title: Reversible Simulations of Elastic Collisions

abstract:
  Consider a system of N identical hard spherical particles moving in a
d-dimensional box and undergoing elastic, possibly multi-particle, collisions.
We develop a new algorithm that recovers the pre-collision state from the
post-collision state of the system, across a series of consecutive collisions,
with essentially no memory overhead. The challenge in achieving reversibility
for an n-particle collision (where, n << N) arises from the presence of nd-d-1
degrees of freedom during each collision, and from the complex geometrical
constraints placed on the colliding particles. To reverse the collisions in a
traditional simulation setting, all of the particular realizations of these
degrees of freedom during the forward simulation must be saved. This limitation
is addressed here by first performing a pseudo-randomization of angles,
ensuring determinism in the reverse path for any values of n and d. To address
the more difficult problem of geometrical and dynamic constraints, a new
approach is developed which correctly samples the constrained phase space. Upon
combining the pseudo-randomization with correct phase space sampling, perfect
reversibility of collisions is achieved, as illustrated for n <= 3, d=2, and
n=2, d=3 (and, in principle, generalizable to larger n). This result enables
for the first time reversible simulations of elastic collisions with
essentially zero memory accumulation. The reverse computation methodology
uncovers important issues of irreversibility in conventional models, and the
difficulties encountered in arriving at a reversible model for one of the most
basic physical system processes, namely, elastic collisions for hard spheres.
Insights and solution methodologies, with regard to accurate phase space
coverage with reversible random sampling proposed in this context, can help
serve as models and/or starting points for other reversible simulations.


title: Motivating quantum field theory: the boosted particle in a box

abstract:
  It is a maxim often stated, yet rarely illustrated, that the combination of
special relativity and quantum mechanics necessarily leads to quantum field
theory. An elementary illustration is provided, using the familiar particle in
a box, boosted to relativistic speeds. It is shown that quantum fluctuations of
momentum lead to energy fluctuations, that are inexplicable without a framework
that endows the vacuum with dynamical degrees of freedom and allows particle
creation/annihilation.


title:
On the Relation of Delay Equations to First-Order Hyperbolic Partial
  Differential Equations

abstract:
  This paper establishes the equivalence between systems described by a single
first-order hyperbolic partial differential equation and systems described by
integral delay equations. System-theoretic results are provided for both
classes of systems (among them converse Lyapunov results). The proposed
framework can allow the study of discontinuous solutions for nonlinear systems
described by a single first-order hyperbolic partial differential equation
under the effect of measurable inputs acting on the boundary and/or on the
differential equation. An illustrative example shows that the conversion of a
system described by a single first-order hyperbolic partial differential
equation to an integral delay system can simplify considerably the solution of
the corresponding robust feedback stabilization problem.


title:
A new perspective on the Propagation-Separation approach: Taking
  advantage of the propagation condition

abstract:
  The Propagation-Separation approach is an iterative procedure for pointwise
estimation of local constant and local polynomial functions. The estimator is
defined as a weighted mean of the observations with data-driven weights. Within
homogeneous regions it ensures a similar behavior as non-adaptive smoothing
(propagation), while avoiding smoothing among distinct regions (separation). In
order to enable a proof of stability of estimates, the authors of the original
study introduced an additional memory step aggregating the estimators of the
successive iteration steps. Here, we study theoretical properties of the
simplified algorithm, where the memory step is omitted. In particular, we
introduce a new strategy for the choice of the adaptation parameter yielding
propagation and stability for local constant functions with sharp
discontinuities.


title: Stability of the photon indices in Z-source GX 340+0 for spectral states

abstract:
  We show an analysis of the spectral and timing properties of X-ray radiation
from Z-source during its evolutions when the electron temperature of the
Transition Layer (TL) kT_e monotonically decreases from 21 to 3 keV. We analyze
episodes observed with the BeppoSAX and Rossi X-ray Timing Explorer (RXTE). We
reveal that the X-ray broad-band energy spectra during all spectral states can
be reproduced by a {physical} model, composed of a soft blackbody component,
{two Comptonized components (both due to the presence of that TL that
up-scatters both seed photons of T_{s1}<1 keV coming from the disk (first
component, Comptb1), and seed photons of temperature T_{s2}<1.5 keV coming from
the neutron star (second component, Comptb2) and the iron-line (Gaussian)
component. Spectral analysis using this model indicates that the photon
power-law indices Gamma_{com1} and Gamma_{com2} of the Comptonized components
are almost constant, Gamma_{com1} and Gamma_{com2} ~ 2 when kT_e changes from 3
to 21 keV along Z-track. We interpret the detected quasi-stability of the
indices of Comptonized components near a value of 2. Furthermore, this index
stability now found for the Comptonized spectral components of Z-source GX
340+0 is similar to that was previously established in the atoll sources
4U~1728-34, GX 3+1 and early proposed for a number of X-ray neutron stars
(NSs). This behavior of NSs both for atoll and Z-sources, is essentially
different from that observed in black hole binaries where Gamma_{com} increases
during a spectral evolution from the low state to the high state and ultimately
saturates at high mass accretion rate.


title:
Dynamic Configuration of Sensors Using Mobile Sensor Hub in Internet of
  Things Paradigm

abstract:
  Internet of Things (IoT) envisions billions of sensors to be connected to the
Internet. By deploying intelligent low-level computational devices such as
mobile phones in-between sensors and cloud servers, we can reduce data
communication with the use of intelligent processing such as fusing and
filtering sensor data, which saves significant amount of energy. This is also
ideal for real world sensor deployments where connecting sensors directly to a
computer or to the Internet is not practical. Most of the leading IoT
middleware solutions require manual and labour intensive tasks to be completed
in order to connect a mobile phone to them. In this paper we present a mobile
application called Mobile Sensor Hub (MoSHub). It allows variety of different
sensors to be connected to a mobile phone and send the data to the cloud
intelligently reducing network communication. Specifically, we explore
techniques that allow MoSHub to be connected to cloud based IoT middleware
solutions autonomously. For our experiments, we employed Global Sensor Network
(GSN) middleware to implement and evaluate our approach. Such automated
configuration reduces significant amount of manual labour that need to be
performed by technical experts otherwise. We also evaluated different methods
that can be used to automate the configuration process.


title:
An extension of the Wright's 3/2-theorem for the KPP-Fisher delayed
  equation

abstract:
  We present a short proof of the following natural extension of the famous
Wright's 3/2-stability theorem: the conditions $\tau \leq 3/2, \ c \geq 2$
imply the presence of the positive traveling fronts (not necessarily monotone)
$u = \phi(x\cdot \nu+ct), \ |\nu| =1,$ in the delayed KPP-Fisher equation
$u_t(t,x) = \Delta u(t,x) + u(t,x)(1-u(t-\tau,x))$, $u\geq 0,$ $x \in \R^m.$


title:
Blow-up of the mean curvature at the first singular time of the mean
  curvature flow

abstract:
  It is conjectured that the mean curvature blows up at the first singular time
of the mean curvature flow in Euclidean space, at least in dimensions less or
equal to 7. We show that the mean curvature blows up at the singularities of
the mean curvature flow starting from an immersed closed hypersurface with
small L^2-norm of the traceless second fundamental form (observe that the
initial hypersurface is not necessarily convex). As a consequence of the proof
of this result we also obtain the dynamic stability of a sphere along the mean
curvature flow with respect to the L^2-norm.


title:
The Design and Demonstration of an Actor-Based, Application-Aware Access
  Control Evaluation Framework

abstract:
  To date, most work regarding the formal analysis of access control schemes
has focused on quantifying and comparing the expressive power of a set of
schemes. Although expressive power is important, it is a property that exists
in an absolute sense, detached from the application-specific context within
which an access control scheme will ultimately be deployed. In this paper, by
contrast, we formalize the access control suitability analysis problem, which
seeks to evaluate the degree to which a set of candidate access control schemes
can meet the needs of an application-specific workload. This process involves
both reductions to assess whether a scheme is capable of implementing a
workload, as well as cost analysis using ordered measures to quantify the
overheads of using each candidate scheme to service the workload. We develop a
mathematical framework for analyzing instances of the suitability analysis
problem, and evaluate this framework both formally (by quantifying its
efficiency and accuracy properties) and practically (by exploring a group-based
messaging workload from the literature). An ancillary contribution of our work
is the identification of auxiliary machines, which are a useful class of
modifications that can be made to enhance the expressive power of an access
control scheme without negatively impacting the safety properties of the
scheme.


title: Multiple zeta functions and double wrapping in planar N=4 SYM

abstract:
  Using the FiNLIE solution of the AdS/CFT Y-system, we compute the anomalous
dimension of the Konishi operator in planar N=4 SYM up to eight loops, i.e. up
to the leading double wrapping order. At this order a non reducible
Euler-Zagier sum, zeta(1,2,8), appears for the first time. We find that at all
orders in perturbation, every spectral-dependent quantity of the Y-system is
expressed through multiple Hurwitz zeta functions, hence we provide a
Mathematica package to manipulate these functions, including the particular
case of Euler-Zagier sums. Furthermore, we conjecture that only Euler-Zagier
sums can appear in the answer for the anomalous dimension at any order in
perturbation theory.
  We also resum the leading transcendentality terms of the anomalous dimension
at all orders, obtaining a simple result in terms of Bessel functions. Finally,
we demonstrate that exact Bethe equations should be related to an absence of
poles condition that becomes especially nontrivial at double wrapping.


title:
Implications of mass and energy loss due to coronal mass ejections on
  magnetically-active stars

abstract:
  Analysis of a database of solar coronal mass ejections (CMEs) and associated
flares over the period 1996-2007 finds well-behaved power law relationships
between the 1-8 AA flare X-ray fluence and CME mass and kinetic energy. We
extrapolate these relationships to lower and higher flare energies to estimate
the mass and energy loss due to CMEs from stellar coronae, assuming that the
observed X-ray emission of the latter is dominated by flares with a frequency
as a function of energy dn/dE=kE^-alpha. For solar-like stars at saturated
levels of X-ray activity, the implied losses depend fairly weakly on the
assumed value of alpha and are very large: M_dot ~ 5x10^-10 M_sun/yr and E_dot
~ 0.1L_sun. In order to avoid such large energy requirements, either the
relationships between CME mass and speed and flare energy must flatten for
X-ray fluence >~ 10^31 erg, or the flare-CME association must drop
significantly below 1 for more energetic events. If active coronae are
dominated by flares, then the total coronal energy budget is likely to be up to
an order of magnitude larger than the canonical 10^-3 L_bol X-ray saturation
threshold. This raises the question of what is the maximum energy a magnetic
dynamo can extract from a star? For an energy budget of 1% of L_bol, the CME
mass loss rate is about 5x10^-11 M_sun/yr.


title:
About the homological discrete Conley index of isolated invariant
  acyclic continua

abstract:
  This article includes an almost self-contained exposition on the discrete
Conley index and its duality. We work with a local homeomorphism of
$\mathds{R}^d$ and an invariant and isolated acyclic continuum, such as a
cellular set or a fixed point. In this setting, we obtain a complete
description of the first discrete homological Conley index, which is periodic,
that enforces a combinatorial behavior of higher indices. As a consequence, we
prove that isolated (as an invariant set) fixed points of orientation-reversing
homeomorphisms of $\mathds{R}^3$ have fixed point index $\le 1$ and, as a
corollary, that there are no minimal orientation-reversing homeomorphisms in
$\mathds{R}^3$.


title: Lipschitz geometry of complex curves

abstract:
  We describe the Lipschitz geometry of complex curves. For the most part this
is well known material, but we give a stronger version even of known results.
In particular, we give a quick proof, without any analytic restrictions, that
the outer Lipschitz geometry of a germ of a complex plane curve determines and
is determined by its embedded topology. This was first proved by Pham and
Teissier, but in an analytic category.


title: Symplectic Semiclassical Wave Packet Dynamics

abstract:
  The paper gives a symplectic-geometric account of semiclassical Gaussian wave
packet dynamics. We employ geometric techniques to "strip away" the symplectic
structure behind the time-dependent Schr\"odinger equation and incorporate it
into semiclassical wave packet dynamics. We show that the Gaussian wave packet
dynamics is a Hamiltonian system with respect to the symplectic structure,
apply the theory of symplectic reduction and reconstruction to the dynamics,
and discuss dynamic and geometric phases in semiclassical mechanics. A simple
harmonic oscillator example is worked out to illustrate the results: We show
that the reduced semiclassical harmonic oscillator dynamics is completely
integrable by finding the action--angle coordinates for the system, and
calculate the associated dynamic and geometric phases explicitly. We also
propose an asymptotic approximation of the potential term that provides a
practical semiclassical correction term to the approximation by Heller.
Numerical results for a simple one-dimensional example show that the
semiclassical correction term realizes a semiclassical tunneling.


title:
Interpreting motion and force for narrow-band intermodulation atomic
  force microscopy

abstract:
  Intermodulation atomic force microscopy (ImAFM) is a mode of dynamic atomic
force microscopy that probes the nonlinear tip-surface force by measurement of
the mixing of multiple tones in a frequency comb. A high $Q$ cantilever
resonance and a suitable drive comb will result in tip motion described by a
narrow-band frequency comb. We show by a separation of time scales, that such
motion is equivalent to rapid oscillations at the cantilever resonance with a
slow amplitude and phase or frequency modulation. With this time domain
perspective we analyze single oscillation cycles in ImAFM to extract the
Fourier components of the tip-surface force that are in-phase with tip motion
($F_I$) and quadrature to the motion ($F_Q$). Traditionally, these force
components have been considered as a function of the static probe height only.
Here we show that $F_I$ and $F_Q$ actually depend on both static probe height
and oscillation amplitude. We demonstrate on simulated data how to reconstruct
the amplitude dependence of $F_I$ and $F_Q$ from a single ImAFM measurement.
Furthermore, we introduce ImAFM approach measurements with which we reconstruct
the full amplitude and probe height dependence of the force components $F_I$
and $F_Q$, providing deeper insight into the tip-surface interaction. We
demonstrate the capabilities of ImAFM approach measurements on a polystyrene
polymer surface.


title:
Infrared Transmission Spectroscopy of the Exoplanets HD209458b and XO-1b
  Using the Wide Field Camera-3 on the Hubble Space Telescope

abstract:
  Exoplanetary transmission spectroscopy in the near-infrared using
Hubble/NICMOS is currently ambiguous because different observational groups
claim different results from the same data, depending on their analysis
methodologies. Spatial scanning with Hubble/WFC3 provides an opportunity to
resolve this ambiguity. We here report WFC3 spectroscopy of the giant planets
HD209458b and XO-1b in transit, using spatial scanning mode for maximum
photon-collecting efficiency. We introduce an analysis technique that derives
the exoplanetary transmission spectrum without the necessity of explicitly
decorrelating instrumental effects, and achieves nearly photon-limited
precision even at the high flux levels collected in spatial scan mode. Our
errors are within 6-percent (XO-1) and 26-percent (HD209458b) of the
photon-limit at a spectral resolving power of 70, and are better than
0.01-percent per spectral channel. Both planets exhibit water absorption of
approximately 200 ppm at the water peak near 1.38 microns. Our result for XO-1b
contradicts the much larger absorption derived from NICMOS spectroscopy. The
weak water absorption we measure for HD209458b is reminiscent of the weakness
of sodium absorption in the first transmission spectroscopy of an exoplanet
atmosphere by Charbonneau et al. (2002). Model atmospheres having
uniformly-distributed extra opacity of 0.012 cm^2 per gram account
approximately for both our water measurement and the sodium absorption in this
planet. Our results for HD209458b support the picture advocated by Pont et al.
(2013) in which weak molecular absorptions are superposed on a transmission
spectrum that is dominated by continuous opacity due to haze and/or dust.
However, the extra opacity needed for HD209458b is grayer than for HD189733b,
with a weaker Rayleigh component.


title: A Generalized Ito Formula

abstract:
  An Ito formula is developed in a context consistent with the development of
abstract existence and unique- ness theorems for nonlinear stochastic partial
differential equations, which are singular or degenerate. This is a
generalization of an earlier Ito formula for Gelfand triples. After this, an
existence theorem is presented for some singular and degenerate stochastic
equations followed by a few examples.


title:
Evolvability Is Inevitable: Increasing Evolvability Without the Pressure
  to Adapt

abstract:
  Why evolvability appears to have increased over evolutionary time is an
important unresolved biological question. Unlike most candidate explanations,
this paper proposes that increasing evolvability can result without any
pressure to adapt. The insight is that if evolvability is heritable, then an
unbiased drifting process across genotypes can still create a distribution of
phenotypes biased towards evolvability, because evolvable organisms diffuse
more quickly through the space of possible phenotypes. Furthermore, because
phenotypic divergence often correlates with founding niches, niche founders may
on average be more evolvable, which through population growth provides a
genotypic bias towards evolvability. Interestingly, the combination of these
two mechanisms can lead to increasing evolvability without any pressure to
out-compete other organisms, as demonstrated through experiments with a series
of simulated models. Thus rather than from pressure to adapt, evolvability may
inevitably result from any drift through genotypic space combined with
evolution's passive tendency to accumulate niches.


title:
Magnetic, electronic and vibrational properties of metal and fluorinated
  metal phthalocyanines

abstract:
  The magnetic and electronic properties of metal phthalocyanines (MPc) and
fluorinated metal phthalocyanines (F$_{16}$MPc) are studied by means of spin
density functional theory (SDFT). Several metals (M) such as Ca, all first
d-row transition metals and Ag are investigated. By considering different open
shell transition metals it is possible to tune the electronic properties of
MPc, in particular the electronic molecular gap and total magnetic moment.
Besides assigning the structural and electronic properties of MPc and
F$_{16}$MPc, the vibrational modes analysis of the ScPc\textendash ZnPc series
have been studied and correlated to experimental measurements when available.


title: Substitution and $\chi$-Boundedness

abstract:
  A class $\mathcal{G}$ of graphs is said to be {\em $\chi$-bounded} if there
is a function $f:\mathbb{N} \rightarrow \mathbb{R}$ such that for all $G \in
\mathcal{G}$ and all induced subgraphs $H$ of $G$, $\chi(H) \leq f(\omega(H))$.
In this paper, we show that if $\mathcal{G}$ is a $\chi$-bounded class, then so
is the closure of $\mathcal{G}$ under any one of the following three
operations: substitution, gluing along a clique, and gluing along a bounded
number of vertices. Furthermore, if $\mathcal{G}$ is $\chi$-bounded by a
polynomial (respectively: exponential) function, then the closure of
$\mathcal{G}$ under substitution is also $\chi$-bounded by some polynomial
(respectively: exponential) function. In addition, we show that if
$\mathcal{G}$ is a $\chi$-bounded class, then the closure of $\mathcal{G}$
under the operations of gluing along a clique and gluing along a bounded number
of vertices together is also $\chi$-bounded, as is the closure of $\mathcal{G}$
under the operations of substitution and gluing along a clique together.


title: A Geometric Knotspace Template

abstract:
  Early last century witnessed both the complete classification of
2-dimensional manifolds and a proof that classification of 4-dimensional
manifolds is undecidable, setting up 3-dimensional manifolds as a central
battleground of topology to this day. A rather important subset of the
3-manifolds has turned out to be the knotspaces, the manifolds left when a thin
tube around a knot in 3D space is excised. Given a knot diagram it would be
desirable to provide as compact a description of its knotspace as feasible;
hitherto this has been done by computationally tessellating the knotspace of a
given knot into polyhedral complexes using ad hoc methods of uncontrolled
computational complexity. Here we present an extremely compact representation
of the knotspace obtainable directly from a knot diagram; more technically, an
explicit, geometrically-inspired polygonal tessellation of a deformation
retract of the knotspace of arbitrary knots and links. Our template can be
constructed directly from a planar presentation of the knot with C crossings
using at most 12C polygons bounded by 64C edges, in time O(C). We show the
utility of our template by deriving a novel presentation of the fundamental
group, from which we motivate a measure of complexity of the knot diagram.

categories: math.GT math-ph math.MP physics.bio-ph physics.comp-ph


title: On Liouville systems at critical parameters, Part 1: one bubble

abstract:
  In this paper we consider bubbling solutions to the general Liouville system:
\label{abeq1} \Delta_g u_i^k+\sum_{j=1}^n a_{ij}\rho_j^k(\frac{h_j
e^{u_j^k}}{\int h_j e^{u_j^k}}-1)=0\quad\text{in}M, i=1,...,n (n\ge 2) where
$(M,g)$ is a Riemann surface, and $A=(a_{ij})_{n\times n}$ is a constant
non-negative matrix and $\rho_j^k\to \rho_j$ as $k\to \infty$. Among other
things we prove the following sharp estimates. The location of the blowup
point. The convergence rate of $\rho_j^k-\rho_j$, $j=1,..,n$. These results are
of fundamental importance for constructing bubbling solutions. It is
interesting to compare the difference between the general Liouville system and
the SU(3) Toda system on estimates (1) and (2).


title:
Genetic draft, selective interference, and population genetics of rapid
  adaptation

abstract:
  To learn about the past from a sample of genomic sequences, one needs to
understand how evolutionary processes shape genetic diversity. Most population
genetic inference is based on frameworks assuming adaptive evolution is rare.
But if positive selection operates on many loci simultaneously, as has recently
been suggested for many species including animals such as flies, a different
approach is necessary. In this review, I discuss recent progress in
characterizing and understanding evolution in rapidly adapting populations
where random associations of mutations with genetic backgrounds of different
fitness, i.e., genetic draft, dominate over genetic drift. As a result, neutral
genetic diversity depends weakly on population size, but strongly on the rate
of adaptation or more generally the variance in fitness. Coalescent processes
with multiple mergers, rather than Kingman's coalescent, are appropriate
genealogical models for rapidly adapting populations with important
implications for population genetic inference.


title: Deformations and obstructions of pairs (X,D)

abstract:
  We study deformations of pairs (X,D), with X smooth projective variety and D
a smooth or a normal crossing divisor, defined over an algebraically closed
field of characteristic 0. Using the differential graded Lie algebras theory
and the Cartan homotopy construction, we are able to prove in a completely
algebraic way the unobstructedness of the deformations of the pair (X,D) in
many cases, e.g., whenever (X,D) is a log Calabi-Yau pair, in the case of a
smooth divisor D in a Calabi Yau variety X and when D is a smooth divisor in
|-m K_X|, for some positive integer m.


title: Observational Constraints on Local Lorentz Invariance

abstract:
  The idea that local Lorentz invariance might be violated due to new physics
that goes beyond the Standard Model of particle physics and Einstein's General
Relativity has received a great deal of interest in recent years. At the same
time, new experiments have been designed and conducted that are able to test
Lorentz symmetry at unprecedented levels. Much of this theoretical and
experimental progress has been driven by the development of the framework for
investigating Lorentz violation known as the Standard Model Extension (SME).
The SME is the lagrangian-based effective field theory that by definition
contains all Lorentz-violating interaction terms that can be written as
observer scalars involving particle fields in the Standard Model and
gravitational fields in a generalized theory of gravity. This includes all
terms that could arise from a process of spontaneous Lorentz violation as well
as terms that explicitly break Lorentz symmetry. In this article, an overview
of the SME is presented, including its motivations and construction. A very
useful minimal version of the SME in Minkowski spacetime that maintains gauge
invariance and power-counting renormalizability is constructed as well. Data
tables summarizing tests of local Lorentz invariance for the different particle
sectors in the Standard Model and with gravity are maintained by Kosteleck\'y's
group at Indiana University. A partial survey of these tests, including some of
the high-precision sensitivities they attain, is presented here.


title: Theory of scanning gate microscopy

abstract:
  A systematic theory of the conductance measurements of non-invasive (weak
probe) scanning gate microscopy is presented that provides an interpretation of
what precisely is being measured. A scattering approach is used to derive
explicit expressions for the first and second order conductance changes due to
the perturbation by the tip potential in terms of the scattering states of the
unperturbed structure. In the case of a quantum point contact, the first order
correction dominates at the conductance steps and vanishes on the plateaus
where the second order term dominates. Both corrections are non-local for a
generic structure. Only in special cases, such as that of a centrally symmetric
quantum point contact in the conductance quantization regime, can the second
order correction be unambiguously related with the local current density. In
the case of an abrupt quantum point contact we are able to obtain analytic
expressions for the scattering eigenfunctions and thus evaluate the resulting
conductance corrections.


title: Mutations of fake weighted projective planes

abstract:
  In previous work by Coates, Galkin, and the authors, the notion of mutation
between lattice polytopes was introduced. Such a mutation gives rise to a
deformation between the corresponding toric varieties. In this paper we study
one-step mutations that correspond to deformations between weighted projective
planes, giving a complete characterisation of such mutations in terms of
T-singularities. We show also that the weights involved satisfy Diophantine
equations, generalising results of Hacking-Prokhorov.


title:
On the need for optimization of the software development processes in
  short-term projects

abstract:
  Nowadays, most of the software development projects in Mexico are short-term
projects (micro and small projects); for this reason, in this paper we are
presenting a research proposal with the goal of identifying the elements
contributing to their success or failure. With this research, we are trying to
identify and propose techniques and tools that would contribute in the
successful outcome of these projects.


title: Bayesian Ultrahigh-Dimensional Screening Via MCMC

abstract:
  We explore the theoretical and numerical property of a fully Bayesian model
selection method in sparse ultrahigh-dimensional settings, i.e., $p\gg n$,
where $p$ is the number of covariates and $n$ is the sample size. Our method
consists of (1) a hierarchical Bayesian model with a novel prior placed over
the model space which includes a hyperparameter $t_n$ controlling the model
size, and (2) an efficient MCMC algorithm for automatic and stochastic search
of the models. Our theory shows that, when specifying $t_n$ correctly, the
proposed method yields selection consistency, i.e., the posterior probability
of the true model asymptotically approaches one; when $t_n$ is misspecified,
the selected model is still asymptotically nested in the true model. The theory
also reveals insensitivity of the selection result with respect to the choice
of $t_n$. In implementations, a reasonable prior is further assumed on $t_n$
which allows us to draw its samples stochastically. Our approach conducts
selection, estimation and even inference in a unified framework. No additional
prescreening or dimension reduction step is needed. Two novel $g$-priors are
proposed to make our approach more flexible. A simulation study is given to
display the numerical advantage of our method.


title: An Effective Procedure for Computing "Uncomputable" Functions

abstract:
  We give an effective procedure that produces a natural number in its output
from any natural number in its input, that is, it computes a total function.
The elementary operations of the procedure are Turing-computable. The procedure
has a second input which can contain the Goedel number of any Turing-computable
total function whose range is a subset of the set of the Goedel numbers of all
Turing-computable total functions. We prove that the second input cannot be set
to the Goedel number of any Turing-computable function that computes the output
from any natural number in its first input. In this sense, there is no Turing
program that computes the output from its first input. The procedure is used to
define creative procedures which compute functions that are not
Turing-computable. We argue that creative procedures model an aspect of
reasoning that cannot be modeled by Turing machines.


title:
A Non-Binary Associative Memory with Exponential Pattern Retrieval
  Capacity and Iterative Learning: Extended Results

abstract:
  We consider the problem of neural association for a network of non-binary
neurons. Here, the task is to first memorize a set of patterns using a network
of neurons whose states assume values from a finite number of integer levels.
Later, the same network should be able to recall previously memorized patterns
from their noisy versions. Prior work in this area consider storing a finite
number of purely random patterns, and have shown that the pattern retrieval
capacities (maximum number of patterns that can be memorized) scale only
linearly with the number of neurons in the network.
  In our formulation of the problem, we concentrate on exploiting redundancy
and internal structure of the patterns in order to improve the pattern
retrieval capacity. Our first result shows that if the given patterns have a
suitable linear-algebraic structure, i.e. comprise a sub-space of the set of
all possible patterns, then the pattern retrieval capacity is in fact
exponential in terms of the number of neurons. The second result extends the
previous finding to cases where the patterns have weak minor components, i.e.
the smallest eigenvalues of the correlation matrix tend toward zero. We will
use these minor components (or the basis vectors of the pattern null space) to
both increase the pattern retrieval capacity and error correction capabilities.
  An iterative algorithm is proposed for the learning phase, and two simple
neural update algorithms are presented for the recall phase. Using analytical
results and simulations, we show that the proposed methods can tolerate a fair
amount of errors in the input while being able to memorize an exponentially
large number of patterns.


title: Excess-Risk of Distributed Stochastic Learners

abstract:
  This work studies the learning ability of consensus and diffusion distributed
learners from continuous streams of data arising from different but related
statistical distributions. Four distinctive features for diffusion learners are
revealed in relation to other decentralized schemes even under left-stochastic
combination policies. First, closed-form expressions for the evolution of their
excess-risk are derived for strongly-convex risk functions under a diminishing
step-size rule. Second, using these results, it is shown that the diffusion
strategy improves the asymptotic convergence rate of the excess-risk relative
to non-cooperative schemes. Third, it is shown that when the in-network
cooperation rules are designed optimally, the performance of the diffusion
implementation can outperform that of naive centralized processing. Finally,
the arguments further show that diffusion outperforms consensus strategies
asymptotically, and that the asymptotic excess-risk expression is invariant to
the particular network topology. The framework adopted in this work studies
convergence in the stronger mean-square-error sense, rather than in
distribution, and develops tools that enable a close examination of the
differences between distributed strategies in terms of asymptotic behavior, as
well as in terms of convergence rates.


title:
Functional calibration estimation by the maximum entropy on the mean
  principle

abstract:
  We extend the problem of obtaining an estimator for the finite population
mean parameter incorporating complete auxiliary information through calibration
estimation in survey sampling but considering a functional data framework. The
functional calibration sampling weights of the estimator are obtained by
matching the calibration estimation problem with the maximum entropy on the
mean principle. In particular, the calibration estimation is viewed as an
infinite dimensional linear inverse problem following the structure of the
maximum entropy on the mean approach. We give a precise theoretical setting and
estimate the functional calibration weights assuming, as prior measures, the
centered Gaussian and compound Poisson random measures. Additionally, through a
simple simulation study, we show that our functional calibration estimator
improves its accuracy compared with the Horvitz-Thompson estimator.


title: Halo Modification of a Supernova Neutronization Neutrino Burst

abstract:
  We give the first self-consistent calculation of the effect of the scattered
neutrino halo on flavor evolution in supernovae. Our example case is an O-Ne-Mg
core collapse supernova neutronization neutrino burst. We find that the
addition of the halo neutrinos produces qualitative and quantitative changes in
the final flavor states of neutrinos. We also find that the halo neutrinos
produce a novel distortion of the neutrino flavor swap. Our results provide
strong motivation for tackling the full multidimensional and
composition-dependent aspects of this problem in the future.


title: The near-infrared spectral energy distribution of {\beta} Pictoris b

abstract:
  A gas giant planet has previously been directly seen orbiting at 8-10 AU
within the debris disk of the ~12 Myr old star {\beta} Pictoris. The {\beta}
Pictoris system offers the rare opportunity to study the physical and
atmospheric properties of an exoplanet placed on a wide orbit and to establish
its formation scenario. We obtained J (1.265 {\mu}m), H (1.66 {\mu}m), and M'
(4.78 {\mu}m) band angular differential imaging of the system between 2011 and
2012. We detect the planetary companion in our four-epoch observations. We
estimate J = 14.0 +- 0.3, H = 13.5 +- 0.2, and M' = 11.0 +- 0.3 mag. Our new
astrometry consolidates previous semi-major axis (sma=8-10 AU) and excentricity
(e <= 0.15) estimates of the planet. These constraints, and those derived from
radial velocities of the star provides independent upper limits on the mass of
{\beta} Pictoris b of 12 and 15.5 MJup for semi-major axis of 9 and 10 AU. The
location of {\beta} Pictoris b in color-magnitude diagrams suggests it has
spectroscopic properties similar to L0-L4 dwarfs. This enables to derive
Log10(L/Lsun) = -3.87 +- 0.08 for the companion. The analysis with 7
PHOENIX-based atmospheric models reveals the planet has a dusty atmosphere with
Teff = 1700 +- 100 K and log g = 4.0+- 0.5. "Hot-start" evolutionary models
give a new mass of 10+3-2 MJup from Teff and 9+3-2 MJup from luminosity.
Predictions of "cold-start" models are inconsistent with independent
constraints on the planet mass. "Warm-start" models constrain the mass to M >=
6MJup and the initial entropies to values (Sinit >= 9.3Kb/baryon), intermediate
between those considered for cold/hot-start models, but likely closer to those
of hot-start models.


title:
Meshing strategies for the alleviation of mesh-induced effects in
  cohesive element models

abstract:
  One of the main approaches for modeling fracture and crack propagation in
solid materials is adaptive insertion of cohesive elements, in which line-like
(2D) or surface-like (3D) elements are inserted into the finite element mesh to
model the nucleation and propagation of failure surfaces. In this approach,
however, cracks are forced to propagate along element boundaries, following
paths that in general require more energy per unit crack extension (greater
driving forces) than those followed in the original continuum, which in turn
leads to erroneous solutions. In this work we illustrate how the introduction
of a discretization produces two undesired effects, which we term mesh-induced
anisotropy and mesh-induced toughness. Subsequently, we analyze those effects
through polar plots of the path deviation ratio (a measure of the ability of a
mesh to represent straight lines) for commonly adopted meshes. Finally, we
propose to reduce those effects through K-means meshes and through a new type
of mesh, which we term conjugate-directions mesh. The behavior of all meshes
under consideration as the mesh size is reduced is analyzed through a numerical
study of convergence.


title: On Sharp Thresholds of Monotone Properties: Bourgain's Proof Revisited

abstract:
  The purpose of this expository note is to give the proof of a theorem of
Bourgain with some additional details and updated notation. The theorem first
appeared as an appendix to the breakthrough paper by Friedgut, \emph{Sharp
Thresholds of graph properties and the $k$-SAT Problem}. Throughout, we use
notation and definitions akin to those in O'Donnell's book, \emph{Analysis of
Boolean Functions}.


title: Squaring the magic squares of order 4

abstract:
  In this paper, we present the problem of counting magic squares and we focus
on the case of multiplicative magic squares of order 4. We give the exact
number of normal multiplicative magic squares of order 4 with an original and
complete proof, pointing out the role of the action of the symmetric group.
Moreover, we provide a new representation for magic squares of order 4. Such
representation allows the construction of magic squares in a very simple way,
using essentially only five particular 4X4 matrices.


title: Analytic reconstruction of some dynamical systems

abstract:
  We propose a reconstruction of the initial system of ordinary differential
equations from a single observed variable. The suggested approach is applied to
a certain class of systems which includes, in particular, the Rossler system
and other chaotic systems. We develop relations and a method to pass from a
model that involves the observable and its time derivatives to a real original
system. To this end, we first find a set of candidates of the system in an
analytic way. After that, by additionally studying the system, we make a choice
for the sought system.


title: Third minima in thorium and uranium isotopes in a self-consistent theory

abstract:
  Background: Deep third minima have been predicted in some non-self-consistent
models to impact fission pathways of thorium and uranium isotopes. These
predictions have guided the interpretation of resonances seen experimentally.
On the other hand, self-consistent calculations consistently predict very
shallow potential-energy surfaces in the third minimum region. Purpose: We
investigate the interpretation of third-minimum configurations in terms of
dimolecular states. We study the isentropic potential-energy surfaces of
selected even-even thorium and uranium isotopes at several excitation energies.
In order to understand the driving effects behind the presence of third minima,
we study the interplay between pairing and shell effects. Methods: We use the
finite-temperature superfluid nuclear density functional theory. We consider a
traditional functional, SkM*, and a recent functional, UNEDF1, optimized for
fission studies. Results: We predict very shallow or no third minima in the
potential-energy surfaces of 232Th and 232U. In Th and U isotopes with N=136
and 138, the third minima are deeper. We show that the reflection-asymmetric
configurations around the third minimum can be associated with dimolecular
states involving the spherical doubly magic 132Sn and a lighter deformed Zr or
Mo fragment. The potential-energy surfaces for 228,232Th and 232U at several
excitation energies are presented. Conclusions: We show that the neutron shell
effect that governs the existence of the dimolecular states around the third
minimum is consistent with the spherical-to-deformed shape transition in the Zr
and Mo isotopes around N=58. We demonstrate that the thermal reduction of
pairing and enhancement of shell effects at small excitation energies help to
develop deeper third minima. At large excitation energies, shell effects are
washed out and third minima disappear altogether.


title:
A Comparative Analysis of the Relative Efficacy of Vector-Control
  Strategies against Dengue Fever

abstract:
  The model considers the human population, the adult mosquito population and
the population of immature stages, which includes eggs, larvae and pupae. The
model also considers the vertical transmission of dengue in the mosquitoes and
the seasonal variation in the mosquito population. From this basic model
describing the dynamics of dengue infection, we deduce thresholds for avoiding
the introduction of the disease and for the elimination of the disease. In
particular, we deduce a Basic Reproduction Number for dengue that includes
parameters related to the immature stages of the mosquito. By neglecting
seasonal variation, we calculate the equilibrium values of the models
variables. We also present a sensitivity analysis of the impact of four
vector-control strategies on the Basic Reproduction Number and on the Force of
Infection of dengue. Each of the strategies was studied separately from the
others. The analysis presented allows us to conclude that of the available
vector control strategies, adulticide application is the most effective,
followed by the reduction of the exposure to mosquito bites, locating and
destroying breeding places and, finally, larvicides. Current vector-control
methods are concentrated in mechanical destruction of mosquitoes breeding
places. Our results suggest that reducing the contact between vector and hosts
(biting rates) are as efficient as the logistically difficult but very
efficient adult mosquitos control.


title: \lim_{x\to 0}\frac{\sin x}{x}$ and the definition of $\pi$

abstract:
  Leopold Vietoris and Guido Hoheisel showed how the existence of $\lim_{x\to
0}\frac{\sin x}{x}$ can be derived from the trigonometric addition formulas. In
this article two new proofs for this result are given. In addition it is
discussed how this limit is related to the definition of $\pi$.


title:
New bounds on neutrino electric millicharge from limits on neutrino
  magnetic moment

abstract:
  Using the new limit on the neutrino anomalous magnetic moment recently
obtained by the GEMMA experiment on measurements of the cross section for the
reactor antineutrino scattering on free electrons, we get a new direct upper
bound on the neutrino millicharge $\mid q_{\nu} \mid < 1.5 \times 10^{-12}
e_0$. This is a factor of 2 more stringent constraint than the previous bound
obtained from the TEXONO reactor experiment data that is included to the Review
of Particle Properties 2012. We predict that with data from the ongoing new
phase of the GEMMA experiment the upper bound on the neutrino millicharge will
be reduced to $\mid q_{\nu} \mid < 3.7 \times 10^{-13}e_0$ within two years. We
also predict that with the next phase of the considered experiment the upper
bound on the millicharge will be reduced by an order of magnitude over the
present bound and reach the level $\mid q_{\nu} \mid < 1.8 \times 10^{-13}e_0$
within approximately four years.


title: A Mean Field Approximation of the Bolker-Pacala Population Model

abstract:
  We approximate the Bolker-Pacala model of population dynamics with the
logistic Markov chain and analyze the latter. We find the asymptotics of the
degenerated hypergeometric function and use these to prove a local CLT and
large deviations result. We also state global limit theorems and obtain
asymptotics for the first passage time to the boundary of a large interval.


title: Computability of the entropy of one-tape Turing Machines

abstract:
  We prove that the maximum speed and the entropy of a one-tape Turing machine
are computable, in the sense that we can approximate them to any given
precision $\epsilon$. This is contrary to popular belief, as all dynamical
properties are usually undecidable for Turing machines. The result is quite
specific to one-tape Turing machines, as it is not true anymore for two-tape
Turing machines by the results of Blondel et al., and uses the approach of
crossing sequences introduced by Hennie.


title: Total variation distance between two double Wiener-It\^o integrals

abstract:
  Using an approach recently developed by Nourdin and Poly, we improve the rate
in an inequality for the total variation distance between two double
Wiener-It\^o integrals originally due to Davydov and Martynova. An application
to the rate of convergence of a functional of a correlated two-dimensional
fractional Brownian motion towards the Rosenblatt random variable is then
given, following a previous study by Maejima and Tudor.


title: The homotopy theory of bialgebras over pairs of operads

abstract:
  We endow the category of bialgebras over a pair of operads in distribution
with a cofibrantly generated model category structure. We work in the category
of chain complexes over a field of characteristic zero. We split our
construction in two steps. In the first step, we equip coalgebras over an
operad with a cofibrantly generated model category structure. In the second one
we use the adjunction between bialgebras and coalgebras via the free algebra
functor. This result allows us to do classical homotopical algebra in various
categories such as associative bialgebras, Lie bialgebras or Poisson bialgebras
in chain complexes.


title: Dynamics of Shearfree Dissipative Collapse in f(G) Gravity

abstract:
  In this paper, we study the dynamics of shearfree dissipative gravitational
collapse in modified Gauss-Bonnet theory of gravity - so called f(G) gravity.
The field equations of f(G) gravity are applied to shearfree spherical interior
geometry of the dissipative star. We formulate the dynamical as well as
transport equations and then couple them to investigate the process of
collapse. We conclude that the gravitational force in this theory is much
stronger as compared to general relativity which indicates increase in the rate
of collapse. Further, the relation between the Weyl tensor and matter
components is established. This shows that for constant f(G) the vanishing of
the Weyl scalar leads to the homogeneity in energy density and vice versa.


title: Periodic modification of the Boerdijk-Coxeter helix (tetrahelix)

abstract:
  The Boerdijk-Coxeter helix is a helical structure of tetrahedra which
possesses no non-trivial translational or rotational symmetries. In this
document, we develop a procedure by which this structure is modified to obtain
both translational and rotational (upon projection) symmetries along/about its
central axis. We report the finding of several, distinct periodic structures,
and focus on two particular forms related to the pentagonal and icosahedral
aggregates of tetrahedra as well as Buckminster Fuller's "jitterbug
transformation".


title:
Linear maps preserving the higher numerical ranges of tensor product of
  matrices

abstract:
  We study linear maps preserving the higher numerical ranges of tensor product
of matrices.


title: From Integer Sequences to Block Designs via Counting Walks in Graphs

abstract:
  We define numbers of the type Oj(N) and Ej(N) and the corresponding integer
sequences. We prove that these integer sequences, e.g., SO(N) and SE(N)
correspond to the number of odd and even walks in complete graphs. We then
prove that there is a unique family of graphs which have exactly the same
sequence of odd walks between connected nodes and of even walks between pairs
of nodes at distance two, respectively. These graphs are obtained as the
Kronecker product. We show that they are the incidence graphs of block designs,
are distance-regular and Ramanujan graphs.


title: Reheating temperature in non-minimal derivative coupling model

abstract:
  We consider the inflaton as a scalar field described by a non-minimal
derivative coupling model with a power law potential. We study the slow roll
inflation, the rapid oscillation phase, the radiation dominated and the
recombination eras respectively, and estimate e-folds numbers during these
epochs. Using these results and recent astrophysical data we determine the
reheating temperature in terms of the spectral index and the amplitude of the
power spectrum of scalar perturbations.


title: Overview of EIREX 2012: Social Media

abstract:
  The third Information Retrieval Education through EXperimentation track
(EIREX 2012) was run at the University Carlos III of Madrid, during the 2012
spring semester. EIREX 2012 is the third in a series of experiments designed to
foster new Information Retrieval (IR) education methodologies and resources,
with the specific goal of teaching undergraduate IR courses from an
experimental perspective. For an introduction to the motivation behind the
EIREX experiments, see the first sections of [Urbano et al., 2011a]. For
information on other editions of EIREX and related data, see the website at
http://ir.kr.inf.uc3m.es/eirex/. The EIREX series have the following goals: a)
to help students get a view of the Information Retrieval process as they would
find it in a real-world scenario, either industrial or academic; b) to make
students realize the importance of laboratory experiments in Computer Science
and have them initiated in their execution and analysis; c) to create a public
repository of resources to teach Information Retrieval courses; d) to seek the
collaboration and active participation of other Universities in this endeavor.
This overview paper summarizes the results of the EIREX 2012 track, focusing on
the creation of the test collection and the analysis to assess its reliability.


title: Multipartite monogamy of the concurrence

abstract:
  Monogamy of entanglement is generally discussed using a bipartite
entanglement measure as an upper bound. Here we discuss a new kind of
monogamous relation where the upper bound is given by a multipartite measure of
entanglement, the generalized concurrence. We show a new monogamous equality
involving the multipartite concurrence, all the bipartite concurrences and the
genuine tripartite entanglement for pure three qubits system. The result
extends to mixed states in an inequality involving the generalized concurrence
and all the bipartite concurrences. We provide a counter-example showing that
the result cannot be extended for systems with more than three qubits.


title: Notes on teleparallel cosmology with nonminimally coupled scalar field

abstract:
  We consider the spatially flat Friedmann-Lemaitre-Robertson-Walker space time
in the teleparallel model of gravity and assume that the universe is filled
nearly by cold dark matter and a nonminimally coupled scalar field with a
power-law potential as dark energy. We investigate the possibility that the
universe undergoes a transition from quintessence to phantom phase. An
analytical solution for the scalar field is obtained and necessary conditions
required for such a transition are discussed.


title:
Unified model for conductance through DNA with the Landauer-Buttiker
  formalism

abstract:
  In this work, we model the zero-bias conductance for the four different DNA
strands that were used in conductance measurement experiment [A. K. Mahapatro,
K. J. Jeong, G. U. Lee, and D. B. Janes, Nanotechnology 18, 195202 (2007)]. Our
approach consists of three elements: (i) ab initio calculations of DNA, (ii)
Green's function approach for transport calculations, and (iii) the use of two
parameters to determine the decoherence rates. We first study the role of the
backbone. We find that the backbone can alter the coherent transmission
significantly at some energy points by interacting with the bases, though the
overall shape of the transmission stays similar for the two cases. More
importantly, we find that the coherent electrical conductance is tremendously
smaller than what the experiments measure. We consider DNA strands under a
variety of different experimental conditions and show that even in the most
ideal cases, the calculated coherent conductance is much smaller than the
experimental conductance. To understand the reasons for this, we carefully look
at the effect of decoherence. By including decoherence, we show that our model
can rationalize the measured conductance of the four strands, both
qualitatively and quantitatively. We find that the effect of decoherence on G:C
base pairs is crucial in getting agreement with the experiments. However, the
decoherence on G:C base pairs alone does not explain the experimental
conductance in strands containing a number of A:T base pairs. Including
decoherence on A:T base pairs is also essential. By fitting the experimental
trends and magnitudes in the conductance of the four different DNA molecules,
we estimate for the first time that the deocherence rate is 6 meV for G:C and
1.5 meV for A:T base pairs.


title: Reliable Entanglement Verification

abstract:
  Any experiment attempting to verify the presence of entanglement in a
physical system can only generate a finite amount of data. The statement that
entanglement was present in the system can thus never be issued with certainty,
requiring instead a statistical analysis of the data. Because entanglement
plays a central role in the performance of quantum devices, it is crucial to
make statistical claims in entanglement verification experiments that are
reliable and have a clear interpretation. In this work, we apply recent results
by M. Christandl and R. Renner to construct a reliable entanglement
verification procedure based on the concept of confidence regions. The
statements made do not require the specification of a prior distribution, the
assumption of independent measurements nor the assumption of an independent and
identically distributed (i.i.d.) source of states. Moreover, we develop
numerical tools that are necessary to employ this approach in practice,
rendering the procedure ready to be applied to current experiments. We
demonstrate this technique by analyzing the data of a photonic experiment
generating two-photon states whose entanglement is verified with the use of an
accessible nonlinear witness.


title:
Accurate 3D comparison of complex topography with terrestrial laser
  scanner: application to the Rangitikei canyon (N-Z)

abstract:
  Surveying techniques such as Terrestrial Laser Scanner have recently been
used to measure surface changes via 3D point cloud (PC) comparison. Two types
of approaches have been pursued: 3D tracking of homologous parts of the surface
to compute a displacement field, and distance calculation between two point
clouds when homologous parts cannot be defined. This study deals with the
second approach, typical of natural surfaces altered by erosion, sedimentation
or vegetation between surveys. Current comparison methods are based on a
closest point distance or require at least one of the PC to be meshed with
severe limitations when surfaces present roughness elements at all scales. We
introduce a new algorithm performing a direct comparison of point clouds in 3D.
Surface normals are first estimated in 3D at a scale consistent with the local
surface roughness. The measurement of the mean change along the normal
direction is then performed with an explicit calculation of a confidence
interval. Comparison with existing methods demonstrates the higher accuracy of
our approach, as well as an easier workflow due to the absence of surface
meshing or DEM generation. Application of the method in a rapidly eroding
meandering bedrock river (Rangitikei river canyon) illustrates its ability to
handle 3D differences in complex situations (flat and vertical surfaces on the
same scene), to reduce uncertainty related to point cloud roughness by local
averaging and to generate 3D maps of uncertainty levels. Combined with mm-range
local georeferencing of the point clouds, levels of detection down to 6 mm can
be routinely attained in situ over ranges of 50 m. We provide evidence for the
self-affine behavior of different surfaces. We show how this impacts the
calculation of normal vectors and demonstrate the scaling behavior of the level
of change detection.


title:
Cellular Probabilistic Automata - A Novel Method for Uncertainty
  Propagation

abstract:
  We propose a novel density based numerical method for uncertainty propagation
under certain partial differential equation dynamics. The main idea is to
translate them into objects that we call cellular probabilistic automata and to
evolve the latter. The translation is achieved by state discretization as in
set oriented numerics and the use of the locality concept from cellular
automata theory. We develop the method at the example of initial value
uncertainties under deterministic dynamics and prove a consistency result. As
an application we discuss arsenate transportation and adsorption in drinking
water pipes and compare our results to Monte Carlo computations.


title: Social Secret Sharing for Resource Management in Cloud

abstract:
  We first explain the notion of secret sharing and also threshold schemes,
which can be implemented with the Shamir's secret sharing. Subsequently, we
review social secret sharing (NSG'10,NS'10) and its trust function. In a secret
sharing scheme, a secret is shared among a group of players who can later
recover the secret. We review the construction of a social secret sharing
scheme and its application for resource management in cloud, as explained in
NS'12. To clarify the social secret sharing scheme, we first review its trust
function according to NL'06. In this scheme, a secret is maintained by
assigning a trust value to each player based on his behavior, i.e.,
availability.


title: Quasirandom group actions

abstract:
  Let $G$ be a finite group acting transitively on a set $\Omega$. We study
what it means for this action to be {\it quasirandom}, thereby generalizing
Gowers' study of quasirandomness in groups. We connect this notion of
quasirandomness to an upper bound for the convolution of functions associated
with the action of $G$ on $\Omega$. This convolution bound allows us to give
sufficient conditions such that sets $S,T\subset G$ and $\Gamma\subseteq
\Omega$ contain elements $s\in S, t\in T, \gamma\in\Gamma$ such that
$s(\gamma)=t$. Other consequences include an analogue of `the Gowers trick' of
Nikolov and Pyber for general group actions, a sum-product type theorem for
large subsets of a finite field, as well as applications to expanders and to
the study of the diameter and width of a finite simple group.


title:
Thermal vs. Entanglement Entropy: A Measurement Protocol for Fermionic
  Atoms with a Quantum Gas Microscope

abstract:
  We show how to measure the order-two Renyi entropy of many-body states of
spinful fermionic atoms in an optical lattice in equilibrium and
non-equilibrium situations. The proposed scheme relies on the possibility to
produce and couple two copies of the state under investigation, and to measure
the occupation number in a site- and spin-resolved manner, e.g. with a quantum
gas microscope. Such a protocol opens the possibility to measure entanglement
and test a number of theoretical predictions, such as area laws and their
corrections. As an illustration we discuss the interplay between thermal and
entanglement entropy for a one dimensional Fermi-Hubbard model at finite
temperature, and its possible measurement in an experiment using the present
scheme.


title:
Influence of electric current on the Casimir forces between graphene
  sheets

abstract:
  We investigate the dependence of the thermal Casimir force between two
graphene sheets on the drift velocity of the electrons in one graphene sheet.
We show that the drift motion produces a measurable change of the thermal
Casimir force due to the Doppler effect. The thermal Casimir force as well as
the Casimir friction are strongly enhanced in the case of resonant photon
tunneling when the energy of the emitted photon coincides with the energy of
electron-hole pair excitations. In the case of resonant photon tunneling, even
for temperatures above room temperature the Casimir friction is dominated by
quantum friction due to quantum fluctuations. Quantum friction can be detected
in frictional drag experiment between graphene sheets for high electric field.


title: Fulde-Ferrell Pairing instability in Spin-Orbit Coupled Fermi Gas

abstract:
  We consider finite-momentum pairing of superfluid phase in ultracold Fermi
gas with spin-orbit coupling when subjected to an effective Zeeman field. Based
on our two body and mean field many body calculations, we show that the
Fulde-Ferrell type superfluid dominates in zero and finite temperature phase
diagram. We examine the origin and properties of this novel phase
systematically.


title: Wave Mechanics and the Fifth Dimension

abstract:
  Replacing 4D Minkowski space by 5D canonical space leads to a clearer
derivation of the main features of wave mechanics, including the wave function
and the velocity of de Broglie waves. Recent tests of wave-particle duality
could be adapted to investigate whether de Broglie waves are basically 4D or 5D
in nature.


title: Static Cylindrically Symmetric Interior Solutions in f(R) Gravity

abstract:
  We investigate some exact static cylindrically symmetric solutions for a
perfect fluid in the metric $f(R)$ theory of gravity. For this purpose, three
different families of solutions are explored. We evaluate energy density,
pressure, Ricci scalar and functional form of $f(R)$. It is interesting to
mention here that two new exact solutions are found from the last approach, one
is in particular form and the other is in the general form. The general form
gives a complete description of a cylindrical star in $f(R)$ gravity.


title:
Homomorphic Encryption with Access Policies: Characterization and New
  Constructions

abstract:
  A characterization of predicate encryption (PE) with support for homomorphic
operations is presented and we describe the homomorphic properties of some
existing PE constructions. Even for the special case of IBE, there are few
known group-homomorphic cryptosystems. Our main construction is an
XOR-homomorphic IBE scheme based on the quadratic residuosity problem (variant
of the Cocks' scheme), which we show to be strongly homomorphic. We were unable
to construct an anonymous variant that preserves this homomorphic property, but
we achieved anonymity for a weaker notion of homomorphic encryption, which we
call \emph{non-universal}. A related security notion for this weaker primitive
is formalized. Finally, some potential applications and open problems are
considered.


title: A practical approach to cosmological perturbations in modified gravity

abstract:
  The next generation of large scale surveys will not only measure cosmological
parameters within the framework of General Relativity, but will also allow for
precision tests of the framework itself. At the order of linear perturbations,
departures from the growth in the LCDM model can be quantified in terms of two
functions of time and Fourier number k. We argue that in local theories of
gravity, in the quasi-static approximation, these functions must be ratios of
polynomials in k, with the numerator of one function being equal to the
denominator of the other. Moreover, the polynomials are even and of second
degree in practically all viable models considered today. This means that,
without significant loss of generality, one can use data to constraint only
five functions of a single variable, instead of two functions of two variables.
Furthermore, since the five functions are expected to be slowly varying, one
can fit them to data in a non-parametric way with the aid of an explicit
smoothness prior. We discuss practical application of this parametrization to
forecasts and fits.


title:
Physics in a general length space-time geometry: Call for experimental
  revision of the light speed anisotropy

abstract:
  We present a phenomenological model for the nature in the Finsler and Randers
space-time geometries. We show that the parity-odd light speed anisotropy
perpendicular to the gravitational equipotential surfaces encodes the deviation
from the Riemann geometry toward the Randers geometry. We utilize an
asymmetrical ring resonator and propose a setup in order to directly measure
this deviation. We address the constraints that the current technology will
impose on the deviation should the anisotropy be measured on the Earth surface
and the orbits of artificial satellites.


title: Tracing Galaxies Through Cosmic Time with Number Density Selection

abstract:
  A central challenge in observational studies of galaxy formation is how to
associate progenitor galaxies with their descendants at lower redshifts. One
promising approach is to link galaxies at fixed number density, rather than
fixed luminosity or mass. This method is effective if stellar mass rank order
is broadly conserved through cosmic time. In this paper, we use the Guo et al.
(2011) semi-analytical model to analyze under what circumstances this
assumption is valid in the context of a cosmological simulation. Specifically,
we select progenitor galaxies at a constant number density and compare the
stellar mass evolution of their descendants to the evolution at a constant
number density. The median stellar mass of the descendants increases by a
factor of four (0.6 dex) from z = 3 to z = 0. Constant number density selection
reproduces this to within 40% (0.15 dex) over a wide range of number densities.
We show that the discrepancy primarily results from scatter in the stellar mass
growth rates and merging. After applying simple, observationally-based
corrections for these processes, the discrepancy is reduced to 12% (0.05 dex).
We conclude that number density selection can be used to predict the median
descendant mass of high-redshift progenitor galaxies. The main uncertainty in
this study is that semi-analytical models do not reproduce the observed mass
evolution of galaxies, which makes the quantitative aggregate effects of star
formation, merging, and quenching on the rank order of galaxies somewhat
uncertain.


title: Star Formation in the Milky Way. The Infrared View

abstract:
  I present a brief review of some of the most recent and active topics of star
formation process in the Milky Way using mid and far infrared observations, and
motivated by the research being carried out by our science group using data
gathered by the Spitzer and Herschel space telescopes. These topics include
bringing together the scaling relationships found in extragalactic systems with
that of the local nearby molecular clouds, the synthetic modeling of the Milky
Way and estimates of its star formation rate.


title:
SMM J04135+10277: A Candidate Early-Stage "Wet-Dry" Merger of Two
  Massive Galaxies at z=2.8

abstract:
  We report interferometric imaging of CO(J=3-2) emission toward the z=2.846
submillimeter-selected galaxy SMM J04135+10277, using the Combined Array for
Research in Millimeter-wave Astronomy (CARMA). SMM J04135+10277 was previously
thought to be a gas-rich, submillimeter-selected quasar, with the highest
molecular gas mass among high-z quasars reported in the literature. Our maps at
~6x improved linear resolution relative to earlier observations spatially
resolve the emission on ~1.7" scales, corresponding to a (lensing-corrected)
source radius of ~5.2 kpc. They also reveal that the molecular gas reservoir,
and thus, likely the submillimeter emission, is not associated with the host
galaxy of the quasar, but with an optically faint gas-rich galaxy at 5.2", or
41.5 kpc projected distance from the active galactic nucleus (AGN). The
obscured gas-rich galaxy has a dynamical mass of M_dyn sin2(i)=5.6x10^11 M_sun,
corresponding to a gas mass fraction of ~21%. Assuming a typical M_BH/M* ratio
for z>2 quasars, the two galaxies in this system have an approximate mass ratio
of ~1.9. Our findings suggest that this quasar-starburst galaxy pair could
represent an early stage of a rare major, gas-rich/gas-poor ("wet-dry") merger
of two massive galaxies at z=2.8, rather than a single, gas-rich AGN host
galaxy. Such systems could play an important role in the early buildup of
present-day massive galaxies through a submillimeter-luminous starburst phase,
and may remain hidden in larger numbers among rest-frame far-infrared-selected
quasar samples at low and high redshift.


title:
On the Theory of Continuous-Spin Particles: Wavefunctions and
  Soft-Factor Scattering Amplitudes

abstract:
  The most general massless particles allowed by Poincare-invariance are
"continuous-spin" particles (CSPs) characterized by a scale \rho, which at
\rho=0 reduce to familiar helicity particles. Though known long-range forces
are adequately modeled using helicity particles, it is not known whether CSPs
can also mediate long-range forces or what consequences such forces might have.
We present sharp evidence for consistent interactions of CSPs with matter: new
CSP equations of motion, wavefunctions, and covariant radiation amplitudes. In
a companion paper, we use these results to resolve old puzzles concerning CSP
thermodynamics and exhibit a striking correspondence limit where CSP amplitudes
approach helicity-0, 1 or 2 amplitudes.


title:
Rotational Characterization of Hayabusa II Target Asteroid (162173) 1999
  JU3

abstract:
  The Japanese Space Agency's Hayabusa II mission is scheduled to rendezvous
with and return a sample from the near-Earth asteroid (162173) 1999 JU3.
Previous visible-wavelength spectra of this object show significant variability
across multiple epochs which could be the result of a compositionally
heterogeneous surface. We present new visible and near-infrared spectra to
demonstrate that thermally altered carbonaceous chondrites are plausible
compositional analogs, however this is a tentative association due to a lack of
any prominent absorption features in our data. We have also conducted a series
of high signal-to-noise visible-wavelength observations to investigate the
reported surface heterogeneity. Our time series of visible spectra do not show
evidence for variability at a precision level of a few percent. This result
suggests two most likely possibilities. One, that the surface of 1999 JU3 is
homogenous and that unaccounted for systematic effects are causing spectral
variation across epochs. Or two, that the surface of 1999 JU3 is regionally
heterogenous, in which case existing shape models suggest that any
heterogeneity must be limited to terrains smaller than approximately 5% of the
total surface area. These new observations represent the last opportunity
before both the launch and return of the Hayabusa II spacecraft to perform
ground-based characterization of this asteroid. Ultimately, these predictions
for composition and surface properties will be tested upon completion of the
mission.


title:
Multi-momentum and multi-flavour active-sterile neutrino oscillations in
  the early universe: role of neutrino asymmetries and effects on
  nucleosynthesis

abstract:
  We perform a study of the flavour evolution in the early universe of a
multi-flavour active-sterile neutrino system with parameters inspired by the
short-baseline neutrino anomalies. In a neutrino-symmetric bath a "thermal"
population of the sterile state would quickly grow, but in the presence of
primordial neutrino asymmetries a self-suppression as well as a resonant
sterile neutrino production can take place, depending on temperature and chosen
parameters. In order to characterize these effects, we go beyond the usual
average momentum and single mixing approximations and consider a multi-momentum
and multi-flavour treatment of the kinetic equations. We find that the
enhancement obtained in this case with respect to the average momentum
approximation is significant, up to \sim 20 % of a degree of freedom. Such
detailed and computationally demanding treatment further raises the asymmetry
values required to significantly suppress the sterile neutrino production, up
to large and preferentially net asymmetries |L_{\nu}| > O(10^{-2}). For such
asymmetries, however, the active-sterile flavour conversions happen so late
that significant distortions are produced in the electron (anti)neutrino
spectra. The larger |L_{\nu}|, the more the impact of these distortions takes
over as dominant cosmological effect, notably increasing the 4 He abundance in
primordial nucleosynthesis (BBN). The standard expression of the primordial
yields in terms of the effective number of neutrinos and asymmetries is also
greatly altered. We numerically estimate the magnitude of such effects for a
few representative cases and comment on possible implications for forthcoming
cosmological measurements.


title: A Brief History of Curvature

abstract:
  The trace of the stress-energy tensor of the cosmological fluid, proportional
to the Ricci scalar curvature in general relativity, is determined on cosmic
scales for times ranging from the inflationary epoch to the present day in the
expanding Universe. The post-inflationary epoch and the thermal history of the
relativistic fluid, in particular the QCD transition from asymptotic freedom to
confinement and the electroweak phase transition, leave significant imprints on
the scalar curvature. These imprints can be of either sign and are orders of
magnitude larger than the values that would be obtained by naively
extrapolating the pressureless matter of the present epoch back into the
radiation-dominated epoch.


title: Nuclear Activity is more prevalent in Star-Forming Galaxies

abstract:
  We explore the question of whether low and moderate luminosity Active
Galactic Nuclei (AGNs) are preferentially found in galaxies that are undergoing
a transition from active star formation to quiescence. This notion has been
suggested by studies of the UV-to-optical colors of AGN hosts, which find them
to be common among galaxies in the so-called "Green Valley", a region of galaxy
color space believed to be composed mostly of galaxies undergoing
star-formation quenching. Combining the deepest current X-ray and Herschel.
PACS far-infrared (FIR) observations of the two Chandra Deep Fields (CDFs) with
redshifts, stellar masses and rest-frame photometry derived from the extensive
and uniform multi-wavelength data in these fields, we compare the rest-frame
U-V color distributions and SFR distributions of AGNs and carefully constructed
samples of inactive control galaxies. The UV-to-optical colors of AGNs are
consistent with equally massive inactive galaxies at redshifts out to z~2, but
we show that such colors are poor tracers of star formation. While the FIR
distributions of both star-forming AGNs and star-forming inactive galaxies are
statistically similar, we show that AGNs are preferentially found in
star-forming host galaxies, or, in other words, AGNs are less likely to be
found in weakly star-forming or quenched galaxies. We postulate that, among
X-ray selected AGNs of low and moderate accretion luminosities, the supply of
cold gas primarily determines the accretion rate distribution of the nuclear
black holes.


title:
A Herschel and APEX Census of the Reddest Sources in Orion: Searching
  for the Youngest Protostars

abstract:
  We perform a census of the reddest, and potentially youngest, protostars in
the Orion molecular clouds using data obtained with the PACS instrument onboard
the Herschel Space Observatory and the LABOCA and SABOCA instruments on APEX as
part of the Herschel Orion Protostar Survey (HOPS). A total of 55 new protostar
candidates are detected at 70 um and 160 um that are either too faint (m24 > 7
mag) to be reliably classified as protostars or undetected in the Spitzer/MIPS
24 um band. We find that the 11 reddest protostar candidates with log (lambda
F_lambda 70) / (lambda F_lambda 24) > 1.65 are free of contamination and can
thus be reliably explained as protostars. The remaining 44 sources have less
extreme 70/24 colors, fainter 70 um fluxes, and higher levels of contamination.
Taking the previously known sample of Spitzer protostars and the new sample
together, we find 18 sources that have log (lambda F_lambda 70) / (lambda
F_lambda 24) > 1.65; we name these sources "PACS Bright Red sources", or PBRs.
Our analysis reveals that the PBRs sample is composed of Class 0 like sources
characterized by very red SEDs (T_bol < 45 K) and large values of
sub-millimeter fluxes (L_smm/L_bol > 0.6%). Modified black-body fits to the
SEDs provide lower limits to the envelope masses of 0.2 M_sun to 2 M_sun and
luminosities of 0.7 L_sun to 10 L_sun. Based on these properties, and a
comparison of the SEDs with radiative transfer models of protostars, we
conclude that the PBRs are most likely extreme Class 0 objects distinguished by
higher than typical envelope densities and hence, high mass infall rates.


title:
Upper bounds on r-mode amplitudes from observations of low-mass X-ray
  binary neutron stars

abstract:
  We present upper limits on the amplitude of r-mode oscillations, and
gravitational-radiation-induced spin-down rates, in low mass X-ray binary
neutron stars, under the assumption that the quiescent neutron star luminosity
is powered by dissipation from a steady-state r-mode. For masses $< 2
M_{\odot}$ we find dimensionless r-mode amplitudes in the range from about
$1\times 10^{-8}$ to $1.5\times 10^{-6}$. For the accreting millisecond X-ray
pulsar sources with known quiescent spin-down rates these limits suggest that
$\lesssim 1%$ of the observed rate can be due to an unstable r-mode.
Interestingly, the source with the highest amplitude limit, NGC 6440, could
have an r-mode spin-down rate comparable to the observed, quiescent rate for
SAX J1808-3658. Thus, quiescent spin-down measurements for this source would be
particularly interesting. For all sources considered here our amplitude limits
suggest that gravitational wave signals are likely too weak for detection with
Advanced LIGO. Our highest mass model ($2.21\, M_{\odot}$) can support
enhanced, direct Urca neutrino emission in the core and thus can have higher
r-mode amplitudes. Indeed, the inferred r-mode spin-down rates at these higher
amplitudes are inconsistent with the observed spin-down rates for some of the
sources, such as IGR J00291+5934 and XTE J1751-305. In the absence of other
significant sources of internal heat, these results could be used to place an
upper limit on the masses of these sources if they were made of hadronic
matter, or alternatively it could be used to probe the existence of exotic
matter in them if their masses were known.


title: Surface Entanglement in Quantum Spin Networks

abstract:
  We study the ground-state entanglement in systems of spins forming the
boundary of a quantum spin network in arbitrary geometries and dimensionality.
We show that as long as they are weakly coupled to the bulk of the network, the
surface spins are strongly entangled, even when distant and non directly
interacting, thereby generalizing the phenomenon of long-distance entanglement
occurring in quantum spin chains. Depending on the structure of the couplings
between surface and bulk spins, we discuss in detail how the patterns of
surface entanglement can range from multi-pair bipartite to fully multipartite.
In the context of quantum information and communication, these results find
immediate application to the implementation of quantum routers, that is devices
able to distribute quantum correlations on demand among multiple network nodes.

categories: quant-ph cond-mat.mes-hall math-ph math.MP


title:
Thermality and Heat Content of horizons from infinitesimal coordinate
  transformations

abstract:
  Thermal properties of a static horizon, (like the entropy S, heat content TS
etc.) can be obtained either from the surface term of the Einstein-Hilbert
action or by evaluating the Noether charge, corresponding to the
diffeomorphisms generated by the timelike Killing vector field. We show that,
for a wide class of geometries, the same results can be obtained using the
vector field which produces an infinitesimal coordinate transformation between
two physically relevant reference frames, viz. the freely falling frame near
the horizon and the static, accelerated, frame. In particular, the
infinitesimal coordinate transformation from inertial coordinates to uniformly
accelerated frame can be used to obtain the heat content and entropy of the
Rindler horizon. This result offers insight into understanding the observer
dependent degrees of freedom which contribute to the entropy of null surfaces.


title: A preliminary univalent formalization of the p-adic numbers

abstract:
  In this paper we give a preliminary formalization of the p-adic numbers, in
the context of the second author's univalent foundations program. We also
provide the corresponding code verifying the construction in the proof
assistant Coq. Because work in the univalent setting is ongoing, the structure
and organization of the construction of the p-adic numbers we give in this
paper is expected to change as Coq libraries are more suitably rearranged, and
optimized, by the authors and other researchers in the future. So our
construction here should be deemed as a first approximation which is subject to
improvements.


title:
First lower limits on the photon-axion-like particle coupling from very
  high energy gamma-ray observation

abstract:
  The intrinsic flux of very high energy (VHE, Energy > 100 GeV) gamma-rays
from extragalactic sources is attenuated due to pair production in the
interaction with photons of the extragalactic background light (EBL). Depending
on the distance of the source, the Universe should be opaque to VHE photons
above a certain energy. However, indications exist that the Universe is more
transparent than previously thought. A recent statistical analysis of a large
sample of VHE spectra shows that the correction for absorption with current EBL
models is too strong for the data points with the highest attenuation. An
explanation might be the oscillation of VHE photons into hypothetical
axion-like particles (ALPs) in ambient magnetic fields. This mechanism would
decrease the opacity as ALPs propagate unimpeded over cosmological distances.
  Here, a large sample of VHE gamma-ray spectra obtained with imaging air
Cherenkov telescopes is used to set, for the first time, lower limits on the
photon-ALP coupling constant over a large range of ALP masses. The conversion
in different magnetic field configurations, including intra-cluster and
intergalactic magnetic fields together with the magnetic field of the Milky
Way, is investigated taking into account the energy dependence of the
oscillations. For optimistic scenarios of the intervening magnetic fields, a
lower limit on the photon-ALP coupling of the order of
$10^{-12}\mathrm{GeV}^{-1}$ is obtained whereas more conservative model
assumptions result in $2\times10^{-11}\mathrm{GeV}^{-1}$. The latter value is
within reach of future dedicated ALP searches.


title: Efficient pseudo-spectral solvers for the PKN model of hydrofracturing

abstract:
  In the paper, a novel algorithm employing pseudo-spectral approach is
developed for the PKN model of hydrofracturing. The respective solvers based on
this approach compute both the solution and its temporal derivative. In
comparison with conventional solvers, they demonstrate excellent cost
effectiveness in terms of balance between the accuracy of computations and
densities of the temporal and spatial meshes. Various leak-off regimes are
considered.


title: Solving systems of linear equations on a quantum computer

abstract:
  Systems of linear equations are used to model a wide array of problems in all
fields of science and engineering. Recently, it has been shown that quantum
computers could solve linear systems exponentially faster than classical
computers, making for one of the most promising applications of quantum
computation. Here, we demonstrate this quantum algorithm by implementing
various instances on a photonic quantum computing architecture. Our
implementation involves the application of two consecutive entangling gates on
the same pair of polarisation-encoded qubits. We realize two separate
controlled-NOT gates where the successful operation of the first gate is
heralded by a measurement of two ancillary photons. Our work thus demonstrates
the implementation of a quantum algorithm with high practical significance as
well as an important technological advance which brings us closer to a
comprehensive control of photonic quantum information.


title:
Quantum Lyapunov Control Based on the Average Value of an Imaginary
  Mechanical Quantity

abstract:
  The convergence of closed quantum systems in the degenerate cases to the
desired target state by using the quantum Lyapunov control based on the average
value of an imaginary mechanical quantity is studied. On the basis of the
existing methods which can only ensure the single-control Hamiltonian systems
converge toward a set, we design the control laws to make the multi-control
Hamiltonian systems converge to the desired target state. The convergence of
the control system is proved, and the convergence to the desired target state
is analyzed. How to make these conditions of convergence to the target state to
be satisfied is proved or analyzed. Finally, numerical simulations for a three
level system in the degenrate case transfering form an initial eigenstate to a
target superposition state are studied to verify the effectiveness of the
proposed control method.


title: Limitations of gauge invariance

abstract:
  Although gauge invariance preserves the values of physical observables, a
gauge transformation can introduce important alterations of physical
interpretations. To understand this, it is first shown that a gauge
transformation is not, in general, a unitary transformation. Also, physical
interpretations are based on both kinetic energy and potential energy
expressions. While the kinetic energy is a measurable quantity, and hence
gauge-invariant, the potential energy is gauge-dependent. Two basic examples
are examined; one classical and the other quantum-mechanical. The aim is to
show that the use of the Coulomb (or radiation) gauge is always consistent with
the way that fields are generated in the laboratory. Upon transformation out of
the Coulomb gauge, this connection is lost, and physical interpretations can
give rise to misleading inferences.


title: Amplitude analysis and branching fraction measurement of Bs->J/\psi K+K-

abstract:
  An amplitude analysis of the final state structure in the Bs->J/\psi K+K-
decay mode is performed using 1.0/fb of data collected by the LHCb experiment
in 7 TeV center-of-mass energy pp collisions produced by the LHC. A modified
Dalitz plot analysis of the final state is performed using both the invariant
mass spectra and the decay angular distributions. Resonant structures are
observed in the K+K- mass spectrum as well as a significant non-resonant S-wave
contribution. The largest resonant component is the \phi(1020), accompanied by
f0(980), f'2(1525), and four additional resonances. The overall branching
fraction is measured to be B(Bs->J/\psi K+K-)=(7.70 +/-0.08 +/- 0.39 +/- 0.60)x
10^(-4), where the first uncertainty is statistical, the second systematic, and
the third due to the ratio of the number of Bs to B- mesons produced. The mass
and width of the f'2(1525) are measured to be 1522.2 +/- 2.8^{+5.3}_{-2.0} MeV
and 84 +/- 6^{+10}_{-5} MeV, respectively. The final state fractions of the
other resonant states are also reported.


title: K-theory of endomorphisms via noncommutative motives

abstract:
  In this article we study the K-theory of endomorphisms using noncommutative
motives. We start by extending the K-theory of endomorphisms functor from
ordinary rings to (stable) infinity categories. We then prove that this
extended functor KEnd(-) not only descends to the category of noncommutative
motives but moreover becomes co-represented by the noncommutative motive
associated to the tensor algebra S[t] of the sphere spectrum S. Using this
co-representability result, we then classify all the natural transformations of
KEnd(-) in terms of an integer plus a fraction between polynomials with
constant term 1; this solves a problem raised by Almkvist in the seventies.
Finally, making use of the multiplicative co-algebra structure of S[t], we
explain how the (rational) Witt vectors can also be recovered from the
symmetric monoidal category of noncommutative motives. Along the way we show
that the K_0-theory of endomorphisms of a connective ring spectrum R equals the
K_0-theory of endomorphisms of the underlying ordinary ring \pi_0(R).


title:
The asymptotic stability of solitons in the cubic NLS equation on the
  line

abstract:
  We use the inverse scattering transform, the auto-Backlund transformation and
the steepest descent method of Deift and Zhou to obtain the asymptotic
stability of the solitons in the cubic NLS (nonlinear Schrodinger) equation.


title:
Secure Communication Via an Untrusted Non-Regenerative Relay in Fading
  Channels

abstract:
  We investigate a relay network where the source can potentially utilize an
untrusted non-regenerative relay to augment its direct transmission of a
confidential message to the destination. Since the relay is untrusted, it is
desirable to protect the confidential data from it while simultaneously making
use of it to increase the reliability of the transmission. We first examine the
secrecy outage probability (SOP) of the network assuming a single antenna
relay, and calculate the exact SOP for three different schemes: direct
transmission without using the relay, conventional non-regenerative relaying,
and cooperative jamming by the destination. Subsequently, we conduct an
asymptotic analysis of the SOPs to determine the optimal policies in different
operating regimes. We then generalize to the multi-antenna relay case and
investigate the impact of the number of relay antennas on the secrecy
performance. Finally, we study a scenario where the relay has only a single RF
chain which necessitates an antenna selection scheme, and we show that unlike
the case where all antennas are used, under certain conditions the cooperative
jamming scheme with antenna selection provides a diversity advantage for the
receiver. Numerical results are presented to verify the theoretical predictions
of the preferred transmission policies.


title: Boundary towers of layers for some supercritical problems

abstract:
  We show that in some suitable torus-like domains D some supercritical
elliptic problems have an arbitrary large number of sign-changing solutions
with alternate positive and negative layers which concentrate at different
rates along a k-dimensional submanifold of the boundary of D as p approaches
2*_{N,K} from below.


title: Finite-time singularities in the dynamical evolution of contact lines

abstract:
  We study finite-time singularities in the linear advection-diffusion equation
with a variable speed on a semi-infinite line. The variable speed is determined
by an additional condition at the boundary, which models the dynamics of a
contact line of a hydrodynamic flow at a 180 contact angle. Using apriori
energy estimates, we derive conditions on variable speed that guarantee that a
sufficiently smooth solution of the linear advection--diffusion equation blows
up in a finite time. Using the class of self-similar solutions to the linear
advection-diffusion equation, we find the blow-up rate of singularity
formation. This blow-up rate does not agree with previous numerical simulations
of the model problem.


title:
Introduction to Redberry: a computer algebra system designed for tensor
  manipulation

abstract:
  In this paper we introduce Redberry --- an open source computer algebra
system with native support of tensorial expressions. It provides basic computer
algebra tools (algebraic manipulations, substitutions, basic simplifications
etc.) which are aware of specific features of indexed expressions: contractions
of indices, permutational symmetries, multiple index types etc. Redberry
supports conventional \LaTeX-style input notation for tensorial expressions.
The high energy physics package includes tools for Feynman diagrams
calculation: Dirac and SU(N) algebra, Levi-Civita simplifications and tools for
one-loop calculations in quantum field theory. In the paper we give detailed
overview of Redberry features: from basic manipulations with tensors to real
Feynman diagrams calculation, accompanied by many examples. Redberry is written
in Java 7 and provides convenient Groovy-based user interface inside the
high-level general purpose programming language environment. Redberry is
available from http://redberry.cc


title:
A Dark Energy Model interacting with Dark Matter described by an
  effective EoS

abstract:
  In this latter author would like to consider interaction between a dark
energy based on Generalized Uncertainty Principle (GUP) and a Dark Matter
described by effective EoS: $P =
(\gamma-1)\rho+p_{0}+\omega_{H}H+\omega_{H2}H^{2}+\omega_{dH}\dot{H}$ [1]-[3],
which could be interpreted as a modification concerning to the some interaction
between fluid $P=(\gamma-1)\rho$ with different components of the Darkness of
the Universe. Two types of interaction, called sign-changeable,
$Q=q(3Hb\rho_{m}+\beta\dot{\rho}_{m})$ [4],[5] and
$Q=3Hb\rho_{m}+\beta\dot{\rho}_{m}$ are considered. EoS parameter of the
mixture $\omega_{tot}$ are investigated. Statefinder diagnostics provided also.


title: Measuring nonclassical correlations of two-photon states

abstract:
  The threshold between classical and nonclassical two-qubit states is drawn at
the place when these states can no longer be described by classical
correlations, i.e., quantum discord or entanglement appear. However, to check
if the correlations are classical (in terms of quantum discord and
entanglement) it is sufficient to witness the lack of quantum discord because
its zero value implies the lack of entanglement. We explain how the indicator
of quantum discord introduced by Girolami and Adesso [Phys. Rev. Lett. 108,
150403 (2012)] can be practically measured in linear-optical systems using
standard beam splitters and photon detectors. We study the efficiency of the
setup assuming both ideal and real components and show that the efficiency of
the proposed implementation is better than the full two-photon quantum
tomography. Thus, we demonstrate that a class of experiments previously
available on NMR platform can be implemented in optical systems.


title:
On solutions of the reduced model for the dynamical evolution of contact
  lines

abstract:
  We solve the linear advection-diffusion equation with a variable speed on a
semi-infinite line. The variable speed is determined by an additional condition
at the boundary, which models the dynamics of a contact line of a hydrodynamic
flow at a 180 contact angle. We use Laplace transform in spatial coordinate and
Green's function for the fourth-order diffusion equation to show local
existence of solutions of the initial-value problem associated with the set of
over-determining boundary conditions. We also analyze the explicit solution in
the case of a constant speed (dropping the additional boundary condition).