title: A Combined Approach for Constraints over Finite Domains and Arrays

abstract:
  Arrays are ubiquitous in the context of software verification. However,
effective reasoning over arrays is still rare in CP, as local reasoning is
dramatically ill-conditioned for constraints over arrays. In this paper, we
propose an approach combining both global symbolic reasoning and local
consistency filtering in order to solve constraint systems involving arrays
(with accesses, updates and size constraints) and finite-domain constraints
over their elements and indexes. Our approach, named FDCC, is based on a
combination of a congruence closure algorithm for the standard theory of arrays
and a CP solver over finite domains. The tricky part of the work lies in the
bi-directional communication mechanism between both solvers. We identify the
significant information to share, and design ways to master the communication
overhead. Experiments on random instances show that FDCC solves more formulas
than any portfolio combination of the two solvers taken in isolation, while
overhead is kept reasonable.


title: Semi-Dirac dispersion relation in photonic crystals

abstract:
  A semi-Dirac cone refers to a peculiar type of dispersion relation that is
linear along the symmetry line but quadratic in the perpendicular direction.
Here, I demonstrate that a photonic crystal consisting of a square array of
elliptical dielectric cylinders is able to produce this particular dispersion
relation in the Brillouin zone center. A perturbation method is used to
evaluate the linear slope and to affirm that the dispersion relation is a
semi-Dirac type. Effective medium parameters calculated from a boundary
effective medium theory not only explain the unexpected topological transition
in the iso-frequency surfaces occurring at the semi-Dirac point, they also
offer a perspective on the property at that point, where the photonic crystal
behaves as a zero-refractive-index material along the symmetry axis but
functions like at a photonic band edge in the perpendicular direction.


title: Sparse Time Frequency Representations and Dynamical Systems

abstract:
  In this paper, we establish a connection between the recently developed
data-driven time-frequency analysis \cite{HS11,HS13-1} and the classical second
order differential equations. The main idea of the data-driven time-frequency
analysis is to decompose a multiscale signal into a sparsest collection of
Intrinsic Mode Functions (IMFs) over the largest possible dictionary via
nonlinear optimization. These IMFs are of the form $a(t) \cos(\theta(t))$ where
the amplitude $a(t)$ is positive and slowly varying. The non-decreasing phase
function $\theta(t)$ is determined by the data and in general depends on the
signal in a nonlinear fashion. One of the main results of this paper is that we
show that each IMF can be associated with a solution of a second order ordinary
differential equation of the form $\ddot{x}+p(x,t)\dot{x}+q(x,t)=0$. Further,
we propose a localized variational formulation for this problem and develop an
effective $l^1$-based optimization method to recover $p(x,t)$ and $q(x,t)$ by
looking for a sparse representation of $p$ and $q$ in terms of the polynomial
basis. Depending on the form of nonlinearity in $p(x,t)$ and $q(x,t)$, we can
define the degree of nonlinearity for the associated IMF. %and the
corresponding coefficients for the associated highest order nonlinear terms.
This generalizes a concept recently introduced by Prof. N. E. Huang et al.
\cite{Huang11}. Numerical examples will be provided to illustrate the
robustness and stability of the proposed method for data with or without noise.
This manuscript should be considered as a proof of concept.


title: Differential Entropy Dynamics: A Possible Cause of Coherence Resonance

abstract:
  Coherence resonance can be explained using differential entropy and mutual
information. This theory explores the role of external noise in stabilising
chaotic circuits such as the uni-junction transistor relaxation oscillator.The
phenomenon of coherence resonance maximizes differential entropy and mutual
information.Thus most natural chaotic oscillators show coherence resonance in
the presence of an external driving noise.


title: On a conjecture about tricyclic graphs with maximal energy

abstract:
  For a given simple graph $G$, the energy of $G$, denoted by $\mathcal
{E}(G)$, is defined as the sum of the absolute values of all eigenvalues of its
adjacency matrix, which was defined by I. Gutman. The problem on determining
the maximal energy tends to be complicated for a given class of graphs. There
are many approaches on the maximal energy of trees, unicyclic graphs and
bicyclic graphs, respectively. Let $P^{6,6,6}_n$ denote the graph with $n\geq
20$ vertices obtained from three copies of $C_6$ and a path $P_{n-18}$ by
adding a single edge between each of two copies of $C_6$ to one endpoint of the
path and a single edge from the third $C_6$ to the other endpoint of the
$P_{n-18}$. Very recently, Aouchiche et al. [M. Aouchiche, G. Caporossi, P.
Hansen, Open problems on graph eigenvalues studied with AutoGraphiX, {\it
Europ. J. Comput. Optim.} {\bf 1}(2013), 181--199] put forward the following
conjecture: Let $G$ be a tricyclic graphs on $n$ vertices with $n=20$ or
$n\geq22$, then $\mathcal{E}(G)\leq \mathcal{E}(P_{n}^{6,6,6})$ with equality
if and only if $G\cong P_{n}^{6,6,6}$. Let $G(n;a,b,k)$ denote the set of all
connected bipartite tricyclic graphs on $n$ vertices with three vertex-disjoint
cycles $C_{a}$, $C_{b}$ and $C_{k}$, where $n\geq 20$. In this paper, we try to
prove that the conjecture is true for graphs in the class $G\in G(n;a,b,k)$,
but as a consequence we can only show that this is true for most of the graphs
in the class except for 9 families of such graphs.


title: Generalized BF state in quantum gravity

abstract:
  The BF state is known as a simple wave function that satisfies three
constraints in canonical quantum gravity without a cosmological constant. It is
constructed from a product of the group delta functions. Applying the chiral
asymmetric extension, the BF state is generalized to the state for real values
of the Barbero-Immirzi parameter.


title:
Why Colloidal Systems can be described by Statistical Mechanics: Some
  not very original comments on the Gibbs paradox

abstract:
  Colloidal particles are distinguishable. Moreover, their thermodynamic
properties are extensive. Statistical Mechanics predicts such behaviour if one
accepts that the configurational integral of a system of N colloids must be
divided by N!. In many textbooks it is argued that the factor N! corrects for
the fact that identical particles (in the quantum mechanical sense) are
indistinguishable. Clearly, this argument does not apply to colloids. This
articles explains why, nevertheless, all is well. The point has been made
before, but has not yet sunk in. I also discuss the effect of polydispersity.


title:
Nilpotent and absolutely anticommuting symmetries in the
  Freedman-Townsend model: augmented superfield formalism

abstract:
  We derive the off-shell nilpotent and absolutely anticommuting
Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations,
corresponding to the (1-form) Yang-Mills (YM) and (2-form) tensorial gauge
symmetries of the four (3 + 1)-dimensional (4D) Freedman-Townsend (FT) model,
by exploiting the augmented version of Bonora-Tonin's (BT) superfield approach
to BRST formalism where the 4D flat Minkowskian theory is generalized onto the
(4, 2)-dimensional supermanifold. One of the novel observations is the fact
that we are theoretically compelled to go beyond the horizontality condition
(HC) to invoke an additional set of gauge-invariant restrictions (GIRs) for the
derivation of the full set of proper (anti-)BRST symmetries. To obtain the
(anti-)BRST symmetry transformations, corresponding to the tensorial (2-form)
gauge symmetries within the framework of augmented version of BT-superfield
approach, we are logically forced to modify the FT-model to incorporate an
auxiliary 1-form field and the kinetic term for the antisymmetric (2-form)
gauge field. This is also a new observation in our present investigation. We
point out some key differences between the modified FT-model and Lahiri-model
(LM) of the dynamical non-Abelian 2-form gauge theories.


title: Molecular Structures in Hidden Charm Meson and Charmed Baryon Spectrum

abstract:
  Using a constituent quark model we study the mass and decay channels of meson
meson and meson baryon structures in the charm sector.
  We show that the $X(3872)$ and $X(3940)$ resonances can be described as mixed
charmonium-molecular states with $J^{PC}=1^{++}$, whereas the $X(3915)$ and the
$Y(3940)$ can be assigned to similar mixed states with $J^{PC}=0^{++}$.
  In the baryon spectrum we identify the $\Lambda^+_c(2940)$ as a $D^*N$
molecule with $(I)J^P=(0)3/2^-$ and the recently reported $X_c(3250)$ as a
$D^*\Delta$ resonance with $(I)J^P=(1)5/2^-$ or $(I)J^P=(2)3/2^-$.


title: Bipartite Rigidity

abstract:
  We develop a bipartite rigidity theory for bipartite graphs parallel to the
classical rigidity theory for general graphs, and define for two positive
integers $k,l$ the notions of $(k,l)$-rigid and $(k,l)$-stress free bipartite
graphs. This theory coincides with the study of Babson--Novik's balanced
shifting restricted to graphs. We establish bipartite analogs of the cone,
contraction, deletion, and gluing lemmas, and apply these results to derive a
bipartite analog of the rigidity criterion for planar graphs. Our result
asserts that for a planar bipartite graph $G$ its balanced shifting, $G^b$,
does not contain $K_{3,3}$; equivalently, planar bipartite graphs are
generically $(2,2)$-stress free. We also discuss potential applications of this
theory to Jockusch's cubical lower bound conjecture and to upper bound
conjectures for embedded simplicial complexes.


title: Bipartite Minors

abstract:
  We introduce a notion of bipartite minors and prove a bipartite analog of
Wagner's theorem: a bipartite graph is planar if and only if it does not
contain $K_{3,3}$ as a bipartite minor. Similarly, we provide a forbidden minor
characterization for outerplanar graphs and forests. We then establish a
recursive characterization of bipartite $(2,2)$-Laman graphs --- a certain
family of graphs that contains all maximal bipartite planar graphs.


title:
Generation of a neutral, high-density electron-positron plasma in the
  laboratory

abstract:
  We report on the laser-driven generation of purely neutral, relativistic
electron-positron pair plasmas. The overall charge neutrality, high average
Lorentz factor ($\gamma_{e/p} \approx 15$), small divergence ($\theta_{e/p}
\approx 10 - 20$ mrad), and high density ($n_{e/p}\simeq 10^{15}$cm$^{-3}$) of
these plasmas open the pathway for the experimental study of the dynamics of
this exotic state of matter, in regimes that are of relevance to
electron-positron astrophysical plasmas.


title:
Fractional Brownian motion with Hurst index $H=0$ and the Gaussian
  Unitary Ensemble

abstract:
  The goal of this paper is to establish a relation between characteristic
polynomials of $N\times N$ GUE random matrices $\mathcal{H}$ as $N\to\infty$,
and Gaussian processes with logarithmic correlations. We introduce a
regularized version of fractional Brownian motion with zero Hurst index, which
is a Gaussian process with stationary increments and logarithmic increment
structure. Then we prove that this process appears as a limit of
$D_N(z)=-\log|\det(\mathcal{H}-zI)|$ on mesoscopic scales as $N\to\infty$. By
employing a Fourier integral representation, we use this to prove a continuous
analogue of a result by Diaconis and Shahshahani [J. Appl. Probab. 31A (1994)
49-62]. On the macroscopic scale, $D_N(x)$ gives rise to yet another type of
Gaussian process with logarithmic correlations. We give an explicit
construction of the latter in terms of a Chebyshev-Fourier random series.


title: Ramond-Ramond S-matrix elements from T-dual Ward identity

abstract:
  Recently it has been speculated that the Ward identities associated with the
string dualities and the gauge symmetries can be used as guiding principles to
find all components of the scattering amplitude of $n$ supergravitons from a
given component of the S-matrix. In this paper, we apply the Ward identities
associated with the T-duality and the gauge symmetries on the disk-level
S-matrix element of one RR $(p-3)$-form, one NSNS and one NS states, to find
the corresponding S-matrix elements of the RR $(p-1)$-form, $(p+1)$-form or the
RR$(p+3)$-form on the world volume of a D$_p$-brane. Moreover, we apply these
Ward identities on the S-matrix element of one RR $(p-3)$-form and two NSNS
states to find the corresponding S-matrix elements of the RR $(p-1)$-form,
$(p+1)$-form, $(p+3)$-form or the RR $(p+5)$-form.


title:
Auxiliary Hamiltonian representation of the nonequilibrium Dyson
  equation

abstract:
  The nonequilibrium Dyson (or Kadanoff-Baym) equation, which is an equation of
motion with long-range memory kernel for real-time Green functions, underlies
many numerical approaches based on the Keldysh formalism. In this paper we map
the problem of solving the Dyson equation in real-time onto a noninteracting
auxiliary Hamiltonian with additional bath degrees of freedom. The solution of
the auxiliary model does not require the evaluation of a memory kernel and can
thus be implemented in a very memory efficient way. The mapping is derived for
a self-energy which is local in space and is thus directly applicable within
nonequilibrium dynamical mean-field theory (DMFT). We apply the method to study
the interaction quench in the Hubbard model for an optical lattice with a
narrow confinement, using inhomogeneous DMFT in combination with second-order
weak-coupling perturbation theory. We find that, although the quench excites
pronounced density oscillations, signatures of the two-stage relaxation similar
to the homogeneous system can be observed by looking at the time-dependent
occupations of natural orbitals.


title: Golden ratio lepton mixing and nonzero reactor angle with $A_5$

abstract:
  We furnish a supersymmetric extension of the Standard Model with a flavour
discrete symmetry $A_5$ under which the lepton fields transform as an
irreducible triplet. Additional (`flavon') superfields are used to break $A_5$
into a $\mathbb{Z}_2 \times \mathbb{Z}_2$ subgroup in the charged-lepton sector
and another $\mathbb{Z}_2$ subgroup in the neutrino sector. The first column of
the resulting lepton mixing matrix is predicted and has entries which are
related to the golden ratio. Using the observed $\theta_{13}$ as input, our
model predicts a solar mixing angle $\theta_{12}$ in very good agreement with
experiment; it also predicts a correlation between the atmospheric mixing angle
$\theta_{23}$ and the $CP$-violating Dirac phase $\delta$.


title:
On the absolute stability regions corresponding to partial sums of the
  exponential function

abstract:
  Certain numerical methods for initial value problems have as stability
function the nth partial sum of the exponential function. We study the
stability region, i.e., the set in the complex plane over which the nth partial
sum has at most unit modulus. It is known that the asymptotic shape of the part
of the stability region in the left half-plane is a semi-disk. We quantify this
by providing disks that enclose or are enclosed by the stability region or its
left half-plane part. The radius of the smallest disk centered at the origin
that contains the stability region (or its portion in the left half-plane) is
determined for $1\le n\le 20$. Bounds on such radii are proved for $n\ge 2$;
these bounds are shown to be optimal in the limit $n\to +\infty$. We prove that
the stability region and its complement, restricted to the imaginary axis,
consist of alternating intervals of length tending to $\pi$, as $n\to\infty$.
Finally, we prove that a semi-disk in the left half-plane with vertical
boundary being the imaginary axis and centered at the origin is included in the
stability region if and only if $n\equiv 0 \mod 4$ or $n\equiv 3\mod 4$. The
maximal radii of such semi-disks are exactly determined for $1\le n\le 20$.


title: Probing evolution of binaries influenced by the spin-orbit resonances

abstract:
  We evolve isolated comparable mass spinning compact binaries experiencing
Schnittman's post-Newtonian spin-orbit resonances in an inertial frame
associated with $j_0$, the initial direction of the total angular momentum. We
argue that accurate gravitational wave (GW) measurements of the initial
orientations of the two spins and orbital angular momentum from $j_0$ should
allow us to distinguish between the two possible families of spin-orbit
resonances. Therefore, these measurements have the potential to provide direct
observational evidence of possible binary formation scenarios. The above
statements should also apply for binaries that do not remain in a resonant
plane when they become detectable by GW interferometers. The resonant plane,
characterized by the vanishing scalar triple product involving the two spins
and the orbital angular momentum, naturally appears in the one parameter family
of equilibrium solutions, discovered by Schnittman. We develop a prescription
to compute the time-domain inspiral templates for binaries residing in these
resonant configurations and explore their preliminary data analysis
consequences.


title: Inequalities for eigenvalues of the weighted Hodge Laplacian

abstract:
  In this paper, we obtain "universal" inequalities for eigenvalues of the
weighted Hodge Laplacian on a compact self-shrinker of Euclidean space. These
inequalities generalize the Yang-type and Levitin-Parnovski inequalities for
eigenvalues of the Laplacian and Laplacian. From the recursion formula of Cheng
and Yang \cite{ChengYang07}, the Yang-type inequality for eigenvalues of the
weighted Hodge Laplacian are optimal in the sense of the order of eigenvalues.


title: Non-Relativistic Holography -- A Group-Theoretical Perspective

abstract:
  We give a review of some group-theoretical results related to
non-relativistic holography. Our main playgrounds are the Schr\"odinger
equation and the Schr\"odinger algebra. We first recall the interpretation of
non-relativistic holography as equivalence between representations of the
Schr\"odinger algebra describing bulk fields and boundary fields. One important
result is the explicit construction of the boundary-to-bulk operators in the
framework of representation theory, and that these operators and the
bulk-to-boundary operators are intertwining operators. Further, we recall the
fact that there is a hierarchy of equations on the boundary, invariant w.r.t.
Schr\"odinger algebra. We also review the explicit construction of an analogous
hierarchy of invariant equations in the bulk, and that the two hierarchies are
equivalent via the bulk-to-boundary intertwining operators. The derivation of
these hierarchies uses a mechanism introduced first for semi-simple Lie groups
and adapted to the non-semisimple Schr\"odinger algebra. These requires
development of the representation theory of the Schr\"odinger algebra which is
reviewed in some detail. We also recall the $q$-deformation of the
Schr\"odinger algebra. Finally, the realization of the Schr\"odinger algebra
via difference operators is reviewed.


title: Entropy current and equilibrium partition function in fluid dynamics

abstract:
  Existence of an entropy current with non-negative divergence puts a lot of
constraints on the transport coefficients of a fluid, so does the existence of
equilibrium. In all the cases we have studied so far we have seen an overlap
between these two sets of constraints. In this note we shall try to explore the
reason for such an overlap. We shall also see how a part of the entropy current
could be determined from the equilibrium partition function.


title: Status and prospects for BESIII

abstract:
  In this paper the status and prospects for BESIII is presented.The BEPCII
machine is in good status and recently reached its highest luminosity of
7.08*10^32cm^-2s^-1. The BESIII detectors have been running stably since 2009.
Upgrade plans for its sub-detectors have been proposed and the upgrade is
undergoing. The major upgrade comes from the drift chamber and the time of of
flight counter. The other sub-detectors show good status and no upgrade are
needed. Given the current status and upgrade plan of the BESIII detectors, it's
foreseen that the BESIII is able to work for 8 to 10 years from now.


title: Asymmetric regular types

abstract:
  We study asymmetric regular types. If $\frak p$ is regular and $A$-asymmetric
then there exists a strict order such that Morley sequences in $\frak p$ over
$A$ are strictly increasing (we allow Morley sequences to be indexed by
elements of a linear order). We prove that for all $M\supseteq A$ maximal
Morley sequences in $\frak p$ over $A$ consisting of elements of $M$ have the
same (linear) order type, denoted by $\Inv_{\frak p,A}(M)$, which does not
depend on the particular choice of the order witnessing the asymmetric
regularity. In the countable case we determine all possibilities for
$\Inv_{\frak p,A}(M)$: either it can be any countable linear order, or in any
$M\supseteq A$ it is a dense linear order (provided that it has at least two
elements). Then we study relationship between $\Inv_{\frak p,A}(M)$ and
$\Inv_{\frak q,A}(M)$ when $\frak p$ and $\frak q$ are strongly regular,
$A$-asymmetric, and such that $\frak p_{\strok A}$ and $\frak q_{\strok A}$ are
not weakly orthogonal. We distinguish two kinds on non-orthogonality: bounded
and unbounded. In the bounded case we prove that $\Inv_{\frak p,A}(M)$ and
$\Inv_{\frak q,A}(M)$ are either isomorphic or anti-isomorphic. In the
unbounded case, $\Inv_{\frak p,A}(M)$ and $\Inv_{\frak q,A}(M)$ may have
distinct cardinalities but we prove that their Dedekind completions are either
isomorphic or anti-isomorphic. We provide examples of all four situations.


title:
Study of F4TCNQ dopant diffusion using transport measurements in organic
  semiconductors

abstract:
  In this paper, we report on electrical transport in F4TCNQ doped organic
semiconductor (host) materials. By monitoring the conductance of the sample
in-situ during and after deposition, we show that sequential deposition of
F4TCNQ and host semiconductor results in bulk doping of the semiconductor. In
addition, the doping density (and conductivity) of the host can be easily
controlled by adjusting the thickness of the bottom F4TCNQ layer. This
alternative scheme for doping is simpler than the conventional way of doping
small molecules which involves simultaneous co-evaporation of host and dopant.
In the sequential doping scheme outlined here, bulk doping of the host takes
place due to rapid diffusion of F4TCNQ in the host material. The motion of
F4TCNQ in the host is complex and is not always described by a simple diffusion
process. In situ transport measurements provide a quick and easy way of
measuring dopant diffusion in new hosts. Based on the doping results, we also
outline a possible route to improved transconductance for organic thin film
transistors in a manufacturing environment.


title:
Observational constraint on the interacting dark energy models including
  the Sandage-Loeb test

abstract:
  Two types of interacting dark energy models are investigated using the type
Ia supernova (SNIa), observational $H(z)$ data (OHD), cosmic microwave
background (CMB) shift parameter and the secular Sandage-Loeb (SL) test. We
find that the inclusion of SL test can obviously provide more stringent
constraint on the parameters in both models. For the constant coupling model,
the interaction term including the SL test is estimated at $\delta=-0.01 \pm
0.01 (1\sigma) \pm 0.02 (2\sigma)$, which has been improved to be only a half
of original scale on corresponding errors. Comparing with the combination of
SNIa and OHD, we find that the inclusion of SL test directly reduces the
best-fit of interaction from 0.39 to 0.10, which indicates that the
higher-redshift observation including the SL test is necessary to track the
evolution of interaction. For the varying coupling model, we reconstruct the
interaction $\delta (z)$, and find that the interaction is also negative
similar as the constant coupling model. However, for high redshift, the
interaction generally vanishes at infinity. The constraint result also shows
that the $\Lambda$CDM model still behaves a good fit to the observational data,
and the coincidence problem is still quite severe. However, the phantom-like
dark energy with $w_X<-1$ is slightly favored over the $\Lambda$CDM model.


title: Modified gravity from the quantum part of the metric

abstract:
  It is shown that if a metric in quantum gravity can be decomposed as a sum of
classical and quantum parts then Einstein quantum gravity looks approximately
like modified gravity with a nonminimal interaction between gravity and matter.


title: A Model for the Generation and Transmission of Variations in Evolution

abstract:
  The inheritance of characteristics induced by the environment has often been
opposed to the theory of evolution by natural selection. Yet, while evolution
by natural selection requires new heritable traits to be produced and
transmitted, it does not prescribe, per se, the mechanisms by which this is
operated. The mechanisms of inheritance are not, however, unconstrained, since
they are themselves subject to natural selection. We introduce a general,
analytically solvable mathematical model to compare the adaptive value of
different schemes of inheritance. Our model allows for variations to be
inherited, randomly produced, or environmentally induced, and, irrespectively,
to be either transmitted or not during reproduction. The adaptation of the
different schemes for processing variations is quantified for a range of
fluctuating environments, following an approach that links quantitative
genetics with stochastic control theory.


title:
Strong Anisotropy of Dirac Cone in SrMnBi2 and CaMnBi2 Revealed by
  Angle-Resolved Photoemission Spectroscopy

abstract:
  The Dirac materials, such as graphene and three-dimensional topological
insulators, have attracted much attention because they exhibit novel quantum
phenomena with their low energy electrons governed by the relativistic Dirac
equations. One particular interest is to generate Dirac cone anisotropy so that
the electrons can propagate differently from one direction to the other,
creating an additional tunability for new properties and applications. While
various theoretical approaches have been proposed to make the isotropic Dirac
cones of graphene into anisotropic ones, it has not yet been met with success.
There are also some theoretical predictions and/or experimental indications of
anisotropic Dirac cone in novel topological insulators and AMnBi2 (A=Sr and Ca)
but more experimental investigations are needed. Here we report systematic high
resolution angle-resolved photoemission measurements that have provided direct
evidence on the existence of strongly anisotropic Dirac cones in SrMnBi2 and
CaMnBi2. Distinct behaviors of the Dirac cones between SrMnBi2 and CaMnBi2 are
also observed. These results have provided important information on the strong
anisotropy of the Dirac cones in AMnBi2 system that can be governed by the
spin-orbital coupling and the local environment surrounding the Bi square net.


title: Ising-like phase transition of an n-component Eulerian face-cubic model

abstract:
  By means of Monte Carlo simulations and a finite-size scaling analysis, we
find a critical line of an n-component Eulerian face-cubic model on the square
lattice and the simple cubic lattice in the region v>1, where v is the bond
weight. The phase transition belongs to the Ising universality class
independent of n. The critical properties of the phase transition can also be
captured by the percolation of the complement of the Eulerian graph.


title: Five Disruptive Technology Directions for 5G

abstract:
  New research directions will lead to fundamental changes in the design of
future 5th generation (5G) cellular networks. This paper describes five
technologies that could lead to both architectural and component disruptive
design changes: device-centric architectures, millimeter Wave, Massive-MIMO,
smarter devices, and native support to machine-2-machine. The key ideas for
each technology are described, along with their potential impact on 5G and the
research challenges that remain.


title: Bethe free-energy approximations for disordered quantum systems

abstract:
  Given a locally consistent set of reduced density matrices, we construct
approximate density matrices which are globally consistent with the local
density matrices we started from when the trial density matrix has a tree
structure. We employ the cavity method of statistical physics to find the
optimal density matrix representation by slowly decreasing the temperature in
an annealing algorithm, or by minimizing an approximate Bethe free energy
depending on the reduced density matrices and some cavity messages originated
from the Bethe approximation of the entropy. We obtain the classical Bethe
expression for the entropy within a naive (mean-field) approximation of the
cavity messages, which is expected to work well at high temperatures. In the
next order of the approximation, we obtain another expression for the Bethe
entropy depending only on the diagonal elements of the reduced density
matrices. In principle, we can improve the entropy approximation by considering
more accurate cavity messages in the Bethe approximation of the entropy. We
compare the annealing algorithm and the naive approximation of the Bethe
entropy with exact and approximate numerical simulations for small and large
samples of the random transverse Ising model on random regular graphs.


title: Supermembrane in D=5: component action

abstract:
  Based on the connection between partial breaking of global supersymmetry,
coset approach, which realized the given pattern of supersymmetry breaking, and
the Nambu-Goto actions for the extended objects, we have constructed on-shell
component action for N=1, D=5 supermembrane and its dual cousins. We
demonstrate that the proper choice of the components and the use of the
covariant (with respect to broken supersymmetry) derivatives drastically
simplify the action: it can be represented as a sum of four terms each having
an explicit geometric meaning.


title:
Stochastic continuum armed bandit problem of few linear parameters in
  high dimensions

abstract:
  We consider a stochastic continuum armed bandit problem where the arms are
indexed by the $\ell_2$ ball $B_{d}(1+\nu)$ of radius $1+\nu$ in
$\mathbb{R}^d$. The reward functions $r :B_{d}(1+\nu) \rightarrow \mathbb{R}$
are considered to intrinsically depend on $k \ll d$ unknown linear parameters
so that $r(\mathbf{x}) = g(\mathbf{A} \mathbf{x})$ where $\mathbf{A}$ is a full
rank $k \times d$ matrix. Assuming the mean reward function to be smooth we
make use of results from low-rank matrix recovery literature and derive an
efficient randomized algorithm which achieves a regret bound of $O(C(k,d)
n^{\frac{1+k}{2+k}} (\log n)^{\frac{1}{2+k}})$ with high probability. Here
$C(k,d)$ is at most polynomial in $d$ and $k$ and $n$ is the number of rounds
or the sampling budget which is assumed to be known beforehand.


title: On Optimal Disc Covers and a New Characterization of the Steiner Center

abstract:
  Given N points in the plane $P_1 P_2...P_N$ and a location $\Omega$, the
union of discs with diameters $[\Omega P_i], i = 1, 2,...N$ covers the convex
hull of the points. The location $\Omega_s$ minimizing the area covered by the
union of discs, is shown to be the Steiner center of the convex hull of the
points. Similar results for $d$-dimensional Euclidean space are conjectured.


title: Eigenvalue gaps for the Laplacian on hypersurfaces of the sphere

abstract:
  We provide lower estimates for the eigenvalues of the laplacian for
hypersurfaces of the round sphere.


title: A Galois-Grothendieck-type correspondence for groupoid actions

abstract:
  In this paper we present a Galois-Grothendieck-type correspondence for
groupoid actions. As an application a Galois-type correspondence is also given.


title:
Chemical Bonding in Aqueous Ferrocyanide: Experimental and Theoretical
  X-ray Spectroscopic Study

abstract:
  Resonant inelastic X-ray scattering (RIXS) and X-ray absorption (XA)
experiments at the iron L- and nitrogen K-edge are combined with high-level
first principles restricted active space self-consistent field (RASSCF)
calculations for a systematic investigation of the nature of the chemical bond
in potassium ferrocyanide in aqueous solution. The atom- and site-specific RIXS
excitations allow for direct observation of ligand-to-metal (Fe L-edge) and
metal-to-ligand (N K-edge) charge transfer bands and thereby evidence for
strong {\sigma}-donation and {\pi}-back-donation. The effects are identified by
comparing experimental and simulated spectra related to both the unoccupied and
occupied molecular orbitals in solution.


title:
Quasi-isotropic expansion for a two-fluid cosmological model containing
  radiation and string gas

abstract:
  The quasi-isotropic expansion for a simple two-fluid cosmological model,
including radiation and string gas is constructed. The first non-trivial order
expressions for the metric coefficients, energy densities and velocities are
explicitly written down. Their small and large time asymptotics are studied. It
is found that the large time asymptotic for the anisotropic component of the
metric coefficients grows faster than that of the isotropic
(trace-proportional) component.


title: Fluctuations of Parabolic Equations with Large Random Potentials

abstract:
  In this paper, we present a fluctuation analysis of a type of parabolic
equations with large, highly oscillatory, random potentials around the
homogenization limit. With a Feynman-Kac representation, the Kipnis-Varadhan's
method, and a quantitative martingale central limit theorem, we derive the
asymptotic distribution of the rescaled error between heterogeneous and
homogenized solutions under different assumptions in dimension $d\geq 3$. The
results depend highly on whether a stationary corrector exits.


title: The augmented base locus of real divisors over arbitrary fields

abstract:
  We show that the augmented base locus coincides with the exceptional locus
(i.e. null locus) for any nef $\mathbb{R}$-Cartier divisor on any scheme
projective over a field (of any characteristic). Next we prove a semi-ampleness
criterion in terms of the augmented base locus generalizing a result of Keel.
We also study nef divisors with positive top intersection number, and discuss
some problems related to augmented base loci of log divisors.


title: Differential Operators on Modular Extensions

abstract:
  We determine necessary and sufficient conditions on the ring of differential
operators of a finite purely inseparable field extension of positive
characteristic for determining whether the extension is modular.


title: Equivariant Motivic Homotopy Theory

abstract:
  In this paper we study a model structure on a category of schemes with a
group action and the resulting unstable and stable equivariant motivic homotopy
theories. The new model structure introduced here samples a comparison to the
one by Voevodsky and Hu-Kriz-Ormsby. We show that it allows to detect
equivariant motivic weak equivalences on fixed points and how this property
leads to a topologically convenient behavior of stable equivalences. We also
prove a negative result concerning descent for equivariant algebraic K-theory.


title: Doping of Bi2Te3 using electron irradiation

abstract:
  Electron irradiation is investigated as a way to dope the topological
insulator Bi2Te3. For this, p-type Bi2Te3 single crystals have been irradiated
with 2.5 MeV electrons at room temperature and electrical measurements have
been performed in-situ as well as ex-situ in magnetic fields up to 14 T. The
defects created by irradiation act as electron donors allowing the compensation
of the initial hole-type conductivity of the material as well as the conversion
of the conductivity from p- to n-type. The changes in carrier concentration are
investigated using Hall effect and Shubnikov-de Haas (SdH) oscillations,
clearly observable in the p-type samples before irradiation, but also after the
irradiation-induced conversion of the conductivity to n-type. The SdH patterns
observed for the magnetic field along the trigonal axis can be entirely
explained assuming the contribution of only one valence and conduction band,
respectively, and Zeeman-splitting of the orbital levels.


title:
Overfrustrated and Underfrustrated Spin-Glasses in d=3 and 2: Evolution
  of Phase Diagrams and Chaos Including Spin-Glass Order in d=2

abstract:
  In spin-glass systems, frustration can be adjusted continuously and
considerably, without changing the antiferromagnetic bond probability p, by
using locally correlated quenched randomness, as we demonstrate here on
hypercubic lattices and hierarchical lattices. Such overfrustrated and
underfrustrated Ising systems on hierarchical lattices in d=3 and 2 are
studied. With the removal of just 51 % of frustration, a spin-glass phase
occurs in d=2. With the addition of just 33 % frustration, the spin-glass phase
disappears in d=3. Sequences of 18 different phase diagrams for different
levels of frustration are calculated in both dimensions. In general,
frustration lowers the spin-glass ordering temperature. At low temperatures,
increased frustration favors the spin-glass phase (before it disappears) over
the ferromagnetic phase and symmetrically the antiferromagnetic phase. When any
amount, including infinitesimal, frustration is introduced, the chaotic
rescaling of local interactions occurs in the spin-glass phase. Chaos increases
with increasing frustration, as seen from the increased positive value of the
calculated Lyapunov exponent $\lambda$, starting from $\lambda =0$ when
frustration is absent. The calculated runaway exponent $y_R$ of the
renormalization-group flows decreases with increasing frustration to $y_R=0$
when the spin-glass phase disappears. From our calculations of entropy and
specific heat curves in d=3, it is seen that frustration lowers in temperature
the onset of both long- and short-range order in spin-glass phases, but is more
effective on the former. From calculations of the entropy as a function of
antiferromagnetic bond concentration p, it is seen that the ground-state and
low-temperature entropy already mostly sets in within the ferromagnetic and
antiferromagnetic phases, before the spin-glass phase is reached.


title: The Blaschke-Santalo Inequality

abstract:
  The Blaschke-Santal\'o Inequality is the assertion that the volume product of
a centrally symmetric convex body in Euclidean space is maximized by (and only
by) ellipsoids. In this paper we give a Fourier analytic proof of this fact.


title:
The complete experiment for photoproduction of pseudoscalar mesons in a
  truncated partial wave analysis

abstract:
  The complete experiment problem in the truncated partial wave analysis of
pseudoscalar meson photoproduction with suppressed t-channel exchanges is
investigated. The focus is set to ambiguities of the group S observables with
the unpolarized differential cross section, $\sigma_0$, and the three
single-spin observables, $\Sigma$, $T$ and $P$. For this purpose, the approach
and formalism already worked out by Omelaenko in 1981 is revisited in this
work. A numerical study using multipoles of the PWA solution MAID2007 shows how
only one additional double polarization observable can resolve all ambiguities.
Therefore, the possibility emerges to perform a complete experiment with only
five observables.


title:
Rejection of randomly coinciding 2{\nu}2{\beta} events in ZnMoO4
  scintillating bolometers

abstract:
  Random coincidence of 2{\nu}2{\beta} decay events could be one of the main
sources of background for 0{\nu}2{\beta} decay in cryogenic bolometers due to
their poor time resolution. Pulse-shape discrimination by using front edge
analysis, the mean-time and \c{hi}2 methods was applied to discriminate
randomly coinciding 2{\nu}2{\beta} events in ZnMoO4 cryogenic scintillating
bolometers. The background can be effectively rejected on the level of 99% by
the mean-time analysis of heat signals with the rise time about 14 ms and the
signal-to-noise ratio 900, and on the level of 98% for the light signals with 3
ms rise time and signal-to-noise ratio of 30 (under a requirement to detect 95%
of single events). Importance of the signal-to-noise ratio, correct finding of
the signal start and choice of an appropriate sampling frequency are discussed.


title: Vector bundles from generalized pairs of cocycles

abstract:
  It is interesting to know, how far we can generalize the notion of a
group-valued cocycle keeping the property to determine a bundle. We find a
generalization for pairs of cocycles and show how these generalized pairs of
cocycles can still determine vector bundles.


title: Maximizing the number of nonnegative subsets

abstract:
  Given a set of $n$ real numbers, if the sum of elements of every subset of
size larger than $k$ is negative, what is the maximum number of subsets of
nonnegative sum? In this note we show that the answer is $\binom{n-1}{k-1} +
\binom{n-1}{k-2} + \cdots + \binom{n-1}{0}+1$, settling a problem of Tsukerman.
We provide two proofs, the first establishes and applies a weighted version of
Hall's Theorem and the second is based on an extension of the nonuniform
Erd\H{o}s-Ko-Rado Theorem.


title:
Reuse of existing applications during the development of Enterprise
  Portals integrating Web Services

abstract:
  During these last years, the use of the web technologies in the enterprises
becomes an essential factor to define a new business model. Among these
technologies, web services and enterprise portals have gathered to integrate
existing heterogeneous systems such as e-commerce, eservices hub and
e-learning. However, the design and the modeling of the portals, on the one
hand, and their integration with the existing applications, on the other hand,
are still two points open for discussion. The first problem is related to the
development of the lifecycle that can be used for designing and modeling the
enterprise portals. For the second problem, which is the integration of the
existing applications, the discussion is intended towards the use of
technologies based on web services. In This paper, we present a software
engineering solution for the development of Web services-based enterprise
portals.


title:
Simulations of gamma quanta scattering in a single module of the J-PET
  detector

abstract:
  This article describes simulations of scattering of annihilation gamma quanta
in a strip of plastic scintillator. Such strips constitute basic detection
modules in a newly proposed Positron Emission Tomography which utilizes plastic
scintillators instead of inorganic crystals. An algorithm simulating chain of
Compton scatterings was elaborated and series of simulations have been
conducted for the scintillator strip with the cross section of 5 mm x 19 mm.
Obtained results indicate that secondary interactions occur only in the case of
about 8% of events and out of them only 25$\%$ take place in the distance
larger than 0.5 cm from the primary interaction. It was also established that
light signals produced at primary and secondary interactions overlap with the
delay which distribution is characterized by FWHM of about 40 ps.


title: $3$-class field towers of exact length $3$

abstract:
  The $p$-group generation algorithm is used to verify that the Hilbert
$3$-class field tower has length $3$ for certain imaginary quadratic fields $K$
with $3$-class group $\mathrm{Cl}_3(K) \cong [3,3]$. Our results provide the
first examples of finite $p$-class towers of length $> 2$ for an odd prime $p$.


title:
Boundary spikes of a Keller-Segel chemotaxis system with saturated
  logarithmic sensitivity

abstract:
  In this paper, we study the nonconstant positive steady states of a
Keller-Segel chemotaxis system over a bounded domain $\Omega\subset
\mathbb{R}^N$, $N\geq 1$. The sensitivity function is chosen to be $\phi(v)=\ln
(v+c)$ where $c$ is a positive constant. For the chemical diffusion rate being
small, we construct positive solutions with a boundary spike supported on a
platform. Moreover, this spike approaches the most curved part of the boundary
of the domain as the chemical diffusion rate shrinks to zero. We also conduct
extensive numerical simulations to illustrate the formation of stable boundary
and interior spikes of the system. These spiky solutions can be used to model
the self--organized cell aggregation phenomenon in chemotaxis.


title:
Global solutions of a Keller--Segel system with saturated logarithmic
  sensitivity function

abstract:
  We study a Keller-Segel type chemotaxis model with a modified sensitivity
function in a bounded domain $\Omega\subset \mathbb{R}^N$, $N\geq2$. The global
existence of classical solutions to the fully parabolic system is established
provided that the ratio of the chemotactic coefficient to the motility of cells
is not too large.


title: Boundary conditions at spatial infinity from a Hamiltonian point of view

abstract:
  We show that the ADM mass and momentum are geometric invariants of
asymptotically flat initial data sets


title:
Identities involving the $\left(h,q\right)$-Genocchi polynomials and
  $\left(h,q\right)$-Zeta-type function

abstract:
  The fundamental objective of this paper is to obtain some interesting
properties for $\left(h,q\right)$-Genocchi numbers and polynomials by using the
fermionic $p$-adic $q$-integral on $\mathbb{Z}_{p}$ and mentioned in the paper
$q$-Bernstein polynomials. By considering the $q$-Euler zeta function defined
by T. Kim, which can also be obtained by applying the Mellin transformation to
the generating function of $\left(h,q\right)$-Genocchi polynomials, we study
$\left(h,q\right)$-Zeta-type function. We derive symmetric properties of
$\left(h,q\right)$-Zeta function and from these properties we give symmetric
property of $\left(h,q\right)$-Genocchi polynomials.


title:
Analysis of Regularized LS Reconstruction and Random Matrix Ensembles in
  Compressed Sensing

abstract:
  Performance of regularized least-squares estimation in noisy compressed
sensing is analyzed in the limit when the dimensions of the measurement matrix
grow large. The sensing matrix is considered to be from a class of random
ensembles that encloses as special cases standard Gaussian, row-orthogonal,
geometric and so-called T-orthogonal constructions. Source vectors that have
non-uniform sparsity are included in the system model. Regularization based on
l1-norm and leading to LASSO estimation, or basis pursuit denoising, is given
the main emphasis in the analysis. Extensions to l2-norm and "zero-norm"
regularization are also briefly discussed. The analysis is carried out using
the replica method in conjunction with some novel matrix integration results.
Numerical experiments for LASSO are provided to verify the accuracy of the
analytical results. The numerical experiments show that for noisy compressed
sensing, the standard Gaussian ensemble is a suboptimal choice for the
measurement matrix. Orthogonal constructions provide a superior performance in
all considered scenarios and are easier to implement in practical applications.
It is also discovered that for non-uniform sparsity patterns the T-orthogonal
matrices can further improve the mean square error behavior of the
reconstruction when the noise level is not too high. However, as the additive
noise becomes more prominent in the system, the simple row-orthogonal
measurement matrix appears to be the best choice out of the considered
ensembles.


title:
Supersymmetric Dark Matter candidates in light of constraints from
  collider and astroparticle observables

abstract:
  The Standard Model of particle physics has been strengthened by the recent
discovery of the long-awaited Higgs boson. The standard cosmological model has
met the challenge of the high precision observations in cosmology and
astroparticle physics. However these two standard models face both several
theoretical issues, such as the naturalness problem in the Higgs sector of the
Standard Model, as well as observational issues, in particular the fact that an
unknown kind of matter called Dark Matter accounts for the majority of the
matter content in our Universe. Attempts to solve such problems have led to the
development of New Physics models during the last decades. Supersymmetry is one
such model which addresses the fine-tuning problem in the Higgs sector and
provides viable Dark Matter candidates. Current high energy and high precision
experiments give many new opportunities to probe the supersymmetric models. It
is in this context that this thesis is written. Considering the Minimal
Supersymmetric Standard Model (MSSM), the simplest supersymmetric extension of
the Standard Model of particle physics, and its conventional Dark Matter
candidate, the neutralino, it is shown that collider constraints could provide
informations on the very early Universe at the inflation area. It is also
demonstrated that the Indirect Detection of Dark Matter, despite several
drawbacks, can be a powerful technique to probe supersymmetric Dark Matter
models. Beyond the MSSM it is shown that unique characteristics of the Dark
Matter candidate in the NMSSM could be probed at colliders. The study of a
supersymmetric model with an extended gauge symmetry, the UMSSM, is also
developed. The features of another Dark Matter candidate of this model, the
Right-Handed sneutrino, are analysed. More general constraints such as those
coming from low energy observables are finally considered in this model.


title:
Qualitative analysis of stationary Keller-Segel chemotaxis models with
  logistic growth

abstract:
  We study the stationary Keller--Segel chemotaxis models with logistic
cellular growth over a one-dimensional region subject to the Neumann boundary
condition. We show that nonconstant solutions emerge in the sense of Turing's
instability as the chemotaxis rate $\chi$ surpasses a threshold number. By
taking the chemotaxis rate as the bifurcation parameter, we carry out
bifurcation analysis on the system to obtain the explicit formulas of
bifurcation values and small amplitude nonconstant positive solutions. Moreover
we show that solutions stay strictly positive in the continuum of each branch.
The stabilities of these steady state solutions are well studied when the
creation and degradation rate of the chemical is assumed to be a linear
function. Finally we investigate the asymptotic behaviors of the monotone
steady states. We construct solutions with interesting patterns such as a
boundary spike when the chemotaxis rate is large enough and/or the cell
motility is small.


title: A higgs-like dilaton: viability and implications

abstract:
  We re-examine the feasibility of the higgs-like particle discovered at the
LHC being a dilaton: the Goldstone boson of spontaneous breaking of scale
invariance. We review the expected phenomenological deviations from the SM
higgs and compare with other Goldstone higgs scenarios, with particular
emphasis on double higgs production.


title:
Modeling and stabilizability of voltage-actuated piezoelectric beams
  with magnetic effects

abstract:
  Models for piezoelectric beams and structures with piezoelectric patches
generally ignore magnetic effects. This is because the magnetic energy has a
relatively small effect on the overall dynamics. Piezoelectric beam models are
known to be exactly observable, and can be exponentially stabilized in the
energy space by using a mechanical feedback controller. In this paper, a
variational approach is used to derive a model for a piezoelectric beam that
includes magnetic effects. It is proven that the partial differential equation
model is well-posed. Magnetic effects have a strong effect on the
stabilizability of the control system. For almost all system parameters the
piezoelectric beam can be strongly stabilized, but is not exponentially
stabilizable in the energy space. Strong stabilization is achieved using only
electrical feedback. Furthermore, using the same electrical feedback, an
exponentially stable closed-loop system can be obtained for a set of system
parameters of zero Lebesgue measure. These results are compared to those of a
beam without magnetic effects.


title: Extended and Revised Analysis of Singly Ionized Tin: Sn II

abstract:
  The electronic structure of singly ionized tin (SnII) is partly a
one-electron and partly a three-electron system with ground configuration
5s25p. The excited configurations are of the type 5s2nl in the one-electron
part, and 5s5p2, 5p3 and 5s5pnl (nl = 6s, 5d) in the three-electron system with
quartet and doublet levels. The spectrum analyzed in this work was recorded on
a 3 m normal incidence vacuum spectrograph of the Antigonish laboratory
(Canada) in the wavelength region 300 - 2080 {\AA} using a triggered spark
source. The existing interpretation of the one-electron level system was
confirmed in this paper, while the 2S1/2 level of the 5s5p2 configuration has
been revised. The analysis has been extended to include new configurations 5p3,
5s5p5d and 5s5p6s with the aid of superposition-of-configurations Hartree-Fock
calculations with relativistic corrections. The ionization potential obtained
from the ng series was found to be 118023.7(5) cm-1 (14.63307(6) eV). We give a
complete set of critically evaluated data on energy levels, observed
wavelengths and transition probabilities of Sn II in the range 888 - 10740
{\AA} involving excitation of the n = 5 electrons.


title: A monotonicity formula for mean curvature flow with surgery

abstract:
  We prove a monotonicity formula for mean curvature flow with surgery. This
formula differs from Huisken's monotonicity formula by an extra term involving
the mean curvature. As a consequence, we show that a surgically modified flow
which is sufficiently close to a smooth flow in the sense of geometric measure
theory is, in fact, free of surgeries. This result has applications to the
longtime behavior of mean curvature flow with surgery in Riemannian
three-manifolds.


title: Communication-Efficient Algorithms For Distributed Optimization

abstract:
  This thesis is concerned with the design of distributed algorithms for
solving optimization problems. We consider networks where each node has
exclusive access to a cost function, and design algorithms that make all nodes
cooperate to find the minimum of the sum of all the cost functions. Several
problems in signal processing, control, and machine learning can be posed as
such optimization problems. Given that communication is often the most
energy-consuming operation in networks, it is important to design
communication-efficient algorithms. The main contributions of this thesis are a
classification scheme for distributed optimization and a set of corresponding
communication-efficient algorithms.
  The class of optimization problems we consider is quite general, since each
function may depend on arbitrary components of the optimization variable, and
not necessarily on all of them. In doing so, we go beyond the common assumption
in distributed optimization and create additional structure that can be used to
reduce the number of communications. This structure is captured by our
classification scheme, which identifies easier instances of the problem, for
example the standard distributed optimization problem, where all functions
depend on all the components of the variable.
  In our algorithms, no central node coordinates the network, all the
communications occur between neighboring nodes, and the data associated with
each node is processed locally. We show several applications including average
consensus, support vector machines, network flows, and several distributed
scenarios for compressed sensing. We also propose a new framework for
distributed model predictive control. Through extensive numerical experiments,
we show that our algorithms outperform prior distributed algorithms in terms of
communication-efficiency, even some that were specifically designed for a
particular application.


title:
Competitive Fragmentation Modeling of ESI-MS/MS spectra for putative
  metabolite identification

abstract:
  Electrospray tandem mass spectrometry (ESI-MS/MS) is commonly used in high
throughput metabolomics. One of the key obstacles to the effective use of this
technology is the difficulty in interpreting measured spectra to accurately and
efficiently identify metabolites. Traditional methods for automated metabolite
identification compare the target MS or MS/MS spectrum to the spectra in a
reference database, ranking candidates based on the closeness of the match.
However the limited coverage of available databases has led to an interest in
computational methods for predicting reference MS/MS spectra from chemical
structures.
  This work proposes a probabilistic generative model for the MS/MS
fragmentation process, which we call Competitive Fragmentation Modeling (CFM),
and a machine learning approach for learning parameters for this model from
MS/MS data. We show that CFM can be used in both a MS/MS spectrum prediction
task (ie, predicting the mass spectrum from a chemical structure), and in a
putative metabolite identification task (ranking possible structures for a
target MS/MS spectrum).
  In the MS/MS spectrum prediction task, CFM shows significantly improved
performance when compared to a full enumeration of all peaks corresponding to
substructures of the molecule. In the metabolite identification task, CFM
obtains substantially better rankings for the correct candidate than existing
methods (MetFrag and FingerID) on tripeptide and metabolite data, when querying
PubChem or KEGG for candidate structures of similar mass.


title:
Translationally invariant multipartite Bell inequalities involving only
  two-body correlators

abstract:
  Bell inequalities are natural tools that allow one to certify the presence of
nonlocality in quantum systems. The known constructions of multipartite Bell
inequalities contain, however, correlation functions involving all observers,
making their experimental implementation difficult. The main purpose of this
work is to explore the possibility of witnessing nonlocality in multipartite
quantum states from the easiest-to-measure quantities, that is, the two-body
correlations. In particular, we determine all three and four-partite Bell
inequalities constructed from one and two-body expectation values that obey
translational symmetry, and show that they reveal nonlocality in multipartite
states. Also, by providing a particular example of a five-partite Bell
inequality, we show that nonlocality can be detected from two-body correlators
involving only nearest neighbours. Finally, we demonstrate that any
translationally invariant Bell inequality can be maximally violated by a
translationally invariant state and the same set of observables at all sites.
We provide a numerical algorithm allowing one to seek for maximal violation of
a translationally invariant Bell inequality.


title:
Turbulent pitch-angle scattering and diffusive transport of hard-X-ray
  producing electrons in flaring coronal loops

abstract:
  Recent observations from {\em RHESSI} have revealed that the number of
non-thermal electrons in the coronal part of a flaring loop can exceed the
number of electrons required to explain the hard X-ray-emitting footpoints of
the same flaring loop. Such sources cannot, therefore, be interpreted on the
basis of the standard collisional transport model, in which electrons stream
along the loop while losing their energy through collisions with the ambient
plasma; additional physical processes, to either trap or scatter the energetic
electrons, are required. Motivated by this and other observations that suggest
that high energy electrons are confined to the coronal region of the source, we
consider turbulent pitch angle scattering of fast electrons off low frequency
magnetic fluctuations as a confinement mechanism, modeled as a spatial
diffusion parallel to the mean magnetic field. In general, turbulent scattering
leads to a reduction of the collisional stopping distance of non-thermal
electrons along the loop and hence to an enhancement of the coronal HXR source
relative to the footpoints. The variation of source size $L$ with electron
energy $E$ becomes weaker than the quadratic behavior pertinent to collisional
transport, with the slope of $L(E)$ depending directly on the mean free path
$\lambda$ again pitch angle scattering. Comparing the predictions of the model
with observations, we find that $\lambda \sim$$(10^8-10^9)$ cm for $\sim30$
keV, less than the length of a typical flaring loop and smaller than, or
comparable to, the size of the electron acceleration region.

categories: astro-ph.SR astro-ph.HE physics.plasm-ph physics.space-ph


title:
An ultrafast reconfigurable nanophotonic switch using wavefront shaping
  of light in a nonlinear nanomaterial

abstract:
  We demonstrate a new concept for reconfigurable nanophotonic devices
exploiting ultrafast nonlinear control of shaped wavefronts in a multimode
nanomaterial consisting of semiconductor nanowires. Femtosecond pulsed laser
excitation of the nanowire mat is shown to provide an efficient nonlinear
mechanism to control both destructive and constructive interference in a shaped
wavefront. Modulations of up to 63% are induced by optical pumping, due to a
combination of multimode dephasing and induced transient absorption. We show
that part of the nonlinear phase dynamics can be inverted to provide a
dynamical revival of the wavefront into an optimized spot with up to 18%
increase of the peak to background ratio caused by pulsed laser excitation. The
concepts of multimode nonlinear switching demonstrated here are generally
extendable to other photonic and plasmonic systems and enable new avenues for
ultrafast and reconfigurable nanophotonic devices.


title: Kinematical Hilbert Space for Einstein-Cartan Theory

abstract:
  Kinematical Hilbert space for Einstein-Cartan theory is constructed via von
Neumann ideas of infinity-dimensional tensor product of Hilbert spaces. Field
of comframe is considered as basic variable what is in contrast with standard
euclidean LQG which is build by Wilson loops of Ashtekar-Barbero-Immirzi
connection.


title:
Double-ended queues and joint moments of left-right canonical operators
  on full Fock space

abstract:
  We follow the guiding line offered by canonical operators on the full Fock
space, in order to identify what kind of cumulant functionals should be
considered for the concept of bi-free independence introduced in the recent
work of Voiculescu. By following this guiding line we arrive to consider, for a
general noncommutative probability space (A, phi), a family of "(l,r)-cumulant
functionals" which enlarges the family of free cumulant functionals of the
space. In the motivating case of canonical operators on the full Fock space we
find a simple formula for a relevant family of (l,r)-cumulants of a (2d)-tuple
(A_1, ..., A_d, B_1, ..., B_d), with A_1, ... , A_d canonical operators on the
left and B_1, ... , B_d canonical operators on the right. This extends a known
one-sided formula for free cumulants of A_1, ..., A_d, which establishes a
basic operator model for the R-transform of free probability.


title:
Electronic structure, cohesive properties and magnetism of SrRuO$_3$; a
  theoretical investigation

abstract:
  We have performed an extensive test of the ability of density functional
theory within several approximations for the exchange-correlation functional,
local density approximation+Hubbard $U$ and local density approximation +
dynamic mean field theory to describe magnetic and electronic properties of
SrRuO$_3$. We focus on the ferromagnetic phase, illustrating differences
between the orthorhombic low temperature structure vs the cubic high
temperature structure. We assess how magnetism, spectral function, and cohesive
properties are affected by methodology, on-site Hubbard $U$ and double counting
corrections. Further, we compare the impact of the impurity solver on the
quasiparticle weight $Z$, which is in turn compared to experimental results.
The spectral functions resulting from the different treatments are also
compared to experimental data. The impact of spin-orbit coupling is also
studied, allowing us to determine the orbital moments. In the orthorhombic
phase the orbital moments are found to be tilted with respect to the spin
moments, emphasising the importance of taking into account the distortion of
the oxygen octahedra.


title: Quasiregular mappings on sub-Riemannian manifolds

abstract:
  We study mappings on sub-Riemannian manifolds which are quasi-regular with
respect to the Carnot-Caratheodory distances and discuss several related
notions. On H-type Carnot groups, quasiregular mappings have been introduced
earlier using an analytic definition, but so far, a good working definition in
the same spirit is not available in the setting of general sub-Riemannian
manifolds. In the present paper we adopt therefore a metric rather than
analytic viewpoint.
  As a first main result, we prove that the sub-Riemannian lens space admits
nontrivial uniformly quasiregular (UQR) mappings, that is, quasiregular
mappings with a uniform bound on the distortion of all the iterates. In doing
so, we also obtain new examples of UQR maps on the standard sub-Riemannian
spheres. The proof is based on a method for building conformal traps on
sub-Riemannian spheres using quasiconformal flows, and an adaptation of this
approach to quotients of spheres.
  One may then study the quasiregular semigroup generated by a UQR mapping. In
the second part of the paper we follow Tukia to prove the existence of a
measurable conformal structure which is invariant under such a semigroup. Here,
the conformal structure is specified only on the horizontal distribution, and
the pullback is defined using the Margulis--Mostow derivative (which
generalizes the classical and Pansu derivatives).


title:
Submillimeter polarisation and magnetic field properties in the
  envelopes of proto-planetary nebulae CRL 618 and OH 231.8+4.2

abstract:
  We have carried out continuum and line polarisation observations of two
Proto-planetary nebulae (PPNe), CRL 618 and OH 231.8+4.2, using the
Submillimeter Array (SMA) in its compact configuration. The frequency range of
observations, 330-345 GHz, includes the CO(J=3-2) line emission. CRL 618 and OH
231.8+4.2 show quadrupolar and bipolar optical lobes, respectively, surrounded
by a dusty envelope reminiscent of their AGB phase. We report a detection of
dust continuum polarised emission in both PPNe above 4 sigma but no molecular
line polarisation detection above a 3 sigma limit. OH 231.8+4.2 is slightly
more polarised on average than CRL 618 with a mean fractional polarisation of
4.3 and 0.3 per cent, respectively. This agrees with the previous finding that
silicate dust shows higher polarisation than carbonaceous dust. In both
objects, an anti-correlation between the fractional polarisation and the
intensity is observed. Neither PPNe show a well defined toroidal equatorial
field, rather the field is generally well aligned and organised along the polar
direction. This is clearly seen in CRL 618 while in the case of OH 231.8+4.2,
the geometry indicates an X-shaped structure coinciding overall with a
dipole/polar configuration. However in the later case, the presence of a
fragmented and weak toroidal field should not be discarded. Finally, in both
PPNe, we observed that the well organised magnetic field is parallel with the
major axis of the 12CO outflow. This alignment could indicate the presence of a
magnetic outflow launching mechanism. Based on our new high resolution data we
propose two scenarios to explain the evolution of the magnetic field in evolved
stars.


title: Impact of Dark Matter Velocity Distributions on Capture Rates in the Sun

abstract:
  Dark matter could be captured in the Sun and self-annihilate, giving rise to
an observable neutrino flux. Indirect searches for dark matter looking for this
signal with neutrino telescopes have resulted in tight constraints on the
interaction cross-section of dark matter with ordinary matter. We investigate
how robust limits are against astro-physical uncertainties. We study the effect
of the velocity distribution of dark matter in our Galaxy on capture rates in
the Sun. We investigate four sources of uncertainties: orbital speed of the
Sun, escape velocity of dark matter from the halo, dark matter velocity
distribution functions and existence of a dark disc. We find that even extreme
cases currently discussed do not decrease the sensitivity of indirect detection
significantly because the capture is achieved over a broad range of the
velocity distribution by integration over the velocity distribution. The effect
of the uncertainty in the high-velocity tail of dark matter halo is very
marginal as the capture process is rather inefficient at this region. The
difference in capture rate in the Sun for various scenarios is compared to the
expected change in event rates for direct detection. The possibility of
co-rotating structure with the Sun can largely boost the signal and hence makes
the interpretation of indirect detection conservative compared to direct
detection.


title: Minimal Pancyclicity

abstract:
  A pancyclic graph is a simple graph containing a cycle of length $k$ for all
$3\leq k\leq n$. Let $m(n)$ be the minimum number of edges of all pancyclic
graphs on $n$ vertices. Exact values are given for $m(n)$ for $n\leq 37$,
combining calculations from an exhaustive search on graphs with up to 29
vertices with a construction that works for up to 37 vertices. The behavior of
$m(n)$ in general is also explored, including a proof of the conjecture that
$m(n+1)>m(n)$ for all $n$ in some special cases.


title:
Searching for a dipole modulation in the large-scale structure of the
  Universe

abstract:
  Several statistical anomalies in the CMB temperature anisotropies seem to
defy the assumption of a homogeneous and isotropic universe. In particular, a
dipole modulation has been detected both in WMAP and Planck data. We adapt the
methodology proposed by Eriksen et al. (2007) on CMB data to galaxy surveys,
tracing the large-scale structure. We analyse the NRAO VLA Sky Survey (NVSS)
data at a resolution of ~2 degrees for three different flux thresholds: 2.5,
5.0 and 10.0 mJy respectively. No evidence of a dipole modulation is found.
This result suggests that the origin of the dipole asymmetry found in the CMB
cannot be assigned to secondary anisotropies produced at redshifts around z =
1. However, it could still have been generated at redshifts higher or lower,
such as the integrated Sachs-Wolfe effect produced by the local structures.
Other all-sky surveys, like the infrared WISE catalogue, could help to explore
with a high sensitivity a redshift interval closer than the one probed with
NVSS.


title:
Cosmic variance of the local Hubble flow in large-scale cosmological
  simulations

abstract:
  The increasing precision in the determination of the Hubble parameter has
reached a per cent level at which large-scale cosmic flows induced by
inhomogeneities of the matter distribution become non-negligible. Here we use
large-scale cosmological N-body simulations to study statistical properties of
the local Hubble parameter as measured by local observers. We show that the
distribution of the local Hubble parameter depends not only on the scale of
inhomogeneities, but also on how one defines the positions of observers in the
cosmic web and what reference frame is used. Observers located in random dark
matter haloes measure on average lower expansion rates than those at random
positions in space or in the centres of cosmic voids, and this effect is
stronger from the halo rest frames compared to the CMB rest frame. We compare
the predictions for the local Hubble parameter with observational constraints
based on type Ia supernovae (SNIa) and CMB observations. Due to cosmic
variance, for observers located in random haloes we show that the Hubble
constant determined from nearby SNIa may differ from that measured from the CMB
by 0.8 per cent at 1sigma statistical significance. This scatter is too small
to significantly alleviate a recently claimed discrepancy between current
measurements assuming a flat LCDM model. However, for observers located in the
centres of the largest voids permitted by the standard LCDM model, we find that
Hubble constant measurements from SNIa would be biased high by 5 per cent,
rendering this tension inexistent in this extreme case.


title: From Sobolev Inequality to Doubling

abstract:
  In various analytical contexts, it is proved that a weak Sobolev inequality
implies a doubling property for the underlying measure.


title: Commability of groups quasi-isometric to trees

abstract:
  Commability is the finest equivalence relation between locally compact groups
such that $G$ and $H$ are equivalent whenever there is a continuous proper
homomorphism $G \to H$ with cocompact image. Answering a question of Cornulier,
we show that all non-elementary locally compact groups acting geometrically on
locally finite simplicial trees are commable, thereby strengthening previous
forms of quasi-isometric rigidity for trees. We further show that 6
homomorphisms always suffice, and provide the first example of a pair of
locally compact groups which are commable but without commation consisting of
less than 6 homomorphisms. Our strong quasi-isometric rigidity also applies to
products of symmetric spaces and Euclidean buildings, possibly with some
factors being trees.


title: Description of ion motion in a Paul trap immersed in a cold atomic gas

abstract:
  We investigate the problem of a single ion in a radio-frequency trap and
immersed in an ultracold Bose gas either in a condensed or a non-condensed
phase. We develop master equation formalism describing the sympathetic cooling
and we determine the cooling rates of ions. We show that cold atomic reservoir
modifies the stability diagram of the ion in the Paul trap creating the regions
where the ion is either cooled or heated due to the energy quanta exchanged
with the time-dependent potential.


title:
Critical study and discrimination of different formulations of
  electromagnetic force density and consequent stress tensors inside matter

abstract:
  By examination of the exerted electromagnetic (EM) force on boundary of an
object in a few examples, we look into the compatibility of the stress tensors
corresponding to different formulae of the EM force density with special
relativity. Ampere-Lorentz's formula of the EM force density is physically
justifiable in that the electric field and the magnetic flux density act on the
densities of the total charges and the total currents, unlike Minkowski's
formula which completely excludes the densities of the bounded charges and the
bounded currents inside homogeneous media. Abraham's formula is fanciful and
devoid of physical meaning. Einstein-Laub's formula seems to include the
densities of the total charges and the total currents at first sight, but
grouping the bounded charges and the bounded currents into point-like dipoles
erroneously results in the hidden momentum being omitted, hence the error in
[Phys. Rev. Lett. 108, 193901 (2012)]. Naturally, the Ampere-Lorentz stress
tensor accords with special relativity. The Minkowski stress tensor is also
consistent with special relativity. It is worth noting that the mathematical
expression of the Minkowski stress tensor can be quite different from the
well-known form of this stress tensor in the literature. We show that the
Einstein-Laub stress tensor is incompatible with special relativity, and
therefore we rebut the Einstein-Laub force density. Since the Abraham momentum
density of the EM fields is inherently corresponding to the Einstein-Laub force
density [Phys. Rev. Lett 111, 043602 (2013)], our rebuttal may also shed light
on the controversy over the momentum of light.


title: Linear Triangle Dynamics: The Pedal Map and Beyond

abstract:
  We present a moduli space for similar triangles, then classify triangle maps
$f$ that arise from linear maps on this space, with the well-studied pedal map
as a special case. Each linear triangle map admits a Markov partition, showing
that $f$ is mixing, hence ergodic.


title: CII in the Interstellar Medium: Excitation by H2 Revisited

abstract:
  C$^+$ is a critical constituent of many regions of the interstellar medium,
as it can be a major reservoir of carbon and, under a wide range of conditions,
the dominant gas coolant. Emission from its 158$\mu$m fine structure line is
used to trace the structure of photon dominated regions in the Milky Way and is
often employed as a measure of the star formation rate in external galaxies.
Under most conditions, the emission from the single [CII] line is proportional
to the collisional excitation rate coefficient. We here used improved
calculations of the deexcitation rate of [CII] by collisions with H$_2$ to
calculate more accurate expressions for interstellar C$^+$ fine structure
emission, its critical density, and its cooling rate. The collision rates in
the new quantum calculation are $\sim$ 25% larger than those previously
available, and narrow the difference between rates for excitation by atomic and
molecular hydrogen. This results in [CII] excitation being quasi-independent of
the molecular fraction and thus dependent only on the total hydrogen particle
density. A convenient expression for the cooling rate at temperatures between
20 K and 400 K, assuming an LTE H$_2$ ortho to para ration is $\Lambda ({\rm
LTE~OPR}) = \left(11.5 + 4.0\,e^{-100\,\mathrm K/T^{\rm
kin}}\right)\;e^{-91.25\,\mathrm K/T^{\rm kin}}\,n ({\rm C}^{+})\,n({\rm
H}_2)\times 10^{-24}\;{\rm ergs}~{\rm cm}^{-3}~{\rm s}^{-1}$. The present work
should allow more accurate and convenient analysis of the [\CII] line emission
and its cooling.


title: Stochastic areas of diffusions and applications in risk theory

abstract:
  In this paper we study the stochastic area swept by a regular
time-homogeneous diffusion till a stopping time. This unifies some recent
literature in this area. Through stochastic time change we establish a link
between the stochastic area and the stopping time of another associated
time-homogeneous diffusion. Then we characterize the Laplace transform of the
stochastic area in terms of the eigenfunctions of the associated diffusion. We
also explicitly obtain the integer moments of the stochastic area in terms of
scale and speed densities of the associated diffusion. Specifically we study in
detail three stopping times: the first passage time to a constant level, the
first drawdown time and the Azema-Yor stopping time. We also study the total
occupation area of the diffusion below a constant level. We show applications
of the results to a new structural model of default (Yildirim 2006), the Omega
risk model of bankruptcy in risk analysis (Gerber, Shiu and Yang 2012), and a
diffusion risk model with surplus-dependent tax (Albrecher and Hipp 2007, Li,
Tang and Zhou 2013).


title: Lyapunov stable Galerkin models of post-transient incompressible flows

abstract:
  A method for deriving provably stable low-dimensional Galerkin models of
post-transient incompressible flows is introduced. The proposed approach
involves an iterative procedure for expansion modes that satisfy Lyapunov
stability in the neighborhood of a fixed point. The approach is demonstrated
using two prototypical flow configurations: a two-dimensional mixing layer, and
two-dimensional flow inside a lid-driven cavity. This new methodology can be a
building block in an effort to develop more accurate and more robust
low-dimensional models of incompressible flows.


title: Distributed Data Placement via Graph Partitioning

abstract:
  With the widespread use of shared-nothing clusters of servers, there has been
a proliferation of distributed object stores that offer high availability,
reliability and enhanced performance for MapReduce-style workloads. However,
relational workloads cannot always be evaluated efficiently using MapReduce
without extensive data migrations, which cause network congestion and reduced
query throughput. We study the problem of computing data placement strategies
that minimize the data communication costs incurred by typical relational query
workloads in a distributed setting.
  Our main contribution is a reduction of the data placement problem to the
well-studied problem of {\sc Graph Partitioning}, which is NP-Hard but for
which efficient approximation algorithms exist. The novelty and significance of
this result lie in representing the communication cost exactly and using
standard graphs instead of hypergraphs, which were used in prior work on data
placement that optimized for different objectives (not communication cost).
  We study several practical extensions of the problem: with load balancing,
with replication, with materialized views, and with complex query plans
consisting of sequences of intermediate operations that may be computed on
different servers. We provide integer linear programs (IPs) that may be used
with any IP solver to find an optimal data placement. For the no-replication
case, we use publicly available graph partitioning libraries (e.g., METIS) to
efficiently compute nearly-optimal solutions. For the versions with
replication, we introduce two heuristics that utilize the {\sc Graph
Partitioning} solution of the no-replication case. Using the TPC-DS workload,
it may take an IP solver weeks to compute an optimal data placement, whereas
our reduction produces nearly-optimal solutions in seconds.


title: Efficient Learning and Planning with Compressed Predictive States

abstract:
  Predictive state representations (PSRs) offer an expressive framework for
modelling partially observable systems. By compactly representing systems as
functions of observable quantities, the PSR learning approach avoids using
local-minima prone expectation-maximization and instead employs a globally
optimal moment-based algorithm. Moreover, since PSRs do not require a
predetermined latent state structure as an input, they offer an attractive
framework for model-based reinforcement learning when agents must plan without
a priori access to a system model. Unfortunately, the expressiveness of PSRs
comes with significant computational cost, and this cost is a major factor
inhibiting the use of PSRs in applications. In order to alleviate this
shortcoming, we introduce the notion of compressed PSRs (CPSRs). The CPSR
learning approach combines recent advancements in dimensionality reduction,
incremental matrix decomposition, and compressed sensing. We show how this
approach provides a principled avenue for learning accurate approximations of
PSRs, drastically reducing the computational costs associated with learning
while also providing effective regularization. Going further, we propose a
planning framework which exploits these learned models. And we show that this
approach facilitates model-learning and planning in large complex partially
observable domains, a task that is infeasible without the principled use of
compression.


title:
Point-Map-Probabilities of a Point Process and Mecke's Invariant Measure
  Equation

abstract:
  A compatible point-shift $F$ maps, in a translation invariant way, each point
of a stationary point process $\Phi$ to some point of $\Phi$. It is fully
determined by its associated point-map, $f$, which gives the image of the
origin by $F$. It was proved by J. Mecke that if $F$ is bijective, then the
Palm probability of $\Phi$ is left invariant by the translation of $-f$. The
initial question motivating this paper is the following generalization of this
invariance result: in the non-bijective case, what probability measures on the
set of counting measures are left invariant by the translation of $-f$? The
point-map probabilities of $\Phi$ are defined from the action of the semigroup
of point-map translations on the space of Palm probabilities, and more
precisely from the compactification of the orbits of this semigroup action. If
the point-map probability exists, is uniquely defined, and if it satisfies
certain continuity properties, it then provides a solution to this invariant
measure problem. Point-map probabilities are objects of independent interest.
They are shown to be a strict generalization of Palm probabilities: when $F$ is
bijective, the point-map probability of $\Phi$ boils down to the Palm
probability of $\Phi$. When it is not bijective, there exist cases where the
point-map probability of $\Phi$ is singular with respect to its Palm
probability. A tightness based criterion for the existence of the point-map
probabilities of a stationary point process is given. An interpretation of the
point-map probability as the conditional law of the point process given that
the origin has $F$-pre-images of all orders is also provided. The results are
illustrated by a few examples.


title:
Preliminary Results on 3D Channel Modeling: From Theory to
  Standardization

abstract:
  Three dimensional beamforming (3D) (also elevation beamforming) is now
gaining a growing interest among researchers in wireless communication. The
reason can be attributed to its potential to enable a variety of strategies
like sector or user specific elevation beamforming and cell-splitting. Since
these techniques cannot be directly supported by current LTE releases, the 3GPP
is now working on defining the required technical specifications. In
particular, a large effort is currently made to get accurate 3D channel models
that support the elevation dimension. This step is necessary as it will
evaluate the potential of 3D and FD(Full Dimensional) beamforming techniques to
benefit from the richness of real channels. This work aims at presenting the
on-going 3GPP study item "Study on 3D-channel model for Elevation Beamforming
and FD-MIMO studies for LTE", and positioning it with respect to previous
standardization works.


title:
Signatures of alpha clustering in light nuclei from relativistic nuclear
  collisions

abstract:
  We argue that relativistic nuclear collisions may provide experimental
evidence of alpha clustering in light nuclei. A light alpha-clustered nucleus
has a large intrinsic deformation. When collided against a heavy nucleus at
very high energies, this deformation transforms into the deformation of the
fireball in the transverse plane. The subsequent collective evolution of the
fireball leads to harmonic flow reflecting the deformation of the initial
shape, which can be measured with standard methods of relativistic heavy-ion
collisions. We illustrate the feasibility of the idea by modeling the 12C-208Pb
collisions and point out that very significant quantitative and qualitative
differences between the alpha-clustered and uniform 12C nucleus occur in such
quantities as the triangular flow, its event-by-event fluctuations, or the
correlations of the elliptic and triangular flows. The proposal offers a
possibility of studying low-energy nuclear phenomena with "snapshots" made with
relativistic heavy-ion collisions.


title: Quantum Non-Barking Dogs

abstract:
  Quantum weak measurements with states both pre- and postselected offer a
window into a hitherto neglected sector of quantum mechanics. A class of such
systems involves time dependent evolution with transitions possible. In this
paper we explore two very simple systems in this class. The first is a toy
model representing the decay of an excited atom. The second is the tunneling of
a particle through a barrier. The postselection criteria are chosen as follows:
at the final time, the "atom" remains in its initial excited state for the
first example and the particle remains behind the barrier for the second. We
then ask what weak values are predicted in the physical environment of the
"atom" (to which no net energy has been transferred) and in the region beyond
the barrier (to which the particle has not tunneled). Previous work suggests
that very large weak values might arise in these regions for long durations
between pre- and postselection times. Our calculations reveal some distinct
differences between the two model systems.


title: Probing the proton and its excitations in full QCD

abstract:
  We present a first look at the application of variational techniques for the
extraction of the electromagnetic properties of an excited nucleon system. In
particular, we include preliminary results for charge radii and magnetic
moments of the proton, its first even-parity excitation and the $\Delta^{+}$.


title:
Ergodic properties of invariant measures for systems with average
  shadowing property

abstract:
  In this paper, we explore a topological system $f:M\rightarrow M$ with
average shadowing property. We extend Sigmund's results and show that every
non-empty, compact and connected subset $V\subseteq\mathcal {M}_{inv}(f)$
coincides with $V_f(y)$, where $\mathcal {M}_{inv}(f)$ denotes the space of
invariant Borel probability measures on M, and $V_f(y)$ denotes the
accumulation set of time average of Dirac measures supported at the orbit of
$y$. We also show that the set $M_{V}=\{y\in M\,\,|\,\,V_{f}(y)=V\}$ is dense
in $\Delta_{V}=\bigcup_{\nu\in V}supp(\nu)$. In particular, if
$\Delta_{max}=\bigcup_{\nu\in\mathcal {M}_{inv}(f)}supp(\nu)$ is isolated or
coincides with $M$, then $M_{max}=\{y: V_{f}(y)=\mathcal {M}_{inv}(f)\}$ is
residual in $\Delta_{max}$.


title: Thermodynamic properties of LiCu$_{2}$O$_{2}$ multiferroic compound

abstract:
  A spin model of quasi-one dimensional LiCu$_{2}$O$_{2}$ compound with ground
state of ellipsoidal helical structure in which the helical axis is along the
diagonal of CuO$_{4}$ squares has been adopted. By taking into account the
interchain coupling and exchange anisotropy, the exotic magnetic properties and
ferroelectricity induced by spiral spin order have been studied by performing
Monte Carlo simulation. The simulation results qualitatively reproduce the main
characters of ferroelectric and magnetic behaviors of LiCu$_{2}$O$_{2}$
compound and confirm the low-temperature incollinear spiral ordering.
Furthermore, by performing the calculations of spin structure factor, we
systematically investigate the effects of different exchange coupling on the
lower-temperature magnetic transition, and find that the spiral spin order
depends not only on the ratio of nearest and next-nearest neighbor inchain spin
coupling but also strongly on the exchange anisotropy.


title:
Goodness of fit in nonlinear dynamics: Misspecified rates or
  misspecified states?

abstract:
  This paper introduces diagnostic tests for the nature of lack of fit in
ordinary differential equation models (ODEs) proposed for data. We present a
hierarchy of three possible sources of lack of fit: unaccounted-for stochastic
variation, misspecification of functional forms in rate equations, and omission
of dynamic variables in the description of the system. We represent lack of fit
by allowing a parameter vector to vary over time, and propose generic testing
procedures that do not rely on specific alternative models. Instead, different
sources for lack of fit are characterized in terms of nonparametric
relationships among latent variables. The tests are carried out through a
combination of residual bootstrap and permutation methods. We demonstrate the
effectiveness of these tests on simulated data and on real data from laboratory
ecological experiments and electro-cardiogram data.


title:
Observed Gravitational Wave Effects: Amaldi 1980 Frascati-Rome Classical
  Bar Detectors, 2013 Perth-London Zener-Diode Quantum Detectors, Earth
  Oscillation Mode Frequencies

abstract:
  Amaldi et al. in 1981 reported two key discoveries from the Frascati and Rome
gravitational wave cryogenic bar detectors: (a) Rome events delayed by within a
few seconds to tens of seconds from the Frascati events, and (b) the Frascati
Fourier-analysed data frequency peaks being the same as the earth oscillation
frequencies from seismology. The time delay effects have been dismissed as
being inconsistent with gravitational waves having speed c. However using data
from zener diode quantum detectors, from Perth and London, for January 1-3,
2013, we report the same effects, and in excellent agreement with the Amaldi
results. The time delay effects appear to be gravitational wave reverberations,
recently observed, and for gravitational wave speeds of some 500km/s, as
detected in numerous experiments. We conclude that the Amaldi et al.
discoveries were very significant.


title: The subgroup commutativity degree of finite P-groups

abstract:
  The subgroup commutativity degree of a group G has been defined in [6] as the
probability that two subgroups of G commute, or equivalently that the product
of two subgroups is again a subgroup. Problem 4.3 of [6] asks whether there
exist families of groups other than dihedral, quasi-dihedral or generalized
quaternion (all of 2-power cardinality), whose subgroup commutativity degree
tends to 0 as the size of the group tends to infinity. An affirmative answer to
this question has been provided by Aivazidis [1, 2] for the family of
projective special linear groups over fields of even characteristic and for the
family of the simple Suzuki groups. In this short note we indicate another
family of groups with this property, namely the finite P-groups.


title:
Soft X-ray Extended Emissions of Short Gamma-Ray Bursts as
  Electromagnetic Counterparts of Compact Binary Mergers; Possible Origin and
  Detectability

abstract:
  We investigate the possible origin of extended emissions (EEs) of short
gamma-ray bursts with an isotropic energy of ~ 10^(50-51) erg and a duration of
a few 10 s to ~ 100 s, based on a compact binary (neutron star (NS)-NS or
NS-black hole (BH)) merger scenario. We analyze the evolution of magnetized
neutrino-dominated accretion disks of mass ~ 0.1 M_sun around BHs formed after
the mergers, and estimate the power of relativistic outflows via the
Blandford-Znajek (BZ) process. We show that a rotation energy of the BH up to >
10^52 erg can be extracted with an observed time scale of > 30 (1+z) s with a
relatively small disk viscosity parameter of alpha < 0.01. Such a BZ power
dissipates by clashing with non-relativistic pre-ejected matter of mass M ~
10^-(2-4) M_sun, and forms a mildly relativistic fireball. We show that the
dissipative photospheric emissions from such fireballs are likely in the soft
X-ray band (1-10 keV) for M ~ 10^-2 M_sun possibly in NS-NS mergers, and in the
BAT band (15-150 keV) for M ~ 10^-4 M_sun possibly in NS-BH mergers. In the
former case, such soft EEs can provide a good chance of ~ 6 yr^-1 for
simultaneous detections of the gravitational waves with a ~ 0.1 deg angular
resolution by soft X-ray survey facilities like Wide-Field MAXI.


title: On quadratic orbital networks

abstract:
  These are some informal remarks on quadratic orbital networks over finite
fields. We discuss connectivity, Euler characteristic, number of cliques,
planarity, diameter and inductive dimension. We find a non-trivial disconnected
graph for d=3. We prove that for d=1 generators, the Euler characteristic is
always non-negative and for d=2 and large enough p the Euler characteristic is
negative. While for d=1, all networks are planar, we suspect that for d larger
or equal to 2 and large enough prime p, all networks are non-planar. As a
consequence on bounds for the number of complete sub graphs of a fixed
dimension, the inductive dimension of all these networks goes 1 as p goes to
infinity.


title: What is Ramsey-equivalent to a clique?

abstract:
  A graph G is Ramsey for H if every two-colouring of the edges of G contains a
monochromatic copy of H. Two graphs H and H' are Ramsey-equivalent if every
graph G is Ramsey for H if and only if it is Ramsey for H'. In this paper, we
study the problem of determining which graphs are Ramsey-equivalent to the
complete graph K_k. A famous theorem of Nesetril and Rodl implies that any
graph H which is Ramsey-equivalent to K_k must contain K_k. We prove that the
only connected graph which is Ramsey-equivalent to K_k is itself. This gives a
negative answer to the question of Szabo, Zumstein, and Zurcher on whether K_k
is Ramsey-equivalent to K_k.K_2, the graph on k+1 vertices consisting of K_k
with a pendent edge.
  In fact, we prove a stronger result. A graph G is Ramsey minimal for a graph
H if it is Ramsey for H but no proper subgraph of G is Ramsey for H. Let s(H)
be the smallest minimum degree over all Ramsey minimal graphs for H. The study
of s(H) was introduced by Burr, Erdos, and Lovasz, where they show that
s(K_k)=(k-1)^2. We prove that s(K_k.K_2)=k-1, and hence K_k and K_k.K_2 are not
Ramsey-equivalent.
  We also address the question of which non-connected graphs are
Ramsey-equivalent to K_k. Let f(k,t) be the maximum f such that the graph
H=K_k+fK_t, consisting of K_k and f disjoint copies of K_t, is
Ramsey-equivalent to K_k. Szabo, Zumstein, and Zurcher gave a lower bound on
f(k,t). We prove an upper bound on f(k,t) which is roughly within a factor 2 of
the lower bound.


title:
Critical Field of Spin Torque Oscillator with Perpendicularly Magnetized
  Free Layer

abstract:
  The oscillation properties of a spin torque oscillator consisting of a
perpendicularly magnetized free layer and an in-plane magnetized pinned layer
are studied based on an analysis of the energy balance between spin torque and
damping. The critical value of an external magnetic field applied normal to the
film plane is found, below which the controllable range of the oscillation
frequency by the current is suppressed. The value of the critical field depends
on the magnetic anisotropy, the saturation magnetization, and the spin torque
parameter.