection $\pi_{uv}$ so that the edges of $H$ are of the form
$(u_i,v_{\pi_{uv}(i)})$. Lifts have been studied as a means to efficiently
construct expanders. In this work, we study lifts obtained from groups and
group actions. We derive the spectrum of such lifts via the representation
theory principles of the underlying group. Our main results are:
  (1) There is a constant $c_1$ such that for every $k\geq 2^{c_1nd}$, there
does not exist an abelian $k$-lift $H$ of any $n$-vertex $d$-regular base graph
with $H$ being almost Ramanujan (nontrivial eigenvalues of the adjacency matrix
at most $O(\sqrt{d})$ in magnitude). This can be viewed as an analogue of the
well-known no-expansion result for abelian Cayley graphs.
  (2) A uniform random lift in a cyclic group of order $k$ of any $n$-vertex
$d$-regular base graph $G$, with the nontrivial eigenvalues of the adjacency
matrix of $G$ bounded by $\lambda$ in magnitude, has the new nontrivial
eigenvalues also bounded by $\lambda+O(\sqrt{d})$ in magnitude with probability
$1-ke^{-\Omega(n/d^2)}$. In particular, there is a constant $c_2$ such that for
every $k\leq 2^{c_2n/d^2}$, there exists a lift $H$ of every Ramanujan graph in
a cyclic group of order $k$ with $H$ being almost Ramanujan. We use this to
design a quasi-polynomial time algorithm to construct almost Ramanujan
expanders deterministically.
  The existence of expanding lifts in cyclic groups of order $k=2^{O(n/d^2)}$
can be viewed as a lower bound on the order $k_0$ of the largest abelian group
that produces expanding lifts. Our results show that the lower bound matches
the upper bound for $k_0$ (upto $d^3$ in the exponent).


title: On a non-local spectrogram for denoising one-dimensional signals

abstract:
  In previous works, we investigated the use of local filters based on partial
differential equations (PDE) to denoise one-dimensional signals through the
image processing of time-frequency representations, such as the spectrogram. In
this image denoising algorithms, the particularity of the image was hardly
taken into account. We turn, in this paper, to study the performance of
non-local filters, like Neighborhood or Yaroslavsky filters, in the same
problem. We show that, for certain iterative schemes involving the Neighborhood
filter, the computational time is drastically reduced with respect to
Yaroslavsky or nonlinear PDE based filters, while the outputs of the filtering
processes are similar. This is heuristically justified by the connection
between the (fast) Neighborhood filter applied to a spectrogram and the
corresponding Nonlocal Means filter (accurate) applied to the Wigner-Ville
distribution of the signal. This correspondence holds only for time-frequency
representations of one-dimensional signals, not to usual images, and in this
sense the particularity of the image is exploited. We compare though a series
of experiments on synthetic and biomedical signals the performance of local and
non-local filters.


title: Examples of compact K-contact manifolds with no Sasakian metric

abstract:
  Using the Hard Lefschetz Theorem for Sasakian manifolds, we find two examples
of compact K-contact nilmanifolds with no compatible Sasakian metric in
dimensions five and seven, respectively


title:
Remotely sensed transport in microwave photoexcited GaAs/AlGaAs
  two-dimensional electron system

abstract:
  We demonstrate a strong correlation between the magnetoresistive and the
concurrent microwave reflection from the microwave photo-excited GaAs/AlGaAs
two-dimensional electron system (2DES). These correlations are followed as a
function of the microwave power, the microwave frequency, and the applied
current. Notably, the character of the reflection signal remains unchanged even
when the current is switched off in the GaAs/AlGaAs Hall bar specimen. The
results suggest a perceptible microwave-induced change in the electronic
properties of the 2DES, even in the absence of an applied current.


title: Constraining anisotropic models of the early Universe with WMAP9 data

abstract:
  We constrain several models of the early Universe that predict a statistical
anisotropy of the cosmic microwave background (CMB) sky. We make use of WMAP9
maps deconvolved with beam asymmetries. As compared to previous releases of
WMAP data, they do not exhibit the anomalously large quadrupole of statistical
anisotropy. This allows to strengthen the limits on the parameters of models
established earlier in the literature. In particular, the amplitude of the
special quadrupole is constrained as |g_*|<0.072 at 95% C.L. (-0.046<g_*<0.048
at 68% C.L.) independently of the preferred direction in the sky. The upper
limit is obtained on the total number of e-folds in anisotropic inflation with
the Maxwellian term nonminimally coupled to the inflaton, namely N_{tot}
<N_{CMB} +82 at 95% C.L. (+14 at 68% C.L.) for N_{CMB}=60. We also constrain
models of the (pseudo)conformal universe. The strongest constraint is obtained
for spectator scenarios involving a long stage of subhorizon evolution after
conformal rolling, which reads h^2 < 0.006 at 95% C.L., in terms of the
relevant parameter. The analogous constraint is much weaker in dynamical
models, e.g., Galilean genesis.


title: Baryon properties in meson mediums from lattice QCD

abstract:
  We present results for the ground-state mass shifts of octet baryons due to
the presence of a medium of pions or kaons from a lattice QCD calculation
performed at a single value of the quark mass, corresponding to a pion mass of
$m_\pi$ ~ 390 MeV, and a spatial volume V ~ (4fm)^3. We use a canonical
approach in which correlators are formed using a single baryon propagator and a
fixed number of meson propagators, up to n=9. From the ground-state energies we
calculate two- and three-body interaction parameters. We also extract
combinations of low-energy constants by comparing our results to tree level
chiral perturbation theory at non-zero isospin/kaon chemical potential.


title:
The Rokhlin property for endomorphisms and strongly self-absorbing
  C*-algebras

abstract:
  In this paper we define a Rokhlin property for automorphisms of non-unital
C*-algebras and for endomorphisms. We show that the crossed product of a
C*-algebra by a Rokhlin automorphism preserves absorption of a strongly
self-absorbing C*-algebra, and use this result to deduce that the same result
holds for crossed products by endomorphisms in the sense of Stacey. This
generalizes earlier results of the second named author and W. Winter.


title: A note on wormholes in slightly modified gravitational theories

abstract:
  Wormholes that meet the flare-out condition violate the weak energy condition
in classical general relativity. The purpose of this note is to show that even
a slight modification of the gravitational theory could, under certain
conditions, avoid this violation for matter threading the wormhole. The first
part discusses some general criteria based on the field equations, while the
second part assumes a specific equation of state describing normal matter,
together with a particular type of shape function. The analysis is confined to
wormholes with zero tidal forces.


title:
On a cross-diffusion segregation problem arising from a model of
  interacting particles

abstract:
  We prove the existence of solutions of a cross-diffusion parabolic population
problem. The system of partial differential equations is deduced as the limit
equations satisfied by the densities corresponding to an interacting particles
system modeled by stochastic differential equations. According to the values of
the diffusion parameters related to the intra and inter-population repulsion
intensities, the system may be classified in terms of an associated matrix. For
proving the existence of solutions when the matrix is positive definite, we use
a fully discrete finite element approximation in a general functional setting.
If the matrix is only positive semi-definite, we use a regularization technique
based on a related cross-diffusion model under more restrictive functional
assumptions. We provide some numerical experiments demonstrating the weak and
strong segregation effects corresponding to both types of matrices.


title: Is there a metamaterial route to high temperature superconductivity?

abstract:
  Superconducting properties of a material, such as electron-electron
interactions and the critical temperature of superconducting transition can be
expressed via the effective dielectric response function of the material. Such
a description is valid on the spatial scales below the superconducting
coherence length (the size of the Cooper pair), which equals ~100 nm in a
typical BCS superconductor. Searching for natural materials exhibiting larger
electron-electron interactions constitutes a traditional approach to high
temperature superconductivity research. Here we point out that recently
developed field of electromagnetic metamaterials deals with somewhat related
task of dielectric response engineering on sub-100 nm scale. We argue that the
metamaterial approach to dielectric response engineering may considerably
increase the critical temperature of a composite superconductor-dielectric
metamaterial.


title:
Proximity effect in superconductor/conical magnet/ferromagnet
  heterostructures

abstract:
  At the interface between a superconductor and a ferromagnetic metal
spin-singlet Cooper pairs can penetrate into the ferromagnetic part of the
heterostructure with an oscillating and decaying spin-singlet Cooper pair
density. However, if the interface allows for a spin-mixing effect, equal-spin
spin-triplet Cooper pairs can be generated that can penetrate much further into
the ferromagnetic part of the heterostructure, known as the long-range
proximity effect. Here, we present results of spin-mixing based on
self-consistent solutions of the microscopic Bogoliubov-de Gennes equations
incorporating a tight-binding model. In particular, we include a conical magnet
into our model heterostructure to generate the spin-triplet Cooper pairs and
analyse the influence of conical and ferromagnetic layer thickness on the
unequal-spin and equal-spin spin-triplet pairing correlations. It will be show
that, in agreement with experimental observations, a minimum thickness of the
conical magnet is necessary to generate a sufficient amount of equal-spin
spin-triplet Cooper pairs allowing for the long-range proximity effect.


title: Null twisted geometries

abstract:
  We define and investigate a quantisation of null hypersurfaces in the context
of loop quantum gravity on a fixed graph. The main tool we use is the
parametrisation of the theory in terms of twistors, which has already proved
useful in discussing the interpretation of spin networks as the quantization of
twisted geometries. The classical formalism can be extended in a natural way to
null hypersurfaces, with the Euclidean polyhedra replaced by null polyhedra
with space-like faces, and SU(2) by the little group ISO(2). The main
difference is that the simplicity constraints present in the formalims are all
first class, and the symplectic reduction selects only the helicity subgroup of
the little group. As a consequence, information on the shapes of the polyhedra
is lost, and the result is a much simpler, abelian geometric picture. It can be
described by an Euclidean singular structure on the 2-dimensional space-like
surface defined by a foliation of space-time by null hypersurfaces. This
geometric structure is naturally decomposed into a conformal metric and scale
factors, forming locally conjugate pairs. Proper action-angle variables on the
gauge-invariant phase space are described by the eigenvectors of the Laplacian
of the dual graph. We also identify the variables of the phase space amenable
to characterize the extrinsic geometry of the foliation. Finally, we quantise
the phase space and its algebra using Dirac's algorithm, obtaining a notion of
spin networks for null hypersurfaces. Such spin networks are labelled by SO(2)
quantum numbers, and are embedded non-trivially in the unitary,
infinite-dimensional irreducible representations of the Lorentz group.


title: The ALHAMBRA survey: evolution of galaxy clustering since $z \sim 1$

abstract:
  We study the clustering of galaxies as function of luminosity and redshift in
the range $0.35 < z < 1.25$ using data from the Advanced Large Homogeneous Area
Medium Band Redshift Astronomical (ALHAMBRA) survey. The ALHAMBRA data used in
this work cover $2.38 \mathrm{deg}^2$ in 7 independent fields, after applying a
detailed angular selection mask, with accurate photometric redshifts, $\sigma_z
\lesssim 0.014 (1+z)$, down to $I_{\rm AB} < 24$. Given the depth of the
survey, we select samples in $B$-band luminosity down to $L^{\rm th} \simeq
0.16 L^{*}$ at $z = 0.9$. We measure the real-space clustering using the
projected correlation function, accounting for photometric redshifts
uncertainties. We infer the galaxy bias, and study its evolution with
luminosity. We study the effect of sample variance, and confirm earlier results
that the COSMOS and ELAIS-N1 fields are dominated by the presence of large
structures. For the intermediate and bright samples, $L^{\rm med} \gtrsim
0.6L^{*}$, we obtain a strong dependence of bias on luminosity, in agreement
with previous results at similar redshift. We are able to extend this study to
fainter luminosities, where we obtain an almost flat relation, similar to that
observed at low redshift. Regarding the evolution of bias with redshift, our
results suggest that the different galaxy populations studied reside in haloes
covering a range in mass between $\log_{10}[M_{\rm
h}/(h^{-1}\mathrm{M}_{\odot})] \gtrsim 11.5$ for samples with $L^{\rm med}
\simeq 0.3 L^{*}$ and $\log_{10}[M_{\rm h}/(h^{-1}\mathrm{M}_{\odot})] \gtrsim
13.0$ for samples with $L^{\rm med} \simeq 2 L^{*}$, with typical occupation
numbers in the range of $\sim 1 - 3$ galaxies per halo.


title:
Hysteretic electrical transport in BaTiO$_3$/Ba$_{1-x}$Sr$_x$TiO$_3$/Ge
  heterostructures

abstract:
  We present electrical transport measurements of heterostructures comprised of
BaTiO$_3$ and Ba$_{1-x}$Sr$_x$TiO$_3$ epitaxially grown on Ge. The Sr-alloying
imparts compressive strain to the BaTiO$_3$, which enables the thermal
expansion mismatch between BaTiO$_3$ and Ge to be overcome to achieve $c$-axis
oriented growth. The conduction bands of BaTiO$_3$ and Ba$_{1-x}$Sr$_x$TiO$_3$
are nearly aligned with the conduction band of Ge, which facilitates electron
transport. Electrical transport measurements through the dielectric stack
exhibit rectifying behavior and hysteresis, where the latter is consistent with
ferroelectric switching.


title:
First Search for Exotic Z Boson Decays into Photons and Neutral Pions in
  Hadron Collisions

abstract:
  A search for forbidden and exotic Z boson decays in the diphoton mass
spectrum is presented for the first time in hadron collisions, based on data
corresponding to 10.0 fb^-1 of integrated luminosity from proton-antiproton
collisions at sqrt(s) = 1.96 TeV collected by the CDF experiment. No evidence
of signal is observed, and 95% credibility level Bayesian upper limits are set
on the branching ratios of decays of the Z boson to a photon and neutral pion
(which is detected as a photon), a pair of photons, and a pair of neutral
pions. The observed branching ratio limits are 2.01 x 10^-5 for Z to
\pi^0\gamma, 1.46 x 10^-5 for Z to \gamma\gamma, and 1.52 x 10^-5 for Z to
\pi^0\pi^0. The Z to \pi^0\gamma\ and Z to \gamma\gamma\ limits improve by
factors of 2.6 and 3.6, respectively, the most stringent results from other
experiments. The Z to \pi^0\pi^0 branching ratio limit is the first
experimental result on this decay.


title:
Remote sensor response study in the regime of the microwave
  radiation-induced magnetoresistance oscillations

abstract:
  A concurrent remote sensing and magneto-transport study of the microwave
excited two dimensional electron system (2DES) at liquid Helium temperatures
has been carried out using a carbon detector to remotely sense the microwave
activity of the 2D electron system in the GaAs/AlGaAs heterostructure during
conventional magnetotransport measurements. Various correlations are observed
and reported between the oscillatory magnetotransport and the remotely sensed
reflection. In addition, the oscillatory remotely sensed signal is shown to
exhibit a power law type variation in its amplitude, similar to the
radiation-induced magnetoresistance oscillations.


title: A family of optimal locally recoverable codes

abstract:
  A code over a finite alphabet is called locally recoverable (LRC) if every
symbol in the encoding is a function of a small number (at most $r$) other
symbols. We present a family of LRC codes that attain the maximum possible
value of the distance for a given locality parameter and code cardinality. The
codewords are obtained as evaluations of specially constructed polynomials over
a finite field, and reduce to a Reed-Solomon code if the locality parameter $r$
is set to be equal to the code dimension. The size of the code alphabet for
most parameters is only slightly greater than the code length. The recovery
procedure is performed by polynomial interpolation over $r$ points. We also
construct codes with several disjoint recovering sets for every symbol. This
construction enables the system to conduct several independent and simultaneous
recovery processes of a specific symbol by accessing different parts of the
codeword. This property enables high availability of frequently accessed data
("hot data").


title:
Adler function and hadronic vacuum polarization from lattice vector
  correlators

abstract:
  We study a representation of the hadronic vacuum polarization based on the
time-momentum representation of the vector correlator. This representation
suggests a way to compute the hadronic vacuum polarization and the associated
Adler function for any value of virtuality, irrespective of the flavor
structure of the current. We present results on both of these
phenomenologically important functions, derived from local-conserved two-point
lattice vector correlation functions, computed on a subset of light two-flavor
ensembles made available to us through the CLS effort.


title: An Efficient Parallel Solver for SDD Linear Systems

abstract:
  We present the first parallel algorithm for solving systems of linear
equations in symmetric, diagonally dominant (SDD) matrices that runs in
polylogarithmic time and nearly-linear work. The heart of our algorithm is a
construction of a sparse approximate inverse chain for the input matrix: a
sequence of sparse matrices whose product approximates its inverse. Whereas
other fast algorithms for solving systems of equations in SDD matrices exploit
low-stretch spanning trees, our algorithm only requires spectral graph
sparsifiers.


title: Nonparametric Estimation of Multi-View Latent Variable Models

abstract:
  Spectral methods have greatly advanced the estimation of latent variable
models, generating a sequence of novel and efficient algorithms with strong
theoretical guarantees. However, current spectral algorithms are largely
restricted to mixtures of discrete or Gaussian distributions. In this paper, we
propose a kernel method for learning multi-view latent variable models,
allowing each mixture component to be nonparametric. The key idea of the method
is to embed the joint distribution of a multi-view latent variable into a
reproducing kernel Hilbert space, and then the latent parameters are recovered
using a robust tensor power method. We establish that the sample complexity for
the proposed method is quadratic in the number of latent components and is a
low order polynomial in the other relevant parameters. Thus, our non-parametric
tensor approach to learning latent variable models enjoys good sample and
computational efficiencies. Moreover, the non-parametric tensor power method
compares favorably to EM algorithm and other existing spectral algorithms in
our experiments.


title:
Grain fragmentation in sheared granular flow: weakening effects, energy
  dissipation, and strain localization

abstract:
  We describe the shear flow of a disordered granular material in the presence
of grain fracture using the shear-transformation-zone (STZ) theory of amorphous
plasticity adapted to systems with a hard-core inter-particle interaction. To
this end, we develop the equations of motion for this system within a
statistical-thermodynamic framework analogous to that used in the analysis of
molecular glasses. For hard-core systems, the amount of internal,
configurational disorder is characterized by the compactivity $X = \partial V /
\partial S_C$, where $V$ and $S_C$ are respectively the volume and
configurational entropy. Grain breakage is described by a constitutive equation
for the temporal evolution of a characteristic grain size $a$, based on
fracture mechanics. We show that grain breakage is a weakening mechanism,
significantly lowering the flow stress at large strain rates, if the material
is rate-strengthening in character. We show in addition that if the granular
material is sufficiently aged, spatial inhomogeneity in configurational
disorder results in strain localization. We also show that grain splitting
contributes significantly to comminution at small shear strains, while grain
abrasion becomes dominant at large shear displacements.

categories: cond-mat.soft cond-mat.dis-nn cond-mat.mtrl-sci cond-mat.stat-mech physics.geo-ph


title:
Nuclear magnetic resonance studies of pseudospin fluctuations in
  URu$_2$Si$_2$

abstract:
  We report $^{29}$Si NMR measurements in single crystals and aligned powders
of URu$_2$Si$_2$ in the hidden order and paramagnetic phases. The
spin-lattice-relaxation data reveal evidence of pseudospin fluctuations of U
moments in the paramagnetic phase. We find evidence for partial suppression of
the density of states below 30 K, and analyze the data in terms of a two
component spin-fermion model. We propose that this behavior is a realization of
a pseudogap between the hidden order transition $T_{HO}$ and 30 K. This
behavior is then compared to other materials that demonstrate precursor
fluctuations in a pseudogap regime above a ground state with long-range order.


title: Recent progress in attractors for quintic wave equations

abstract:
  We report on new results concerning the global well-posedness, dissipativity
and attractors of the damped quintic wave equations in bounded domains of R^3.


title: Left-orderability and cyclic branched coverings

abstract:
  We provide an alternative proof of a sufficient condition for the fundamental
group of the $n^{th}$ cyclic branched cover of $S^3$ along a prime knot $K$ to
be left-orderable, which is originally due to Boyer-Gordon-Watson. As an
application of this sufficient condition, we show that for any $(p,q)$
two-bridge knot, with $p\equiv 3 \text{ mod } 4$, there are only finitely many
cyclic branched covers whose fundamental groups are not left-orderable. This
answers a question posed by D{\c a}bkowski, Przytycki and Togha.


title: Holographic Q-lattices

abstract:
  We introduce a new framework for constructing black hole solutions that are
holographically dual to strongly coupled field theories with explicitly broken
translation invariance. Using a classical gravitational theory with a
continuous global symmetry leads to constructions that involve solving ODEs. We
study in detail $D=4$ Einstein-Maxwell theory coupled to a complex scalar field
with a simple mass term. We construct black holes dual to metallic phases which
exhibit a Drude-type peak in the optical conductivity, but there is no evidence
of an intermediate scaling that has been reported in other holographic lattice
constructions. We also construct black holes dual to insulating phases which
exhibit a suppression of spectral weight at low frequencies. We show that the
model also admits a novel $AdS_3\times\mathbb{R}$ solution.


title: Abstraction Level Taxonomy of Programming Language Frameworks

abstract:
  The main purpose of this article is to describe the taxonomy of computer
languages according to the levels of abstraction. There exists so many computer
languages because of so many reasons like the evolution of better computer
languages over the time; the socio-economic factors as the proprietary
interests, commercial advantages; expressive power; ease of use of novice;
orientation toward special purposes; orientation toward special hardware; and
diverse ideas about most suitability. Moreover, the important common properties
of most of these languages are discussed here. No programming language is
designed in a vacuity, but it solves some specific kinds of problems. There is
a different framework for each problem and best suitable framework for each
problem. A single framework is not best for all types of problems. So, it is
important to select vigilantly the frameworks supported by the language. The
five generation of the computer programming languages are explored in this
paper to some extent.


title:
Cosmological signatures of tilted isocurvature perturbations:
  reionization and 21cm fluctuations

abstract:
  We investigate cosmological signatures of uncorrelated isocurvature
perturbations whose power spectrum is blue-tilted with spectral index 2<p<4.
Such an isocurvature power spectrum can promote early formation of small-scale
structure, notably dark matter halos and galaxies, and may thereby resolve the
shortage of ionizing photons suggested by observations of galaxies at high
redshifts (z~7-8) but that are required to reionize the universe at z~10. We
mainly focus on how the formation of dark matter halos can be modified, and
explore the connection between the spectral shape of CMB anisotropies and the
reionization optical depth as a powerful probe of a highly blue-tilted
isocurvature primordial power spectrum. We also study the consequences for 21cm
line fluctuations due to neutral hydrogens in minihalos. Combination of
measurements of the reionization optical depth and 21cm line fluctuations will
provide complementary probes of a highly blue-tilted isocurvature power
spectrum.


title: A model of quark and lepton mixing

abstract:
  We propose a model of quark and lepton mixing based on the tetrahedral A(4)
family symmetry with quark-lepton unification via the tetra-colour Pati-Salam
gauge group SU(4)_{PS}, together with SU(2)_L x U(1)_R. The "tetra-model"
solves many of the flavour puzzles and remarkably gives ten predictions at
leading order, including all six PMNS parameters. The Cabibbo angle is
approximately given by 1/4, due to the tetra-vacuum alignment (1,4,2),
providing the Cabibbo connection between quark and lepton mixing. Higher order
corrections are responsible for the smaller quark mixing angles and CP
violation and provide corrections to the Cabibbo and lepton mixing angles and
phases. The tetra-model involves an SO(10)-like pattern of Dirac and heavy
right-handed neutrino masses, with the strong up-type quark mass hierarchy
cancelling in the see-saw mechanism, leading to a normal hierarchy of neutrino
masses with an atmospheric angle in the first octant of 40 +/- 1 degree, a
solar angle of 34 +/- 1 degree, a reactor angle of 9.0 +/- 0.5 degree,
depending on the ratio of neutrino masses m_2/m_3, and a Dirac CP violating
oscillation phase of 260 +/- 5 degrees.


title:
Clustering in the Phase Space of Dark Matter Haloes. II. Stable
  Clustering and Dark Matter Annihilation

abstract:
  We present a model for the structure of the particle phase space average
density ($P^2SAD$) in galactic haloes, introduced recently as a novel measure
of the clustering of dark matter. Our model is based on the stable clustering
hypothesis in phase space, the spherical collapse model, and tidal disruption
of substructures, which is calibrated against the Aquarius simulations. Using
this model, we can predict the behaviour of $P^2SAD$ in the numerically
unresolved regime, down to the decoupling mass limit of generic WIMP models.
This prediction can be used to estimate signals sensitive to the small scale
structure of dark matter. For example, the dark matter annihilation rate can be
estimated for arbitrary velocity-dependent cross sections in a convenient way
using a limit of $P^2SAD$ to zero separation in physical space. We illustrate
our method by computing the global and local subhalo annihilation boost to that
of the smooth dark matter distribution in a Milky-Way-size halo. Two cases are
considered, one where the cross section is velocity independent and one that
approximates Sommerfeld-enhanced models. We find that the global boost is
$\sim10-30$, which is at the low end of current estimates (weakening
expectations of large extragalactic signals), while the boost at the solar
radius is below the percent level. We make our code to compute $P^2SAD$
publicly available, which can be used to estimate various observables that
probe the nanostructure of dark matter haloes.


title: The Bose-Hubbard model is QMA-complete

abstract:
  The Bose-Hubbard model is a system of interacting bosons that live on the
vertices of a graph. The particles can move between adjacent vertices and
experience a repulsive on-site interaction. The Hamiltonian is determined by a
choice of graph that specifies the geometry in which the particles move and
interact. We prove that approximating the ground energy of the Bose-Hubbard
model on a graph at fixed particle number is QMA-complete. In our QMA-hardness
proof, we encode the history of an n-qubit computation in the subspace with at
most one particle per site (i.e., hard-core bosons). This feature, along with
the well-known mapping between hard-core bosons and spin systems, lets us prove
a related result for a class of 2-local Hamiltonians defined by graphs that
generalizes the XY model. By avoiding the use of perturbation theory in our
analysis, we circumvent the need to multiply terms in the Hamiltonian by large
coefficients.


title:
Mean field theory of competing orders in metals with antiferromagnetic
  exchange interactions

abstract:
  It has long been known that two-dimensional metals with antiferromagnetic
exchange interactions have a weak-coupling instability to the superconductivity
of spin-singlet, d-wave electron pairs. We examine additional possible
instabilities in the spin-singlet particle-hole channel, and study their
interplay with superconductivity. We perform an unrestricted Hartree-Fock-BCS
analysis of bond order parameters in a single band model on the square lattice
with nearest-neighbor exchange and repulsion, while neglecting on-site
interactions. The dominant particle-hole instability is found to be an
incommensurate, bi-directional, bond density wave with wavevectors along the
(1,1) and (1,-1) directions, and an internal d-wave symmetry. The magnitude of
the ordering wavevector is close to the separation between points on the Fermi
surface which intersect the antiferromagnetic Brillouin zone boundary. The
temperature dependence of the superconducting and bond order parameters
demonstrates their mutual competition. We also obtain the spatial dependence of
the two orders in a vortex lattice induced by an applied magnetic field:
"halos" of the bond order appear around the cores of the vortices.


title:
Ground State Phase Diagram of Generic XY Pyrochlore Magnets with Quantum
  Fluctuations

abstract:
  Motivated by recent experimental and theoretical progress on the Er2Ti2O7
pyrochlore XY antiferromagnet, we study the problem of quantum
order-by-disorder in pyrochlore XY systems. We consider the most general
nearest-neighbor pseudo spin-1/2 Hamiltonian for such a system characterized by
anisotropic spin-spin couplings J_e = [J_\pm, J_{\pm\pm}, J_{z\pm}, J_{zz}] and
construct zero-temperature phase diagrams. Combining symmetry arguments and
spin-wave calculations, we show that the ground state phase boundaries between
the two candidate ground states of the \Gamma_5 irreducible representation, the
\psi_2 and \psi_3 (basis) states, are rather accurately determined by a cubic
equation in J_{\pm}J_{\pm\pm})/J_{z\pm}^2. Depending on the value of J_{zz},
there can be one or three phase boundaries that separate alternating regions of
\psi_2 and \psi_3 states. In particular, we find for sufficiently small
J_{zz}/J_{\pm} a narrow \psi_2 sliver sandwiched between two \psi_3 regions in
the J_{\pm\pm}/J_\pm vs J_{z\pm}/J_\pm phase diagram. Our results further
illustrate the very large potential sensitivity of the ground state of XY
pyrochlore systems to minute changes in their spin Hamiltonian. Using the
experimentally determined J_3 and g-tensor values for Er2Ti2O7, we show that
the heretofore neglected long-range 1/r^3 magnetostatic dipole-dipole
interactions do not change the conclusion that Er2Ti2O7 has a \psi_2 ground
state induced via a quantum order-by-disorder mechanism. We propose that the
CdDy2Se4 chalcogenide spinel, in which the Dy^{3+} ions form a pyrochlore
lattice and may be XY-like, could prove interesting to investigate.


title: The trouble with twisting (2,0) theory

abstract:
  We consider a twisted version of the abelian $(2,0)$ theory placed upon a
Lorenzian six-manifold with a product structure, $M_6=C \times M_4 $. This is
done by an investigation of the free tensor multiplet on the level of equations
of motion, where the problem of its formulation in Euclidean signature is
circumvented by letting the time-like direction lie in the two-manifold $C$ and
performing a topological twist along $M_4$ alone. A compactification on $C$ is
shown to be necessary to enable the possibility of finding a topological field
theory. The hypothetical twist along a Euclidean $C$ is argued to amount to the
correct choice of linear combination of the two supercharges scalar on $M_4$.
This procedure is expected and conjectured to result in a topological field
theory, but we arrive at the surprising conclusion that this twisted theory
contains no $Q$-exact and covariantly conserved stress tensor unless $M_4$ has
vanishing curvature. This is to our knowledge a phenomenon which has not been
observed before in topological field theories. In the literature, the setup of
the twisting used here has been suggested as the origin of the conjectured
AGT-correspondence, and our hope is that this work may somehow contribute to
the understanding of it.


title: The dark matter of galaxy voids

abstract:
  How do observed voids relate to the underlying dark matter distribution? To
examine the spatial distribution of dark matter contained within voids
identified in galaxy surveys, we apply Halo Occupation Distribution models
representing sparsely and densely sampled galaxy surveys to a high-resolution
N-body simulation. We compare these galaxy voids to voids found in the halo
distribution, low-resolution dark matter, and high-resolution dark matter. We
find that voids at all scales in densely sampled surveys - and medium- to
large-scale voids in sparse surveys - trace the same underdensities as dark
matter, but they are larger in radius by ~20%, they have somewhat shallower
density profiles, and they have centers offset by ~0.4Rv rms. However, in
void-to-void comparison we find that shape estimators are less robust to
sampling, and the largest voids in sparsely sampled surveys suffer
fragmentation at their edges. We find that voids in galaxy surveys always
correspond to underdensities in the dark matter, though the centers may be
offset. When this offset is taken into account, we recover almost identical
radial density profiles between galaxies and dark matter. All mock catalogs
used in this work are available at http://www.cosmicvoids.net.


title: Local Observables in a Landscape of Infrared Gauge Modes

abstract:
  Cosmological local observables are at best statistically determined by the
fundamental theory describing inflation. When the scalar inflaton is coupled
uniformly to a collection of subdominant massless gauge vectors, rotational
invariance is obeyed locally. However, the statistical isotropy of fluctuations
is spontaneously broken by gauge modes whose wavelength exceed our causal
horizon. This leads to a landscape picture where primordial correlators depend
on the position of the observer. We compute the stochastic corrections to the
curvature power spectrum, show the existence of a new local observable (the
shape of the quadrupole), and constrain the theory using Planck limits.


title:
The central mass and mass-to-light profile of the Galactic globular
  cluster M15

abstract:
  We analyze line-of-sight velocity and proper motion data of stars in the
Galactic globular cluster M15 using a new method to fit dynamical models to
discrete kinematic data. Our fitting method maximizes the likelihood for
individual stars and, as such, does not suffer the same loss of spatial and
velocity information incurred when spatially binning data or measuring velocity
moments. In this paper, we show that the radial variation in M15 of the
mass-to-light ratio is consistent with previous estimates and theoretical
predictions, which verifies our method. Our best-fitting axisymmetric Jeans
models do include a central dark mass of $\sim2 \pm 1\cdot 10^3M_\odot$, which
can be explained by a high concentration of stellar remnants at the cluster
center. This paper shows that, from a technical point of view and with current
computing power, spatial binning of data is no longer necessary. This not only
leads to more accurate fits, but also avoids biased mass estimates due to the
loss of resolution. Furthermore, we find that the mass concentration in M15 is
significantly higher than previously measured, and is in close agreement with
theoretical predictions for core-collapsed globular clusters without a central
intermediate-mass black hole.


title: The RoboPol optical polarization survey of gamma-ray - loud blazars

abstract:
  We present first results from RoboPol, a novel-design optical polarimeter
operating at the Skinakas Observatory in Crete. The data, taken during the May
- June 2013 commissioning of the instrument, constitute a single-epoch linear
polarization survey of a sample of gamma-ray - loud blazars, defined according
to unbiased and objective selection criteria, easily reproducible in
simulations, as well as a comparison sample of, otherwise similar, gamma-ray -
quiet blazars. As such, the results of this survey are appropriate for both
phenomenological population studies and for tests of theoretical population
models. We have measured polarization fractions as low as $0.015$ down to $R$
magnitude of 17 and as low as $0.035$ down to 18 magnitude. The hypothesis that
the polarization fractions of gamma-ray - loud and gamma-ray - quiet blazars
are drawn from the same distribution is rejected at the $10^{-3}$ level. We
therefore conclude that gamma-ray - loud and gamma-ray - quiet sources have
different optical polarization properties. This is the first time this
statistical difference is demonstrated in optical wavelengths. The polarization
fraction distributions of both samples are well-described by exponential
distributions with averages of $\langle p \rangle =6.4 ^{+0.9}_{-0.8}\times
10^{-2}$ for gamma-ray--loud blazars, and $\langle p \rangle =3.2
^{+2.0}_{-1.1}\times 10^{-2}$ for gamma-ray--quiet blazars. The most probable
value for the difference of the means is $3.4^{+1.5}_{-2.0}\times 10^{-2}$. The
distribution of polarization angles is statistically consistent with being
uniform.


title:
Future Electron-Positron Colliders and the 4-Dimensional Composite Higgs
  Model

abstract:
  In this note we analyse the prospects of a future electron-positron collider
in testing a particular realisation of a composite Higgs model encompassing
partial compositeness, namely, the 4-Dimensional Composite Higgs Model. We
study the main Higgs production channels for three possible energy stages and
different luminosity options of such a machine and confront our results to the
expected experimental accuracies in the various Higgs decay channels accessible
herein and, for comparison, also at the Large Hadron Collider.


title: Exploring a Dark Sector Through the Higgs Portal at a Lepton Collider

abstract:
  We investigate the prospects for detecting a hidden sector at an $e^+ e^-$
collider. The hidden sector is assumed to be composed of invisible particles
that carry no charges under the Standard Model gauge interactions, and whose
primary interactions with ordinary matter are through the Higgs portal. We
consider both the cases when the decays of an on-shell Higgs into a pair of
hidden sector particles are kinematically allowed, and the case when such
decays are kinematically forbidden. We find that at collider energies below a
TeV, the most sensitive channel involves production of an on-shell or off-shell
Higgs in association with a Z boson, and the subsequent decay of the Higgs into
invisible hidden sector states. Focusing on this channel, we find that with
order a thousand inverse fb of data at 250 GeV, the decay branching fraction of
an on-shell Higgs to invisible hidden sector states can be constrained to lie
below half a percent. The corresponding limits on Higgs portal dark matter will
be stronger than the bounds from current and upcoming direct detection
experiments in much of parameter space. With the same amount of data at 500
GeV, assuming order one couplings, decays of an off-shell Higgs to hidden
sector states with a total mass up to about 200 GeV can also be probed. Both
the on-shell and off-shell cases represent a significant improvement in
sensitivity when compared to the Large Hadron Collider (LHC).


title: Constraints on RG Flows from Holographic Entanglement Entropy

abstract:
  We examine the RG flow of a candidate c-function, extracted from the
holographic entanglement entropy of a strip-shaped region, for theories with
broken Lorentz invariance. We clarify the conditions on the geometry that lead
to a break-down of monotonic RG flows as is expected for generic
Lorentz-violating field theories. Nevertheless we identify a set of simple
criteria on the UV behavior of the geometry which guarantee a monotonic
c-function. Our analysis can thus be used as a guiding principle for the
construction of monotonic RG trajectories, and can also prove useful for
excluding possible IR behaviors of the theory.


title: Hadwiger Integration of Random Fields

abstract:
  Hadwiger integrals employ the intrinsic volumes as measures for integration
of real-valued functions. We provide a formula for the expected values of
Hadwiger integrals of Gaussian-related random fields. The expected Hadwiger
integrals of random fields are both theoretically interesting and potentially
useful in applications such as sensor networks, image processing, and cell
dynamics. Furthermore, combining the expected integrals with a functional
version of Hadwiger's theorem, we obtain expected values of more general
valuations on Gaussian-related random fields.


title: Topological insulators with arbitrarily tunable entanglement

abstract:
  We elucidate how Chern and topological insulators fulfill an area law for the
entanglement entropy. By explicit construction of a family of lattice
Hamiltonians, we are able to demonstrate that the area law contribution can be
tuned to an arbitrarily small value, but is topologically protected from
vanishing exactly. We prove this by introducing novel methods to bound
entanglement entropies from correlations using perturbation bounds, drawing
intuition from ideas of quantum information theory. This rigorous approach is
complemented by an intuitive understanding in terms of entanglement edge
states. These insights have a number of important consequences: The area law
has no universal component, no matter how small, and the entanglement scaling
cannot be used as a faithful diagnostic of topological insulators. This holds
for all Renyi entropies which uniquely determine the entanglement spectrum
which is hence also non-universal. The existence of arbitrarily weakly
entangled topological insulators furthermore opens up possibilities of devising
correlated topological phases in which the entanglement entropy is small and
which are thereby numerically tractable, specifically in tensor network
approaches.


title: Status of the MAJORANA DEMONSTRATOR experiment

abstract:
  The MAJORANA DEMONSTRATOR neutrinoless double beta-decay experiment is
currently under construction at the Sanford Underground Research Facility in
South Dakota, USA. An overview and status of the experiment are given.


title:
Low Background Materials and Assay - A Supplement to the Cosmic Frontier
  CF1 Summary

abstract:
  This White Paper provides a supplement to the Snowmass Summary from CF1
(Cosmic Frontier WIMP Direct Detection). It was largely prepared during the
August 2013 Community Planning Meeting and relies on information gathered from
the larger dark matter community. It is a more detailed answer to the CF1
Charge: "Identify the common infrastructure required to meet the scientific and
technical goals of dark matter direct detection." The community as a whole
recognizes that sensitive searches for WIMPs require identification,
quantification, and procurement of radiopure materials. The lack of sufficient
resources in this area is a major project risk for future experiments and can
limit scientific reach


title: Synthetic Data Generation using Benerator Tool

abstract:
  Datasets of different characteristics are needed by the research community
for experimental purposes. However, real data may be difficult to obtain due to
privacy concerns. Moreover, real data may not meet specific characteristics
which are needed to verify new approaches under certain conditions. Given these
limitations, the use of synthetic data is a viable alternative to complement
the real data. In this report, we describe the process followed to generate
synthetic data using Benerator, a publicly available tool. The results show
that the synthetic data preserves a high level of accuracy compared to the
original data. The generated datasets correspond to microdata containing
records with social, economic and demographic data which mimics the
distribution of aggregated statistics from the 2011 Irish Census data.


title:
Discovery of Megaparsec-Scale, Low Surface Brightness Nonthermal
  Emission in Merging Galaxy Clusters using the Green Bank Telescope

abstract:
  We present results on 12 X-ray bright clusters observed at 1.4 GHz with the
Green Bank Telescope. After subtraction of point sources, we reach a median
(best) 1-sigma noise level of 0.01 (0.006) microJy/sq. arcsec, and find a
significant excess of diffuse, low surface brightness emission in 11 of 12
clusters. We present initial 1.4 GHz Very Large Array results on Abell 2319. We
find: (a) four new detections tentatively classified as two halos (A2065,
A2069) and two relics (A2067, A2073); (b) the first detection of the radio halo
in A2061 at 1.4 GHz, making it a possible ultra-steep spectrum halo (alpha ~
1.8); (c) a ~2 Mpc radio halo in the sloshing, minor-merger cluster A2142; (d)
a >2x increase of the giant radio halo extent and luminosity in A2319; (e) a
~7x increase to the integrated radio flux and >4x increase to the observed
extent of the peripheral, polarized radio relic in A1367 to ~600 kpc; (f)
significant excess emission of ambiguous nature in three clusters. Our radio
halo detections agree with the well-known X-ray/radio luminosity correlation,
but are larger and fainter than expected. The volume averaged synchrotron
emissivities are 1-2 orders of magnitude below the previous characteristic
values. Some of the halo-like detections may represent previously unseen, very
low surface brightness emission or blends of shock structures and sub-Mpc scale
turbulent regions. Four of the five tentative halos contain one or more X-ray
cold fronts, suggesting a possible connection between gas sloshing and particle
acceleration on large scales. We see evidence for a possible inter-cluster
filament between A2061 and A2067. For our faintest detections, we note the
possibility of residual contamination from faint radio galaxies. We also
quantify the sensitivity of the NVSS to extended emission as a function of
angular size.[abridged]


title: On time-local generators of quantum evolution

abstract:
  We present a basic introduction to the dynamics of open quantum systems based
on local-in-time master equations. We characterize the properties of time-local
generators giving rise to legitimate completely positive trace preserving
quantum evolutions. The analysis of Markovian and non-Markovian quantum
dynamics is presented as well. The whole discussion is illustrated by the
family of many instructive examples.


title: Sparse Matrix Factorization

abstract:
  We investigate the problem of factorizing a matrix into several sparse
matrices and propose an algorithm for this under randomness and sparsity
assumptions. This problem can be viewed as a simplification of the deep
learning problem where finding a factorization corresponds to finding edges in
different layers and values of hidden units. We prove that under certain
assumptions for a sparse linear deep network with $n$ nodes in each layer, our
algorithm is able to recover the structure of the network and values of top
layer hidden units for depths up to $\tilde O(n^{1/6})$. We further discuss the
relation among sparse matrix factorization, deep learning, sparse recovery and
dictionary learning.


title: Measurement of the Cotton Mouton effect of water vapour

abstract:
  In this paper we report on a measurement of the Cotton Mouton effect of water
vapour. Measurement performed at room temperature ($T=301$ K) with a wavelength
of 1064 nm gave the value $\Delta n_u = (6.67 \pm 0.45) \cdot 10^{-15}$ for the
unit magnetic birefringence (1 T magnetic field and atmospheric pressure).


title:
Velocity Dispersions and Dynamical Masses for a Large Sample of
  Quiescent Galaxies at z > 1: Improved Measures of the Growth in Mass and Size

abstract:
  We present Keck LRIS spectroscopy for a sample of 103 massive galaxies with
redshifts 0.9 < z < 1.6. Of these, 56 are quiescent with high signal-to-noise
absorption line spectra, enabling us to determine robust stellar velocity
dispersions for the largest sample yet available beyond a redshift of 1.
Together with effective radii measured from deep Hubble Space Telescope images,
we calculate dynamical masses and address key questions relating to the
puzzling size growth of quiescent galaxies over 0 < z < 2. We examine the
relationship between stellar and dynamical masses at high redshift, finding
that it closely follows that determined locally. We also confirm the utility of
the locally-established empirical calibration which enables high-redshift
velocity dispersions to be estimated photometrically, and we determine its
accuracy to be 35%. To address recent suggestions that progenitor bias - the
continued arrival of recently-quenched larger galaxies - can largely explain
the size evolution of quiescent galaxies, we examine the growth at fixed
velocity dispersion assuming this quantity is largely unaffected by the merger
history. We demonstrate that significant size and mass growth have clearly
occurred in individual systems. Parameterizing the relation between mass and
size growth over 0 < z < 1.6 as R \propto M^alpha, we find alpha = 1.6 +- 0.3,
in agreement with theoretical expectations from simulations of minor mergers.
Relaxing the assumption that the velocity dispersion is unchanging, we examine
growth assuming a constant ranking in galaxy velocity dispersion. This approach
is applicable only to the large-dispersion tail of the distribution, but yields
a consistent growth rate of alpha = 1.4 +- 0.2. Both methods confirm that
progenitor bias alone is insufficient to explain our new observations and that
quiescent galaxies have grown in both size and stellar mass over 0 < z < 1.6.


title:
A Study of Actor and Action Semantic Retention in Video Supervoxel
  Segmentation

abstract:
  Existing methods in the semantic computer vision community seem unable to
deal with the explosion and richness of modern, open-source and social video
content. Although sophisticated methods such as object detection or
bag-of-words models have been well studied, they typically operate on low level
features and ultimately suffer from either scalability issues or a lack of
semantic meaning. On the other hand, video supervoxel segmentation has recently
been established and applied to large scale data processing, which potentially
serves as an intermediate representation to high level video semantic
extraction. The supervoxels are rich decompositions of the video content: they
capture object shape and motion well. However, it is not yet known if the
supervoxel segmentation retains the semantics of the underlying video content.
In this paper, we conduct a systematic study of how well the actor and action
semantics are retained in video supervoxel segmentation. Our study has human
observers watching supervoxel segmentation videos and trying to discriminate
both actor (human or animal) and action (one of eight everyday actions). We
gather and analyze a large set of 640 human perceptions over 96 videos in 3
different supervoxel scales. Furthermore, we conduct machine recognition
experiments on a feature defined on supervoxel segmentation, called supervoxel
shape context, which is inspired by the higher order processes in human
perception. Our ultimate findings suggest that a significant amount of
semantics have been well retained in the video supervoxel segmentation and can
be used for further video analysis.


title: Current Services In Cloud Computing: A Survey

abstract:
  Due to the fast development of the Cloud Computing technologies, the rapid
increase of cloud services are became very remarkable. The fact of integration
of these services with many of the modern enterprises cannot be ignored.
Microsoft, Google, Amazon, SalesForce.com and the other leading IT companies
are entered the field of developing these services. This paper presents a
comprehensive survey of current cloud services, which are divided into eleven
categories. Also the most famous providers for these services are listed.
Finally, the Deployment Models of Cloud Computing are mentioned and briefly
discussed.


title: The effect of points fattening on Hirzebruch surfaces

abstract:
  The purpose of this note is to study initial sequences of zero-dimensional
subschemes of Hirzebruch surfaces and classify subschemes whose initial
sequence has the minimal possible growth.


title:
Thermodynamic and transport properties of single crystalline
  RCo$_{2}$Ge$_{2}$ (R = Y, La-Nd, Sm-Tm)

abstract:
  Single crystals of RCo$_{2}$Ge$_{2}$ (R = Y, La-Nd, Sm-Tm) were grown using a
self-flux method and were characterized by room-temperature powder x-ray
diffraction; anisotropic, temperature and field dependent magnetization;
temperature and field dependent, in-plane resistivity; and specific heat
measurements. In this series, the majority of the moment-bearing members order
antiferromagnetically; YCo$_{2}$Ge$_{2}$ and LaCo$_{2}$Ge$_{2}$ are
non-moment-bearing. Ce is trivalent in CeCo$_{2}$Ge$_{2}$ at high temperatures,
and exhibits an enhanced electronic specific heat coefficient due to Kondo
effect at low temperatures. In addition, CeCo$_{2}$Ge$_{2}$ shows two
low-temperature anomalies in temperature-dependent magnetization and specific
heat measurements. Three members (R = Tb-Ho) have multiple phase transitions
above 1.8 K. Eu appears to be divalent with total angular momentum L = 0. Both
EuCo$_{2}$Ge$_{2}$ and GdCo$_{2}$Ge$_{2}$ manifest essentially isotropic
paramagnetic properties consistent with J = S = 7/2. Clear magnetic anisotropy
for rare-earth members with finite L was observed, with ErCo$_{2}$Ge$_{2}$ and
TmCo$_{2}$Ge$_{2}$ manifesting planar anisotropy and the rest members
manifesting axial anisotropy. The experimentally estimated crystal electric
field (CEF) parameters B$_{2}^{0}$ were calculated from the anisotropic
paramagnetic $\theta_{ab}$ and $\theta_{c}$ values and follow a trend that
agrees well with theoretical predictions. The ordering temperatures, T$_{N}$,
as well as the polycrystalline averaged paramagnetic Curie-Weiss temperature,
$\Theta_{avg}$, for the heavy rare-earth members deviate from the de Gennes
scaling, as the magnitude of both are the highest for Tb, which is sometimes
seen for extremely axial systems. Except for SmCo$_{2}$Ge$_{2}$, metamagnetic
transitions were observed at 1.8 K for all members that ordered
antiferromagnetically.


title: Impact of Limpware on HDFS: A Probabilistic Estimation

abstract:
  With the advent of cloud computing, thousands of machines are connected and
managed collectively. This era is confronted with a new challenge: performance
variability, primarily caused by large-scale management issues such as hardware
failures, software bugs, and configuration mistakes. In our previous work we
highlighted one overlooked cause: limpware - hardware whose performance
degrades significantly compared to its specification. We showed that limpware
can cause severe impact in current scale-out systems. In this report, we
quantify how often these scenarios happen in Hadoop Distributed File System.


title: The opaque square

abstract:
  The problem of finding small sets that block every line passing through a
unit square was first considered by Mazurkiewicz in 1916. We call such a set
{\em opaque} or a {\em barrier} for the square. The shortest known barrier has
length $\sqrt{2}+ \frac{\sqrt{6}}{2}= 2.6389\ldots$. The current best lower
bound for the length of a (not necessarily connected) barrier is $2$, as
established by Jones about 50 years ago. No better lower bound is known even if
the barrier is restricted to lie in the square or in its close vicinity. Under
a suitable locality assumption, we replace this lower bound by $2+10^{-12}$,
which represents the first, albeit small, step in a long time toward finding
the length of the shortest barrier. A sharper bound is obtained for interior
barriers: the length of any interior barrier for the unit square is at least $2
+ 10^{-5}$. Two of the key elements in our proofs are: (i) formulas established
by Sylvester for the measure of all lines that meet two disjoint planar convex
bodies, and (ii) a procedure for detecting lines that are witness to the
invalidity of a short bogus barrier for the square.


title:
A Modular, Operator Splitting Scheme for Fluid-Structure Interaction
  Problems with Thick Structures

abstract:
  We present an operator-splitting scheme for fluid-structure interaction (FSI)
problems in hemodynamics, where the thickness of the structural wall is
comparable to the radius of the cylindrical fluid domain. The equations of
linear elasticity are used to model the structure, while the Navier-Stokes
equations for an incompressible viscous fluid are used to model the fluid. The
operator splitting scheme, based on Lie splitting, separates the elastodynamics
structure problem, from a fluid problem in which structure inertia is included
to achieve unconditional stability. We prove energy estimates associated with
unconditional stability of this modular scheme for the full nonlinear FSI
problem defined on a moving domain, without requiring any sub-iterations within
time steps. Two numerical examples are presented, showing excellent agreement
with the results of monolithic schemes. First-order convergence in time is
shown numerically. Modularity, unconditional stability without temporal
sub-iterations, and simple implementation are the features that make this
operator-splitting scheme particularly appealing for multi-physics problems
involving fluid-structure interaction.


title: High-power liquid-lithium jet target for neutron production

abstract:
  A compact Liquid-Lithium Target (LiLiT) was built and tested with a
high-power electron gun at Soreq Nuclear Research Center. The lithium target,
to be bombarded by the high-intensity proton beam of the Soreq Applied Research
Accelerator Facility (SARAF), will constitute an intense source of neutrons
produced by the 7Li(p,n)7Be reaction for nuclear astrophysics research and as a
pilot setup for accelerator-based Boron Neutron Capture Therapy (BNCT). The
liquid-lithium jet target acts both as neutron-producing target and beam dump
by removing the beam thermal power (>5 kW, >1 MW/cm3) with fast transport. The
target was designed based on a thermal model, accompanied by a detailed
calculation of the 7Li(p,n) neutron yield, energy distribution and angular
distribution. Liquid lithium is circulated through the target loop at ~200oC
and generates a stable 1.5 mm-thick film flowing at a velocity up to 7 m/s onto
a concave supporting wall. Electron beam irradiation demonstrated that the
liquid-lithium target can dissipate electron power areal densities of > 4
kW/cm2 and volume power density of ~ 2 MW/cm3 at a lithium flow of ~4 m/s while
maintaining stable temperature and vacuum conditions. The LiLiT setup is
presently in online commissioning stage for high-intensity proton beam
irradiation (1.91- 2.5 MeV, 1-2 mA) at SARAF.


title: Hidden Superconformal Symmetry of the Cosmological Evolution

abstract:
  In the superconformal formulation of supergravity, the standard supergravity
action appears as a result of spontaneous symmetry breaking when the conformal
compensator scalar field, the conformon, acquires a nonzero value, giving rise
to the Planck mass. After that, many symmetries of the original theory become
well hidden, and therefore they are often ignored. However, recent developments
demonstrated that superconformal invariance is more than just a tool: it plays
an important role in generalizing previously existing formulations of
supergravity and developing new classes of inflationary models. In this paper
we describe hidden superconformal symmetry of the cosmological evolution. In
this formulation, inflation can be equivalently described as the conformon
instability, and creation of the universe `from nothing' can be interpreted as
spontaneous symmetry breaking due to emergence of a classical conformon field.
We develop a general formalism that allows to describe the cosmological
evolution simultaneously with the evolution of the conformon. We find a set of
gauge invariant physical observables, including the superconformally invariant
generalizations of the square of the Weyl tensor, which are necessary for
invariant description of the cosmological singularities.

categories: hep-th astro-ph.CO gr-qc hep-ph math-ph math.MP


title:
Area law violation for the mutual information in a nonequilibrium steady
  state

abstract:
  We study the nonequilibrium steady state of an infinite chain of free
fermions, resulting from an initial state where the two sides of the system are
prepared at different temperatures. The mutual information is calculated
between two adjacent segments of the chain and is found to scale
logarithmically in the subsystem size. This provides the first example of the
violation of the area law in a quantum many-body system outside a zero
temperature regime. The prefactor of the logarithm is obtained analytically
and, furthermore, the same prefactor is shown to govern the logarithmic
increase of mutual information in time, before the system relaxes locally to
the steady state.


title:
Systematic Determination of Absolute Absorption Cross-section of
  Individual Carbon Nanotubes

abstract:
  Determination of optical absorption cross-section is always among the central
importance of understanding a material. However its realization on individual
nanostructures, such as carbon nanotubes, is experimentally challenging due to
the small extinction signal using conventional transmission measurements. Here
we develop a technique based on polarization manipulation to enhance the
sensitivity of single-nanotube absorption spectroscopy by two-orders of
magnitude. We systematically determine absorption cross-section over broad
spectral range at single-tube level for more than 50 chirality-defined
single-walled nanotubes. Our data reveals chirality-dependent one-dimensional
photo-physics through the behaviours of exciton oscillator strength and
lifetime. We also establish an empirical formula to predict absorption spectrum
of any nanotube, which provides the foundation to determine quantum
efficiencies in important photoluminescence and photovoltaic processes.


title:
A note on the Trace Theorem for domains which are locally subgraph of a
  Holder continuous function

abstract:
  The purpose of this note is to prove a version of the Trace Theorem for
domains which are locally subgraph of a H\" older continuous function. More
precisely, let $\eta\in C^{0,\alpha}(\omega)$, $0<\alpha<1$ and let
$\Omega_{\eta}$ be a domain which is locally subgraph of a function $\eta$. We
prove that mapping $\gamma_{\eta}:u\mapsto u({\bf x},\eta({\bf x}))$ can be
extended by continuity to a linear, continuous mapping from
$H^1(\Omega_{\eta})$ to $H^s(\omega)$, $s<\alpha/2$. This study is motivated by
analysis of fluid-structure interaction problems.


title:
The proximity force approximation for the Casimir energy of plate-sphere
  and sphere-sphere systems in the presence of one extra compactified universal
  dimension

abstract:
  The Casimir energies for plate-sphere system and sphere-sphere system under
PFA in the presence of one extra compactified universal dimension are analyzed.
We find that the Casimir energy between a plate and a sphere in the case of
sphere-based PFA is divergent. The Casimir energy of plate-sphere system in the
case of plate-based PFA is finite and keeps negative. The extra-dimension
corrections to the Casimir energy will be more manifest if the sphere is larger
or farther away from the plate. It is shown that the negative Casimir energy
for two spheres is also associated with the sizes of spheres and extra space.
The larger spheres and the longer distance between them make the influence from
the additional dimension stronger.


title: U-dualities in Type II string theories and M-theory

abstract:
  In this thesis the recently developed duality covariant approach to string
and M-theory is investigated. In this formalism the U-duality symmetry of
M-theory or T-duality symmetry of Type II string theory becomes manifest upon
extending coordinates that describe a background.
  The effective potential of Double Field Theory is formulated only up to a
boundary term and thus does not capture possible topological effects that may
come from a boundary. By introducing a generalised normal we derive a
manifestly duality covariant boundary term that reproduces the known
Gibbons-Hawking action of General Relativity, if the section condition is
imposed. It is shown that the full potential can be represented as a sum of the
scalar potential of gauged supergravity and a topological term that is a full
derivative. The latter is conjectured to capture non-trivial topological
information of the corresponding background, such as monodromy around an exotic
brane.
  Next we show that the Scherk-Schwarz reduction of M-theory extended geometry
successfully reproduces known structures of maximal gauged supergravities.
Local symmetries of the extended space defined by a generalised Lie derivatives
reduce to gauge transformations and lead to the embedding tensor written in
terms of twist matrices. The scalar potential of maximal gauged supergravity
that follows from the effective potential is shown to be duality invariant with
no need of section condition. Instead, this condition, that assures the closure
of the algebra of generalised diffeomorphisms, takes the form of the quadratic
constraints on the embedding tensor.


title: Frame patterns in n-cycles

abstract:
  In this paper, we study the distribution of the number of occurrences of the
simplest frame pattern, called the $\mu$ pattern, in $n$-cycles. Given an
$n$-cycle $C$, we say that a pair $\langle i,j \rangle$ matches the $\mu$
pattern if $i < j$ and as we traverse around $C$ in a clockwise direction
starting at $i$ and ending at $j$, we never encounter a $k$ with $i < k < j$.
We say that $ \langle i,j \rangle$ is a nontrivial $\mu$-match if $i+1 < j$.
Also, an $n$-cycle $C$ is incontractible if there is no $i$ such that $i+1$
immediately follows $i$ in $C$.
  We show that the number of incontractible $n$-cycles in the symmetric group
$S_n$ is $D_{n-1}$, where $D_n$ is the number of derangements in $S_n$.
Further, we prove that the number of $n$-cycles in $S_n$ with exactly $k$
$\mu$-matches can be expressed as a linear combination of binomial coefficients
of the form $\binom{n-1}{i}$ where $i \leq 2k+1$. We also show that the
generating function $NTI_{n,\mu}(q)$ of $q$ raised to the number of nontrivial
$\mu$-matches in $C$ over all incontractible $n$-cycles in $S_n$ is a new
$q$-analogue of $D_{n-1}$, which is different from the $q$-analogues of the
derangement numbers that have been studied by Garsia and Remmel and by Wachs.
We show that there is a rather surprising connection between the charge
statistic on permutations due to Lascoux and Sch\"uzenberger and our
polynomials in that the coefficient of the smallest power of $q$ in
$NTI_{2k+1,\mu}(q)$ is the number of permutations in $S_{2k+1}$ whose charge
path is a Dyck path. Finally, we show that $NTI_{n,\mu}(q)|_{q^{\binom{n-1}{2}
-k}}$ and $NT_{n,\mu}(q)|_{q^{\binom{n-1}{2} -k}}$ are the number of partitions
of $k$ for sufficiently large $n$.


title: Quantum ideal hydrodynamics on the lattice

abstract:
  After discussing the problem of defining the hydrodynamic limit from
microscopic scales, we give an introduction to ideal hydrodynamics in the
Lagrange picture, and show that it can be viewed as a field theory, which can
be quantized using the usual Feynman sum-over-paths prescription. We then argue
that this picture can be connected to the usually neglected thermal microscopic
scale in the hydrodynamic expansion. After showing that this expansion is
generally non-perturbative, we show how the lattice can be used to understand
the impact quantum and thermal fluctuations can have on the fluid behavior.


title:
On the growth of solutions to the minimal surface equation over domains
  containing a halfplane

abstract:
  We consider minimal graphs u(x,y)>0 over unbounded domains D (with u
vanishing on the boundary of D). Assuming D contains a sector properly
containing a halfplane, we obtain estimates on growth and provide examples
illustrating a range of growth.


title: New Concepts for Old Black Holes

abstract:
  It has been argued that the AMPS paradox implies catastrophic breakdown of
the equivalence principle in the neighborhood of a black hole horizon, or even
the non-existence of any spacetime at all behind the horizon. Maldacena and the
author suggested a different resolution of the paradox based on the close
relationship between Einstein-Rosen bridges and Einstein-Podolsky-Rosen
entanglement. In this paper the new mechanisms required by the proposal are
reviewed: the ER=EPR connection: precursors: timefolds: and the black hole
interior as a fault-tolerant, negative information message. Along the way a
model of an ADS black hole as a single long-string is explained, and used to
clarify the relation between Wilson loops and precursors.


title:
Eliminating Network Protocol Vulnerabilities Through Abstraction and
  Systems Language Design

abstract:
  Incorrect implementations of network protocol message specifications affect
the stability, security, and cost of network system development. Most
implementation defects fall into one of three categories of well defined
message constraints. However, the general process of constructing network
protocol stacks and systems does not capture these categorical con- straints.
We introduce a systems programming language with new abstractions that capture
these constraints. Safe and efficient implementations of standard message
handling operations are synthesized by our compiler, and whole-program analysis
is used to ensure constraints are never violated. We present language examples
using the OpenFlow protocol.


title:
The de la Vallee Poussin mean and polynomial approximation for
  exponential weight

abstract:
  We study the de la Vallee Poussin mean for exponential weights and give a
polynomial approximation on real line. H. N. Mhasker proved the corresponding
result for Freud-type weights. Our proof is valid for Erdos-type weights.


title: The Tricomi Equation

abstract:
  The Tricomi equation is a second-order partial differential equation of mixed
elliptic-hyperbolic type. It was first analyzed in the work by Francesco
Giacomo Tricomi (1923) on the well-posedness of a boundary value problem. The
Tricomi equation can be transformed into the corresponding elliptic or
hyperbolic Euler-Poisson-Darboux equation, and has a close connection with
transonic flow and isometric embedding. It has different degeneracy from a
closely related equation, the Keldysh equation.


title: Untwisting algebras with van den Bergh duality into Calabi-Yau algebras

abstract:
  Jake Goodman and Ulrich Kr\"ahmer have recently shown that a twisted
Calabi-Yau algebra $A$ with modular automorphism $\sigma$ and dimension $d$ can
be "untwisted," in the sense that the Ore extensions $A[X;\sigma]$ and
$A[X^{\pm1};\sigma]$ are Calabi-Yau algebras of dimension $d+1$. In this note
we show that this in fact extends more generally to the case where we start
with an algebra with van den Bergh duality.


title: Spectral dimension of quantum geometries

abstract:
  The spectral dimension is an indicator of geometry and topology of spacetime
and a tool to compare the description of quantum geometry in various approaches
to quantum gravity. This is possible because it can be defined not only on
smooth geometries but also on discrete (e.g., simplicial) ones. In this paper,
we consider the spectral dimension of quantum states of spatial geometry
defined on combinatorial complexes endowed with additional algebraic data: the
kinematical quantum states of loop quantum gravity (LQG). Preliminarily, the
effects of topology and discreteness of classical discrete geometries are
studied in a systematic manner. We look for states reproducing the spectral
dimension of a classical space in the appropriate regime. We also test the
hypothesis that in LQG, as in other approaches, there is a scale dependence of
the spectral dimension, which runs from the topological dimension at large
scales to a smaller one at short distances. While our results do not give any
strong support to this hypothesis, we can however pinpoint when the topological
dimension is reproduced by LQG quantum states. Overall, by exploring the
interplay of combinatorial, topological and geometrical effects, and by
considering various kinds of quantum states such as coherent states and their
superpositions, we find that the spectral dimension of discrete quantum
geometries is more sensitive to the underlying combinatorial structures than to
the details of the additional data associated with them.


title: Hybridizing localized and itinerant electrons: a recipe for pseudogaps

abstract:
  In a system where selective Mott localization is realized, some electrons
show a gap to charge excitations while others do not. A hybridization between
these two kind of electrons will lead to a smoothening of this sharp difference
and can even bring the system back to a complete delocalization. We show here
that there is a large region of parameters at finite hybridization where the
selective localization persists and the system shows a partial filling of the
selective gap with incoherent states, giving rise to a pseudogap. This result
is illustrated here in a two orbital Hubbard model with Hund's coupling, but is
based on quite general assumptions and should hold for a larger class of
systems, and possibly be a paradigm for the pseudogap mechanism in cuprates.


title:
Schouten identities for Feynman graph amplitudes; the Master Integrals
  for the two-loop massive sunrise graph

abstract:
  A new class of identities for Feynman graph amplitudes, dubbed Schouten
identities, valid at fixed integer value of the dimension d is proposed. The
identities are then used in the case of the two loop sunrise graph with
arbitrary masses for recovering the second order differential equation for the
scalar amplitude in d=2 dimensions, as well as a chained sets of equations for
all the coefficients of the expansions in (d-2). The shift from $d\approx2$ to
$d\approx4$ dimensions is then discussed.


title:
Device-dependent and device-independent quantum key distribution without
  a shared reference frame

abstract:
  Standard quantum key distribution (QKD) protocols typically assume that the
distant parties share a common reference frame. In practice, however,
establishing and maintaining a good alignment between distant observers is
rarely a trivial issue, which may significantly restrain the implementation of
long-distance quantum communication protocols. Here we propose simple QKD
protocols that do not require the parties to share any reference frame, and
study their security and feasibility in both the usual device-dependent
case--in which the two parties use well characterized measurement devices--as
well as in the device-independent case--in which the measurement devices can be
untrusted, and the security relies on the violation of a Bell inequality. To
illustrate the practical relevance of these ideas, we present a
proof-of-principle demonstration of our protocols using polarization entangled
photons distributed over a coiled 10-km-long optical fiber. We consider two
situations, in which either the fiber spool freely drifts, or randomly chosen
polarization transformations are applied. The correlations obtained from
measurements allow, with high probability, to generate positive asymptotic
secret key rates in both the device-dependent and device-independent scenarios
(under the fair-sampling assumption for the latter case).


title:
Estimating Stellar Radial Velocity Variability from Kepler and GALEX:
  Implications for the Radial Velocity Confirmation of Exoplanets

abstract:
  We cross-match the GALEX and Kepler surveys to create a unique dataset with
both ultraviolet (UV) measurements and highly precise photometric variability
measurements in the visible light spectrum. As stellar activity is driven by
magnetic field modulations, we have used UV emission from the magnetically
heated gas in the stellar atmosphere to serve as our proxy for the more
well-known stellar activity indicator, R'HK. The R'HK approximations were in
turn used to estimate the level of astrophysical noise expected in radial
velocity (RV) measurements and these were then searched for correlations with
photometric variability. We find significant scatter in our attempts to
estimate RV noise for magnetically active stars, which we attribute to
variations in the phase and strength of the stellar magnetic cycle that drives
the activity of these targets. However, for stars we deem to be magnetically
quiet, we do find a clear correlation between photometric variability and
estimated levels of RV noise (with variability up to ~ 10 m/s). We conclude,
that for these quiet stars, we can use photometric measurements as a proxy to
estimate the RV noise expected. As a result, the procedure outlined in this
paper may help select targets best-suited for RV follow-up necessary for planet
confirmation.


title: Synchronous control of dual-channel all-optical multi-state switching

abstract:
  We have experimentally observed optical multistabilities (OMs) simultaneously
on both the signal and generated Stokes fields in an optical ring cavity with a
coherently-prepared multilevel atomic medium. The two observed OMs, which are
governed by different physical processes, are coupled via the multilevel atomic
medium and exhibit similar threshold behaviors. By modulating the cavity input
(signal) field with positive or negative pulses, dual-channel all-optical
multi-state switching has been realized and synchronously controlled, which can
be useful for increasing communication and computation capacities.


title:
Testing Asteroseismology with red giants in eclipsing binary and
  multiple-star systems

abstract:
  Red-giant stars are proving to be an incredible source of information for
testing models of stellar evolution, as asteroseismology has opened up a window
into their interiors. Such insights are a direct result of the unprecedented
data from space missions CoRoT and Kepler as well as recent theoretical
advances. Eclipsing binaries are also fundamental astrophysical objects, and
when coupled with asteroseismology, they would provide two independent methods
to obtain masses and radii and exciting opportunities to develop highly
constrained stellar models. Gaulme et al. (2013) reported the discovery of 13
bona fide candidates (12 previously unknown) to be eclipsing binaries, one to
be an non-eclipsing binary with tidally induced oscillations, and 10 more to be
hierarchical triple systems, all of which include a pulsating red giant. When
ground-based support in terms of atmospheric abundance and radial velocities
are completed, these red giants in eclipsing binary systems have the potential
to become some of the most accurately studied stars.


title:
Deformations of functions on surfaces by isotopic to the identity
  diffeomorphisms

abstract:
  Let $M$ be a compact surface and $P$ be either $\mathbb{R}$ or $S^1$. For a
smooth map $f:M\to P$ and a closed subset $V\subset M$, denote by
$\mathcal{S}(f,V)$ the group of diffeomorphisms $h$ of $M$ preserving $f$, i.e.
satisfying the relation $f\circ h = f$, and fixed on $V$. Let also
$\mathcal{S}'(f,V)$ be its subgroup consisting of diffeomorphisms isotopic
relatively $V$ to the identity map $\mathrm{id}_{M}$ via isotopies that are not
necessarily $f$-preserving. The groups $\pi_0 \mathcal{S}(f,V)$ and $\pi_0
\mathcal{S}'(f,V)$ can be regarded as analogues of mapping class group for
$f$-preserving diffeomorphisms. The paper describes precise algebraic structure
of groups $\pi_0 \mathcal{S}'(f,V)$ and some of their subgroups and quotients
for a large class of smooth maps $f:M\to P$ containing all Morse maps, where
$M$ is orientable and distinct from $2$-sphere and $2$-torus. In particular, it
is shown that for certain subsets $V$ "adapted" in some sense with $f$, the
groups $\pi_0 \mathcal{S}'(f,V)$ are solvable and Bieberbach.


title: Network Traffic Adaptation For Cloud Games

abstract:
  With the arrival of cloud technology, game accessibility and ubiquity have a
bright future; Games can be hosted in a centralize server and accessed through
the Internet by a thin client on a wide variety of devices with modest
capabilities: cloud gaming. However, current cloud gaming systems have very
strong requirements in terms of network resources, thus reducing the
accessibility and ubiquity of cloud games, because devices with little
bandwidth and people located in area with limited and unstable network
connectivity, cannot take advantage of these cloud services. In this paper we
present an adaptation technique inspired by the level of detail (LoD) approach
in 3D graphics. It delivers multiple platform accessibility and network
adaptability, while improving user's quality of experience (QoE) by reducing
the impact of poor and unstable network parameters (delay, packet loss, jitter)
on game interactivity. We validate our approach using a prototype game in a
controlled environment and characterize the user QoE in a pilot experiment. The
results show that the proposed framework provides a significant QoE
enhancement.


title:
Fidelity susceptibility and topological phase transition of a two
  dimensional spin-orbit coupled Fermi superfluid

abstract:
  We investigate the fidelity susceptibility (FS) of a two-dimensional
spin-orbit coupled (SOC) Fermi superfluid and the topological phase transition
driven by a Zeeman field in the perspective of its ground-state wave-function.
Without Zeeman coupling, FS shows new features characterizing the BCS-BEC
crossover induced by SOC. In the presence of a Zeeman field, the topological
phase transition is explored using both FS and the topological invariant. In
particular, we obtain the analytical result of the topological invariant which
explicitly demonstrates that the topological phase transition corresponds to a
sudden change of the ground state wave-function. Consequently, FS diverges at
the phase transition point with its critical behavior being: $\chi \propto
ln|h-h_{c}|$ . Based on this observation, we conclude that the topological
phase transition can be detected by measuring the momentum distribution in cold
atoms experiment.


title:
Sequential Tests of Multiple Hypotheses Controlling False Discovery and
  Nondiscovery Rates

abstract:
  We propose a general and flexible procedure for testing multiple hypotheses
about sequential (or streaming) data that simultaneously controls both the
false discovery rate (FDR) and false nondiscovery rate (FNR) under minimal
assumptions about the data streams which may differ in distribution, dimension,
and be dependent. All that is needed is a test statistic for each data stream
that controls the conventional type I and II error probabilities, and no
information or assumptions are required about the joint distribution of the
statistics or data streams. The procedure can be used with sequential, group
sequential, truncated, or other sampling schemes. The procedure is a natural
extension of Benjamini and Hochberg's (1995) widely-used fixed sample size
procedure to the domain of sequential data, with the added benefit of
simultaneous FDR and FNR control that sequential sampling affords. We prove the
procedure's error control and give some tips for implementation in commonly
encountered testing situations.