title:
From BGP to RTT and Beyond: Matching BGP Routing Changes and Network
  Delay Variations with an Eye on Traceroute Paths

abstract:
  Many organizations have the mission of assessing the quality of broadband
access services offered by Internet Service Providers (ISPs). They deploy
network probes that periodically perform network measures towards selected
Internet services. By analyzing the data collected by the probes it is often
possible to gain a reasonable estimate of the bandwidth made available by the
ISP. However, it is much more difficult to use such data to explain who is
responsible of the fluctuations of other network qualities. This is especially
true for latency, that is fundamental for several nowadays network services. On
the other hand, there are many publicly accessible BGP routers that collect the
history of routing changes and that are good candidates to be used for
understanding if latency fluctuations depend on interdomain routing.
  In this paper we provide a methodology that, given a probe that is located
inside the network of an ISP and that executes latency measures and given a set
of publicly accessible BGP routers located inside the same ISP, decides which
routers are best candidates (if any) for studying the relationship between
variations of network performance recorded by the probe and interdomain routing
changes. We validate the methodology with experimental studies based on data
gathered by the RIPE NCC, an organization that is well-known to be independent
and that publishes both BGP data within the Routing Information Service (RIS)
and probe measurement data within the Atlas project.


title: Threefold Post Correspondence System

abstract:
  We introduce the concept of a threefold Post correspondence system (3PCS for
short) and we consider it as an instance of the threefold Post correspondence
problem. With each 3PCS, we associate three Post correspondence systems, i.e.,
three instances of the Post correspondence problem. We conjecture that for each
3PCS, the question of the threefold Post correspondence problem or for some
associated Post correspondence system the question of the Post correspondence
problem is decidable.


title: Skew Handling in Aggregate Streaming Queries on GPUs

abstract:
  Nowadays, the data to be processed by database systems has grown so large
that any conventional, centralized technique is inadequate. At the same time,
general purpose computation on GPU (GPGPU) recently has successfully drawn
attention from the data management community due to its ability to achieve
significant speed-ups at a small cost. Efficient skew handling is a well-known
problem in parallel queries, independently of the execution environment. In
this work, we investigate solutions to the problem of load imbalances in
parallel aggregate queries on GPUs that are caused by skewed data. We present a
generic load-balancing framework along with several instantiations, which we
experimentally evaluate. To the best of our knowledge, this is the first
attempt to present runtime load-balancing techniques for database operations on
GPUs.


title: Optical spectropolarimetry of V4332 Sagittarii

abstract:
  The eruption of V4332 Sgr was observed in 1994. During the outburst, the
object became extremely red, so it has been considered as to belong to red
transients of the V838 Mon type. Optical spectroscopy obtained a few years
after the eruption showed a faint M-type stellar spectrum underlying numerous
molecular and atomic emission features. It has recently been suggested that the
central object in V4332 Sgr is now hidden in a dusty disc and that the
photospheric spectrum of this object observed in the optical results from
scattering of the radiation of the central star on dust grains in the
circumstellar matter. Recent polarimetric photometry has shown that the optical
radiation of the object is indeed strongly polarized. We present and analyse
our spectropolarimetric observations of V4332 Sgr obtained with the VLT in the
optical region. The optical continuum of V4332 Sgr is linearly polarized with a
typical degree of 16.6%. A clear depolarization is observed in the spectral
regions where emission features contribute significantly to the observed flux.
The only prominent exception is the CaI 6573 emission line, which is polarized
in 21%. The results of our spectropolarimetric observations are in accord with
the proposed geometry of the system and the advocated nature of the observed
optical spectrum of V4332 Sgr. The continuum is not seen directly but results
from scattering on dust within the disc and polar outflow, while most of the
gas emission comes from the polar outflow excited by the radiation field of the
central source. Additionally, the observed polarization patterns suggest a
stratification of the outflow.


title: On countable coverings of word values in profinite groups

abstract:
  We prove the following results. Let w be a multilinear commutator word. If G
is a profinite group in which all w-values are contained in a union of
countably many periodic subgroups, then the verbal subgroup w(G) is locally
finite. If G is a profinite group in which all w-values are contained in a
union of countably many subgroups of finite rank, then the verbal subgroup w(G)
has finite rank as well. As a by-product of the techniques developed in the
paper we also prove that if G is a virtually soluble profinite group in which
all w-values have finite order, then w(G) is locally finite and has finite
exponent.


title:
Tannaka duality for enhanced triangulated categories II: $t$-structures
  and homotopy types

abstract:
  We consider the effect of $t$-structures on the Tannaka duality theory for dg
categories developed in our previous paper. We associate non-negative dg
coalgebras $C$ to dg functors on the hearts of $t$-structures, and relate dg
$C$-comodules to the original dg category. We give several applications for
pro-algebraic homotopy types associated to various cohomology theories, and for
motivic Galois groups.


title:
Probing the jet base of the blazar PKS1830-211 from the chromatic
  variability of its lensed images. Serendipitous ALMA observations of a strong
  gamma-ray flare

abstract:
  The launching mechanism of the jets of active galactic nuclei is
observationally poorly constrained, due to the large distances to these objects
and the very small scales (sub-parsec) involved. In order to better constrain
theoretical models, it is especially important to get information from the
region close to the physical base of the jet, where the plasma acceleration
takes place. In this paper, we report multi-epoch and multi-frequency continuum
observations of the z=2.5 blazar PKS1830-211 with ALMA, serendipitously
coincident with a strong $\gamma$-ray flare reported by Fermi-LAT. The blazar
is lensed by a foreground z=0.89 galaxy, with two bright images of the compact
core separated by 1". Our ALMA observations individually resolve these two
images (although not any of their substructures), and we study the change of
their relative flux ratio with time (four epochs spread over nearly three times
the time delay between the two lensed images) and frequency (between 350 and
1050 GHz, rest-frame of the blazar), during the $\gamma$-ray flare. In
particular, we detect a remarkable frequency-dependent behaviour of the flux
ratio, which implies the presence of a chromatic structure in the blazar (i.e.,
a core-shift effect). We rule out the possiblity of micro- and milli-lensing
effects and propose instead a simple model of plasmon ejection in the blazar's
jet to explain the time and frequency variability of the flux ratio. We suggest
that PKS1830-211 is likely one of the best sources to probe the activity at the
base of a blazar's jet at submillimeter wavelengths, thanks to the peculiar
geometry of the system. The implications of the core-shift in absorption
studies of the foreground z=0.89 galaxy (e.g., constraints on the cosmological
variations of fundamental constants) are discussed.


title: The half-skyrmion phase in a chiral-quark model

abstract:
  The Chiral Dilaton Model, where baryons arise as non-topological solitons
built from the interaction of quarks and chiral mesons, shows in the high
density low temperature regime a two phase scenario in the nuclear matter phase
diagram. Dense soliton matter described by the Wigner-Seitz approximation
generates a periodic potential in terms of the sigma and pion fields that leads
to the formation of a band structure. The analysis up to three times nuclear
matter density shows that soliton matter undergoes two separate phase
transitions: a delocalization of the baryon number density leading to $B=1/2$
structures, as in skyrmion matter, at moderate densities, and quark
deconfinement at larger densities. This description fits well into the
so-called quarkyonic phase where, before deconfinement, nuclear matter should
undergo structural changes involving the restoration of fundamental symmetries
of QCD.


title:
Binding energy of a holographic deuteron and tritium in anti-de-Sitter
  space/conformal field theory (AdS/CFT)

abstract:
  In the large 't Hooft coupling limit, the hadronic size of baryon is small
and nucleon-nucleon potential is obtained from massless pseudo-scalar exchanges
and an infinite tower of spin one mesons exchanges. In this paper we use the
holographic nucleon-nucleon interaction and obtain the corresponding potential
and binding energy for deuteron and tritium nuclei. The obtained potentials are
repulsive at short distances and clearly become zero by increasing distance as
we expected.


title: Computing the metric dimension of a graph from primary subgraphs

abstract:
  Let $G$ be a connected graph. Given an ordered set $W = \{w_1, w_2,\dots
w_k\}\subseteq V(G)$ and a vertex $u\in V(G)$, the representation of $u$ with
respect to $W$ is the ordered $k$-tuple $(d(u,w_1), d(u,w_2),\dots,$
$d(u,w_k))$, where $d(u,w_i)$ denotes the distance between $u$ and $w_i$. The
set $W$ is a metric generator for $G$ if every two different vertices of $G$
have distinct representations. A minimum cardinality metric generator is called
a \emph{metric basis} of $G$ and its cardinality is called the \emph{metric
dimension} of G. It is well known that the problem of finding the metric
dimension of a graph is NP-Hard. In this paper we obtain closed formulae for
the metric dimension of graphs with cut vertices. The main results are applied
to specific constructions including rooted product graphs, corona product
graphs, block graphs and chains of graphs.


title:
Using THELI pipeline in order to reduce Abell 226 multi-band optical
  images

abstract:
  In this paper we review THELI (Erben & Schrimer, 2005), an image processing
pipeline developed to reduce multi-pointing optical images taken by mosaic CCD
cameras. This pipeline works on raw images by removing several instrumental
contaminations, implementing photometric calibration and astrometric alignment,
and constructing a deep co-added mosaic image complemented by a weight map. We
demonstrate the procedure of reducing NGC3923 images from raw data to the final
results. We also demonstrate the quality of our data reduction strategy using
mag-count and mag-error in mag plots. Emphasis is mainly placed on photometric
calibration which is of great interest to us due to our scientific case. Based
on the cross-association of the extracted catalogue against a reference
catalogue of stellar magnitudes, zero-point calibration is performed. Our data
reduction strategy and the method employed for cross-correlating large
catalogues is also presented.


title: Strong metric dimension of rooted product graphs

abstract:
  Let $G$ be a connected graph. A vertex $w$ strongly resolves a pair $u$, $v$
of vertices of $G$ if there exists some shortest $u-w$ path containing $v$ or
some shortest $v-w$ path containing $u$. A set $W$ of vertices is a strong
resolving set for $G$ if every pair of vertices of $G$ is strongly resolved by
some vertex of $W$. The smallest cardinality of a strong resolving set for $G$
is called the strong metric dimension of $G$. It is known that the problem of
computing this invariant is NP-hard. This suggests finding the strong metric
dimension for special classes of graphs or obtaining good bounds on this
invariant. In this paper we study the problem of finding exact values or sharp
bounds for the strong metric dimension of rooted product of graphs and express
these in terms of invariants of the factor graphs.


title: Finding linear patterns of complexity one

abstract:
  We study the following generalization of Roth's theorem for 3-term arithmetic
progressions. For s>1, define a nontrivial s-configuration to be a set of
s(s+1)/2 integers consisting of s distinct integers x_1,...,x_s as well as all
the averages (x_i+x_j)/2. Our main result states that if a set A contained in
{1,2,...,N} has density at least (log N)^{-c(s)} for some positive constant
c(s)>0 depending on s, then A contains a nontrivial s-configuration. We also
deduce, as a corollary, an improvement of a problem involving sumfree subsets.


title: Flux-induced Nernst effect in a superconducting loop

abstract:
  When a superconducting ring encloses a magnetic flux that is not an integer
multiple of half the quantum of flux, a voltage arises in the direction
perpendicular to the temperature gradient. This effect is entirely due to
thermal fluctuations. We study the dependence of this voltage on the
temperature gradient, flux, position, average temperature, BCS coherence
length, thermal coherence length, and the Kramer--Watts-Tobin parameter. The
largest voltages were obtained for fluxes close to $0.3\Phi_0$, average
temperatures slightly below the critical temperature, thermal coherence length
of the order of the perimeter of the ring and BCS coherence length that is not
negligible in comparison to the thermal coherence length. As a rough comparison
between the flux-induced and the field-induced effects, we also considered a
two dimensional sample.


title:
Many-body Green's function GW and Bethe-Salpeter study of the optical
  excitations in a paradigmatic model dipeptide

abstract:
  We study within the many-body Green's function GW and Bethe-Salpeter
formalisms the excitation energies of a paradigmatic model dipeptide, focusing
on the four lowest-lying local and charge-transfer excitations. Our GW
calculations are performed at the self-consistent level, updating first the
quasiparticle energies, and further the single-particle wavefunctions within
the static Coulomb-hole plus screened-exchange approximation to the GW
self-energy operator. Important level crossings, as compared to the starting
Kohn-Sham LDA spectrum, are identified. Our final Bethe-Salpeter singlet
excitation energies are found to agree, within 0.07 eV, with CASPT2 reference
data, except for one charge-transfer state where the discrepancy can be as
large as 0.5 eV. Our results agree best with LC-BLYP and CAM-B3LYP calculations
with enhanced long-range exchange, with a 0.1 eV mean absolute error. This has
been achieved employing a parameter-free formalism applicable to metallic or
insulating extended or finite systems.


title: Unidirectional Input/Output Streaming Complexity of Reversal and Sorting

abstract:
  We consider unidirectional data streams with restricted access, such as
read-only and write-only streams. For read-write streams, we also introduce a
new complexity measure called expansion, the ratio between the space used on
the stream and the input size. We give tight bounds for the complexity of
reversing a stream of length $n$ in several of the possible models. In the
read-only and write-only model, we show that $p$-pass algorithms need memory
space ${\Theta}(n/p)$. But if either the output stream or the input stream is
read-write, then the complexity falls to ${\Theta}(n/p^2)$. It becomes
$polylog(n)$ if $p = O(log n)$ and both streams are read-write. We also study
the complexity of sorting a stream and give two algorithms with small
expansion. Our main sorting algorithm is randomized and has $O(1)$ expansion,
$O(log n)$ passes and $O(log n)$ memory.


title:
Kronecker's limit formula, holomorphic modular functions and
  $q$-expansions on certain moonshine groups

abstract:
  For any square-free integer $N$ such that the "moonshine group"
$\Gamma_0(N)^+$ has genus zero, the Monstrous Moonshine Conjectures relate the
Hauptmoduli of $\Gamma_0(N)^+$ to certain McKay-Thompson series associated to
the representation theory of the Fischer-Griess monster group. In particular,
the Hauptmoduli admits a $q$-expansion which has integer coefficients. In this
article, we study the holomorphic function theory associated to higher genus
moonshine groups $\Gamma_0(N)^+$. For all moonshine groups of genus up to and
including three, we prove that the corresponding function field admits two
generators whose $q$-expansions have integer coefficients, has lead coefficient
equal to one, and has minimal order of pole at infinity. As corollary, we
derive a polynomial relation which defines the underlying projective curve, and
we deduce whether $i\infty$ is a Weierstrass point. Our method of proof is
based on modular forms and includes extensive computer assistance, which, at
times, applied Gauss elimination to matrices with thousands of entries, each
one of which was a rational number whose numerator and denominator were
thousands of digits in length.


title: E-theory for C[0,1]-algebras with finitely many singular points

abstract:
  We study the E-theory group $E_{[0,1]}(A,B)$ for a class of C*-algebras over
the unit interval with finitely many singular points, called elementary
$C[0,1]$-algebras. We use results on E-theory over non-Hausdorff spaces to
describe $E_{[0,1]}(A,B)$ where $A$ is a sky-scraper algebra. Then we compute
$E_{[0,1]}(A,B)$ for two elementary $C[0,1]$-algebras in the case where the
fibers $A(x)$ and $B(y)$ of $A$ and $B$ are such that $E^1(A(x),B(y)) = 0$ for
all $x,y\in [0,1]$. This result applies whenever the fibers satisfy the UCT,
their $K_0$-groups are torsion-free and their $K_1$-groups are zero. In that
case we show that $E_{[0,1]}(A,B)$ is isomorphic to
$\text{Hom}(\mathbb{K}_0(A), \mathbb{K}_0(B))$, the group of morphisms of the
K-theory sheaves of $A$ and $B$. As an application, we give a streamlined
partially new proof of a classification result due to the first author and
Elliott.


title: An Index for Intersecting Branes in Matrix Models

abstract:
  We introduce an index indicating the occurrence of chiral fermions at the
intersection of branes in matrix models. This allows to discuss the stability
of chiral fermions under perturbations of the branes.


title: Optimal Branch Exchange for Distribution System Reconfiguration

abstract:
  The feeder reconfiguration problem chooses the on/off status of the switches
in a distribution network in order to minimize a certain cost such as power
loss. It is a mixed integer nonlinear program and hence hard to solve. A
popular heuristic search consists of repeated application of branch exchange,
where some loads are transferred from one feeder to another feeder while
maintaining the radial structure of the network, until no load transfer can
further reduce the cost. Optimizing each branch exchange step is itself a mixed
integer nonlinear program. In this paper we propose an efficient algorithm for
optimizing a branch exchange step. It uses an AC power flow model and is based
on the recently developed convex relaxation of optimal power flow. We provide a
bound on the gap between the optimal cost and that of our solution. We prove
that our algorithm is optimal when the voltage magnitudes are the same at all
buses. We illustrate the effectiveness of our algorithm through the simulation
of real- world distribution feeders.


title: Non-abelian Gauge Fields from Defects in Spin-Networks

abstract:
  \emph{Effective} gauge fields arise in the description of the dynamics of
defects in lattices of graphene in condensed matter. The interactions between
neighboring nodes of a lattice/spin-network are described by the Hubbard model
whose effective field theory at long distances is given by the Dirac equation
for an \emph{emergent} gauge field. The spin-networks in question can be used
to describe the geometry experienced by a non-inertial observer in flat
spacetime moving at a constant acceleration in a given direction. We expect
such spin-networks to describe the structure of quantum horizons of black holes
in loop quantum gravity. We argue that the abelian and non-abelian gauge fields
of the Standard Model can be identified with the emergent degrees of freedom
required to describe the dynamics of defects in symmetry reduced spin-networks.


title:
Maximizing Kepler science return per telemetered pixel: Detailed models
  of the focal plane in the two-wheel era

abstract:
  Kepler's immense photometric precision to date was maintained through
satellite stability and precise pointing. In this white paper, we argue that
image modeling--fitting the Kepler-downlinked raw pixel data--can vastly
improve the precision of Kepler in pointing-degraded two-wheel mode. We argue
that a non-trivial modeling effort may permit continuance of photometry at
10-ppm-level precision. We demonstrate some baby steps towards precise models
in both data-driven (flexible) and physics-driven (interpretably parameterized)
modes. We demonstrate that the expected drift or jitter in positions in the
two-weel era will help with constraining calibration parameters. In particular,
we show that we can infer the device flat-field at higher than pixel
resolution; that is, we can infer pixel-to-pixel variations in intra-pixel
sensitivity. These results are relevant to almost any scientific goal for the
repurposed mission; image modeling ought to be a part of any two-wheel
repurpose for the satellite. We make other recommendations for Kepler
operations, but fundamentally advocate that the project stick with its core
mission of finding and characterizing Earth analogs. [abridged]


title:
Maximizing Kepler science return per telemetered pixel: Searching the
  habitable zones of the brightest stars

abstract:
  In today's mailing, Hogg et al. propose image modeling techniques to maintain
10-ppm-level precision photometry in Kepler data with only two working reaction
wheels. While these results are relevant to many scientific goals for the
repurposed mission, all modeling efforts so far have used a toy model of the
Kepler telescope. Because the two-wheel performance of Kepler remains to be
determined, we advocate for the consideration of an alternate strategy for a >1
year program that maximizes the science return from the "low-torque" fields
across the ecliptic plane. Assuming we can reach the precision of the original
Kepler mission, we expect to detect 800 new planet candidates in the first year
of such a mission. Our proposed strategy has benefits for transit timing
variation and transit duration variation studies, especially when considered in
concert with the future TESS mission. We also expect to help address the first
key science goal of Kepler: the frequency of planets in the habitable zone as a
function of spectral type.


title: On small energy stabilization in the NLS with a trapping potential

abstract:
  We describe the asymptotic behavior of small energy solutions of an NLS with
a trapping potential. In particular we generalize work of Soffer and Weinstein,
and of Tsai et. al. The novelty is that we allow generic spectra associated to
the potential. This is yet a new application of the idea to interpret the
nonlinear Fermi Golden Rule as a consequence of the Hamiltonian structure.


title: Towards secure communication using intra-particle entanglement

abstract:
  We explore the use of the resource of intra-particle entanglement for secure
quantum key distribution in the device-independent scenario. By virtue of the
local nature of such entanglement, Bell tests must be implemented locally,
which leads to a natural decoupling of device errors from channel errors. We
consider a side channel attack on the sender's state preparation device, for
which the intra-particle-entanglement based scheme is shown to be more secure
than the one that uses separable states. Of practical relevance is the fact
that such entanglement can be easily generated using linear optics.


title: Human Genome Variation and the concept of Genotype Networks

abstract:
  Genotype networks are a method used in systems biology to study the
"innovability" of a set of genotypes having the same phenotype. In the past
they have been applied to determine the genetic heterogeneity, and stability to
mutations, of systems such as metabolic networks and RNA folds. Recently, they
have been the base for re-conciliating the two neutralist and selectionist
schools on evolution.
  Here, we adapted the concept of genotype networks to the study of population
genetics data, applying them to the 1000 Genomes dataset. We used networks
composed of short haplotypes of Single Nucleotide Variants (SNV), and defined
phenotypes as the presence or absence of a haplotype in a human population. We
used coalescent simulations to determine if the number of samples in the 1000
Genomes dataset is large enough to represent the genetic variation of real
populations. The result is a scan of how properties related to the genetic
heterogeneity and stability to mutations are distributed along the human
genome. We found that genes involved in acquired immunity, such as some HLA and
MHC genes, tend to have the most heterogeneous and connected networks; and we
have also found that there is a small, but significant difference between
networks of coding regions and those of non-coding regions, suggesting that
coding regions are both richer in genotype diversity, and more stable to
mutations. Together, the work presented here may constitute a starting point
for applying genotype networks to study genome variation, as larger datasets of
next-generation data will become availa


title:
Spin state of Co$^{3+}$ in LaCo$_{1-x}$Rh$_{x}$O$_{3}$ investigated by
  structural phenomena

abstract:
  Neutron diffraction for a polycrystalline sample of
LaCo$_{0.8}$Rh$_{0.2}$O$_{3}$ and synchrotron x-ray diffraction for
polycrystalline samples of LaCo$_{0.9}$Rh$_{0.1}$O$_{3}$ and
LaCo$_{0.8}$Rh$_{0.2}$O$_{3}$ have been carried out in order to investigate the
structural properties related with the spin state of Co$^{3+}$ ions. We have
found that the values of the Co(Rh)-O bond lengths in the Co(Rh)O$_{6}$
octahedron of LaCo$_{0.8}$Rh$_{0.2}$O$_{3}$ are nearly identical at 10 K. The
lattice volume for the Rh$^{3+}$ substituted samples decreases with the thermal
expansion coefficient similar to that of LaCoO$_{3}$ from room temperature, and
ceases to decrease around 70 K. These experimental results favor a mixed state
consisting of the high-spin-state and low-spin-state Co$^{3+}$ ions, and
suggest that the high-spin-state Co$^{3+}$ ions are thermally excited in
addition to those pinned by the substituted Rh$^{3+}$ ions.


title: Majority Rule for Belief Evolution in Social Networks

abstract:
  In this paper, we study how an agent's belief is affected by her neighbors in
a social network. We first introduce a general framework, where every agent has
an initial belief on a statement, and updates her belief according to her and
her neighbors' current beliefs under some belief evolution functions, which,
arguably, should satisfy some basic properties. Then, we focus on the majority
rule belief evolution function, that is, an agent will (dis)believe the
statement iff more than half of her neighbors (dis)believe it. We consider some
fundamental issues about majority rule belief evolution, for instance, whether
the belief evolution process will eventually converge. The answer is no in
general. However, for random asynchronous belief evolution, this is indeed the
case.


title: Two-dimensional Einstein numbers and associativity

abstract:
  In this paper, we deal with generalizations of real Einstein numbers to
various spaces and dimensions. We search operations and their properties in
generalized settings. Especially, we are interested in the generalized
operation of hyperbolic addition to more-dimensional spaces, which is
associative and commutative. We extend the theory to some abstract spaces,
especially to Hilbert-like ones. Further, we bring two different
two-dimensional generalizations of Einstein numbers and study properties of
new-defined operations -- mainly associativity, commutativity, and distributive
laws.


title: Singularities and Characteristic Classes for Differentiable Maps

abstract:
  This is a note on my mini-course in the International Workshop on Real and
Complex Singularities held at ICMC-USP (Sao Carlos, Brazil) in July 2012. Here
we introduce a new branch of the Thom polynomial theory for singularities of
holomorphic maps, in which we replace counting singular points by computing
weighted Euler characteristics. The main purpose is to apply this theory to the
study on the vanishing topology of weighted homogeneous map-germs of finite
A-codimension without any corank condition.


title: Commutator Theory and Abelian Algebras

abstract:
  This is the first draft of a set of lecture notes developed for one-half of a
seminar on two approaches to the notion of "Abelian", namely those of universal
algebra, and of category theory. The half pertaining to the universal-algebraic
perspective is covered here. All material has been adapted from the following
sources:
  1. Commutator Theory for Congruence Modular Varieties, by Ralph Freese and
Ralph McKenzie.
  2. Geometrical Methods in Congruence Modular Algebras, by H. Peter Gumm
  3. Congruence Modular Varieties: Commutator Theory and Its Uses, by Ralph
McKenzie and John Snow


title:
Study of Solutions for a quasilinear Elliptic Problem With negative
  exponents

abstract:
  The authors of this paper deal with the existence and regularities of weak
solutions to the homogenous $\hbox{Dirichlet}$ boundary value problem for the
equation $-\hbox{div}(|\nabla u|^{p-2}\nabla
u)+|u|^{p-2}u=\frac{f(x)}{u^{\alpha}}$. The authors apply the method of
regularization and $\hbox{Leray-Schauder}$ fixed point theorem as well as a
necessary compactness argument to prove the existence of solutions and then
obtain some maximum norm estimates by constructing three suitable iterative
sequences. Furthermore, we find that the critical exponent of $m$ in
$\|f\|_{L^{m}(\Omega)}$. That is, when $m$ lies in different intervals, the
solutions of the problem mentioned belongs to different $\hbox{Sobolev}$
spaces. Besides, we prove that the solution of this problem is not in
$W^{1,p}_{0}(\Omega)$ when $\alpha>2$, while the solution of this problem is in
$W^{1,p}_{0}(\Omega)$ when $1<\alpha<2$.


title:
Inelastic quarkonium photoproduction in coherent hadron - hadron
  interactions at LHC energies

abstract:
  In this paper we study the inelastic quarkonium photoproduction in coherent
$pp/pPb/PbPb$ interactions. Considering the ultra relativistic hadrons as a
source of photons, we estimate the total $ h_1 + h_2 \rightarrow h \otimes V +
X$ ($V = J/\Psi$ and $\Upsilon$) cross sections and rapidity distributions at
LHC energies. Our results demonstrate that the experimental analysis of this
process can be used to understand the underlying mechanism governing heavy
quarkonium production.


title:
Shift and broadening of resonance lines of the antiprotonic helium atoms
  in liquid He-4

abstract:
  The shift and broadening of the resonance lines in spectrum of the
antiprotonic helium atoms $\bar{p}\mathrm{He}^{+}$ located in fluid and
superfluid $^4$He have been calculated. The contributions to the shift and
broadening from collective degrees of freedom in liquid $^4$He have been
estimated using the phenomenological response function. Effects due to the
interaction of $\bar{p}\mathrm{He}^{+}$ with a single $^4$He atom have been
calculated in the quasistatic approximation using the experimental pair
correlation function. It has been shown that an implanted
$\bar{p}\mathrm{He}^{+}$ atom establishes a good probe of liquid helium
properties, since this atom practically does not change the target structure.


title:
A proof that the square root of s for s not a perfect square is simply
  normal to base 2

abstract:
  Since E. Borel proved in 1909 that almost all real numbers with respect to
Lebesgue measure are normal to all bases, an open problem has been whether
simple irrationals like square root of 2 are normal to any base. We show that
each number of the form square root of s for s not a perfect square is simply
normal to base 2, that is, the averages of the first n digits of its dyadic
expansion converge to 1/2. The proof is mostly elementary and self contained
but some basic probability is used. The main idea centers on the notion of
tails of an expansion, that is, the sequence of digits with index larger than
any fixed integer n.


title: Interaction effects on dynamic correlations in non-condensed Bose gases

abstract:
  We consider dynamic, i.e., frequency-dependent, correlations in non-condensed
ultracold atomic Bose gases. In particular, we consider the single-particle
correlation function and its power spectrum. We compute this power spectrum for
a one-component Bose gas, and show how it depends on the interatomic
interactions that lead to a finite single-particle relaxation time. As another
example, we consider the power spectrum of spin-current fluctuations for a
two-component Bose gas and show how it is determined by the spin-transport
relaxation time.


title: On certain properties of the compact Zakharov equation

abstract:
  Long-time evolution of a weakly perturbed wavetrain near the modulational
instability threshold is investigated within the framework of the compact
Zakharov equation for unidirectional deep-water waves, recently derived by
Zakharov & Dyachenko (2011). Multiple-scale solutions reveal that a
perturbation to a slightly unstable uniform wavetrain of steepness \mu slowly
evolves according to a Nonlinear Schrodinger equation. In particular, for small
carrier wave steepness \mu<\mu_1~0.27 the perturbation dynamics is of focusing
type and the long-time behavior is characterized by Fermi-Pasta-Ulam
recurrence, the signature of breather interactions. However, the amplitude of
breathers and their likelihood of occurrence tend to diminish as \mu increases
while the Benjamin-Feir index decreases and becomes nil at \mu1. Thus,
homoclinic orbits persist only for small values of wave steepness \mu<<\mu_1,
in agreement with recent experimental and numerical observations of breathers.
When the Zakharov equation is already beyond its range of nominal validity for
\mu>\mu_1, predictions seem to foreshadow a dynamical trend to wave breaking.
In particular, the perturbation dynamics becomes of defocussing type, and
nonlinearities tend to stabilize a linearly unstable wavetrain as
Fermi-Pasta-Ulam recurrence is suppressed. At \mu=\mu_c~0.577, subharmonic
perturbations restabilize and superharmonic instability appears, possibly
indicating that wave dynamic behavior changes at large steepness, in
qualitative agreement with the numerical simulations of Longuet-Higgins and
Cokelet (1978) for steep waves. Indeed, for \mu>\mu_c a multiple-scale
perturbation analysis reveals that a weak narrowband perturbation to a uniform
wavetrain evolves in accord with a modified Korteweg-de Vries/Camassa-Holm type
equation, again implying a possible mechanism conducive to initiating wave
breaking.


title: Minimal fixed point set of maps on Torus Fiber Bundles over the Circle

abstract:
  The main purpose this work is to study the minimal fixed point set of
fiber-preserving maps for spaces which are fiber bundles over the circle and
the fiber is the torus. Using the one-parameter fixed point theory is possible
to describe these sets in terms of the fundamental group and the induced
homomorphism.


title: Biological Averaging in RNA-Seq

abstract:
  RNA-seq has become a de facto standard for measuring gene expression.
Traditionally, RNA-seq experiments are mathematically averaged -- they sequence
the mRNA of individuals from different treatment groups, hoping to correlate
phenotype with differences in arithmetic read count averages at shared loci of
interest. Alternatively, the tissue from the same individuals may be pooled
prior to sequencing in what we refer to as a biologically averaged design. As
mathematical averaging sequences all individuals it controls for both
biological and technical variation; however, is the statistical resolution
gained always worth the additional cost? To compare biological and mathematical
averaging, we examined theoretical and empirical estimates of statistical
efficiency and relative cost efficiency. Though less efficient at a fixed
sample size, we found that biological averaging can be more cost efficient than
mathematical averaging. With this motivation, we developed a differential
expression classifier, ICRBC, that can detect alternatively expressed genes
between biologically averaged samples. In simulation studies, we found that
biological averaging and subsequent analysis with our classifier performed
comparably to existing methods, such as ASC, edgeR, and DESeq, especially when
individuals were pooled evenly and less than 20% of the regulome was expected
to be differentially regulated. In two technically distinct mouse datasets and
one plant dataset, we found that our method was over 87% concordant with edgeR
for the 100 most significant features. We therefore conclude biological
averaging may sufficiently control biological variation to a level that
differences in gene expression may be detectable. In such situations, ICRBC can
enable reliable exploratory analysis at a fraction of the cost, especially when
interest lies in the most differentially expressed loci.


title: BayesOpt: A Library for Bayesian optimization with Robotics Applications

abstract:
  The purpose of this paper is twofold. On one side, we present a general
framework for Bayesian optimization and we compare it with some related fields
in active learning and Bayesian numerical analysis. On the other hand, Bayesian
optimization and related problems (bandits, sequential experimental design) are
highly dependent on the surrogate model that is selected. However, there is no
clear standard in the literature. Thus, we present a fast and flexible toolbox
that allows to test and combine different models and criteria with little
effort. It includes most of the state-of-the-art contributions, algorithms and
models. Its speed also removes part of the stigma that Bayesian optimization
methods are only good for "expensive functions". The software is free and it
can be used in many operating systems and computer languages.


title:
Irradiation Tests and Expected Performance of Readout Electronics of the
  ATLAS Hadronic Endcap Calorimeter for the HL-LHC

abstract:
  The readout electronics of the ATLAS Hadronic Endcap Calorimeter (HEC) will
have to withstand an about 3-5 times larger radiation environment at the future
high-luminosity LHC (HLLHC) compared to their design values. The preamplifier
and summing boards (PSBs), which are equipped with GaAs ASICs and comprise the
heart of the readout electronics, were irradiated with neutrons and protons
with fluences surpassing several times ten years of operation of the HL-LHC.
Neutron tests were performed at the NPI in Rez, Czech Republic, where a 36 MeV
proton beam was directed on a thick heavy water target to produce neutrons. The
proton irradiation was done with 200 MeV protons at the PROSCAN area of the
Proton Irradiation Facility at the PSI in Villigen, Switzerland. In-situ
measurements of S-parameters in both tests allow the evaluation of frequency
dependent performance parameters, like gain and input impedance, as a function
of fluence. The linearity of the ASIC response was measured directly in the
neutron tests with a triangular input pulse of varying amplitude. The results
obtained allow an estimation of the expected performance degradation of the
HEC. For a possible replacement of the PSB chips, alternative technologies were
investigated and exposed to similar neutron radiation levels. In particular,
IHP 250 nm Si CMOS technology has turned out to show good performance and match
the specifications required. The performance measurements of the current PSB
devices, the expected performance degradations under HL-LHC conditions, and
results from alternative technologies will be presented.


title: Weak commutation relations of unbounded operators: nonlinear extensions

abstract:
  We continue our analysis of the consequences of the commutation relation
$[S,T]=\Id$, where $S$ and $T$ are two closable unbounded operators. The {\em
weak} sense of this commutator is given in terms of the inner product of the
Hilbert space $\H$ where the operators act. {We also consider what we call,
adopting a physical terminology}, a {\em nonlinear} extension of the above
commutation relations.


title: Self-gravitating branes again

abstract:
  We raise on theoretical grounds the question of the physical relevance of
Israel matching conditions and their generalizations to higher codimensions,
the standard cornerstone of the braneworld and other membrane scenarios. Our
reasoning is twofold: First, the incapability of the conventional matching
conditions to accept the Nambu-Goto probe limit (even the geodesic limit of the
Israel matching conditions is not acceptable since being the geodesic equation
a kinematical fact it should be preserved for all gravitational theories or
defects, which is not the case for these conditions). Second, in our
D-dimensional spacetime (maybe D=4), classical defects of any possible
codimension should be compatible. These matching conditions fail to accept
codimension-2 and 3 defects for D=4 (which represents effectively the spacetime
at certain length and energy scales) and most probably fail to accept high
enough codimensional defects for any D since there is no high enough Lovelock
density to support them. Here, we propose alternative matching conditions which
seem to satisfy the previous criteria. Instead of varying the brane-bulk action
with respect to the bulk metric at the brane position, we vary with respect to
the brane embedding fields so that the gravitational back-reaction is included.
For a codimension-2 brane in 6-dim EGB gravity we prove its consistency for an
axially symmetric cosmological configuration. The cosmologies found have the
LFRW behaviour and extra correction terms. For a radiation brane one solution
avoids a cosmological singularity and undergoes accelerated expansion near the
minimum scale factor. In the presence of an induced gravity term, there
naturally appears in the theory the effective cosmological constant scale
lambda/(M_6^4 r_c^2), which for a brane tension lambda\sim M_6^4 (e.g. TeV^4)
and r_c \sim H_0^{-1} gives the observed value of the cosmological constant.


title:
Minimum Distance Estimation of Milky Way Model Parameters and Related
  Inference

abstract:
  We propose a method to estimate the location of the Sun in the disk of the
Milky Way using a method based on the Hellinger distance and construct
confidence sets on our estimate of the unknown location using a bootstrap based
method. Assuming the Galactic disk to be two-dimensional, the sought solar
location then reduces to the radial distance separating the Sun from the
Galactic center and the angular separation of the Galactic center to Sun line,
from a pre-fixed line on the disk. On astronomical scales, the unknown solar
location is equivalent to the location of us earthlings who observe the
velocities of a sample of stars in the neighborhood of the Sun. This unknown
location is estimated by undertaking pairwise comparisons of the estimated
density of the observed set of velocities of the sampled stars, with densities
estimated using synthetic stellar velocity data sets generated at chosen
locations in the Milky Way disk according to four base astrophysical models.
The "match" between the pair of estimated densities is parameterized by the
affinity measure based on the familiar Hellinger distance. We perform a novel
cross-validation procedure to establish a desirable "consistency" property of
the proposed method.


title: Extended pseudo-fermions from non commutative bosons

abstract:
  We consider some modifications of the two dimensional canonical commutation
relations, leading to {\em non commutative bosons} and we show how biorthogonal
bases of the Hilbert space of the system can be obtained out of them. Our
construction extends those recently introduced by one of us (FB), modifying the
canonical anticommutation relations. We also briefly discuss how bicoherent
states, producing a resolution of the identity, can be defined.


title: More mathematics for pseudo-bosons

abstract:
  We propose an alternative definition for pseudo-bosons. This simplifies the
mathematical structure, minimizing the required assumptions. Some physical
examples are discussed, as well as some mathematical results related to the
biorthogonal sets arising out of our framework.


title: Pseudo-fermions in an electronic loss-gain circuit

abstract:
  In some recent papers a loss-gain electronic circuit has been introduced and
analyzed within the context of PT-quantum mechanics. In this paper we show that
this circuit can be analyzed using the formalism of the so-called
pseudo-fermions. In particular we discuss the time behavior of the circuit, and
we construct two biorthogonal bases associated to the Liouville matrix $\Lc$
used in the treatment of the dynamics. We relate these bases to $\Lc$ and
$\Lc^\dagger$, and we also show that a self-adjoint Liouville-like operator
could be introduced in the game. Finally, we describe the time evolution of the
circuit in an {\em Heisenberg-like} representation, driven by a non
self-adjoint hamiltonian.


title: Testing Dvali-Gabadadze-Porrati Gravity with Planck

abstract:
  Recently, the Planck collaboration has released the first cosmological papers
providing the highest resolution, full sky, maps of the cosmic microwave
background (CMB) temperature anisotropies. In this paper we study a
phenomenological model which interpolates between the pure $\Lambda$CDM model
and the Dvali-Gabadadze-Porrati (DGP) braneworld model with an additional
parameter $\alpha$. Firstly, we calculate the "distance information" of Planck
data which includes the "shift parameter" $R$, the "acoustic scale" $l_A$, and
the photon decoupling epoch $z_\ast$ in different cosmological models and find
that this information is almost independent on the input models we use. Then,
we compare the constraints on the free parameter $\alpha$ of the DGP model from
the "distance information" of Planck and WMAP data and find that the Planck
data with high precision do not improve the constraint on $\alpha$, but give
the higher median value and the better limit on the current matter density
fraction $\Omega_m$. Then, combining the "distance information" of Planck
measurement, baryon acoustic oscillations (BAO), type Ia supernovae (SNIa) and
the prior on the current Hubble constant (HST), we obtain the tight constraint
on the parameter $\alpha < 0.20$ at $95\%$ confidence level, which implies that
the flat DGP model has been ruled out by the current cosmological data.
Finally, we allow the additional parameter $\alpha < 0$ in our calculations and
interestingly obtain $\alpha=-0.29\pm0.20$ ($68\%$ C.L.), which means the
current data slightly favor the effective equation of state $w_{\rm eff}<-1$.
More importantly, the tension between constraints on $H_0$ from different
observational data has been eased.


title: Decomposing Berge graphs and detecting balanced skew partitions

abstract:
  A hole in a graph is an induced cycle on at least four vertices. A graph is
Berge if it has no odd hole and if its complement has no odd hole. In 2002,
Chudnovsky, Robertson, Seymour and Thomas proved a decomposition theorem for
Berge graphs saying that every Berge graph either is in a well understood basic
class, or has some kind of decomposition. Then, Chudnovsky proved stronger
theorems. One of them restricts the allowed decompositions to 2-joins and
balanced skew partitions.
  We prove that the problem of deciding whether a graph has a balanced skew
partition is NP-hard. We give an $O(n^9)$-time algorithm for the same problem
restricted to Berge graphs. Our algorithm is not constructive: it only
certifies whether a graph has a balanced skew partition or not. It relies on a
new decomposition theorem for Berge graphs that is more precise than the
previously known theorems. Our theorem also implies that every Berge graph can
be decomposed in a first step by using only balanced skew partitions, and in a
second step by using only 2-joins. Our proof of this new theorem uses at an
essential step one of the theorems of Chudnovsky.


title: Cylindric and polyadic algebras, new perspectives

abstract:
  We generalize the notion of Monk's schema in such a way to integrate finite
dimensions. This allows us to lift a plathora of deep results proved for finite
dimensions to the infinite dimensional case, like the solution to problem 2.12
in Henkin Monk and Tarski part one, solved by Hirsch and Hodkinson. This
lifting argument was already used in a joint paper with Robin Hirsch, but in a
narrower context, accepted for publication in the Journal of Symbolic Logic. We
also give a general new definition of a schema for infinite dimensions covering
Monk's schema and Halmos' schema. Several algebraic properties (like
amalgamation) are proved for instances of systems of varieties definable by
such a schema like MV algebras, reducts of Heyting polyadic algebras and
Ferenczi's cylindric polyadic algebras. Finally, two serious errors in two
publications in prestigeous journals are pointed out. One is fixed, the
alledged result in the second is weakened.


title:
Collective Multipole excitations of exotic nuclei in relativistic
  continuum random phase approximation

abstract:
  Journal of Combinatorial Theory, Series B, 98(1):173-225, 2008n exotic nuclei
are studied in the framework of a fully self-consistent relativistic continuum
random phase approximation (RCRPA). In this method the contribution of the
continuum spectrum to nuclear excitations is treated exactly by the single
particle Green's function. Different from the cases in stable nuclei, there are
strong low-energy excitations in neutron-rich nuclei and proton-rich nuclei.
The neutron or proton excess pushes the centroid of the strength function to
lower energies and increases the fragmentation of the strength distribution.
The effect of treating the contribution of continuum exactly are also
discussed.


title: Strip Planarity Testing of Embedded Planar Graphs

abstract:
  In this paper we introduce and study the strip planarity testing problem,
which takes as an input a planar graph $G(V,E)$ and a function $\gamma:V
\rightarrow \{1,2,\dots,k\}$ and asks whether a planar drawing of $G$ exists
such that each edge is monotone in the $y$-direction and, for any $u,v\in V$
with $\gamma(u)<\gamma(v)$, it holds $y(u)<y(v)$. The problem has strong
relationships with some of the most deeply studied variants of the planarity
testing problem, such as clustered planarity, upward planarity, and level
planarity. We show that the problem is polynomial-time solvable if $G$ has a
fixed planar embedding.


title: On the reliability of measuring differential rotation of spotted stars

abstract:
  Cross-correlation of consecutive Doppler images is one of the most common
techniques used to detect surface differential rotation (hereafter DR) on
spotted stars. The disadvantage of a single cross-correlation is, however, that
the expected DR pattern can be overwhelmed by sudden changes in the apparent
spot configuration. Another way to reconstruct the image shear using Doppler
imaging is to include a predefined latitude-dependent rotation law in the
inversion code (`sheared image method'). However, special but not unusual spot
distributions, such like a large polar cap or an equatorial belt (e.g., small
random spots evenly distributed along the equator), can distort the rotation
profile similarly as the DR does, consequently, yielding incorrect measure of
the DR from the sheared image method. To avoid these problems, the technique of
measuring DR from averaged cross-correlations using time-series Doppler images
(`ACCORD') is introduced and the reliability of this tool is demonstrated on
artificial data.


title: A Compensator Characterization of Planar Point Processes

abstract:
  Martingale techniques play a fundamental role in the analysis of point
processes on the real line. In particular, the compensator of a point process
uniquely determines and is determined by its distribution, and an explicit
formula involving conditional interarrival distributions is well-known. In two
dimensions there are many possible definitions of a point process compensator
and we focus here on the one that has been the most useful in practice: the
so-called *-compensator. Although existence of the *-compensator is well
understood, in general it does not determine the law of the point process and
it must be calculated on a case-by-case basis. However, it will be proven that
when the point process satisfies a certain property of conditional independence
(usually denoted by (F4)), the *- compensator determines the law of the point
process and an explicit regenerative formula can be given. The basic building
block of the planar model is the single line process (a point process with
incomparable jump points). Its law can be characterized by a class of avoidance
probabilities that are the two-dimensional counterpart of the survival function
in one dimension. Conditional avoidance probabilities then play the same role
in the construction of the *-compensator as conditional survival probabilities
do for compensators in one dimension.


title: Conditionally flat functors on spaces and groups

abstract:
  Consider an extension of groups 1 -> K -> G -> Q -> 1 which enjoys the
property that the quotient by the lower central series Gamma_{c+1} produces
another extension 1 -> K/ Gamma_{c+1} K -> G /Gamma_{c+1} G -> Q / Gamma_{c+1}
Q -> 1, of nilpotent groups of class c. We say that the extension is
Gamma_{c+1}-flat. Let us pull back the original extension along any
homomorphism X -> Q. Does the pullback extension enjoy the same
Gamma_{c+1}-flatness property?
  To answer this question we consider not only quotients by the lower central
series, but any localization functor in the category of groups. In fact we
start by studying the analogous question for spaces, where we replace
extensions by fibration sequences. We prove that the only homotopical
localization functors which behave well under pull-backs are nullifications. In
the category of groups, nullifications also enjoy this property, and so do all
epireflections arising from a variety of groups. In particular the answer to
the question about the nilpotent quotients is positive.


title: Modes in modern music from a topological viewpoint

abstract:
  The aim of this paper is twofold: on one side we review the classical concept
of musical mode from the viewpoint of modern music, reading it as a
superimposition of a base-chord (seventh chord) and a tension-chord (triad). We
associate to each modal scale an oriented plane graph whose homotopy properties
give a measure of the complexity of the base-chord associated to a certain
mode. Using these graphs we prove the existence of special modes which are not
deducible in the standard way.
  On the other side we give a more deep musical insight by developing a braid
theoretical interpretation of some cadential harmonic progressions in modern
music and we use braid theory in order to represent them and voice leadings
among them.
  A striking application is provided by the analysis of an harmonic fragment
from Peru by Tribal Tech We approximate the octatonic scale used in the
improvisation by Scott Henderson, through the special mode myxolydian b2#4 and
we finally associate a braid representation to the fragment we analysed.


title:
Interplay between columnar and smectic stability in suspensions of
  polydisperse colloidal platelets

abstract:
  The phase behavior of a model suspension of colloidal polydisperse platelets
is studied using density-functional theory. Platelets are modelled as parallel
rectangular prisms of square section $l$ and height $h$, with length and height
distributions given by different polydispersities $\delta_l$ and $\delta_h$. We
obtain the phase behavior of the model, including nematic, smectic and columnar
phases and its dependence with the two polydispersities $\delta_l$ and
$\delta_h$. When $\delta_l>\delta_h$ we observe that the smectic phase
stabilises first with respect to the columnar. If $\delta_h>\delta_l$ we
observe the opposite behavior. Other more complicated cases occur, e.g. the
smectic stabilises from the nematic first but then exists a first-order
transition to the columnar phase. Our model assumes plate-rod symmetry, but the
regions of stability of smectic and columnar phases are non-symmetric in the
$\delta_l-\delta_h$ plane due to the different dimensionality of ordering in
the two phases. Microsegregation effects, i.e. different spatial distribution
for different sizes within the periodic cell, take place in both phases.


title:
Subnormal weighted shifts on directed trees and composition operators in
  $L^2$ spaces with non-densely defined powers

abstract:
  It is shown that for every positive integer $n$ there exists a subnormal
weighted shift on a directed tree (with or without root) whose $n$th power is
densely defined while its $(n+1)$th power is not. As a consequence, for every
positive integer $n$ there exists a non-symmetric subnormal composition
operator $C$ in an $L^2$ space over a $\sigma$-finite measure space such that
$C^n$ is densely defined and $C^{n+1}$ is not.


title:
The Universe as a Set of Topological Fluids with Hierarchy and Fine
  Tuning of Coupling Constants in Terms of Graph Manifolds

abstract:
  The hierarchy and fine tuning of the gauge coupling constants are described
on the base of topological invariants (Chern classes interpreted as filling
factors) characterizing a collection of fractional topological fluids emerging
from three dimensional graph manifolds, which play the role of internal spaces
in the Kaluza-Klein approach to the topological BF theory. The hierarchy of BF
gauge coupling constants is simulated by diagonal elements and eigenvalues of
rational linking matrices of tree graph manifolds pasted together from
Brieskorn (Seifert fibered) homology spheres. Specific examples of graph
manifolds are presented which contain in their linking matrices the hierarchy
of coupling constants distinctive for the dimensionless coupling constants in
our Universe. The fine tuning effect is simulated owing to the special
numerical properties of diagonal elements of the linking matrices. We pay a
particular attention to fine tuning problem for the cosmological constant and
propose its model solution.


title: Information Filtering via Collaborative User Clustering Modeling

abstract:
  The past few years have witnessed the great success of recommender systems,
which can significantly help users find out personalized items for them from
the information era. One of the most widely applied recommendation methods is
the Matrix Factorization (MF). However, most of researches on this topic have
focused on mining the direct relationships between users and items. In this
paper, we optimize the standard MF by integrating the user clustering
regularization term. Our model considers not only the user-item rating
information, but also takes into account the user interest. We compared the
proposed model with three typical other methods: User-Mean (UM), Item-Mean (IM)
and standard MF. Experimental results on a real-world dataset,
\emph{MovieLens}, show that our method performs much better than other three
methods in the accuracy of recommendation.


title: Charge Quantization in the $\mathbb{CP}(1)$ Nonlinear Sigma-Model

abstract:
  We investigate the consistency conditions for matter fields coupled to the
four-dimensional (${\cal N} = 1$ supersymmetric) $\mathbb{CP}(1)$ nonlinear
sigma model (the coset space $SU(2)_G/U(1)_H$). We find that consistency
requires that the $U(1)_H$ charge of the matter be quantized, in units of half
of the $U(1)_H$ charge of the Nambu-Goldstone (NG) boson, if the matter has a
nonsingular kinetic term and the dynamics respect the full group $SU(2)_G$. We
can then take the linearly realized group $U(1)_H$ to comprise the weak
hypercharge group $U(1)_Y$ of the Standard Model. Thus we have charge
quantization without a Grand Unified Theory (GUT), completely avoiding problems
like proton decay, doublet-triplet splitting, and magnetic monopoles. We
briefly investigate the phenomenological implications of this model-building
framework. The NG boson is fractionally charged and completely stable. It can
be naturally light, avoiding constraints while being a component of dark matter
or having applications in nuclear physics. We also comment on the extension to
other NLSMs on coset spaces, which will be explored more fully in a followup
paper.


title:
Constraining Alternative Gravity Theories Using The Solar Neutrino
  Problem

abstract:
  The neutrino flavor oscillation is studied in some classes of alternative
gravity theories in a plane specified by $\theta =\pi /2$, exploiting the
spherical symmetry and general equations for oscillation phases are given. We
first calculate the phase in a general static spherically symmetric model and
then we discuss some spherically symmetric solutions in alternative gravity
theories. Among them we discuss the effect of cosmological term in
Schwarzschild-(anti)de Sitter solution, which is the vacuum solution in $F(R)$
theory, the effect of charge and Gauss-Bonnet coupling parameter on the
oscillation phase is presented. Finally we discuss a charged solution with
spherical symmetry in $F(R)$ theory and also its implication to the oscillation
phase. We calculate the oscillation length and transition probability in these
spherically symmetric spacetime and have presented a graphical representation
for transition probability with various choice for parameters in our theory.
From this we could constrain parameters appearing in these alternative theories
using standard solar neutrino results.


title: Algorithms for square-$3PC(\cdot, \cdot)$-free Berge graphs

abstract:
  We consider the class of graphs containing no odd hole, no odd antihole, and
no configuration consisting of three paths between two nodes such that any two
of the paths induce a hole, and at least two of the paths are of length 2. This
class generalizes claw-free Berge graphs and square-free Berge graphs. We give
a combinatorial algorithm of complexity $O(n^{7})$ to find a clique of maximum
weight in such a graph. We also consider several subgraph-detection problems
related to this class.


title: Generalized Onsager theory for strongly anisometric patchy colloids

abstract:
  The implications of soft `patchy' interactions on the orientational
disorder-order transition of strongly elongated colloidal rods and flat disks
is studied within a simple Onsager-van der Waals density functional theory. The
theory provides a generic framework for studying the liquid crystal phase
behaviour of highly anisometric cylindrical colloids, which carry a distinct
geometrical pattern of repulsive or attractive soft interactions localised on
the particle surface. In this paper, we apply our theory to the case of charged
rods and disks for which the local electrostatic interactions can be described
by a screened-Coulomb potential. We consider infinitely thin rod-like cylinders
with a uniform line charge and infinitely thin discotic cylinders with several
distinctly different surface charge patterns. Irrespective of the backbone
shape, the isotropic-nematic phase diagrams of charged colloids feature a
generic destabilization of nematic order, a dramatic narrowing of the biphasic
density region and a reentrant phenomenon upon reducing the electrostatic
screening. At higher particle density the electrostatic repulsion leads to a
complete suppression of nematic order in favour of spatially inhomogeneous
liquid crystals.


title:
Xe anions in stable Mg-Xe compounds: the mechanism of missing Xe in
  earth atmosphere

abstract:
  The reactivity of noble gas elements is important for both fundamental
chemistry and geological science. The discovery of the oxidation of Xe extended
the doctrinal boundary of chemistry that a complete shell is inert to reaction.
The oxidations of Xe by various geological substances have been researched in
order to explain the missing Xe in earth atmosphere. Among many proposals, the
chemistry mechanisms are straightforward as they identify chemical processes
that can capture Xe in earth interior. However, all the mechanisms based on
current noble gas chemistry face the same difficulty: the earth lower mantle
and core are rich in metals and therefore their chemical environment is
reductive. On the other hand, up till now, the opposite chemical inclination,
the reductive propensity, i.e. gaining electrons and forming anions, has not
been proposed and examined for noble gas elements. In this work, we
demonstrate, using first principles calculations and an efficient structure
prediction method, that Xe and Kr can form stable MgXe and MgKr compounds under
high pressure. These compounds are intermetallic and Xe or Kr is negatively
charged. We also find that elevated temperature has large effect in stabilizing
MgXe and MgKr compounds. Our results show that the earth has the capability of
capturing Xe but not Kr, which is consistent to the depletion of Xe in earth
atmosphere. The stability of these compounds suggests that chemical species
with completely filled shell may still gain more electrons filling their outer
shell in chemical reactions.


title: On the 6d origin of discrete additional data of 4d gauge theories

abstract:
  Starting with a choice of gauge algebras, specification of a 4d gauge theory
involves additional data, namely the gauge groups and the discrete theta
angles. Equivalently, one needs to specify the set of charges of allowed line
operators. In this note, we study how these additional data are represented in
6d, when the 4d theory in question is an N=4 super Yang-Mills theory or an N=2
class S theory. We will see that the Z_N symmetry of the so-called T_N theory
plays an important role. As a byproduct, we will find that the superconformal
index of class S theories can be refined so that it can give 2d q-deformed
Yang-Mills theory with different gauge groups associated to the same gauge
algebra.


title: Noncommutative deformations and flops

abstract:
  We prove that the functor of noncommutative deformations of every flipping or
flopping irreducible rational curve in a 3-fold is representable, and hence
associate to every such curve a noncommutative deformation algebra. This new
invariant extends and unifies known invariants for flopping curves in 3-folds,
such as the width of Reid, and the bidegree of the normal bundle. It also
applies in the settings of flips and singular schemes. We show that the
noncommutative deformation algebra is finite dimensional, and give a new way of
obtaining the commutative deformations of the curve, allowing us to make
explicit calculations of these deformations for certain (-3,1)-curves.
  We then show how our new invariant also controls the homological algebra of
flops. For any flopping curve in a projective 3-fold with only Gorenstein
terminal singularities, we construct an autoequivalence of the derived category
of the 3-fold by twisting around a universal family over the noncommutative
deformation algebra, and prove that this autoequivalence is an inverse of
Bridgeland's flop-flop functor. This demonstrates that it is strictly necessary
to consider noncommutative deformations of curves in order to understand the
derived autoequivalences of a 3-fold, and thus the Bridgeland stability
manifold.


title:
The precise determination of mass through the oscillations of a very
  high-Q superconductor oscillating system

abstract:
  The present paper is based upon the fact that if an object is part of a
highly stable oscillating system, it is possible to obtain an extremely precise
measure for its mass in terms of the energy trapped in this resonance. The
subject is timely since there is great interest in Metrology on the
establishment of a new electronic standard for the kilogram. Our contribution
to such effort includes both the proposal of an alternative definition for mass
in terms of energy, as well as the description of a realistic experimental
system in which this definition might actually be applied. The setup consists
of an oscillating type-II superconducting loop (the SEO system) subjected to
the gravity and magnetic fields. The system is shown to be able to reach a
dynamic equilibrium by trapping energy up to the point it levitates against the
surrounding magnetic and gravitational fields, behaving as an extremely high-Q
spring-load system. The proposed energy-mass equation applied to the
electromechanical oscillating system eventually produces a new experimental
relation between mass and standardized constants.


title: Denoising Using Projection Onto Convex Sets (POCS) Based Framework

abstract:
  Two new optimization techniques based on projections onto convex space (POCS)
framework for solving convex optimization problems are presented. The dimension
of the minimization problem is lifted by one and sets corresponding to the cost
function are defined. If the cost function is a convex function in R^N the
corresponding set is also a convex set in R^{N+1}. The iterative optimization
approach starts with an arbitrary initial estimate in R^{N+1} and an orthogonal
projection is performed onto one of the sets in a sequential manner at each
step of the optimization problem. The method provides globally optimal
solutions in total-variation (TV), filtered variation (FV), L_1, and entropic
cost functions. A new denoising algorithm using the TV framework is developed.
The new algorithm does not require any of the regularization parameter
adjustment. Simulation examples are presented.


title:
Analytically Solvable Model of Spreading Dynamics with Non-Poissonian
  Processes

abstract:
  Non-Poissonian bursty processes are ubiquitous in natural and social
phenomena, yet little is known about their effects on the large-scale spreading
dynamics. In order to characterize these effects we devise an analytically
solvable model of Susceptible-Infected (SI) spreading dynamics in infinite
systems for arbitrary inter-event time distributions and for the whole time
range. Our model is stationary from the beginning, and the role of lower bound
of inter-event times is explicitly considered. The exact solution shows that
for early and intermediate times the burstiness accelerates the spreading as
compared to a Poisson-like process with the same mean and same lower bound of
inter-event times. Such behavior is opposite for late time dynamics in finite
systems, where the power-law distribution of inter-event times results in a
slower and algebraic convergence to fully infected state in contrast to the
exponential decay of the Poisson-like process. We also provide an intuitive
argument for the exponent characterizing algebraic convergence.


title:
Kepler White Paper: Asteroseismology of Solar-Like Oscillators in a
  2-Wheel Mission

abstract:
  We comment on the potential for continuing asteroseismology of solar-type and
red-giant stars in a 2-wheel Kepler Mission. Our main conclusion is that by
targeting stars in the ecliptic it should be possible to perform high-quality
asteroseismology, as long as favorable scenarios for 2-wheel pointing
performance are met. Targeting the ecliptic would potentially facilitate unique
science that was not possible in the nominal Mission, notably from the study of
clusters that are significantly brighter than those in the Kepler field. Our
conclusions are based on predictions of 2-wheel observations made by a space
photometry simulator, with information provided by the Kepler Project used as
input to describe the degraded pointing scenarios. We find that elevated levels
of frequency-dependent noise, consistent with the above scenarios, would have a
significant negative impact on our ability to continue asteroseismic studies of
solar-like oscillators in the Kepler field. However, the situation may be much
more optimistic for observations in the ecliptic, provided that pointing resets
of the spacecraft during regular desaturations of the two functioning reaction
wheels are accurate at the < 1 arcsec level. This would make it possible to
apply a post-hoc analysis that would recover most of the lost photometric
precision. Without this post-hoc correction---and the accurate re-pointing it
requires---the performance would probably be as poor as in the Kepler-field
case. Critical to our conclusions for both fields is the assumed level of
pointing noise (in the short-term jitter and the longer-term drift). We suggest
that further tests will be needed to clarify our results once more detail and
data on the expected pointing performance becomes available, and we offer our
assistance in this work.


title:
Three dimensional compressible Navier-Stokes equation - self-similar and
  traveling wave solutions

abstract:
  We investigate the three dimensional compressible Navier-Stokes and the
continuity equations in Cartesian coordinates for Newtonian fluids. The
polytropic equation of sate is used as closing condition. The key idea is the
three-dimensional generalization of the well-known self-similar Ansatz which
was already used for non-compressible viscous flow in our former study (Commun.
in Theor. Phys. 56, (2011) 745). In the second method the three dimensional
traveling wave Ansatz was applied. The geometrical interpretations of the trial
functions are also discussed.


title:
Measurement of the Decays $B^0_s\to J/\psi\,\phi(1020)$, $B^0_{s}\to
  J/\psi\,f'_2(1525)$ and $B^0_s\to J/\psi\,K^+K^-$ at Belle

abstract:
  We report a measurement of the branching fraction of the decay $B^0_s\to
J/\psi\,\phi(1020)$, evidence and a branching fraction measurement for
$B^0_s\to J/\psi\,f'_2(1525)$, and the determination of the total $B^0_s\to
J/\psi\,K^+K^-$ branching fraction, including the resonant and non-resonant
contributions to the $K^+K^-$ channel. We also determine the $S$-wave
contribution within the $\phi(1020)$ mass region. The absolute branching
fractions are $\mathcal{B}[B^0_s\to J/\psi\,\phi(1020)]=(1.25 \pm
0.07\left(\mathrm{stat}\right)\pm 0.08\left(\mathrm{syst}\right)\pm
0.22\left(f_s\right))\times 10^{-3}$, $\mathcal{B}[B^0_s\to
J/\psi\,f'_2(1525)]=(0.26\pm 0.06\left(\mathrm{stat}\right)\pm
0.02\left(\mathrm{syst}\right) \pm 0.05\left(f_s\right))\times 10^{-3}$ and
$\mathcal{B}[B^0_s\to J/\psi\,K^+K^-] = (1.01\pm 0.09\left(\mathrm{stat}\right)
\pm 0.10\left(\mathrm{syst}\right)\pm 0.18\left(f_s\right))\times 10^{-3}$,
where the last systematic error is due to the branching fraction of
$b\bar{b}\to B^{(*)}_s B^{(*)}_s$. The branching fraction ratio is found to be
$\mathcal{B}[B^0_s\to J/\psi\,f'_2(1525)]/\mathcal{B}[B^0_s\to
J/\psi\,\phi(1020)]=(21.5\pm 4.9\left(\mathrm{stat}\right)
\pm2.6\left(\mathrm{syst}\right))%$. All results are based on a 121.4 fb$^{-1}$
data sample collected at the $\Upsilon(5S)$ resonance by the Belle experiment
at the KEKB asymmetric-energy $e^+e^-$ collider.


title:
Small Deviations for Time-Changed Brownian Motions and Applications to
  Second-Order Chaos

abstract:
  We prove strong small deviations results for Brownian motion under
independent time-changes satisfying their own asymptotic criteria. We then
apply these results to certain stochastic integrals which are elements of
second-order homogeneous chaos.


title: A Report on Realizability

abstract:
  Besides recalling the basic definitions of Realizability Lattices, Abstract
Krivine Structures, Ordered Combinatory Algebras and Tripos and reviewing its
relationships, we propose a new foundational framework for realizability.
Motivated by Streicher's paper "Krivine's Classical Realizability from a
Categorical Perspective" [9], we define the concept of Krivine's Ordered
Combinatory Algebras (kOKA) as a common platform that is strong enough to do
both: categorical and computational semantics. The OCAs produced by Streicher
from AKSs in [9] are particular cases of kOKAs.


title:
Feedback Communication Systems with Limitations on Incremental
  Redundancy

abstract:
  This paper explores feedback systems using incremental redundancy (IR) with
noiseless transmitter confirmation (NTC). For IR-NTC systems based on {\em
finite-length} codes (with blocklength $N$) and decoding attempts only at {\em
certain specified decoding times}, this paper presents the asymptotic expansion
achieved by random coding, provides rate-compatible sphere-packing (RCSP)
performance approximations, and presents simulation results of tail-biting
convolutional codes.
  The information-theoretic analysis shows that values of $N$ relatively close
to the expected latency yield the same random-coding achievability expansion as
with $N = \infty$. However, the penalty introduced in the expansion by limiting
decoding times is linear in the interval between decoding times. For binary
symmetric channels, the RCSP approximation provides an efficiently-computed
approximation of performance that shows excellent agreement with a family of
rate-compatible, tail-biting convolutional codes in the short-latency regime.
For the additive white Gaussian noise channel, bounded-distance decoding
simplifies the computation of the marginal RCSP approximation and produces
similar results as analysis based on maximum-likelihood decoding for latencies
greater than 200. The efficiency of the marginal RCSP approximation facilitates
optimization of the lengths of incremental transmissions when the number of
incremental transmissions is constrained to be small or the length of the
incremental transmissions is constrained to be uniform after the first
transmission. Finally, an RCSP-based decoding error trajectory is introduced
that provides target error rates for the design of rate-compatible code
families for use in feedback communication systems.


title:
Properties of Star Clusters - I: Automatic Distance and Extinction
  Estimates

abstract:
  Determining star cluster distances is essential to analyse their properties
and distribution in the Galaxy. In particular it is desirable to have a
reliable, purely photometric distance estimation method for large samples of
newly discovered cluster candidates e.g. from 2MASS, UKIDSS-GPS and VISTA-VVV.
Here, we establish an automatic method to estimate distances and reddening from
NIR photometry alone, without the use of isochrone fitting. We employ a
decontamination procedure of JHK photometry to determine the density of stars
foreground to clusters and a galactic model to estimate distances. We then
calibrate the method using clusters with known properties. This allows us to
establish distance estimates with better than 40% accuracy.
  We apply our method to determine the extinction and distance values to 378
known open clusters and 397 cluster candidates from the list of Froebrich,
Scholz and Raftery (2003). We find that the sample is biased towards clusters
of a distance of approximately 3kpc, with typical distances between 2 and 6kpc.
Using the cluster distances and extinction values, we investigate how the
average extinction per kiloparsec distance changes as a function of Galactic
longitude. We find a systematic dependence that can be approximated by
A_H(l)[mag/kpc]=0.10+0.001*|l-180deg|/deg for regions more than 60deg from the
Galactic Centre.


title: Long-range interactions in randomly driven granular fluids

abstract:
  We study the long-range spatial correlations in the nonequilibrium steady
state of a randomly driven granular fluid with the emphasis on obtaining the
explicit form of the static structure factors. The presence of immobile
particles immersed in such a fluidized bed of fine particles leads to the
confinement of the fluctuation spectrum of the hydrodynamic fields, which
results in effective long-range interactions between the intruders. The
analytical predictions are in agreement with the results of discrete element
method simulations. By changing the shape and orientation of the intruders, we
address how the effective force is affected by small changes in the boundary
conditions.


title:
Dimensional crossover of the electronic structure in LaNiO3 ultrathin
  films: Orbital reconstruction, Fermi surface nesting, and the origin of the
  metal-insulator transition

abstract:
  Dimensionality control in the LaNiO3 (LNO) heterostructure has attracted
attention due to its two-dimensional (2D) electronic structure was predicted to
have an orbital ordered insulating ground state, analogous to that of the
parent compound of high-Tc cuprate superconductors [P. Hansmann et al., Phys.
Rev. Lett. 103, 016401 (2009)]. Here, we directly measured the electronic
structure of LNO ultrathin films using in situ angle-resolved photoemission
spectroscopy (ARPES). We recognized the dimensional crossover of the electronic
structure around 3-unit cells (UC)-thick LNO film and observed the orbital
reconstruction. However, complete orbital ordering was not achieved. Instead,
we observed that the Fermi surface nesting effect became strong in the 2D LNO
ultrathin film. These results indicated that the orbital reconstruction should
be described by taking into account the strong nesting effect to search for the
novel phenomena, such as superconductivity in 2D LNO heterostructure. In
addition, the APRES spectra showed that the Fermi surface existed down to a
1-UC-thick film, which showed insulating behavior in transport measurements. We
suggested that the metal-insulator transition in the transport properties may
originate from Anderson localization.


title: A light composite scalar in eight-flavor QCD on the lattice

abstract:
  In search for a composite Higgs boson (techni-dilaton) in the walking
technicolor, we present our preliminary results on the first observation of a
light flavor-singlet scalar in a candidate theory for the walking technicolor,
the Nf=8 QCD, which was found in our previous paper to have spontaneous chiral
symmetry breaking together with remnants of the conformality. Based on
simulations with the HISQ-type action on several lattice sizes with various
fermion masses, we find evidence of a flavor-singlet scalar meson with mass
comparable to that of the Nambu-Goldstone pion in both the small fermion-mass
region, where chiral perturbation theory works, and the intermediate
fermion-mass region where the hyperscaling relation holds. We further discuss
its chiral limit extrapolation in comparison with other states studied in our
previous paper: the scalar has a mass much smaller than that of the vector
meson, which is compared to the Nambu-Goldstone pion having a vanishing mass in
that limit.


title:
Bell violation with entangled photons, free of the coincidence-time
  loophole

abstract:
  In a local realist world view, physical properties are defined prior to and
independent of measurement, and no physical influence can propagate faster than
the speed of light. Proper experimental violation of a Bell inequality would
show that the world cannot be described within local realism. Such experiments
usually require additional assumptions that make them vulnerable to a number of
"loopholes." A recent experiment [Giustina et al, Nature, 2013] violated a Bell
inequality without being vulnerable to the detection (or fair-sampling)
loophole, therefore not needing the fair-sampling assumption. Here we analyze
the more subtle coincidence-time loophole, and propose and prove the validity
of two different methods of data analysis that avoid it. Both methods are
general and can be used both for pulsed and continuous-wave experiments. We
apply them to demonstrate that the experiment mentioned above violates local
realism without being vulnerable to the coincidence-time loophole, therefore
not needing the corresponding fair-coincidence assumption.


title: Projective Structures in Loop Quantum Cosmology

abstract:
  Projective structures have successfully been used for the construction of
measures in the framework of loop quantum gravity. In the present paper, we
establish such structures for the configuration space $\mathbb{R}\sqcup
\mathbb{R}_{\mathbb{Bohr}}$, recently introduced in the context of homogeneous
isotropic loop quantum cosmology. In contrast to the traditional space
$\mathbb{R}_{\mathbb{Bohr}}$, the first one is canonically embedded into the
quantum configuration space of the full theory. In particular, for the
embedding of states into a corresponding symmetric sector of loop quantum
gravity, this is advantageous. However, in contrast to the traditional space,
there is no Haar measure on $\mathbb{R}\sqcup \mathbb{R}_{\mathbb{Bohr}}$
defining a canonical kinematical $L^2$-Hilbert space on which operators can be
represented. The introduced projective structures allow to construct a family
of natural measures on $\mathbb{R}\sqcup \mathbb{R}_{\mathbb{Bohr}}$ whose
corresponding $L^2$-Hilbert spaces we finally investigate.


title:
A Case-Study on Teaching Undergraduate-Level Software Engineering Course
  Using Inverted-Classroom, Large-Group, Real-Client and Studio-Based
  Instruction Model

abstract:
  We present a case-study on teaching an undergraduate level course on Software
Engineering (second year and fifth semester of bachelors program in Computer
Science) at a State University (New Delhi, India) using a novel teaching
instruction model. Our approach has four main elements: inverted or flipped
classroom, studio-based learning, real-client projects and deployment, large
team and peer evaluation. We present our motivation and approach, challenges
encountered, pedagogical benefits, findings (both positive and negative) and
recommendations. Our motivation was to teach Software Engineering using an
active learning (significantly increasing the engagement and collaboration with
the Instructor and other students in the class), team-work, balance between
theory and practice, imparting both technical and managerial skills encountered
in real-world and problem-based learning (through an intensive semester-long
project). We conduct a detailed survey (anonymous, optional and online) and
present the results of student responses. Survey results reveal that for nearly
every students (class size: 89) the instruction model was new, interesting and
had a positive impact on the motivation in addition to meeting the learning
outcome of the course.


title: On the quantization of the nonintegrable phase in electrodynamics

abstract:
  Using the fact that the nonintegrable phase factor can reformulate the gauge
theory in terms of path dependent vector potentials, the quantization condition
for the nonintegrable phase is investigated. It is shown that the
path-dependent formalism can provide compact description of the flux
quantization and the charge quantization at the existence of a magnetic
monopole. Moreover, the path-dependent formalism gives suggestions for
searching of the quantized flux in different configurations and for other
possible reasons of the charge quantization. As an example, the developed
formalism is employed for a (1+1) dimensional world, showing the relationship
between the fundamental unit of the charge and the fine structure constant for
this world.


title:
The plasma oscillations in a two-dimensional electron-hole liquid under
  influence Rashba spin-orbit coupling

abstract:
  The plasma oscillations of the two-dimensional electron-hole system in the
presence of a Rashba spin-orbit coupling are studied. Only the intra-Landau
level excitations are taken into account when the electrons and holes are
situated on their lowest Landau levels, the filling factor $v^{2}$ being less
than 1. The ground state of the two-dimensional electron-hole system is
supposed to be the electron-hole liquid. The dispersion relations for the
optical and acoustical plasmon modes were obtained. The acoustical plasmon
branch has a linear dispersion law in the range of small wave vectors and
monotonically increases with saturation at higher values of wave vectors. The
optical plasmon branch has a quadratic dependence in the range of long
wavelength and a monotonic increasing with saturation as in the case of
acoustical branch.


title: A Polynomial Translation of pi-calculus FCPs to Safe Petri Nets

abstract:
  We develop a polynomial translation from finite control pi-calculus processes
to safe low-level Petri nets. To our knowledge, this is the first such
translation. It is natural in that there is a close correspondence between the
control flows, enjoys a bisimulation result, and is suitable for practical
model checking.


title: A General, Tractable and Accurate Model for a Cascade of Caches

abstract:
  Performance evaluation of caching systems is an old and widely investigated
research topic. The research community is once again actively working on this
topic because the Internet is evolving towards new transfer modes, which
envisage to cache both contents and instructions within the network. In
particular, there is interest in characterizing multi-cache systems, in which
requests not satisfied by a cache are forwarded to other caches.
  In this field, this paper contributes as follows. First, we devise a simple
but accurate approximate analysis for caches fed by general "renewal" traffic
patterns. Second, we characterize and model the traffic statistics for the
output (miss) stream. Third, we show in the simple example case of tandem
caches how the resulting output stream model can be conveniently exploited to
analyze the performance of subsequent cache stages. The main novelty of our
work stems in the ability to handle traffic patterns beyond the traditional
independent reference model, thus permitting simple assessment of cascade of
caches as well as improved understanding of the phenomena involved in cache
hierarchies.


title:
Understanding Evolutionary Potential in Virtual CPU Instruction Set
  Architectures

abstract:
  We investigate fundamental decisions in the design of instruction set
architectures for linear genetic programs that are used as both model systems
in evolutionary biology and underlying solution representations in evolutionary
computation. We subjected digital organisms with each tested architecture to
seven different computational environments designed to present a range of
evolutionary challenges. Our goal was to engineer a general purpose
architecture that would be effective under a broad range of evolutionary
conditions. We evaluated six different types of architectural features for the
virtual CPUs: (1) genetic flexibility: we allowed digital organisms to more
precisely modify the function of genetic instructions, (2) memory: we provided
an increased number of registers in the virtual CPUs, (3) decoupled sensors and
actuators: we separated input and output operations to enable greater control
over data flow. We also tested a variety of methods to regulate expression: (4)
explicit labels that allow programs to dynamically refer to specific genome
positions, (5) position-relative search instructions, and (6) multiple new flow
control instructions, including conditionals and jumps. Each of these features
also adds complication to the instruction set and risks slowing evolution due
to epistatic interactions. Two features (multiple argument specification and
separated I/O) demonstrated substantial improvements int the majority of test
environments. Some of the remaining tested modifications were detrimental,
thought most exhibit no systematic effects on evolutionary potential,
highlighting the robustness of digital evolution. Combined, these observations
enhance our understanding of how instruction architecture impacts evolutionary
potential, enabling the creation of architectures that support more rapid
evolution of complex solutions to a broad range of challenges.


title: Transience and multifractal analysis

abstract:
  We study dimension theory for dissipative dynamical systems, proving a
conditional variational principle for the quotients of Birkhoff averages
restricted to the recurrent part of the system. On the other hand, we show that
when the whole system is considered (and not just its recurrent part) the
conditional variational principle does not necessarily hold. Moreover, we
exhibit the first example of a topologically transitive map having
discontinuous Lyapunov spectrum. The mechanism producing all these pathological
features on the multifractal spectra is transience, that is, the non-recurrent
part of the dynamics.


title:
The Discovery of the Higgs Boson with the CMS Detector and its
  Implications for Supersymmetry and Cosmology

abstract:
  The discovery of the long awaited Higgs boson is described using data from
the CMS detector at the LHC. In the SM the masses of fermions and the heavy
gauge bosons are generated by the interactions with the Higgs field, so all
couplings are related to the observed masses. Indeed, all observed couplings
are consistent with the predictions from the Higgs mechanism, both to vector
bosons and fermions implying that masses are indeed consistent of being
generated by the interactions with the Higgs field. However, on a cosmological
scale the mass of the universe seems not to be related to the Higgs field: the
baryonic mass originates from the binding energy of the quarks inside the
nuclei and dark matter is not even predicted in the SM, so the origin of its
mass is unknown. The dominant energy component in the universe, the dark
energy, yields an accelerated expansion of the universe, so its repulsive
gravity most likely originates from a kind of vacuum energy. The Higgs field
would be the prime candidate for this, if the energy density would not be many
orders of magnitude too high, as will be calculated. The Higgs mass is found to
be 125.7$\pm$0.3(stat.)$\pm$0.3(syst.) GeV, which is below 130 GeV, i.e. in the
range predicted by supersymmetry. This may be the strongest hint for
supersymmetry in spite of the fact that the predicted supersymmetric particles
have not been discovered so far.


title:
A note on the equivariant formal group law of the equivariant complex
  cobordism ring

abstract:
  For a finite abelian group $G$, we compute the $G$-equivariant formal group
law corresponding to the $G$-equivariant complex cobordism spectrum with its
canonical complex orientation.


title:
Leidenfrost temperature increase for impacting droplets on
  carbon-nanofiber surfaces

abstract:
  Droplets impacting on a superheated surface can either exhibit a contact
boiling regime, in which they make direct contact with the surface and boil
violently, or a film boiling regime, in which they remain separated from the
surface by their own vapor. The transition from the contact to the film boiling
regime depends not only on the temperature of the surface and kinetic energy of
the droplet, but also on the size of the structures fabricated on the surface.
Here we experimentally show that surfaces covered with carbon-nanofibers delay
the transition to film boiling to much higher temperature compared to smooth
surfaces. We present physical arguments showing that, because of the small
scale of the carbon fibers, they are cooled by the vapor flow just before the
liquid impact, thus permitting contact boiling up to much higher temperatures
than on smooth surfaces. We also show that, as long as the impact is in the
film boiling regime, the spreading factor of impacting droplets follows the
same $\We^{3/10}$ scaling (with $\We$ the Weber number) found for smooth
surfaces, which is caused by the vapor flow underneath the droplet.


title: A Pedestrian Approach to the Measurement Problem in Quantum Mechanics

abstract:
  The quantum theory of measurement has been a matter of debate for over eighty
years. Most of the discussion has focused on theoretical issues with the
consequence that operational prescriptions, which are integral to experimental
physics, have been largely ignored. This has undoubtedly exacerbated attempts
to find a solution to the "measurement problem". In this paper, we fully
embrace the ensemble interpretation of quantum mechanics that obviates the need
to entertain reduction of the state vector, one of the primary dilemmas of the
measurement problem. The other major aspect of the measurement problem, the
necessity of describing measurements in terms of classical concepts, remains.
However, we argue that the ultimate interface with experiments is described by
operational prescriptions and not in terms of the concepts of classical theory.
The pedestrian approach presented here suggests that the measurement problem
is, in some sense, ill-posed and might never be resolved. This state of affairs
is, in part, the result of searching for a theoretical answer to what is
fundamentally an experimental question. This point of view is tenable so long
as one is willing to view physical theories as providing models of nature
rather than complete descriptions of reality. Among other things, these
considerations lead us to suggest that the Copenhagen interpretation's
insistence on the classicality of the measurement apparatus should be replaced
by the requirement that a measurement, which is specified operationally, should
simply be of sufficient precision.


title:
On counterexamples to a conjecture of Wills and Ehrhart polynomials
  whose roots have equal real parts

abstract:
  As a discrete analog to Minkowski's theorem on convex bodies, Wills
conjectured that the Ehrhart coefficients of a centrally symmetric lattice
polytope with exactly one interior lattice point are maximized by those of the
cube of side length two. We discuss several counterexamples to this conjecture
and, on the positive side, we identify a family of lattice polytopes that
fulfill the claimed inequalities. This family is related to the recently
introduced class of $l$-reflexive polytopes.


title: $g$-factor anisotropy in nanowire-based InAs quantum dots

abstract:
  The determination and control of the electron $g$-factor in semiconductor
quantum dots (QDs) are fundamental prerequisites in modern concepts of
spintronics and spin-based quantum computation. We study the dependence of the
$g$-factor on the orientation of an external magnetic field in quantum dots
(QDs) formed between two metallic contacts on stacking fault free InAs
nanowires. We extract the $g$-factor from the splitting of Kondo resonances and
find that it varies continuously in the range between $|g^*| = 5$ and 15.