title: Dynamic AdS/QCD and the Spectrum of Walking Gauge Theories

abstract:
  We present a simple AdS/QCD model in which the formation of the chiral
condensate is dynamically determined. The gauge dynamics is input through the
running of the quark bilinear's anomalous dimension, gamma. The condensate
provides a dynamically generated infra-red wall in the computation of mesonic
bound state masses and decay constants. As an example, we use the model, with
perturbative computations of the running of gamma, to study SU(3) gauge theory
with a continuous number of quark flavours, Nf. We follow the behaviour of the
spectrum as we approach the conformal window through a walking gauge theory
regime. We show such walking theories display a BKT phase transition, with
Miransky scaling, as one approaches the edge of the conformal window at the
critical value of Nf. We show that these walking theories possess an enhanced
quark condensate, a light Higgs like excitation and argue that the
non-perturbative contribution to S falls to zero. We also study the deformation
of the BKT transition when the quarks have a current mass which may be of use
for understanding lattice simulations of walking theories.


title: Small Depth Proof Systems

abstract:
  A proof system for a language L is a function f such that Range(f) is exactly
L. In this paper, we look at proofsystems from a circuit complexity point of
view and study proof systems that are computationally very restricted. The
restriction we study is: they can be computed by bounded fanin circuits of
constant depth (NC^0), or of O(log log n) depth but with O(1) alternations
(polylog AC^0). Each output bit depends on very few input bits; thus such proof
systems correspond to a kind of local error-correction on a theorem-proof pair.
  We identify exactly how much power we need for proof systems to capture all
regular languages. We show that all regular language have polylog AC^0 proof
systems, and from a previous result (Beyersdorff et al, MFCS 2011, where NC^0
proof systems were first introduced), this is tight. Our technique also shows
that MAJ has polylog AC^0 proof system. We explore the question of whether TAUT
has NC^0 proof systems. Addressing this question about 2TAUT, and since 2TAUT
is closely related to reachability in graphs, we ask the same question about
Reachability. We show that both Undirected Reachability and Directed
UnReachability have NC^0 proof systems, but Directed Reachability is still
open.
  In the context of how much power is needed for proof systems for languages in
NP, we observe that proof systems for a good fraction of languages in NP do not
need the full power of AC^0; they have SAC^0 or coSAC^0 proof systems.


title:
Limits on Primordial Black Hole evaporation with the H.E.S.S. array of
  Cherenkov telescopes

abstract:
  Data collected by the H.E.S.S. array between 2004 and 2012 have been used to
search for photon bursts from primordial black hole explosions. Bursts were
searched for in a 30 second time-window. The duration of the search window has
been optimized to increase the burst signal while keeping the statistical
background low. No evidence for a burst signal was found. Preliminary upper
limits on the local rate of PBH explosions of $1.4\times 10^{4} {pc}^{-3}
{yr}^{-1}$ have been obtained, which improve previously published limits by
almost an order of magnitude


title: Extremely Metal-Poor Galaxies: The HI Content

abstract:
  Extremely metal-poor (XMP) galaxies are chemically, and possibly dynamically,
primordial objects in the local Universe. Our objective is to characterize the
HI content of the XMP galaxies as a class, using as a reference the list of 140
known local XMPs compiled by Morales-Luis et al. (2011). We have observed 29
XMPs, which had not been observed before at 21 cm, using the Effelsberg radio
telescope. This information was complemented with HI data published in
literature for a further 53 XMPs. In addition, optical data from the literature
provided morphologies, stellar masses, star-formation rates and metallicities.
Effelsberg HI integrated flux densities are between 1 and 15 Jy km/s, while
line widths are between 20 and 120 km/s. HI integrated flux densities and line
widths from literature are in the range 0.1 - 200 Jy km/s and 15 - 150 km/s,
respectively. Of the 10 new Effelsberg detections, two sources show an
asymmetric double-horn profile, while the remaining sources show either
asymmetric (7 sources) or symmetric (1 source) single-peak 21 cm line profiles.
An asymmetry in the HI line profile is systematically accompanied by an
asymmetry in the optical morphology. Typically, the g-band stellar
mass-to-light ratios are ~0.1, whereas the HI gas mass-to-light ratios may be
up to 2 orders of magnitude larger. Moreover, HI gas-to-stellar mass ratios
fall typically between 10 and 20, denoting that XMPs are extremely gas-rich. We
find an anti-correlation between the HI gas mass-to-light ratio and the
luminosity, whereby fainter XMPs are more gas-rich than brighter XMPs,
suggesting that brighter sources have converted a larger fraction of their HI
gas into stars. The dynamical masses inferred from the HI line widths imply
that the stellar mass does not exceed 5% of the dynamical mass, while the
\ion{H}{i} mass constitutes between 20 and 60% of the dynamical mass.
(abridged)


title:
Carleson measures, Riemann-Stieltjes and multiplication operators on a
  general family of function spaces

abstract:
  Let $\mu$ be a nonnegative Borel measure on the unit disk of the complex
plane. We characterize those measures $\mu$ such that the general family of
spaces of analytic functions, $F(p,q,s)$, which contain many classical function
spaces, including the Bloch space, $BMOA$ and the $Q_s$ spaces, are embedded
boundedly or compactly into the tent-type spaces $T^{\infty}_{p,s}(\mu)$. The
results are applied to characterize boundedness and compactness of
Riemann-Stieltjes operators and multiplication operators on $F(p,q,s)$.


title: Oriented chromatic number of Halin graphs

abstract:
  Oriented chromatic number of an oriented graph $G$ is the minimum order of an
oriented graph $H$ such that $G$ admits a homomorphism to $H$. The oriented
chromatic number of an unoriented graph $G$ is the maximal chromatic number
over all possible orientations of $G$. In this paper, we prove that every Halin
graph has oriented chromatic number at most 8, improving a previous bound by
Hosseini Dolama and Sopena, and confirming the conjecture given by Vignal.


title: Some reflections on why Lobachevsky geometry was recognized

abstract:
  Sometimes arguments that preceded recognition of non-Euclidean (Lobachevsky)
geometry are represented in a simplified `black and white' pattern:
`conservators made nonsense of genius'. Although there is something in this
point of view, the real situation was more complicated, and up to some time
there were decent grounds for not recognizing the importance of the new theory.
We try to explain why non-Euclidean geometry was not recognized at once. We
show how important for such recognition was discovery of applications of the
new geometry.
  These reflections have practical importance for modern mathematics because
they are related to the question: how a mathematician should choose directions
for research?


title: Rigidity of causal maps

abstract:
  We show that order-invariant injective maps on the noncompactly causal
symmetric space $SO_0 (1,n)/SO_0 (1,n-1)$ belong to $O(1,n)^+$.


title:
A connection between the Uncertainty Principles on the real line and on
  the circle

abstract:
  The purpose of this short note is to exhibit a new connection between the
Heisenberg Uncertainty Principle on the line and the Breitenberger Uncertainty
Principle on the circle, by considering the commutator of the multiplication
and difference operators on Bernstein functions


title:
The influence of van der Waals forces on droplet morphological
  transitions and solvation forces in nanochannels

abstract:
  The morphological phase transition between a sessile and lenticular shapes of
a droplet placed in a nanochannel is observed upon increasing the droplet
volume. The phase diagram for this system is discussed within the macro- and
mesoscopic approaches. On the mesoscopic level, the van der Waals forces are
taken into account via the effective interface potential acting between the
channel walls and the droplet. We discuss the contact angle dependence on the
droplet volume and the distance between the walls; this angle turns out to be
smaller than the macroscopic Young's angle. The droplet presence induces the
solvation force acting between the channel walls. It can be both attractive and
repulsive, depending on the width of the channel.


title: Functional framework for representing and transforming quantum channels

abstract:
  We develop a framework which aims to simplify the analysis of quantum states
and quantum operations by harnessing the potential of function programming
paradigm. We show that the introduced framework allows a seamless manipulation
of quantum channels, in particular to convert between different representations
of quantum channels, and thus that the use of functional programming concepts
facilitates the manipulation of abstract objects used in the language of
quantum theory.
  For the purpose of our presentation we will use Mathematica computer algebra
system. This choice is motivated twofold. First, it offers a rich programming
language based on the functional paradigm. Second, this programming language is
combined with powerful symbolic and numeric manipulation capabilities.


title: Twistor deformation of rank one local systems

abstract:
  We determine the twistor deformation of rank one local systems on compact
Kaehler manifolds which correspond to smooth twistor modules of rank one in the
sense of C. Sabbah. Our proof is rather elementary, and uses a natural
description of the moduli space of rank one local systems together with the
canonical morphism to the Picard variety. The corresponding assertion for
smooth twistor modules of rank one follows from the theory of C. Simpson and
has been known to the specialists, according to T. Mochizuki.


title:
Microscopic theory for the phase separation of self-propelled repulsive
  disks

abstract:
  Motivated by recent experiments on colloidal suspensions, we study
analytically and numerically a microscopic model for self-propelled particles
lacking alignment interactions. In this model, even for purely repulsive
interactions, a dynamical instability leading to phase separation has been
reported. Starting from the many-body Smoluchowski equation, we develop a
mean-field description based on a novel closure scheme and derive the effective
hydrodynamic equations. We demonstrate that the microscopic origin of the
instability is a force imbalance due to an anisotropic pair distribution
leading to self-trapping. The phase diagram can be understood in terms of two
quantities: a minimal drive and the force imbalance. At sufficiently high
propulsion speeds there is a reentrance into the disordered fluid.


title: Thermal right-handed neutrino production rate in the relativistic regime

abstract:
  The production rate of right-handed neutrinos from a Standard Model plasma at
a temperature above a hundred GeV is evaluated up to NLO in Standard Model
couplings. The results apply in the so-called relativistic regime, referring
parametrically to a mass M ~ pi T, generalizing thereby previous NLO results
which only apply in the non-relativistic regime M >> pi T. The non-relativistic
expansion is observed to converge for M > 15 T, but the smallness of any loop
corrections allows it to be used in practice already for M > 4 T. In the latter
regime any non-covariant dependence of the differential rate on the spatial
momentum is shown to be mild. The loop expansion breaks down in the
ultrarelativistic regime M << pi T, but after a simple mass resummation it
nevertheless extrapolates reasonably well towards a result obtained previously
through complete LPM resummation, apparently confirming a strong enhancement of
the rate at high temperatures (which facilitates chemical equilibration). When
combined with other ingredients the results may help to improve upon the
accuracy of leptogenesis computations operating above the electroweak scale.


title: Hard Asymptotic Sets for One-Dimensional Cellular Automata

abstract:
  We prove that the (language of the) asymptotic set (and the nonwandering set)
of a one-dimensional cellular automaton can be $\SIGMA^1_1$-hard. We do not go
into much detail, since the constructions are relatively standard.


title:
Cosmology with hybrid expansion law: scalar field reconstruction of
  cosmic history and observational constraints

abstract:
  In this paper, we consider a simple form of expansion history of Universe
referred to as the hybrid expansion law - a product of power-law and
exponential type of functions. The ansatz by construction mimics the power-law
and de Sitter cosmologies as special cases but also provides an elegant
description of the transition from deceleration to cosmic acceleration. We
point out the Brans-Dicke realization of the cosmic history under
consideration. We construct potentials for quintessence, phantom and tachyon
fields, which can give rise to the hybrid expansion law in general relativity.
We investigate observational constraints on the model with hybrid expansion law
applied to late time acceleration as well as to early universe a la
nucleosynthesis.


title:
Refined analytic torsion as analytic function on the representation
  variety and applications

abstract:
  We prove that refined analytic torsion on a manifold with boundary is an
analytic section of the determinant line bundle over the representation
variety. As a fundamental application we establish a gluing formula for refined
analytic torsion on connected components of the complex representation space
which contain a unitary point. Finally we provide a new proof of Bruening-Ma
gluing formula for the Ray-Singer torsion associated to a non-Hermitian
connection. Our proof is quite different from the one given by Bruening and Ma
and uses a temporal gauge transformation.


title:
Origin of electronic dimers in the spin-density wave phase of Fe-based
  superconductors

abstract:
  We investigate the emergent impurity-induced states arising from point-like
scatterers in the spin-density wave phase of iron-based superconductors within
a microscopic five-band model. Independent of the details of the band-structure
and disorder potential, it is shown how stable magnetic (pi,pi) unidirectional
nematogens are formed locally by the impurities. Interestingly, these
nematogens exhibit a dimer structure in the electronic density, are directed
along the antiferromagnetic a-axis, and have typical lengths of order 10
lattice constants in excellent agreement with recent scanning tunnelling
experiments. These electronic dimers provide a natural explanation of the
dopant-induced transport anisotropy found e.g. in the 122 iron pnictides.


title:
The analytic torsion and its asymptotic behaviour for sequences of
  hyperbolic manifolds of finite volume

abstract:
  In this paper we study the regularized analytic torsion of finite volume
hyperbolic manifolds. We consider sequences of coverings $X_i$ of a fixed
hyperbolic orbifold $X_0$. Our main result is that for certain sequences of
coverings and strongly acyclic flat bundles, the analytic torsion divided by
the index of the covering, converges to the $L^2$-torsion. Our results apply to
certain sequences of arithmetic groups, in particular to sequences of principal
congruence subgroups of $\SO^0(d,1)(\Z)$ and to sequences of principal
congruence subgroups or Hecke subgroups of Bianchi groups.


title:
Tectonic "short circuit" of sub-horizontal fluid-saturated bodies as a
  possible mechanism of the earthquake

abstract:
  An alternative earthquake mechanism is proposed. The traditional stress
mechanism of fracture formation assigned a support role. As a proximate cause
of the earthquake the destruction of the roofs of sub-horizontal
fluid-saturated bodies (SHFB) is considered. This collapse may occur due to
redistribution of fluid pressure within the system of SHFB connected by cracks
(tectonic or other nature). It can cause both shifts of rock blocks
contributing to seismic shocks and various effects characteristic of foreshocks
and aftershocks.


title: Evolution algebra of a "chicken" population

abstract:
  We consider an evolution algebra which corresponds to a bisexual population
with a set of females partitioned into finitely many different types and the
males having only one type. We study basic properties of the algebra. This
algebra is commutative (and hence flexible), not associative and not
necessarily power associative, in general. Moreover it is not unital. A
condition is found on the structural constants of the algebra under which the
algebra is associative, alternative, power associative, nilpotent, satisfies
Jacobi and Jordan identities. In a general case, we describe the full set of
idempotent elements and the full set of absolute nilpotent elements. The set of
all operators of left (right) multiplications is described. Under some
conditions on the structural constants it is proved that the corresponding
algebra is centroidal. Moreover the classification of 2-dimensional and some
3-dimensional algebras are obtained.


title:
The Waveform Digitiser of the Double Chooz Experiment: Performance and
  Quantisation Effects on PhotoMultiplier Tube Signals

abstract:
  We present the waveform digitiser used in the Double Chooz experiment. We
describe the hardware and the custom-built firmware specifically developed for
the experiment. The performance of the device is tested with regards to
digitising low light level signals from photomultiplier tubes and measuring
pulse charge. This highlights the role of quantisation effects and leads to
some general recommendations on the design and use of waveform digitisers.


title: Sagittarius dwarf spheroidal galaxy observed by H.E.S.S

abstract:
  Dwarf spheroidal galaxies are characterized by a large measured mass-to-light
ratio and are not expected to be the site of high-luminosity non-thermal
high-energy gamma-ray emissions. Therefore they are among the most promising
candidates for indirect searches of dark matter particle annihilation signals
in gamma rays. The Sagittarius dwarf spheroidal galaxy has been regularly
observed by the High Energy Stereoscopic System (H.E.S.S.) of Cherenkov
telescopes for more than 90 hours, searching for TeV gamma-ray emission from
annihilation of dark matter particles. In absence of a significant signal, new
constraints on the annihilation crosssection of the dark matter particles
applicable for Majorana Weakly Interacting Massive Particles (WIMPs) are
derived.


title: A refinement of the Hodge stratification for connected reductive groups

abstract:
  For connected reductive groups G over a finite extension F of Q_p and L the
maximal unramified extension of F we study the sets H_{\mu, N}(G) of elements b
in G(L) with given Hodge points of (b\sigma), (b\sigma)^2, ..., (b\sigma)^N. We
explain the relationship to stratifications of some moduli scheme of abelian
varieties defined by Goren and Oort respectively Andreatta and Goren. We show
that for sufficiently large N the Newton point is constant on the sets H_{\mu,
N}(G) and compute such N for certain classes of groups.


title: New Hamiltonian analysis of Regge Teitelboim minisuperspace cosmology

abstract:
  A new Hamiltonian formulation of the minisuperspace cosmology following from
the geodetic brane gravity model introduced by Regge and Teitelboim is
presented. The model is considered in the framework of higher derivative
theories which facilitates Hamiltonian formulation. The analysis is done using
the equivalent first order approach. The constraint algebra is shown to realize
a truncated Virasoro algebra. The gauge generator containing the exact number
of gauge parameters is constructed. Equivalence between the gauge and
reparametrization symmetries has been demonstrated. Complete gauge fixed
computations have been provided and formal quantization is indicated.


title:
Solution of the alpha-potential mystery in the gamma-process and its
  impact on the Nd/Sm ratio in meteorites

abstract:
  The 146Sm/144Sm ratio in the early solar system has been constrained by Nd/Sm
isotope ratios in meteoritic material. Predictions of 146Sm and 144Sm
production in the gamma-process in massive stars are at odds with these
constraints and this is partly due to deficiences in the prediction of the
reaction rates involved. The production ratio depends almost exclusively on the
(gamma,n)/(gamma,alpha) branching at 148Gd. A measurement of
144Sm(alpha,gamma)148Gd at low energy had discovered considerable discrepancies
between cross section predictions and the data. Although this reaction cross
section mainly depends on the optical alpha+nucleus potential, no global
optical potential has yet been found which can consistently describe the
results of this and similar alpha-induced reactions at the low energies
encountered in astrophysical environments. The untypically large deviation in
144Sm(alpha,gamma) and the unusual energy dependence can be explained, however,
by low-energy Coulomb excitation which is competing with compound nucleus
formation at very low energies. Considering this additional reaction channel,
the cross sections can be described with the usual optical potential
variations, compatible with findings for (n,alpha) reactions in this mass
range. Low-energy (alpha,gamma) and (alpha,n) data on other nuclei can also be
consistently explained in this way. Since Coulomb excitation does not affect
alpha-emission, the 148Gd(gamma,alpha) rate is much higher than previously
assumed. This leads to small 146Sm/144Sm stellar production ratios, in even
more pronounced conflict with the meteorite data.


title:
Theoretical estimation of metabolic network robustness against multiple
  reaction knockouts using branching process approximation

abstract:
  In our previous study, we showed that the branching process approximation is
useful for estimating metabolic robustness, measured using the impact degree.
By applying a theory of random family forests, we here extend the branching
process approximation to consider the knockout of {\it multiple} reactions,
inspired by the importance of multiple knockouts reported by recent
computational and experimental studies. In addition, we propose a better
definition of the number of offspring of each reaction node, allowing for an
improved estimation of the impact degree distribution obtained as a result of a
single knockout. Importantly, our proposed approach is also applicable to
multiple knockouts. The comparisons between theoretical predictions and
numerical results using real-world metabolic networks demonstrate the validity
of the modeling based on random family forests for estimating the impact degree
distributions resulting from the knockout of multiple reactions.


title:
The nature of the giant diffuse non-thermal source in the A3411-A3412
  complex

abstract:
  VLA deep radio images at 1.4 GHz in total intensity and polarization reveal a
diffuse non-thermal source in the interacting clusters A3411 - A3412. Moreover
a small-size low power radio halo at the center of the merging cluster A3411 is
found. We present here new optical and X-ray data and discuss the nature and
properties of the diffuse non-thermal source. We suggest that the giant diffuse
radio source is related to the presence of a large scale filamentary structure
and to multiple mergers in the A3411-A3412 complex.


title: Millisecond extragalactic radio bursts as magnetar flares

abstract:
  Properties of the population of millisecond extragalactic radio bursts
discovered by Thornton et al. (2013) are in good correspondence with the
hypothesis that such events are related to hyperflares of magnetars, as was
proposed by us after the first observation of an extragalactic millisecond
radio burst by Lorimer et al. (2007). We also point that some of multiple
millisecond radio bursts from M31 discovered by Rubio-Herrera et al. (2013)
also can be related to weaker magnetar bursts.


title: Long range rapidity correlations in soft interaction at high energies

abstract:
  In this paper we take the next step (following the successful description of
inclusive hadron production) in describing the structure of the bias events
without the aid of Monte Carlo codes. Two new results are presented :(i) a
method for calculating the two particle correlation functions in the
BFKLPomeron calculus in zero transverse dimension;and (ii) an estimation of the
values of these correlations in a model of soft interactions. Comparison with
the multiplicity data at the LHC is given.


title: Semiclassical Strings on Curved Branes

abstract:
  We study semiclassical strings in the near horizon geometry of certain curved
branes. We investigate the rigidly rotating strings in the near horizon
geometry of NS5-branes wrapped on AdS3 x S3 and in the presence of background
NS-NS flux. We study several string solutions corresponding to giant magnon,
single spike and more general folded strings for the fundamental string in this
background. We comment that in the S-dual background the situation changes
drastically.


title: Linear-Time FPT Algorithms via Network Flow

abstract:
  In the area of parameterized complexity, to cope with NP-Hard problems, we
introduce a parameter k besides the input size n, and we aim to design
algorithms (called FPT algorithms) that run in O(f(k)n^d) time for some
function f(k) and constant d. Though FPT algorithms have been successfully
designed for many problems, typically they are not sufficiently fast because of
huge f(k) and d. In this paper, we give FPT algorithms with small f(k) and d
for many important problems including Odd Cycle Transversal and Almost 2-SAT.
More specifically, we can choose f(k) as a single exponential (4^k) and d as
one, that is, linear in the input size. To the best of our knowledge, our
algorithms achieve linear time complexity for the first time for these
problems. To obtain our algorithms for these problems, we consider a large
class of integer programs, called BIP2. Then we show that, in linear time, we
can reduce BIP2 to Vertex Cover Above LP preserving the parameter k, and we can
compute an optimal LP solution for Vertex Cover Above LP using network flow.
Then, we perform an exhaustive search by fixing half-integral values in the
optimal LP solution for Vertex Cover Above LP. A bottleneck here is that we
need to recompute an LP optimal solution after branching. To address this
issue, we exploit network flow to update the optimal LP solution in linear
time.


title: Argon Assisted Growth of Epitaxial Graphene on Cu(111)

abstract:
  The growth of graphene by catalytic decomposition of ethylene on Cu(111) in
an ultra-high vacuum system was investigated with low energy electron
diffraction, low energy electron microscopy, and atomic force microscopy.
Attempts to form a graphene overlayer using ethylene at pressures as high as 10
mTorr and substrate temperatures as high as 900 $^\circ$C resulted in almost no
graphene growth. By using an argon overpressure, the growth of epitaxial
graphene on Cu(111) was achieved. The suppression of graphene growth without
the use of an argon overpressure is attributed to Cu sublimation at elevated
temperatures. During the initial stages of growth, a random distribution of
rounded graphene islands is observed. The predominant rotational orientation of
the islands is within $\pm1^\circ$ of the Cu(111) substrate lattice.


title: High Dispersion Spectroscopy of the Superflare Star KIC6934317

abstract:
  We conducted the high-resolution spectroscopic observation with Subaru/HDS
for a G-type star (KIC6934317). We selected this star from the data of the
Kepler spacecraft. This star produces a lot of superflares, and the total
energy of the largest superflare on this star is ~10^3 times larger (~2.2*10^35
erg) than that of the most energetic flare on the Sun (~10^32 erg). The core
depth and emission flux of Ca II infrared triplet lines and Ha line show high
chromospheric activity in this star, in spite of its low lithium abundance and
the small amplitude of the rotational modulation. Using the empirical relations
between emission flux of chromospheric lines and X-ray flux, this star is
considered to show much higher coronal activity than that of the Sun. It
probably has large starspots which can store a large amount of magnetic energy
enough to give rise to superflares. We also estimated the stellar parameters,
such as effective temperature, surface gravity, metallicity, projected
rotational velocity (v sin_i), and radial velocity. KIC6934317 is then
confirmed to be an early G-type main sequence star. The value of v sin_i is
estimated to be ~1.91 km s^-1. In contrast, the rotational velocity is
calculated to be ~20 km s^-1 by using the period of the brightness variation as
the rotation period. This difference can be explained by its small inclination
angle (nearly pole-on). The small inclination angle is also supported by the
contrast between the large superflare amplitude and the small stellar
brightness variation amplitude. The lithium abundance and isochrones implies
that the age of this star is more than about a few Gyr, though a problem why
this star with such an age has a strong activity remains unsolved.


title: Power-law Spatial Dispersion from Fractional Liouville Equation

abstract:
  A microscopic model in the framework of fractional kinetics to describe
spatial dispersion of power-law type is suggested. The Liouville equation with
the Caputo fractional derivatives is used to obtain the power-law dependence of
the absolute permittivity on the wave vector. The fractional differential
equations for electrostatic potential in the media with power-law spatial
dispersion are derived. The particular solutions of these equations for the
electric potential of point charge in this media are considered.

categories: math-ph cond-mat.stat-mech math.MP physics.plasm-ph


title: The n-th smallest term for any finite sequence of real numbers

abstract:
  In this paper we find the formula that gives the n-th smallest term in a
given finite sequence of real numbers.


title: Physical properties of high-mass clumps in different stages of evolution

abstract:
  (Abridged) Aims. To investigate the first stages of the process of high-mass
star formation, we selected a sample of massive clumps previously observed with
the SEST at 1.2 mm and with the ATNF ATCA at 1.3 cm. We want to characterize
the physical conditions in such sources, and test whether their properties
depend on the evolutionary stage of the clump.
  Methods. With ATCA we observed the selected sources in the NH3(1,1) and (2,2)
transitions and in the 22 GHz H2O maser line. Ammonia lines are a good
temperature probe that allow us to accurately determine the mass and the
column-, volume-, and surface densities of the clumps. We also collected all
data available to construct the spectral energy distribution of the individual
clumps and to determine if star formation is already occurring, through
observations of its most common signposts, thus putting constraints on the
evolutionary stage of the source. We fitted the spectral energy distribution
between 1.2 mm and 70 microns with a modified black body to derive the dust
temperature and independently determine the mass.
  Results. The clumps are cold (T~10-30 K), massive (M~10^2-10^3 Mo), and dense
(n(H2)>~10^5 cm^-3) and they have high column densities (N(H2)~10^23 cm^-2).
All clumps appear to be potentially able to form high-mass stars. The most
massive clumps appear to be gravitationally unstable, if the only sources of
support against collapse are turbulence and thermal pressure, which possibly
indicates that the magnetic field is important in stabilizing them.
  Conclusions. After investigating how the average properties depend on the
evolutionary phase of the source, we find that the temperature and central
density progressively increase with time. Sources likely hosting a ZAMS star
show a steeper radial dependence of the volume density and tend to be more
compact than starless clumps.


title: On a weight system conjecturally related to $\mathfrak{sl}_2$

abstract:
  We introduce a new series $R_k$, $k=2,3,4,\dots$, of integer valued weight
systems. The value of the weight system $R_k$ on a chord diagram is a signed
number of cycles of even length $2k$ in the intersection graph of the diagram.
We show that this value depends on the intersection graph only. We check that
for small orders of the diagrams, the value of the weight system $R_k$ on a
diagram of order exactly $2k$ coincides with the coefficient of $c^k$ in the
value of the $\mathfrak{sl}_2$-weight system on the projection of the diagram
to primitive elements.


title: Approximate Nash Equilibria via Sampling

abstract:
  We prove that in a normal form n-player game with m actions for each player,
there exists an approximate Nash equilibrium where each player randomizes
uniformly among a set of O(log(m) + log(n)) pure strategies. This result
induces an $N^{\log \log N}$ algorithm for computing an approximate Nash
equilibrium in games where the number of actions is polynomial in the number of
players (m=poly(n)), where $N=nm^n$ is the size of the game (the input size).
  In addition, we establish an inverse connection between the entropy of Nash
equilibria in the game, and the time it takes to find such an approximate Nash
equilibrium using the random sampling algorithm.


title: Constraining the Higgs boson width with ZZ production at the LHC

abstract:
  We point out that existing measurements of $pp \to ZZ$ cross-section at the
LHC in a broad range of ZZ invariant masses allow one to derive a
model-independent upper bound on the Higgs boson width, thanks to strongly
enhanced off-shell Higgs contribution. Using CMS data and considering events in
the interval of ZZ invariant masses from 100 to 800 GeV, we find $\Gamma_H \le
38.8 \times \Gamma_H^{SM} \approx 163$ MeV, at the $95\%$ confidence level.
Restricting ZZ invariant masses to $M_{ZZ} \ge 300$ GeV range, we estimate that
this bound can be improved to $\Gamma_H \le 21 \times \Gamma_H^{SM} \approx 88$
MeV. Under the assumption that all couplings of the Higgs boson to Standard
Model particles scale in a universal way, our result can be translated into an
upper limit on the branching fraction of the Higgs boson decay to invisible
final states. We obtain $Br(H \to inv) < 0.84 (0.78)$, depending on the range
of ZZ invariant masses that are used to constrain the width. We believe that an
analysis along these lines should be performed by experimental collaborations
in the near future and also in the run II of the LHC. We estimate that such
analyses can, eventually, be sensitive to the Higgs boson width as small as
$\Gamma_H \sim 10 \times \Gamma_H^{SM}$.


title: Leonardo and the Pseudo-RCO

abstract:
  There are two hypotheses on Leonardo's polyhedron based on the Pseudo-RCO and
drawn for Luca Pacioli's book: Leonardo made an error, or: Leonardo draw it
with intention, as it is. We give arguments, which support the
Intention-hypothesis.


title: One or more Higgs bosons?

abstract:
  Now that one has been found, the search for signs of more scalars is a
primary task of current and future experiments. In the motivated hypothesis
that the extra Higgs bosons of the next-to-minimal supersymmetric Standard
Model (NMSSM) be the lightest new particles around, we outline a possible
overall strategy to search for signs of the CP-even states. This work
complements Ref. arXiv:1304.3670.


title: Computational Universality and 1/f Noise in Elementary Cellular Automata

abstract:
  It is speculated that there is a relationship between 1/f noise and
computational universality in cellular automata. We use genetic algorithms to
search for one-dimensional and two-state, five-neighbor cellular automata which
have 1/f-type spectrum. A power spectrum is calculated from the evolution
starting from a random initial configuration. The fitness is estimated from the
power spectrum in consideration of the similarity to 1/f-type spectrum. The
result shows that the rule with the highest average fitness has a propagating
structure like other computationally universal cellular automata, although
computational universality of the rule has not been proved yet.


title: Optimized next-neighbor image cleaning method for Cherenkov Telescopes

abstract:
  In photo-sensor cameras of Cherenkov telescopes the light images from
particle showers always contain the background noise induced by photons of the
night sky. An image cleaning procedure is needed to reduce the contribution of
those noise photons in further analysis stages. The conventional topological
next neighbor method lacks reconstruction efficiency for low light content
images and image peripheries with low signal levels. We present here a simple
optimization of the traditional next-neighbor image cleaning method that
exploits the limited time duration of shower flashes and short time-difference
between neighboring image pixels. This method reduces greatly the noise
contribution by applying dynamical cuts in the parameter space formed by signal
amplitude and time-difference between neighboring pixels


title:
Microscopic scattering theory for interacting bosons in weak random
  potentials

abstract:
  We develop a diagrammatic scattering theory for interacting bosons in a
three-dimensional, weakly disordered potential. Based on a microscopic N-body
scattering theory, we identify the relevant diagrams including elastic and
inelastic collision processes that are sufficient to describe diffusive quantum
transport. By taking advantage of the statistical properties of the weak
disorder potential, we demonstrate how the N-body dynamics can be reduced to a
nonlinear integral equation of Boltzmann type for the single-particle diffusive
flux. Our theory reduces to the Gross-Pitaevskii mean field description in the
limit where only elastic collisions are taken into account. However, even at
weak interaction strength, inelastic collisions lead to energy redistribution
between the bosons - initially prepared all at the same single-particle energy
- and thereby induce thermalization of the single-particle current. In
addition, we include also weak localization effects and determine the coherent
corrections to the incoherent transport in terms of the coherent backscattering
signal. We find that inelastic collisions lead to an enhancement of the
backscattered cone in a narrow spectral window for increasing interaction
strength.


title:
Interpolation sets and the size of quotients of function spaces on a
  locally compact group

abstract:
  We devise a fairly general method for estimating the size of quotients
between algebras of functions on a locally compact group. This method is based
on the concept of interpolation sets and unifies the approaches followed by
many authors to obtain particular cases.
  Among the applications we find, we obtain that the quotients WAP(G)/B(G) (G
being a locally compact group in the class [IN] or a nilpotent locally compact
group) and CB(G)/LUC(G) (G being any non-compact non-discrete locally compact
group) contain a linearly isometric copy of \ell_\infty(\kappa(G)) where
\kappa(G) is the compact covering number of G, and WAP(G), B(G) and LUC(G)
refer, respectively, to the algebra of weakly almost periodic functions, the
uniform closure of the Fourier-Stieltjes algebra and the bounded right
uniformly continuous functions.


title:
Teaching physics during the 17th century: some examples from the works
  of Evangelista Torricelli

abstract:
  This paper is proposing some physics problems from a book, De Motu Gravium
Naturaliter Descendentium, written by Evangelista Torricelli, with the aim of
showing how physics was taught in a university, that of Pisa, in the 17th
century.


title:
Comparison of Different Trigger and Readout Approaches for Cameras in
  the Cherenkov Telescope Array Project

abstract:
  The Cherenkov Telescope Array (CTA) is a next-generation ground-based
observatory for g -rays with energies between some ten GeV and a few hundred
TeV. CTA is currently in the advanced design phase and will consist of arrays
with different size of prime-focus Cherenkov telescopes, to ensure a proper
energy coverage from the threshold up to the highest energies. The extension of
the CTA array with double-mirror Schwarzschild- Couder telescopes is planned to
improve the array angular resolution over wider field of view.We present an
end-to-end Monte-Carlo comparison of trigger concepts for the different imaging
cameras that will be used on the Cherenkov telescopes. The comparison comprises
three alternative trigger schemes (analog, majority, flexible pattern analysis)
for each camera design. The study also addresses the influence of the
properties of the readout system (analog bandwidth of the electronics, length
of the readout window in time) and uses an offline shower reconstruction to
investigate the impact on key performances such as energy threshold and flux
sensitivity


title: Realization of an all-dielectric zero-index optical metamaterial

abstract:
  Metamaterials offer unprecedented flexibility for manipulating the optical
properties of matter, including the ability to access negative index,
ultra-high index and chiral optical properties. Recently, metamaterials with
near-zero refractive index have drawn much attention. Light inside such
materials experiences no spatial phase change and extremely large phase
velocity, properties that can be applied for realizing directional emission,
tunneling waveguides, large area single mode devices, and electromagnetic
cloaks. However, at optical frequencies previously demonstrated zero- or
negative-refractive index metamaterials require the use of metallic inclusions,
leading to large ohmic loss, a serious impediment to device applications. Here,
we experimentally demonstrate an impedance matched zero-index metamaterial at
optical frequencies based on purely dielectric constituents. Formed from
stacked silicon rod unit cells, the metamaterial possesses a nearly isotropic
low-index response leading to angular selectivity of transmission and directive
emission from quantum dots placed within the material.


title: Magnetic flux concentrations in a polytropic atmosphere

abstract:
  Strongly stratified hydromagnetic turbulence has recently been identified as
a candidate for explaining the spontaneous formation of magnetic flux
concentrations by the negative effective magnetic pressure instability (NEMPI).
Much of this work has been done for isothermal layers for which the density
scale height is constant throughout. We now study the validity of earlier
conclusions about the size and growth rate of magnetic structures in the case
of polytropic layers, which scale height decreases sharply towards the surface.
To allow for a continuous transition from isothermal to polytropic layers, we
employ a generalization of the exponential function known as the q-exponential.
Now, the top of the polytropic layer shifts with the polytropic index such that
the scale height at some reference height is always the same. We use both
mean-field and direct numerical simulations of forced stratified turbulence to
determine the resulting flux concentrations. Magnetic structures begin to form
at a depth where magnetic field strength is about 3-4% the local equipartition
field strength with respect to the turbulent kinetic energy. Unlike the
isothermal case where stronger fields can give rise to magnetic flux
concentrations at larger depths, in the polytropic one the growth rates
decreases for structures deeper down. For vertical fields, magnetic structures
of super-equipartition strengths are formed because such fields survive
downward advection, unlike NEMPI under horizontal magnetic fields. The
horizontal cross-section of such structures is approximately circular. Results
based on isothermal models can be applied locally to polytropic layers. For
vertical fields, magnetic flux concentrations of super-equipartition strengths
form, which supports suggestions that sunspot formation might be a shallow
phenomenon.


title: Analog of Fishtail Anomaly in Plastically Deformed Graphene

abstract:
  By introducing a strain rate generated pseudo-electric field, we discuss a
magnetic response of a plastically deformed graphene. Our results demonstrate
the appearance of dislocation induced paramagnetic moment in a zero applied
magnetic field. More interestingly, it is shown that in the presence of the
magnetoplastic effect, the resulting magnetization exhibits typical features of
the so-called fishtail anomaly (previously observed in superconductors). The
estimates of the model parameters suggest quite an optimistic possibility to
experimentally realize the predicted phenomena in plastically deformed
graphene.


title: Alpha-stable random walk has massive thorns

abstract:
  We introduce and study a class of random walks defined on the integer lattice
$ \mathbb{Z} ^d$ -- a discrete space and time counterpart of the symmetric
$\alpha$-stable process in $\mathbb{R} ^d$. When $0< \alpha <2$ any coordinate
axis in $\mathbb{Z} ^d$, $d\geq 3$, is a non-massive set whereas any cone is
massive. We provide a necessary and sufficient condition for the thorn to be a
massive set.


title: Inequalities for convolutions of functions on commutative hypergroups

abstract:
  The generalized Young inequality on the Lorentz spaces for commutative
hypergroups is introdused and an application of it is given to the theory of
fractional integrals. The boundedness on the Lorentz space and the
Hardy-Littlewood-Sobolev theorem for the fractional integrals on the
commutative hypergroups is proved.


title: Generalized potentials on commutative hypergroups

abstract:
  By the Hardy-Littlewood-Sobolev theorem the classical Riesz potential is
bounded on Lebesgue spaces. E. Nakai and H. Sumitomo [16] extended that theorem
to the Orlicz spaces. We introduce generalized potential operators on
commutative hypergroups and under some assumptions on the kernel we showed the
boundedness of these operators from Lebesgue space into certain Orlicz space.
Our result is an analogue of Theorem 1.3 in [16].


title: First measurements of spin correlations in the np -> d pi^0 reaction

abstract:
  The transverse spin correlations Axx and Ayy in the np-> d pi^0 reaction have
been measured for the first time in quasi-free kinematics at the COSY-ANKE
facility using a polarised deuteron beam incident on a polarised hydrogen cell
target. The results obtained for neutron energies close to 353 MeV and 600 MeV
are in good agreement with the partial wave analysis of data on the
isospin-related pp-> d pi^+ reaction, though the present results cover also the
small-angle region, which was largely absent from these data.


title: Einstein-Euler-Heisenberg Theory and charged black holes

abstract:
  Taking into account the Euler-Heisenberg effective Lagrangian of one-loop
nonperturbative quantum electrodynamics (QED) contributions, we formulate the
Einstein-Euler-Heisenberg theory and study the solutions of nonrotating black
holes with electric and magnetic charges in spherical geometry. In the limit of
strong and weak electromagnetic fields of black holes, we calculate the black
hole horizon radius, area, and total energy up to the leading order of QED
corrections and discuss the black hole irreducible mass, entropy, and maximally
extractable energy as well as the Christodoulou-Ruffini mass formula. We find
that these black hole quantities receive the QED corrections, in comparison
with their counterparts in the Reissner-Nordstr\"om solution. The QED
corrections show the screening effect on black hole electric charges and the
paramagnetic effect on black hole magnetic charges. As a result, the black hole
horizon area, irreducible mass, and entropy increase; however, the black hole
total energy and maximally extractable energy decrease, compared with the
Reissner-Nordstr\"om solution. In addition, we show that the condition for
extremely charged black holes is modified due to the QED correction.


title: The Pin-Bang Theory: Discovering The Pinterest World

abstract:
  Pinterest is an image-based online social network, which was launched in the
year 2010 and has gained a lot of traction, ever since. Within 3 years,
Pinterest has attained 48.7 million unique users. This stupendous growth makes
it interesting to study Pinterest, and gives rise to multiple questions about
it's users, and content. We characterized Pinterest on the basis of large scale
crawls of 3.3 million user profiles, and 58.8 million pins. In particular, we
explored various attributes of users, pins, boards, pin sources, and user
locations, in detail and performed topical analysis of user generated textual
content. The characterization revealed most prominent topics among users and
pins, top image sources, and geographical distribution of users on Pinterest.
We then investigated this social network from a privacy and security
standpoint, and found traces of malware in the form of pin sources. Instances
of Personally Identifiable Information (PII) leakage were also discovered in
the form of phone numbers, BBM (Blackberry Messenger) pins, and email
addresses. Further, our analysis demonstrated how Pinterest is a potential
venue for copyright infringement, by showing that almost half of the images
shared on Pinterest go uncredited. To the best of our knowledge, this is the
first attempt to characterize Pinterest at such a large scale.


title:
Computing exact $D$-optimal designs by mixed integer second-order cone
  programming

abstract:
  Let the design of an experiment be represented by an $s$-dimensional vector
$\mathbf {w}$ of weights with nonnegative components. Let the quality of
$\mathbf {w}$ for the estimation of the parameters of the statistical model be
measured by the criterion of $D$-optimality, defined as the $m$th root of the
determinant of the information matrix $M(\mathbf {w})=\sum_{i=1}^sw_iA_iA_i^T$,
where $A_i,i=1,\ldots,s$ are known matrices with $m$ rows. In this paper, we
show that the criterion of $D$-optimality is second-order cone representable.
As a result, the method of second-order cone programming can be used to compute
an approximate $D$-optimal design with any system of linear constraints on the
vector of weights. More importantly, the proposed characterization allows us to
compute an exact $D$-optimal design, which is possible thanks to high-quality
branch-and-cut solvers specialized to solve mixed integer second-order cone
programming problems. Our results extend to the case of the criterion of
$D_K$-optimality, which measures the quality of $\mathbf {w}$ for the
estimation of a linear parameter subsystem defined by a full-rank coefficient
matrix $K$. We prove that some other widely used criteria are also second-order
cone representable, for instance, the criteria of $A$-, $A_K$-, $G$- and
$I$-optimality. We present several numerical examples demonstrating the
efficiency and general applicability of the proposed method. We show that in
many cases the mixed integer second-order cone programming approach allows us
to find a provably optimal exact design, while the standard heuristics
systematically miss the optimum.


title: Guidelines for the design of evolve and resequencing studies

abstract:
  Standing genetic variation provides a rich reservoir of potentially useful
mutations facilitating the adaptation to novel environments. Experimental
evolution studies have demonstrated that rapid and strong phenotypic responses
to selection can also be obtained in the laboratory. When combined with the
Next Generation Sequencing technology, these experiments promise to identify
the individual loci contributing to adaption. Nevertheless, until now, very
little is known about the design of such evolve and resequencing (E&R) studies.
Here, we use forward simulations of entire genomes to evaluate different
experimental designs that aim to maximize the power to detect selected
variants. We show that low linkage disequilibrium in the starting population,
population size, duration of the experiment and the number of replicates are
the key factors in determining the power and accuracy of E&R studies.
Furthermore, replication of E&R is more important for detecting the targets of
selection than increasing the population size. Using an optimized design
beneficial loci with a selective advantage as low as s=0.005 can be identified
at the nucleotide level. Even when a large number of loci are selected
simultaneously, up to 56% can be reliably detected without incurring large
numbers of false positives. Our computer simulations suggest that, with an
adequate experimental design, E&R studies are a powerful tool to identify
adaptive mutations from standing genetic variation and thereby provide an
excellent means to analyze the trajectories of selected alleles in evolving
populations.


title: Universality Classes of Critical Points in Constrained Glasses

abstract:
  We analyze critical points that can be induced in glassy systems by the
presence of constraints. These critical points are predicted by the Mean Field
Thermodynamic approach and they are precursors of the standard glass transition
in absence of constraints. Through a deep analysis of the soft modes appearing
in the replica field theory we can establish the universality class of these
points. In the case of the "annealed potential" of a symmetric coupling between
two copies of the system, the critical point is in the Ising universality
class. More interestingly, is the case of the "quenched potential" where the a
single copy is coupled with an equilibrium reference configuration, or the
"pinned particle" case where a fraction of particles is frozen in fixed
positions. In these cases we find the Random Field Ising Model (RFIM)
universality class. The effective random field is a "self-generated" disorder
that reflects the random choice of the reference configuration. The RFIM
representation of the critical theory predicts non-trivial relations governing
the leading singular behavior of relevant correlation functions, that can be
tested in numerical simulations.


title: Computational aspects of DNA mixture analysis

abstract:
  Statistical analysis of DNA mixtures is known to pose computational
challenges due to the enormous state space of possible DNA profiles. We propose
a Bayesian network representation for genotypes, allowing computations to be
performed locally involving only a few alleles at each step. In addition, we
describe a general method for computing the expectation of a product of
discrete random variables using auxiliary variables and probability propagation
in a Bayesian network, which in combination with the genotype network allows
efficient computation of the likelihood function and various other quantities
relevant to the inference. Lastly, we introduce a set of diagnostic tools for
assessing the adequacy of the model for describing a particular dataset.


title:
Formal multidimensional integrals, stuffed maps, and topological
  recursion

abstract:
  We show that the large N expansion in the multi-trace 1 formal hermitian
matrix model is governed by the topological recursion of [Eynard and Orantin,
2007] with initial conditions. In terms of a 1d gas of eigenvalues, this model
includes - on top of the squared Vandermonde - multilinear interactions of any
order between the eigenvalues. In this problem, the initial data (W10,W20) of
the topological recursion is characterized: for W10, by a non-linear, non-local
Riemann-Hilbert problem on a discontinuity locus to determine ; for W20, by a
related but linear, non-local Riemann-Hilbert problem on the discontinuity
locus. In combinatorics, this model enumerates discrete surfaces (maps) whose
elementary 2-cells can have any topology - W10 being the generating series of
disks and W20 that of cylinders. In particular, by substitution one may
consider maps whose elementary cells are themselves maps, for which we propose
the name "stuffed maps". In a sense, our results complete the program of the
"moment method" initiated in the 90s to compute the formal 1/N in the one
hermitian matrix model.


title:
Gutzwiller Approach for Elementary Excitations in $S=1$
  Antiferromagnetic Chains

abstract:
  In a previous paper [Phys. Rev. B 85,195144 (2012)], variational Monte Carlo
method (based on Gutzwiller projected states) was generalized to $S=1$ systems.
This method provided very good trial ground states for the gapped phases of
$S=1$ bilinear-biquadratic (BLBQ) Heisenberg chain. In the present paper, we
extend the approach to study the low-lying elementary excitations in $S=1$
chains. We calculate the one-magnon and two-magnon excitation spectra of the
BLBQ Heisenberg chain and the results agree very well with recent data in
literature. In our approach, the difference of the excitation spectrum between
the Haldane phase and the dimer phase (such as the even/odd size effect) can be
understood from their different topology of corresponding mean field theory. We
especially study the Takhtajan-Babujian critical point. Despite the fact that
the `elementary excitations' are spin-1 magnons which are different from the
spin-1/2 spinons in Bethe solution, we show that the excitation spectrum,
critical exponent ($\eta=0.74$) and central charge ($c=1.45$) calculated from
our theory agree well with Bethe ansatz solution and conformal field theory
predictions.


title: An arithmetic transference proof of a relative Szemer\'edi theorem

abstract:
  Recently Conlon, Fox, and the author gave a new proof of a relative
Szemer\'edi theorem, which was the main novel ingredient in the proof of the
celebrated Green-Tao theorem that the primes contain arbitrarily long
arithmetic progressions. Roughly speaking, a relative Szemer\'edi theorem says
that if S is a set of integers satisfying certain conditions, and A is a subset
of S with positive relative density, then A contains long arithmetic
progressions, and our recent results show that S only needs to satisfy a
so-called linear forms condition.
  This note contains an alternative proof of the new relative Szemer\'edi
theorem, where we directly transfer Szemer\'edi's theorem, instead of going
through the hypergraph removal lemma. This approach provides a somewhat more
direct route to establishing the result, and it gives better quantitative
bounds.
  The proof has three main ingredients: (1) a transference principle/dense
model theorem of Green-Tao and Tao-Ziegler (with simplified proofs given later
by Gowers, and independently, Reingold-Trevisan-Tulsiani-Vadhan) applied with a
discrepancy/cut-type norm (instead of a Gowers uniformity norm as it was
applied in earlier works), (2) a counting lemma established by Conlon, Fox, and
the author, and (3) Szemer\'edi's theorem as a black box.


title: Convex and Concave Soft Sets and Some Properties

abstract:
  In this study, after given the definition of soft sets and their basic
operations we define convex soft sets which is an important concept for
operation research, optimization and related problems. Then, we define concave
soft sets and give some properties for the concave sets. For these, we will use
definition and properties of convex-concave fuzzy sets in literature. We also
give different some properties for the convex and concave soft sets.


title:
A Comparative Study of an Asymptotic Preserving Scheme and Unified
  Gas-kinetic Scheme in Continuum Flow Limit

abstract:
  Asymptotic preserving (AP) schemes are targeting to simulate both continuum
and rarefied flows. Many AP schemes have been developed and are capable of
capturing the Euler limit in the continuum regime. However, to get accurate
Navier-Stokes solutions is still challenging for many AP schemes. In order to
distinguish the numerical effects of different AP schemes on the simulation
results in the continuum flow limit, an implicit-explicit (IMEX) AP scheme and
the unified gas kinetic scheme (UGKS) based on Bhatnagar-Gross-Krook (BGk)
kinetic equation will be applied in the flow simulation in both transition and
continuum flow regimes. As a benchmark test case, the lid-driven cavity flow is
used for the comparison of these two AP schemes. The numerical results show
that the UGKS captures the viscous solution accurately. The velocity profiles
are very close to the classical benchmark solutions. However, the IMEX AP
scheme seems have difficulty to get these solutions. Based on the analysis and
the numerical experiments, it is realized that the dissipation of AP schemes in
continuum limit is closely related to the numerical treatment of collision and
transport of the kinetic equation. Numerically it becomes necessary to couple
the convection and collision terms in both flux evaluation at a cell interface
and the collision source term treatment inside each control volume.


title: The dual-mirror Small Size Telescope for the Cherenkov Telescope Array

abstract:
  In this paper, the development of the dual mirror Small Size Telescopes (SST)
for the Cherenkov Telescope Array (CTA) is reviewed. Up to 70 SST, with a
primary mirror diameter of 4 m, will be produced and installed at the CTA
southern site. These will allow investigation of the gamma-ray sky at the
highest energies accessible to CTA, in the range from about 1 TeV to 300 TeV.
The telescope presented in this contribution is characterized by two major
innovations: the use of a dual mirror Schwarzschild-Couder configuration and of
an innovative camera using as sensors either multi-anode photomultipliers
(MAPM) or silicon photomultipliers (SiPM). The reduced plate-scale of the
telescope, achieved with the dual-mirror optics, allows the camera to be
compact (40 cm in diameter), and low-cost. The camera, which has about 2000
pixels of size 6x6 mm^2, covers a field of view of 10{\deg}. The dual mirror
telescopes and their cameras are being developed by three consortia, ASTRI
(Astrofisica con Specchi a Tecnologia Replicante Italiana, Italy/INAF), GATE
(Gamma-ray Telescope Elements, France/Paris Observ.) and CHEC (Compact High
Energy Camera, universities in UK, US and Japan) which are merging their
efforts in order to finalize an end-to-end design that will be constructed for
CTA. A number of prototype structures and cameras are being developed in order
to investigate various alternative designs. In this contribution, these designs
are presented, along with the technological solutions under study.

categories: astro-ph.IM astro-ph.HE hep-ex physics.ins-det


title: Galileo knowledge of optics and the functioning of the telescope revised

abstract:
  What are the historical evidence concerning the turning of the spyglass into
an astronomical instrument, the telescope? In Sidereus Nuncius and in his
private correspondence Galileo tells the reader what he did with the telescope,
but he did not disclose the existence of a theory of the instrument. Still, the
instruments which Galileo produced are extant and can be studied. With replicas
of Galileo's telescopes that magnify 14 and 21 times, we have simulated and
analyzed Galileos practices as he reported them in Sidereus Nuncius. On this
ground, we propose a new solution to this old problem. We establish the
knowledge of optics that Galileo had as it can be read off from the telescopes
he constructed and the way he put them to use. Galileo addressed optical
difficulties associated with illumination, resolution, field of view, and
magnification. His optical knowledge was well thought through, originated as it
did in a radically new optical framework.


title:
Symmetric multivariate polynomials as a basis for three-boson
  light-front wave functions

abstract:
  We develop a polynomial basis to be used in numerical calculations of
light-front Fock-space wave functions. Such wave functions typically depend on
longitudinal momentum fractions that sum to unity. For three particles, this
constraint limits the two remaining independent momentum fractions to a
triangle, for which the three momentum fractions act as barycentric
coordinates. For three identical bosons, the wave function must be symmetric
with respect to all three momentum fractions. Therefore, as a basis, we
construct polynomials in two variables on a triangle that are symmetric with
respect to the interchange of any two barycentric coordinates. We find that,
through the fifth order, the polynomial is unique at each order, and, in
general, these polynomials can be constructed from products of powers of the
second and third-order polynomials. The use of such a basis is illustrated in a
calculation of a light-front wave function in two-dimensional phi^4 theory; the
polynomial basis performs much better than the plane-wave basis used in
discrete light-cone quantization.


title: An outdoor test facility for the Cherenkov Telescope Array mirrors

abstract:
  The Cherenkov Telescopes Array (CTA) is planned to be an Observatory for very
high energy gamma ray astronomy and will consist of several tens of telescopes
which account for a reflective surface of more than 10000 m$^2$. The mirrors of
these telescopes will be formed by a set of facets. Different technological
solutions, for a fast and cost efficient production of light-weight mirror
facets are under test inside the CTA Consortium. Most of them involve composite
structures whose behavior under real observing conditions is not yet fully
tested. An outdoor test facility has been built in one of the candidate sites
for CTA, in Argentina (San Antonio de los Cobres [SAC], 3600m a.s.l) in order
to monitor the optical and mechanical properties of these facets exposed to the
local atmospheric conditions for a given period of time. In this work we
present the preliminary results of the first Middle Size Telescope (MST)
mirror-monitoring campaign, started in 2013.


title: Triggered Clause Pushing for IC3

abstract:
  We propose an improvement of the famous IC3 algorithm for model checking
safety properties of finite state systems. We collect models computed by the
SAT-solver during the clause propagation phase of the algorithm and use them as
witnesses for why the respective clauses could not be pushed forward. It only
makes sense to recheck a particular clause for pushing when its witnessing
model falsifies a newly added clause. Since this trigger test is both
computationally cheap and sufficiently precise, we can afford to keep clauses
pushed as far as possible at all times. Experiments indicate that this strategy
considerably improves IC3's performance.


title: The quantile transform of a simple walk

abstract:
  We examine a new path transform on 1-dimensional simple random walks and
Brownian motion, the quantile transform. This transformation relates to
identities in fluctuation theory due to Wendel, Port, Dassios and others, and
to discrete and Brownian versions of Tanaka's formula. For an n-step random
walk, the quantile transform reorders increments according to the value of the
walk at the start of each increment. We describe the distribution of the
quantile transform of a simple random walk of n steps, using a bijection to
characterize the number of pre-images of each possible transformed path. We
deduce, both for simple random walks and for Brownian motion, that the quantile
transform has the same distribution as Vervaat's transform. For Brownian
motion, the quantile transforms of the embedded simple random walks converge to
a time change of the local time profile. We characterize the distribution of
the local time profile, giving rise to an identity that generalizes a variant
of Jeulin's description of the local time profile of a Brownian bridge or
excursion.


title:
Cofibrant models of diagrams: mixed Hodge structures in rational
  homotopy

abstract:
  We study the homotopy theory of a certain type of diagram categories whose
vertices are in variable categories with a functorial path, leading to a good
calculation of the homotopy category in terms of cofibrant objects. The theory
is applied to the category of mixed Hodge diagrams of differential graded
algebras. Using Sullivan's minimal models, we prove a multiplicative version of
Beilinson's Theorem on mixed Hodge complexes. As a consequence, we obtain
functoriality for the mixed Hodge structures on the rational homotopy type of
complex algebraic varieties. In this context, the mixed Hodge structures on
homotopy groups obtained by Morgan's theory follow from the derived functor of
the indecomposables of mixed Hodge diagrams.


title:
Phase structure of two-dimensional QED at zero temperature with
  flavor-dependent chemical potentials and the role of multidimensional theta
  functions

abstract:
  We consider QED on a two-dimensional Euclidean torus with $f$ flavors of
massless fermions and flavor-dependent chemical potentials. The dependence of
the partition function on the chemical potentials is reduced to a
$(2f-2)$-dimensional theta function. At zero temperature, the system can exist
in an infinite number of phases characterized by certain values of traceless
number densities and separated by first-order phase transitions. Furthermore,
there exist many points in the $(f-1)$-dimensional space of traceless chemical
potentials where two or three phases can coexist for $f=3$ and two, three, four
or six phases can coexist for $f=4$. We conjecture that the maximal number of
coexisting phases grows exponentially with increasing $f$.

categories: hep-th cond-mat.stat-mech hep-lat hep-ph


title: Non-equilibrium spin-current detection with a single Kondo impurity

abstract:
  We present a theoretical study based on the Anderson model of the transport
properties of a Kondo impurity (atom or quantum dot) connected to ferromagnetic
leads, which can sustain a non-equilibrium spin current. We analyze the case
where the spin current is injected by an external source and when it is
generated by the voltage bias. Due to the presence of ferromagnetic contacts, a
static exchange field is produced that eventually destroys the Kondo
correlations. We find that such a field can be compensated by an appropriated
combination of the spin-dependent chemical potentials leading to the
restoration of the Kondo resonance. In this respect, a Kondo impurity may be
regarded as a very sensitive sensor for non-equilibrium spin phenomena.


title: Iron Line Variability of Discoseismic Corrugation Modes

abstract:
  Using a fast semi-analytic raytracing code, we study the variability of
relativistically broadened iron lines due to discoseismic oscillations
concentrated in the inner-most regions of accretion discs around black holes.
The corrugation mode, or c-mode, is of particular interest as its natural
frequency corresponds well to the ~0.1-15Hz range observed for low-frequency
quasi-periodic oscillations (LFQPOs) for lower spins. Comparison of the
oscillation phase dependent variability and QPO-phase stacked iron line
observations will allow such discoseismic models to be confirmed or ruled out
as a source of particular LFQPOs. The spectral range and frequency of the
variability of the iron line due to corrugation modes can also potentially be
used to constrain the black hole spin if observed with sufficient temporal and
spectral resolution.


title: Still No Rindler Firewalls

abstract:
  There has been much discussion on the possibility of firewalls at the
horizon-scale in black hole physics, including questions regarding the presence
or absence of firewalls at apparent horizons, such as the Rindler horizon and
the horizon of the Poincar\'{e} patch of Anti-de Sitter space. We argue against
the presence of such apparent firewalls by demonstrating that one recent
argument for firewalls in black holes does not extend to these cases. We also
include some brief remarks on some claims in the recent firewall literature.


title:
Stability of switched linear hyperbolic systems by Lyapunov techniques
  (full version)

abstract:
  Switched linear hyperbolic partial differential equations are considered in
this paper. They model infinite dimensional systems of conservation laws and
balance laws, which are potentially affected by a distributed source or sink
term. The dynamics and the boundary conditions are subject to abrupt changes
given by a switching signal, modeled as a piecewise constant function and
possibly a dwell time. By means of Lyapunov techniques some sufficient
conditions are obtained for the exponential stability of the switching system,
uniformly for all switching signals. Different cases are considered with or
without a dwell time assumption on the switching signals, and on the number of
positive characteristic velocities (which may also depend on the switching
signal). Some numerical simulations are also given to illustrate some main
results, and to motivate this study.


title:
Polynomial-Time Algorithms for Quadratic Isomorphism of Polynomials: The
  Regular Case

abstract:
  Let $\mathbf{f}=(f\_1,\ldots,f\_m)$ and $\mathbf{g}=(g\_1,\ldots,g\_m)$ be
two sets of $m\geq 1$ nonlinear polynomials over $\mathbb{K}[x\_1,\ldots,x\_n]$
($\mathbb{K}$ being a field). We consider the computational problem of finding
-- if any -- an invertible transformation on the variables mapping $\mathbf{f}$
to $\mathbf{g}$. The corresponding equivalence problem is known as {\tt
Isomorphism of Polynomials with one Secret} ({\tt IP1S}) and is a fundamental
problem in multivariate cryptography. The main result is a randomized
polynomial-time algorithm for solving {\tt IP1S} for quadratic instances, a
particular case of importance in cryptography and somewhat justifying {\it a
posteriori} the fact that {\it Graph Isomorphism} reduces to only cubic
instances of {\tt IP1S} (Agrawal and Saxena). To this end, we show that {\tt
IP1S} for quadratic polynomials can be reduced to a variant of the classical
module isomorphism problem in representation theory, which involves to test the
orthogonal simultaneous conjugacy of symmetric matrices. We show that we can
essentially {\it linearize} the problem by reducing quadratic-{\tt IP1S} to
test the orthogonal simultaneous similarity of symmetric matrices; this latter
problem was shown by Chistov, Ivanyos and Karpinski to be equivalent to finding
an invertible matrix in the linear space $\mathbb{K}^{n \times n}$ of $n \times
n$ matrices over $\mathbb{K}$ and to compute the square root in a matrix
algebra. While computing square roots of matrices can be done efficiently using
numerical methods, it seems difficult to control the bit complexity of such
methods. However, we present exact and polynomial-time algorithms for computing
the square root in $\mathbb{K}^{n \times n}$ for various fields (including
finite fields). We then consider \\#{\tt IP1S}, the counting version of {\tt
IP1S} for quadratic instances. In particular, we provide a (complete)
characterization of the automorphism group of homogeneous quadratic
polynomials. Finally, we also consider the more general {\it Isomorphism of
Polynomials} ({\tt IP}) problem where we allow an invertible linear
transformation on the variables \emph{and} on the set of polynomials. A
randomized polynomial-time algorithm for solving {\tt IP} when
\(\mathbf{f}=(x\_1^d,\ldots,x\_n^d)\) is presented. From an algorithmic point
of view, the problem boils down to factoring the determinant of a linear matrix
(\emph{i.e.}\ a matrix whose components are linear polynomials). This extends
to {\tt IP} a result of Kayal obtained for {\tt PolyProj}.


title:
Steady state rheological behaviour of multi-component magnetic
  suspensions

abstract:
  In this paper we study the rheological behaviour (in the absence of magnetic
field and upon its application) of multi-component magnetic suspensions that
consist of a mixture of magnetic (iron) and non-magnetic (PMMA) particles
dispersed in a liquid carrier. These suspensions exhibit considerably higher
viscosity and yield stress in the absence of magnetic field than
single-component suspensions of the same solid fraction, as a consequence of
the adsorption of the iron particles on the PMMA ones. The adsorbed layer of
iron particles on the PMMA ones is observed through optical microscopy of
dilute samples and confirmed by attenuated total reflectance. Microscopic
observations also show that the resulting non-magnetic-core-magnetic-shell
composites move upon magnetic field application and aggregate into particle
structures aligned with the applied field. These structures, which consist of
both types of particles, give rise to high values of the static and dynamic
yield stresses upon field application. Actually, both quantities are much
higher than those of a suspension with the same volume fraction of magnetic
particles, and increase when the amount of non-magnetic ones increases. These
trends are adequately predicted by a theoretical model that considers that the
main contribution to the yield stress is the change of the suspension magnetic
permeability when particle chains are deformed by the shear.


title:
Random weighted Sobolev inequalities on $\mathbb{R}^d$ and application
  to Hermite functions

abstract:
  We extend a randomisation method, introduced by Shiffman-Zelditch and
developed by Burq-Lebeau on compact manifolds for the Laplace operator, to the
case of $\mathbb{R}^d$ with the harmonic oscillator. We construct measures,
thanks to probability laws which satisfy the concentration of measure property,
on the support of which we prove optimal weighted Sobolev estimates on
$\mathbb{R}^d$. This construction relies on accurate estimates on the spectral
function in a non-compact configuration space. As an application, we show that
there exists a basis of Hermite functions with good decay properties in
$L^{\infty}(\mathbb{R}^d$)$, when $d\geq 2$.


title: Mathematical Formulation of Multi-Layer Networks

abstract:
  A network representation is useful for describing the structure of a large
variety of complex systems. However, most real and engineered systems have
multiple subsystems and layers of connectivity, and the data produced by such
systems is very rich. Achieving a deep understanding of such systems
necessitates generalizing "traditional" network theory, and the newfound deluge
of data now makes it possible to test increasingly general frameworks for the
study of networks. In particular, although adjacency matrices are useful to
describe traditional single-layer networks, such a representation is
insufficient for the analysis and description of multiplex and time-dependent
networks. One must therefore develop a more general mathematical framework to
cope with the challenges posed by multi-layer complex systems. In this paper,
we introduce a tensorial framework to study multi-layer networks, and we
discuss the generalization of several important network descriptors and
dynamical processes --including degree centrality, clustering coefficients,
eigenvector centrality, modularity, Von Neumann entropy, and diffusion-- for
this framework. We examine the impact of different choices in constructing
these generalizations, and we illustrate how to obtain known results for the
special cases of single-layer and multiplex networks. Our tensorial approach
will be helpful for tackling pressing problems in multi-layer complex systems,
such as inferring who is influencing whom (and by which media) in multichannel
social networks and developing routing techniques for multimodal transportation
systems.

categories: physics.soc-ph cond-mat.dis-nn math-ph math.MP


title:
Accurate ro-vibrational spectroscopy of diatomic molecules in a Morse
  oscillator potential

abstract:
  This work presents the bound-state spectra of Morse oscillator, which remains
one of the oldest important model potentials for molecules. Accurate
ro-vibrational energies are obtained by means of a generalized pseudospectral
method that offers an optimal, non-uniform discretization of the radial grid.
Both s-wave ($\ell=0$) and rotational ($\ell \neq 0$) states for low and high
quantum numbers are calculated for four representative diatomic molecules,
namely H$_2$, LiH, HCl and CO. First nine states belonging to a maximum of $n,
\ell =2$ are computed with good accuracy, along with nine other high-lying
states for each of these molecules. Present results \emph{surpass} the accuracy
of \emph{all} hitherto published calculations found so far, except the
tridiagonal J-matrix method, which produces similar accuracy as ours. Detailed
variation of energies with respect to state indices $n,\ell$ show interesting
behavior. A host of new states including the higher ones are reported as well.
This offers a simple general efficient scheme for calculating these and other
similar potentials in molecular physics.


title:
1.06 {\mu}m Q-switched ytterbium-doped fiber laser using few-layer
  topological insulator Bi2Se3 as a saturable absorber

abstract:
  Passive Q-switching of an ytterbium-doped fiber (YDF) laser with few-layer
topological insulator (TI) is, to the best of our knowledge, experimentally
demonstrated for the first time. The few-layer TI: Bi2Se3 (2-4 layer thickness)
is fabricated by the liquid-phase exfoliation method, and has a low saturable
optical intensity of 53 MW/cm2 measured by the Z-scan technique. The optical
deposition technique is used to induce the few-layer TI in the solution onto a
fiber ferrule for successfully constructing the fiber-integrated TI-based
saturable absorber (SA). By inserting this SA into the YDF laser cavity, stable
Q-switching operation at 1.06 {\mu}m is achieved. The Q-switched pulses have
the shortest pulse duration of 1.95 {\mu}s, the maximum pulse energy of 17.9 nJ
and a tunable pulse-repetition-rate from 8.3 to 29.1 kHz. Our results indicate
that the TI as a SA is also available at 1 {\mu}m waveband, revealing its
potential as another wavelength-independent SA (like graphene).


title:
Multi-keyword multi-click advertisement option contracts for sponsored
  search

abstract:
  In sponsored search, advertisement (abbreviated ad) slots are usually sold by
a search engine to an advertiser through an auction mechanism in which
advertisers bid on keywords. In theory, auction mechanisms have many desirable
economic properties. However, keyword auctions have a number of limitations
including: the uncertainty in payment prices for advertisers; the volatility in
the search engine's revenue; and the weak loyalty between advertiser and search
engine. In this paper we propose a special ad option that alleviates these
problems. In our proposal, an advertiser can purchase an option from a search
engine in advance by paying an upfront fee, known as the option price. He then
has the right, but no obligation, to purchase among the pre-specified set of
keywords at the fixed cost-per-clicks (CPCs) for a specified number of clicks
in a specified period of time. The proposed option is closely related to a
special exotic option in finance that contains multiple underlying assets
(multi-keyword) and is also multi-exercisable (multi-click). This novel
structure has many benefits: advertisers can have reduced uncertainty in
advertising; the search engine can improve the advertisers' loyalty as well as
obtain a stable and increased expected revenue over time. Since the proposed ad
option can be implemented in conjunction with the existing keyword auctions,
the option price and corresponding fixed CPCs must be set such that there is no
arbitrage between the two markets. Option pricing methods are discussed and our
experimental results validate the development. Compared to keyword auctions, a
search engine can have an increased expected revenue by selling an ad option.


title: Algorithms and topology for Cayley graphs of groups

abstract:
  Autostackability for finitely generated groups is defined via a topological
property of the associated Cayley graph which can be encoded in a finite state
automaton. Autostackable groups have solvable word problem and an effective
inductive procedure for constructing van Kampen diagrams with respect to a
canonical finite presentation. A comparison with automatic groups is given.
Another characterization of autostackability is given in terms of
prefix-rewriting systems. Every group which admits a finite complete rewriting
system or an asynchronously automatic structure with respect to a prefix-closed
set of normal forms is also autostackable. As a consequence, the fundamental
group of every closed 3-manifold with any of the eight possible uniform
geometries is autostackable.


title:
Efficient variational approach to the impurity problem and its
  application to the dynamical mean-field theory

abstract:
  Within the framework of exact diagonalization (ED), we compute the ground
state of Anderson impurity problem using the variational approach based on the
configuration interaction (CI) expansion. We demonstrate that an accurate
ground state can be obtained by iteratively diagonalizing a matrix with the
dimension that is less than 10$%$ of the full Hamiltonian. The efficiency of
the CI expansion for different problems is analyzed. By way of example, we
apply this method to the single-site dynamical mean field theory using ED as
the impurity solver. Specifically, to demonstrate the usefulness of this
approach, we solve the attractive Hubbard model in the grand-canonical
ensemble, where the s-wave superconducting solution is explicitly obtained.


title: A Sharp Double Inequality for the Inverse Tangent Function

abstract:
  The inverse tangent function can be bounded by different inequalities, for
example by Shafer's inequality. In this publication, we propose a new sharp
double inequality, consisting of a lower and an upper bound, for the inverse
tangent function. In particular, we sharpen Shafer's inequality and calculate
the best corresponding constants. The maximum relative errors of the obtained
bounds are approximately smaller than 0.27% and 0.23% for the lower and upper
bound, respectively. Furthermore, we determine an upper bound on the relative
errors of the proposed bounds in order to describe their tightness
analytically. Moreover, some important properties of the obtained bounds are
discussed in order to describe their behavior and achieved accuracy.


title:
Ferromagnetic models for cooperative behavior: Revisiting Universality
  in complex phenomena

abstract:
  Ferromagnetic models are harmonic oscillators in statistical mechanics.
Beyond their original scope in tackling phase transition and symmetry breaking
in theoretical physics, they are nowadays experiencing a renewal applicative
interest as they capture the main features of disparate complex phenomena,
whose quantitative investigation in the past were forbidden due to data
lacking. After a streamlined introduction to these models, suitably embedded on
random graphs, aim of the present paper is to show their importance in a
plethora of widespread research fields, so to highlight the unifying framework
reached by using statistical mechanics as a tool for their investigation.
Specifically we will deal with examples stemmed from sociology, chemistry,
cybernetics (electronics) and biology (immunology).


title: Cosmological Fast Radio Bursts from Binary Neutron Star Mergers

abstract:
  Fast radio bursts (FRBs) at cosmological distances have recently been
discovered, whose duration is about milliseconds. We argue that the observed
short duration is difficult to explain by giant flares of soft gamma-ray
repeaters, though their event rate and energetics are consistent with FRBs.
Here we discuss binary neutron star (NS-NS) mergers as a possible origin of
FRBs. The FRB rate is within the plausible range of NS-NS merger rate and its
cosmological evolution, while a large fraction of NS-NS mergers must produce
observable FRBs. A likely radiation mechanism is coherent radio emission like
radio pulsars, by magnetic braking when magnetic fields of neutron stars are
synchronized to binary rotation at the time of coalescence. Magnetic fields of
the standard strength (~ 10^{12-13} G) can explain the observed FRB fluxes, if
the conversion efficiency from magnetic braking energy loss to radio emission
is similar to that of isolated radio pulsars. Corresponding gamma-ray emission
is difficult to detect by current or past gamma-ray burst satellites. Since
FRBs tell us the exact time of mergers, a correlated search would significantly
improve the effective sensitivity of gravitational wave detectors.


title: On the Necessity of Mixed Models: Dynamical Frustrations in the Mind

abstract:
  In the present work we will present and analyze some basic processes at the
local and global level in linguistic derivations that seem to go beyond the
limits of Markovian or Turing-like computation, and require, in our opinion, a
quantum processor. We will first present briefly the working hypothesis and
then focus on the empirical domain. At the same time, we will argue that a
model appealing to only one kind of computation (be it quantum or not) is
necessarily insufficient, and thus both linear and non-linear formal models are
to be invoked in order to pursue a fuller understanding of mental computations
within a unified framework.


title:
Conification construction for Kaehler manifolds and its application in
  c-projective geometry

abstract:
  Two Kaehler metrics on one complex manifold are said to be c-projectively
equivalent if their J-planar curves, i.e., curves defined by the property that
their acceleration is complex proportional to their velocity, coincide. The
degree of mobility of a Kaehler metric is the dimension of the space of metrics
that are c-projectively equivalent to it. We give the list of all possible
values of the degree of mobility of simply connected 2n-dimensional Riemannian
Kaehler manifolds. We also describe all such values under the additional
assumption that the metric is Einstein. As an application, we describe all
possible dimensions of the space of essential c-projective vector fields of
Kaehler and Kaehler-Einstein Riemannian metrics. We also show that two
c-projectively equivalent Kaehler Einstein metrics (of arbitrary signature) on
a closed manifold have constant holomorphic curvature or are affinely
equivalent.


title:
Estimate of the fraction of primary photons in the cosmic-ray flux at
  energies ~10^17 eV from the EAS-MSU experiment data

abstract:
  We reanalyze archival EAS-MSU data in order to search for events with
anomalously low content of muons with energies E_mu>10 GeV in extensive air
showers with number of particles N_e>2*10^7. We confirm the first evidence for
nonzero flux of primary cosmic gamma rays at energies E~10^17 eV. The estimated
fraction of primary gamma rays in the flux of cosmic particles with energies
E>5.4*10^16 eV is (0.43 +0.12-0.11)%, which corresponds to the intensity of
(1.2 +0.4-0.3)*10^{-16} cm^{-2} s^{-1} sr^{-1}. The study of arrival directions
does not favour any particular mechanism of the origin of the photon-like
events.


title:
Characterization of the candidate site for the Cherenkov Telescope Array
  at the Observatorio del Teide

abstract:
  The Spanish partners of the future Cherenkov Telescope Array (CTA) have
selected a candidate site for the Northern installation of CTA, at 3 km from
the Observatorio del Teide (OT), in the Canary Island of Tenerife. As the OT is
a very well-characterized astronomical site. We focus here on differences
between the publicly accessible measurements from the OT observatory and those
obtained with instruments deployed at the candidate site. We find that the
winds are generally softer at the candidate site, and the level of background
light comparable to the Observatorio del Roque de los Muchachos (ORM) at La
Palma in the B-band, while it is only slightly higher in the V-band.


title: Video Text Localization using Wavelet and Shearlet Transforms

abstract:
  Text in video is useful and important in indexing and retrieving the video
documents efficiently and accurately. In this paper, we present a new method of
text detection using a combined dictionary consisting of wavelets and a
recently introduced transform called shearlets. Wavelets provide optimally
sparse expansion for point-like structures and shearlets provide optimally
sparse expansions for curve-like structures. By combining these two features we
have computed a high frequency sub-band to brighten the text part. Then K-means
clustering is used for obtaining text pixels from the Standard Deviation (SD)
of combined coefficient of wavelets and shearlets as well as the union of
wavelets and shearlets features. Text parts are obtained by grouping
neighboring regions based on geometric properties of the classified output
frame of unsupervised K-means classification. The proposed method tested on a
standard as well as newly collected database shows to be superior to some
existing methods.


title:
Asymptotic distribution of zeros of a certain class of hypergeometric
  polynomials

abstract:
  We study the weak asymptotic behavior of the zeros of a family of a certain
class of (generalized) hypergeometric polynomials, using the associated
hypergeometric differential equation, as the parameters go to infinity.
  We describe the curve complex on which the zeros cluster, as level curves
associated to integrals on an algebraic curve derived from the equation. In a
certain degenerate case we make a precise conjecture, based and generalizing
work by Duren, Driver et. al, and present experimental evidence for it.


title: Cylindrical Fractional Brownian Motion in Banach Spaces

abstract:
  In this article we introduce cylindrical fractional Brownian motions in
Banach spaces and develop the related stochastic integration theory. Here a
cylindrical fractional Brownian motion is understood in the classical framework
of cylindrical random variables and cylindrical measures. The developed
stochastic integral for deterministic operator valued integrands is based on a
series representation of the cylindrical fractional Brownian motion, which is
analogous to the Karhunen-Lo\`eve expansion for genuine stochastic processes.
In the last part we apply our results to study the abstract stochastic Cauchy
problem in a Banach space driven by cylindrical fractional Brownian motion.


title:
On the gap of Hamiltonians for the adiabatic simulation of quantum
  circuits

abstract:
  The time or cost of simulating a quantum circuit by adiabatic evolution is
determined by the spectral gap of the Hamiltonians involved in the simulation.
In "standard" constructions based on Feynman's Hamiltonian, such a gap
decreases polynomially with the number of gates in the circuit, L. Because a
larger gap implies a smaller cost, we study the limits of spectral gap
amplification in this context. We show that, under some assumptions on the
ground states and the cost of evolving with the Hamiltonians (which apply to
the standard constructions), an upper bound on the gap of order 1/L follows. In
addition, if the Hamiltonians satisfy a frustration-free property, the upper
bound is of order 1/L^2. Our proofs use recent results on adiabatic state
transformations, spectral gap amplification, and the simulation of
continuous-time quantum query algorithms. They also consider a reduction from
the unstructured search problem, whose lower bound in the oracle cost
translates into the upper bounds in the gaps. The impact of our results is that
improving the gap beyond that of standard constructions (i.e., 1/L^2), if
possible, is challenging.


title:
Supplementary information to "Efimov-driven phase transitions of the
  unitary Bose gas"

abstract:
  In quantum physics, Efimov trimers are bound states of three particles that
fall apart like Borromean rings when one of them is removed. Initially
predicted in nuclear physics, these striking bosonic states are hard to
observe, but the "unitary" interactions at which they form is commonly realized
in current cold atoms experiments. There, they set the stage for a new class of
universal physics: Two-body interactions are all but invisible, but three-body
effects allow the emergence of a largely uncharted new world of many-particle
bound states. Three-particle systems were characterized theoretically, and the
ground-state properties of small unitary clusters computed numerically, but the
macroscopic many-body behaviour has remained unknown. Here we show, using a
Path-Integral Monte Carlo algorithm backed up by theoretical arguments, that
the unitary Bose gas presents a first-order phase transition from a normal gas
to a superfluid Efimov liquid. The normal gas is very well described by the
available virial coefficients. At unitarity, the phase diagram of the bosonic
system is universal in rescaled pressure and temperature. A triple point
separates the normal gas, the superfluid Efimov liquid, and a third phase, the
conventional superfluid gas. These two superfluid phases are separated by a
critical line that ends in a critical point at high temperature. This rich
phase diagram should allow for a number of experimental protocols that would
probe these universal transitions between the normal gas, the superfluid gas,
and the superfluid Efimov liquid.


title: Primordial black holes in non-Gaussian regimes

abstract:
  Primordial black holes (PBHs) can form in the early Universe from the
collapse of rare, large density fluctuations. They have never been observed,
but this fact is enough to constrain the amplitude of fluctuations on very
small scales which cannot be otherwise probed. Because PBHs form only in very
rare large fluctuations, the number of PBHs formed is extremely sensitive to
changes in the shape of the tail of the fluctuation distribution - which
depends on the amount of non-Gaussianity present. We first study how local
non-Gaussianity of arbitrary size up to fifth order affects the abundance and
constraints from PBHs, finding that they depend strongly on even small amounts
of non-Gaussianity and the upper bound on the allowed amplitude of the power
spectrum can vary by several orders of magnitude. The sign of the non-linearity
parameters (f_{NL}, g_{NL}, etc) are particularly important. We also study the
abundance and constraints from PBHs in the curvaton scenario, in which case the
complete non-linear probability distribution is known, and find that truncating
to any given order (i.e. to order f_{NL} or g_{NL}, etc) does not give accurate
results.