title:
An inscribed radius estimate for mean curvature flow in Riemannian
  manifolds

abstract:
  We consider a family of embedded, mean convex hypersurfaces in a Riemannian
manifold which evolve by the mean curvature flow. We show that, given any
number $T>0$ and any $\delta>0$, we can find a constant $C_0$ with the
following property: if $t \in [0,T)$ and $p$ is a point on $M_t$ where the
curvature is greater than $C_0$, then the inscribed radius is at least
$\frac{1}{(1+\delta) \, H}$ at the point $p$. The constant $C_0$ depends only
on $\delta$, $T$, and the initial data.


title:
Understanding the spectrum of a distant blazar PKS 1424+240 and its
  implications

abstract:
  We calculate the gamma-ray spectrum of a distant blazar, PKS 1424+240,
located at redshift z > 0.6035, where the optical depth to primary gamma rays
of the highest observed energies is \tau > 5. The spectral shape agrees well
with what is expected from secondary gamma rays produced in line-of-sight
interactions of cosmic rays with background photons. In particular, we find an
acceptable agreement with the source redshifts in the range 0.6 < z < 1.3. We
discuss the implications of existing and future data for models of
extragalactic background light (EBL) and for the redshift of the source. In the
case of a future detection of temporal variability at lower energies, one can
set more restrictive limits on both the source redshift and the EBL model.


title: Composite Spectra in Merging U/LIRGs Caused by Shocks

abstract:
  We present a key result from our optical integral field spectroscopic survey
of 27 nearby ultra luminous and luminous infrared galaxies (U/LIRGs) from the
Great Observatory All-sky LIRG Survey. Using spatially resolved multi-component
emission line fitting to trace the emission line ratios and velocity dispersion
of the ionized gas, we quantify for the first time the widespread shock
ionization in gas-rich merging U/LIRGs. Our results show a fractional
contribution to the total observed \Ha flux from radiative shocks increasing
from a few percent during early merger stages to upwards of 60% of the observed
optical emission line flux in late stage mergers. We compare our resolved
spectroscopy to nuclear spectra and find that 3/4 of the galaxies in our sample
that would be classified as "composite" based on optical spectroscopy are
primarily characterized by a combination of star formation and merger-driven
shocks. Our results have important implications for the interpretation of
"composite" rest-frame optical spectra of U/LIRGs as starburst+AGN, as the
shock emission combined with star formation can mimic "composite" optical
spectra in the absence of any contribution from an AGN.


title:
Iterative approach to the characteristic time for chemical reactions of
  type A + B ! C + D

abstract:
  The analytic solution for the kinetic description of binary reactions can be
seen as the continuum version of a basic discrete iterate mapping. This fact
allows a clear definition of the reaction characteristic time which takes the
backward effect into account.


title: Exploring adiabatic quantum trajectories via optimal control

abstract:
  Adiabatic quantum computation employs a slow change of a time-dependent
control function (or functions) to interpolate between an initial and final
Hamiltonian, which helps to keep the system in the instantaneous ground state.
When the evolution time is finite, the degree of adiabaticity (quantified in
this work as the average ground-state population during evolution) depends on
the particulars of a dynamic trajectory associated with a given set of control
functions. We use quantum optimal control theory with a composite objective
functional to numerically search for controls that achieve the target final
state with a high fidelity while simultaneously maximizing the degree of
adiabaticity. Exploring properties of optimal adiabatic trajectories in model
systems elucidates the dynamic mechanisms that suppress unwanted excitations
from the ground state. Specifically, we discover that the use of multiple
control functions makes it possible to access a rich set of dynamic
trajectories, some of which attain a significantly improved performance (in
terms of both fidelity and adiabaticity) through the increase of the energy gap
during most of the evolution time.


title:
General triallelic frequency spectrum under demographic models with
  variable population size

abstract:
  It is becoming routine to obtain datasets on DNA sequence variation across
several thousands of chromosomes, providing unprecedented opportunity to infer
the underlying biological and demographic forces. Such data make it vital to
study summary statistics which offer enough compression to be tractable, while
preserving a great deal of information. One well-studied summary is the site
frequency spectrum---the empirical distribution, across segregating sites, of
the sample frequency of the derived allele. However, most previous theoretical
work has assumed that each site has experienced at most one mutation event in
its genealogical history, which becomes less tenable for very large sample
sizes. In this work we obtain, in closed-form, the predicted frequency spectrum
of a site that has experienced at most two mutation events, under very general
assumptions about the distribution of branch lengths in the underlying
coalescent tree. Among other applications, we obtain the frequency spectrum of
a triallelic site in a model of historically varying population size. We
demonstrate the utility of our formulas in two settings: First, we show that
triallelic sites are more sensitive to the parameters of a population that has
experienced historical growth, suggesting that they will have use if they can
be incorporated into demographic inference. Second, we investigate a recently
proposed alternative mechanism of mutation in which the two derived alleles of
a triallelic site are created simultaneously within a single individual, and we
develop a test to determine whether it is responsible for the excess of
triallelic sites in the human genome.


title: Flow Control with Dynamic Roughness

abstract:
  The paper discusses a fluid dynamics video showing the use of Dynamic
Roughness to reattach upper surface flow on a stalled NACA 0012-based wing.


title: Bordered Floer Homology and Lefschetz fibrations with corners

abstract:
  Lipshitz, Ozsv\'ath and Thurston defined a bordered Heegaard Floer invariant
CFDA for 3-manifolds with two boundary components, including mapping cylinders
for surface diffeomorphisms. We define a related invariant for certain
4-dimensional cobordisms with corners, by associating a morphism F from CFDA(f)
to CFDA(g) to each such cobordism between two mapping cylinders f and g. Like
the Ozsv\'ath-Szab\'o invariants of cobordisms between closed 3-manifolds, this
morphism arises from counting holomorphic triangles on Heegaard triples. We
demonstrate that the homotopy class of the morphism F only depends on the
symplectic structure of the cobordism in question.


title: Image Restoration using Total Variation with Overlapping Group Sparsity

abstract:
  Image restoration is one of the most fundamental issues in imaging science.
Total variation (TV) regularization is widely used in image restoration
problems for its capability to preserve edges. In the literature, however, it
is also well known for producing staircase-like artifacts. Usually, the
high-order total variation (HTV) regularizer is an good option except its
over-smoothing property. In this work, we study a minimization problem where
the objective includes an usual $l_2$ data-fidelity term and an overlapping
group sparsity total variation regularizer which can avoid staircase effect and
allow edges preserving in the restored image. We also proposed a fast algorithm
for solving the corresponding minimization problem and compare our method with
the state-of-the-art TV based methods and HTV based method. The numerical
experiments illustrate the efficiency and effectiveness of the proposed method
in terms of PSNR, relative error and computing time.


title: Spaces of conics on low degree complete intersections

abstract:
  Let X be a smooth complete intersection. Suppose p and q are general points
of X, we consider conics in X passing through p and q. We show the moduli space
of these conics is a smooth complete intersection. The main ingredients of the
proof are a criterion for characterizing when a smooth projective variety is a
complete intersection, the Grothendieck-Riemann-Roch theorem and the geometry
of the spaces of conics.


title: Localization in the ground state of a triple quantum well

abstract:
  A model is presented, consisting of a single structureless particle on the
line subject to a potential with three minima, with an exactly soluble ground
level. In this model the ground level probability density becomes more
sensitive to the global shape of the potential as the distance between the
minima increases, so that for big enough distances small variations in the
potential bring a qualitative change in the probability density, taking it from
a unimodal, localized, distribution, to a bimodal one. We conjecture that this
effect, of which we have not found any precedent in the literature, may be
relevant in the design and characterization of mesoscopic devices such as
triple quantum well systems.


title: On Crosspatch Knight's Tours

abstract:
  A knight's tour is often represented as a broken line connecting the centers
of successively visited squares. We say that two knight moves form a cross if
the midpoints of their respective segments coincide. We show that no knight
tour exists on a rectangular board in which every move is part of a cross. We
also establish the general structure of pseudotours with this property.


title:
Origin of the energy gap in the narrow-gap semiconductor FeSb2 revealed
  by high-pressure magnetotransport measurements

abstract:
  To elucidate an origin of the two energy gaps in the narrow-gap semiconductor
FeSb2, we have investigated the effects of hydrostatic pressure on the
resistivity, Hall resistance and magnetoresistance at low temperatures. The
larger energy gap evaluated from the temperature dependence of resistivity
above 100 K is enhanced from 30 to 40 meV with pressure from 0 to 1.8 GPa, as
generally observed in conventional semiconductors. In the low-temperature range
where a large Seebeck coefficient was observed, we evaluate the smaller energy
gap from the magnetotransport tensor using a two-carrier model and find that
the smaller gap exhibits a weak pressure dependence in contrast to that of the
larger gap. To explain the pressure variations of the energy gaps, we propose a
simple model that the smaller gap is a gap from the impurity level to the
conduction band and the larger one is a gap between the valence and conduction
bands, suggesting that the observed large Seebeck coefficient is not relevant
to electron correlation effects.


title: Dense Scattering Layer Removal

abstract:
  We propose a new model, together with advanced optimization, to separate a
thick scattering media layer from a single natural image. It is able to handle
challenging underwater scenes and images taken in fog and sandstorm, both of
which are with significantly reduced visibility. Our method addresses the
critical issue -- this is, originally unnoticeable impurities will be greatly
magnified after removing the scattering media layer -- with transmission-aware
optimization. We introduce non-local structure-aware regularization to properly
constrain transmission estimation without introducing the halo artifacts. A
selective-neighbor criterion is presented to convert the unconventional
constrained optimization problem to an unconstrained one where the latter can
be efficiently solved.


title:
Resonant Excitation of Disk Oscillations in Deformed Disks VII:
  Stability Criterion in MHD Systems

abstract:
  In a disk with an oscillatory deformation from an axisymmetric state with
frequency $\omega_{\rm D}$ and azimuthal wavenumber $m_{\rm D}$, a set of two
normal mode oscillations with frequency and azimuthal wavenumber being
($\omega_1$, $m_1$) and ($\omega_2$, $m_2$) resonantly couple through the disk
deformation, when the resonant conditions ($\omega_1+\omega_2+\omega_{\rm D}=0$
and $m_1+m_2+m_{\rm D}=0$) are satisfied. In the case of hydrodynamical disks,
the resonance amplifies the set of the oscillations if
$(E_1/\omega_1)(E_2/\omega_2)>0$ (Kato 2013b), where $E_1$ and $E_2$ are wave
energies of the two oscillations with $\omega_1$ and $\omega_2$, respectively.
In this paper we show that this instability criterion is still valid even when
the oscillations are ideal MHD ones in magnetized disks, if the displacements
associated with the oscillations vanish on the boundary of the system.


title: Linear Extended Whitening Filters

abstract:
  In this paper we present a class of linear whitening filters termed linear
extended whitening filters (EWFs) which are whitening filters that have
desirable secondary properties and can be used for simplifying algorithms, or
achieving desired side-effects on given secondary matrices, random vectors or
random processes. Further, we present an application of EWFs for simplification
of QR decomposition based ML detection algorithm in Wireless Communication.


title:
High-pT hadrons from nuclear collisions: Unifying pQCD with
  hydrodynamics

abstract:
  Hadrons inclusively produced with large pT in high-energy collisions
originate from the jets, whose initial virtuality and energy are of the same
order, what leads to an extremely intensive gluon radiation and dissipation of
energy at the early stage of hadronization. Besides, these jets have a peculiar
structure: the main fraction of the jet energy is carried by a single leading
hadron, so such jets are very rare. The constraints imposed by energy
conservation enforce an early color neutralization and a cease of gluon
radiation. The produced colorless dipole does not dissipate energy anymore and
is evolving to form the hadron wave function. The small and medium pT region is
dominated by the hydrodynamic mechanisms of hadron production from the created
hot medium. The abrupt transition between the hydrodynamic and perturbative QCD
mechanisms causes distinct minima in the pT dependence of the suppression
factor R_{AA} and of the azimuthal asymmetry v2. Combination of these
mechanisms allows to describe the data through the full range of pT at
different collision energies and centralities.


title: Extended by Balk metrics

abstract:
  Let $X$ be a nonempty set and $\mathcal{F}(X)$ be the set of nonempty finite
subsets of $X$. The paper deals with the extended metrics
$\tau:\mathcal{F}(X)\to\mathbb{R}$ recently introduced by Peter Balk. Balk's
metrics and their restriction to the family of sets $A$ with $|A|\leqslant n$
make possible to consider "distance functions" with $n$ variables and related
them quantities. In particular, we study such type generalized diameters
$\diam_{\tau^n}$ and find conditions under which $B\mapsto\diam_{\tau^n}B$ is a
Balk's metric. We prove the necessary and sufficient conditions under which the
restriction $\tau$ to the set of $A\in\mathcal{F}(X)$ with $|A|\leqslant 3$ is
a symmetric $G$-metric. An infinitesimal analog for extended by Balk metrics is
constructed.


title:
On $hp$-Convergence of PSWFs and A New Well-Conditioned
  Prolate-Collocation Scheme

abstract:
  The first purpose of this paper is to provide a rigorous proof for the
nonconvergence of $h$-refinement in $hp$-approximation by the PSWFs, a
surprising convergence property that was first observed by Boyd et al [J. Sci.
Comput., 2013]. The second purpose is to offer a new basis that leads to
spectral-collocation systems with condition numbers independent of $(c,N),$ the
intrinsic bandwidth parameter and the number of collocation points. In
addition, this work gives insights into the development of effective spectral
algorithms using this non-polynomial basis. We in particular highlight that the
collocation scheme together with a very practical rule for pairing up $(c,N)$
significantly outperforms the Legendre polynomial-based method (and likewise
other Jacobi polynomial-based method) in approximating highly oscillatory
bandlimited functions.


title: Phase transitions in systems with non-additive long-range interactions

abstract:
  We consider spin systems with long-range interactions in nonadditive regime.
When the non-additive scaling limit is employed, the energy and the entropy
compete and the system exhibits some phase transitions. Such systems do not
satisfy the additivity, which results in some unfamiliar properties related to
phase transitions. In this paper, the concept of additivity and its consequence
are explained and the recent progress on statistical mechanics of long-range
interacting systems are reviewed. It is shown that the parameter space is
clearly decomposed into the three regions according to the stability of the
uniform state predicted by the mean-field theory. Based on this parameter space
decomposition, recent results on the exactness of MF theory are explained. When
the interaction is non-negative (ferromagnetic), the analysis of the mean-field
theory is exact and a typical spin configuration is always uniform in the
canonical ensemble. However, in the restricted canonical ensemble, i.e., the
canonical ensemble with a restriction of the value of the magnetization, it is
shown that the mean-field theory does not necessarily give the exact
description of the system and phase transitions between the mean-field uniform
states (MF phase) and the inhomogeneous states (non-MF phase) occur. A new
finding is that when the interaction potential changes its sign depending on
the distance, the non-MF phase appears even in the canonical ensemble.


title: Statistics of genome architecture

abstract:
  The main statistical distributions applicable to the analysis of genome
architecture and genome tracks are briefly discussed and critically assessed.
Although the observed features in distributions of element lengths can be
equally well fitted by the different statistical approximations, the
interpretation of observed regularities may strongly depend on the chosen
scheme. We discuss the possible evolution scenarios and describe the main
characteristics obtained with different distributions. The expression for the
assessment of levels in hierarchical chromatin folding is derived and the
quantitative measure of genome architecture inhomogeneity is suggested. This
theory provides the ground for the regular statistical study of genome
architecture and genome tracks.


title: On A Class of Finsler Metrics of Einstein-Reversibility

abstract:
  In this paper, we introduce the notion of Einstein-reversibility for Finsler
met- rics. We study a class of p-power Finsler metrics determined by a Riemann
metric and 1-form which are of Einstein-reversibility. It shows that such a
class of Finsler metrics of Einstein-reversibility are always Einstein metrics.
In particular, we show that all p-power metrics but Randers metrics, square
metrics and 2-dimensional square-root metrics, are always Ricci-flat-parallel.
Further, the local structure is almost determined for 2-dimensional square-root
metrics which are Einsteinian (equivalently, of isotropic flag curvature), and
examples show such metrics are not necessarily Ricci-flat.


title:
Spectral band localization for Schr\"odinger operators on periodic
  graphs

abstract:
  We consider Schr\"odinger operators on periodic discrete graphs. It is known
that the spectrum of these operators has band structure. We obtain a
localization of spectral bands in terms of eigenvalues of Dirichlet and Neumann
operators on a finite graph, which is constructed from the fundamental cell of
the periodic graph. The proof is based on the Floquet decomposition of
Schr\"odinger operators and the minimax principle.


title: Elliptic flow of Lambda, Xi and Omega in 2.76 A TeV Pb+Pb collisions

abstract:
  The elliptic flow v_2 for strange and multi-strange bayons in 2.76 A TeV
Pb+Pb collisions is investigated with VISHNU hybrid model that connects 2+1-d
viscous hydrodynamics with a hadron cascade model. It is found that VISHNU
nicely describes v_2(p_T) data for \Lambda, \Xi and \Omega at various
centralities. Comparing with the ALICE data, it roughly reproduces the
mass-ordering of v_2 among \pi, K, p, \Xi and \Omega within current statistics,
but gives an inverse v_2 mass-ordering between p and \Lambda.


title: A Note on a Class of Finsler Metrics of Isotropic S-Curvature

abstract:
  An $(\alpha,\beta)$-metric is defined by a Riemannian metric and $1$-form. In
this paper, we investigate the known characterization for
$(\alpha,\beta)$-metrics of isotropic S-curvature. We show that such a
characterization should hold in dimension $n\ge 3$, and for the 2-dimensional
case, there is one more class of isotropic S-curvature than the higher
dimensional ones. Further, we construct corresponding examples for every
two-dimensional class, especially for the class that the norm of $\beta$ with
respect to $\alpha$ is not a constant.


title: Magnetic configuration sweep control in Heliac type stellarators

abstract:
  A novel magnetic configuration sweep control system for the TJ-II Heliac
device is described. The system is prepared to establish a reference for
plasma, torus or vessel current while the coil configuration currents are swept
during a single plasma discharge. It can also be run in a special simulation
mode, which does not require powering the TJ-II device, intended for
commissioning and experiment preparation purposes. Preliminary tests with the
system have shown its ability to perform rotational transform scans while
establishing a waveform for torus current independently, despite variable
plasma conditions. This opens up new experimental possibilities to study the
influence of rotational transform and shear independently.


title:
No effects of androgen receptor gene CAG and GGC repeat polymorphisms on
  digit ratio (2D:4D): Meta-analysis

abstract:
  Objectives: A series of meta-analyses assessed whether differentially
efficacious variants (CAG and GGC repeat-length polymorphisms) of the human
androgen receptor gene are associated with digit ratio (2D:4D), a widely
investigated putative pointer to prenatal androgen action. Methods: Extensive
literature search strategies identified a maximum of 16 samples (total N =
2157) eligible for meta-analysis. Results: In contrast to a small-sample (N =
50) initial report, widely cited affirmatively in the literature, meta-analysis
of the entire retrievable evidence base did not support associations between
androgen receptor gene efficacy and 2D:4D. Conclusions: These meta-analytical
nil findings, along with several further suggestive strands of evidence
consistent with these, undermine one validity claim for 2D:4D as a
retrospective pointer to prenatal testosterone action.


title:
Combination of e+/e- ratio from AMS-02 and gamma ray line from Fermi-LAT
  with implication for Dark Matter

abstract:
  The precise AMS-02 data provide definite information for the e+/e- ratio in
100 - 350 GeV region. Assuming that the recent gamma ray line observed by
Fermi-LAT experiment is product of dark matter in space and taken as input. We
make a global fit for the AMS-02 e+/e- spectrum with both dark matter and
pulsar contribution. For this spectrum over 130 GeV, pulsar is the dominant
contribution. We also investigate the constrains on hadron production from dark
matter annihilation.


title: Search for global f-modes and p-modes in the 8B neutrino flux

abstract:
  The impact of global acoustic modes on the 8B neutrino flux time series is
computed for the first time. It is shown that the time fluctuations of the 8B
neutrino flux depend on the amplitude of acoustic eigenfunctions in the region
where the 8B neutrino flux is produced: modes with low n (or order) that have
eigenfunctions with a relatively large amplitude in the Sun's core, strongly
affect the neutrino flux; conversely, modes with high n that have
eigenfunctions with a minimal amplitude in the Sun's core have a very small
impact on the neutrino flux. It was found that the global modes with a larger
impact on the 8B neutrino flux have a frequency of oscillation in the interval
250 \mu Hz to 500 \mu Hz (or a period in the interval 30 minutes to 70
minutes), such as the f-modes (n=0) for the low degrees, radial modes of order
n smaller or equal to 3, and the dipole mode of order n=1. Their corresponding
neutrino eigenfunctions are very sensitive to the solar inner core and are
unaffected by the variability of the external layers of the solar surface. If
time variability of neutrinos is observed for these modes, it will lead to new
ways of improving the sound speed profile inversion in the central region of
the Sun.


title: Stiffness from Disorder in Triangular-Lattice Ising Thin Films

abstract:
  We study the triangular lattice Ising model with a finite number of
vertically stacked layers and demonstrate a low temperature reentrance of two
Berezinskii-Kosterlitz-Thouless transitions, which results in an extended
disordered regime down to $T=0$. Numerical results are complemented with the
derivation of an effective low-temperature dimer theory. Contrary to order by
disorder, we present a new scenario for fluctuation-induced ordering in
frustrated spin systems. While short-range spin-spin correlations are enhanced
by fluctuations, quasi-long-range ordering is precluded at low enough
temperatures by proliferation of topological defects.


title:
Net-baryon number fluctuations with the hadron resonance gas model using
  Tsallis distribution

abstract:
  We explore a hadron resonance gas model using Tsallis non-extensive
distribution to study the energy dependence of the product of the moments,
$S\sigma$ and $\kappa\sigma^2$ of net-proton multiplicity distributions of
published STAR data in \auau collisions at relativistic heavy-ion collider
(RHIC) energies. While excellent agreements are found between model predictions
and measurements of $S\sigma$ and $\kappa \sigma^2$ of most peripheral
collisions and $S\sigma$ of most central collisions, the $\kappa \sigma^2$ for
most central collisions deviates significantly from the predictions
particularly at \sqsn = 19.6 GeV and $27$ GeV. This could be an indication of
the presence of dynamical fluctuations, which are not contained in the
HRG-Tsallis model.


title:
Global multidimensional shock waves for 2-D and 3-D unsteady potential
  flow equations

abstract:
  Although local existence of multidimensional shock waves has been established
in some fundamental references, there are few results on the global existence
of those waves except the ones for the unsteady potential flow equations in
n-dimensional spaces (n > 4) or in special unbounded space-time domains with
non-physical boundary conditions. In this paper, we are concerned with both the
local and global multidimensional conic shock wave problem for the unsteady
potential flow equations when a pointed piston (i.e., the piston degenerates
into a single point at the initial time) or an explosive wave expands fast in
2-D or 3-D static polytropic gas. It is shown that a multidimensional shock
wave solution of such a class of quasilinear hyperbolic problems not only
exists locally, but it also exists globally in the whole space-time and
approaches a self-similar solution as t goes to infinity.


title:
Landau Level Spectroscopy of Dirac Electrons in a Polar Semiconductor
  with Giant Rashba Spin Splitting

abstract:
  Optical excitations of BiTeI with large Rashba spin splitting have been
studied in an external magnetic field ($B$) applied parallel to the polar axis.
A sequence of transitions between the Landau levels (LLs), whose energies are
in proportion to $\sqrt{B}$ were observed, being characteristic of massless
Dirac electrons. The large separation energy between the LLs makes it possible
to detect the strongest cyclotron resonance even at room temperature in
moderate fields. Unlike in 2D Dirac systems, the magnetic field induced
rearrangement of the conductivity spectrum is directly observed.


title: Exceptional surgeries on alternating knots

abstract:
  We give a complete classification of exceptional surgeries on hyperbolic
alternating knots in the 3-sphere. As an appendix, we also show that the
Montesinos knots M (-1/2, 2/5, 1/(2q + 1)) with q at least 5 have no
non-trivial exceptional surgeries. This gives the final step in a complete
classification of exceptional surgery on arborescent knots.


title: A Domain-Specific Language for Discrete Mathematics

abstract:
  This paper discusses a Domain Specific Language (DSL) that has been developed
to enable implementation of concepts of discrete mathematics. A library of data
types and functions provides functionality which is frequently required by
users. Covering the areas of Mathematical Logic, Set Theory, Functions, Graph
Theory, Number Theory, Linear Algebra and Combinatorics, the language's syntax
is close to the actual notation used in the specific fields.


title: 130GeV gamma-ray line through axion conversion

abstract:
  We apply the axion-photon conversion mechanism to the 130 GeV $\gamma$-ray
line observed by the Fermi satellite. Near the Galactic center, some
astrophysical sources and/or particle dark matter can produce energetic axions
(or axionlike particles), and the axions convert to $\gamma$ rays in Galactic
magnetic fields along their flight to the Earth. Since continuum $\gamma$-ray
and antiproton productions are sufficiently suppressed in axion production, the
scenario fits the 130 GeV $\gamma$-ray line without conflicting with cosmic ray
measurements. We derive the axion production cross section and the decay rate
of dark matter to fit the $\gamma$-ray excess as functions of axion parameters.
In the scenario, the $\gamma$-ray spatial distributions depend on both the dark
matter profile and the magnetic field configuration, which will be tested by
future $\gamma$-ray observations, e.g., H.E.S.S. II, CTA, and GAMMA-400. As an
illustrative example, we study realistic supersymmetric axion models, and show
the favored parameters that nicely fit the $\gamma$-ray excess.


title:
Centenary of "Researches on irritability of plants" by Jagadis Chandra
  Bose

abstract:
  This note celebrates the centenary of Jagadis Chandra Bose's classic
monograph entitled "Researches on irritability of plants".


title:
Triggered massive and clustered stars formation by together H II regions
  G38.91-0.44 and G39.30-1.04

abstract:
  We present the radio continuum, infrared, and CO molecular observations of
infrared dark cloud (IRDC) G38.95-0.47 and its adjacent H II regions
G38.91-0.44 (N74), G38.93-0.39 (N75), and G39.30-1.04. The Purple Mountain
Observation (PMO) 13.7 m radio telescope was used to detect12CO J=1-0,13CO
J=1-0 and C18O J=1-0 lines. The carbon monoxide (CO) molecular observations can
ensure the real association between the ionized gas and the neutral material
observed nearby. To select young stellar objects (YSOs) associated this region,
we used the GLIMPSE I catalog. The13CO J=1-0 emission presents two large cloud
clumps. The clump consistent with IRDC G38.95-0.47 shows a triangle- like
shape, and has a steep integrated-intensity gradient toward H II regions
G38.91-0.44 and G39.30-1.04, suggesting that the two H II regions have expanded
into the IRDC. Four submillmeter continuum sources have been detected in the
IRDC G38.95-0.47. Only the G038.95-00.47-M1 source with a mass of 117 Msun has
outflow and infall motions, indicating a newly forming massive star. We
detected a new collimated outflow in the clump compressed by G38.93-0.39. The
derived ages of the three H II regions are 6.1*10^5yr, 2.5*10^5yr, and
9.0*10^5yr, respectively. In the IRDC G38.95-0.47, the significant enhancement
of several Class I YSOs indicates the presence of some recently formed stars.
Comparing the ages of these H II regions with YSOs (Class I sources and massive
G038.95-00.47-M1 source), we suggest that YSOs may be triggered by G38.91-0.44
and G39.30-1.04 together, which supports the radiatively driven implosion
model. It may be the first time that the triggered star formation has occurred
in the IRDC compressed by two H II regions. The new detected outflow may be
driven by a star cluster.


title: Newman's conjecture in various settings

abstract:
  De Bruijn and Newman introduced a deformation of the Riemann zeta function
$\zeta(s)$, and found a real constant $\Lambda$ which encodes the movement of
the zeros of $\zeta(s)$ under the deformation. The Riemann hypothesis (RH) is
equivalent to $\Lambda \le 0$. Newman made the conjecture that $\Lambda \ge 0$
along with the remark that "the new conjecture is a quantitative version of the
dictum that the Riemann hypothesis, if true, is only barely so."
  Newman's conjecture is still unsolved, and previous work could only handle
the Riemann zeta function and quadratic Dirichlet $L$-functions, obtaining
lower bounds very close to zero (for example, for $\zeta(s)$ the bound is at
least $-1.14541 \cdot 10^{-11}$, and for quadratic Dirichlet $L$-functions it
is at least $-1.17 \cdot 10^{-7}$). We generalize the techniques to apply to
automorphic $L$-functions as well as function field $L$-functions. We further
determine the limit of these techniques by studying linear combinations of
$L$-functions, proving that these methods are insufficient.
  We explicitly determine the Newman constants in various function field
settings, which has strong implications for Newman's quantitative version of
RH. In particular, let $\mathcal D \in \bbZ[T]$ be a square-free polynomial of
degree 3. Let $D_p$ be the polynomial in $\bbF_p[T]$ obtained by reducing
$\mathcal D$ modulo $p$. Then the Newman constant $\Lambda_{D_p}$ equals $\log
\frac{|a_p(\mathcal D)|}{2\sqrt{p}}$; by Sato--Tate (if the curve is non-CM)
there exists a sequence of primes such that $\lim_{n \to\infty}
\Lambda_{D_{p_n}} = 0$. We end by discussing connections with random matrix
theory.


title: Flat local morphisms of rings with prescribed depth and dimension

abstract:
  For pairs of integers (n,m) and (d,e) satisfying some nedesary conditions, we
construct a local flat ring morphism of noetherian local rings u:A -->B such
that dim(A)=n, depth(A)=d, dim(B)=m, depth(B)=e.


title: Ladders and simplicity of derived module categories

abstract:
  Recollements of derived module categories are investigated, using a new
technique, ladders of recollements, which are mutation sequences. The position
in the ladder is shown to control whether a recollement restricts from
unbounded to another level of derived category. Ladders also turn out to
control derived simplicity on all levels. An algebra is derived simple if its
derived category cannot be deconstructed, that is, if it is not the middle term
of a non-trivial recollement whose outer terms are again derived categories of
algebras. Derived simplicity on each level is characterised in terms of heights
of ladders.
  These results are complemented by providing new classes of examples of
derived simple algebras, in particular indecomposable commutative rings, as
well as by a finite-dimensional counterexample to the Jordan--H\"older property
for derived module categories. Moreover, recollements are used to compute
homological and K-theoretic invariants.


title: Stratifications of algebras with two simple modules

abstract:
  Let $A$ be a finite-dimensional algebra with two simple modules. It is shown
that if the derived category of $A$ admits a stratification with simple factors
being the base field $k$, then $A$ is derived equivalent to a quasi-hereditary
algebra. As a consequence, if further $k$ is algebraically closed and $A$ has
finite global dimension, then $A$ is either derived simple or derived
equivalent to a quasi-hereditary algebra


title: An Algebraic Framework for Compositional Program Analysis

abstract:
  The purpose of a program analysis is to compute an abstract meaning for a
program which approximates its dynamic behaviour. A compositional program
analysis accomplishes this task with a divide-and-conquer strategy: the meaning
of a program is computed by dividing it into sub-programs, computing their
meaning, and then combining the results. Compositional program analyses are
desirable because they can yield scalable (and easily parallelizable) program
analyses.
  This paper presents algebraic framework for designing, implementing, and
proving the correctness of compositional program analyses. A program analysis
in our framework defined by an algebraic structure equipped with sequencing,
choice, and iteration operations. From the analysis design perspective, a
particularly interesting consequence of this is that the meaning of a loop is
computed by applying the iteration operator to the loop body. This style of
compositional loop analysis can yield interesting ways of computing loop
invariants that cannot be defined iteratively. We identify a class of
algorithms, the so-called path-expression algorithms [Tarjan1981,Scholz2007],
which can be used to efficiently implement analyses in our framework. Lastly,
we develop a theory for proving the correctness of an analysis by establishing
an approximation relationship between an algebra defining a concrete semantics
and an algebra defining an analysis.


title:
Using Information Theory to Study the Efficiency and Capacity of Caching
  in the Computer Networks

abstract:
  Nowadays computer networks use different kind of memory whose speeds and
capacities vary widely. There exist methods of a so-called caching which are
intended to use the different kinds of memory in such a way that the frequently
used data are stored in the faster memory, wheres the infrequent ones are
stored in the slower memory. We address the problems of estimating the caching
efficiency and its capacity. We define the efficiency and capacity of the
caching and suggest a method for their estimation based on the analysis of
kinds of the accessible memory.


title: Coulombic Charge Ice

abstract:
  We consider a classical model of charges $\pm q$ on a pyrochlore lattice in
the presence of long range Coulomb interactions. This model first appeared in
the early literature on charge order in magnetite. In the limit where the
interactions become short-ranged, the model has a ground state with an
extensive entropy and dipolar charge-charge correlations. When long range
interactions are introduced, the exact degeneracy is broken. We study the
thermodynamics of the model and show the presence of a correlated charge liquid
within a temperature window in which the physics is well described as a liquid
of screened charged defects. The structure factor in this phase, which has
smeared pinch points at the reciprocal lattice points, may be used to detect
charge ice experimentally. In addition, the model exhibits fractionally charged
excitations $\pm q/2$ which are shown to interact via a $1/r$ potential. At
lower temperatures, the model exhibits a transition to a long-range ordered
phase. We are able to treat the Coulombic charge ice model and the dipolar spin
ice model on an equal footing by mapping both to a constrained charge model on
the diamond lattice. We find that states of the two ice models are related by a
staggering field which is reflected in the energetics of these two models. From
this perspective we can understand the origin of the spin ice and charge ice
ground states as coming from a dipolar model on a diamond lattice. We study the
properties of charge ice in an external electric field finding that the
correlated liquid is robust to the presence of a field in contrast to the case
of spin ice in a magnetic field. Finally, we comment on the transport
properties of Coulombic charge ice in the correlated liquid phase.


title:
Critical exponents of the binomial Ising Spin Glass in dimension four;
  non-universality

abstract:
  Extensive simulations are made on the bimodal Ising Spin Glass (ISG) in
dimension four. The transition temperature is established using a combination
of standard finite size scaling and of thermodynamic derivative peak data.
Measurements in the thermodynamic limit regime are analysed so as to estimate
critical exponents and confluent correction terms. Comparisons with results on
other 4d ISGs show that the susceptibility and correlation length critical
exponents $\gamma$ and $\nu$ depend on the form of the interaction
distribution. From this observation it can be deduced that critical exponents
are not universal in ISGs.


title: Gaia, counting down to launch

abstract:
  In this contribution I provide an overview of the the European Space Agency's
Gaia mission just ahead of its launch scheduled for November 2013.


title:
Quorums Quicken Queries: Efficient Asynchronous Secure Multiparty
  Computation

abstract:
  We describe an asynchronous algorithm to solve secure multiparty computation
(MPC) over n players, when strictly less than a 1/8 fraction of the players are
controlled by a static adversary. For any function f over a field that can be
computed by a circuit with m gates, our algorithm requires each player to send
a number of field elements and perform an amount of computation that is O (m/n
+ \sqrt{n}). This significantly improves over traditional algorithms, which
require each player to both send a number of messages and perform computation
that is {\Omega}(nm). Additionally, we define the threshold counting problem
and present a distributed algorithm to solve it in the asynchronous
communication model. Our algorithm is load balanced, with computation,
communication and latency complexity of O(log n), and may be of independent
interest to other applications with a load balancing goal in mind.


title: Coalitions in Routing Games: A Worst-Case Perspective

abstract:
  We investigate a routing game that allows for the creation of coalitions,
within the framework of cooperative game theory. Specifically, we describe the
cost of each coalition as its maximin value. This represents the performance
that the coalition can guarantee itself, under any (including worst)
conditions. We then investigate fundamental solution concepts of the considered
cooperative game, namely the core and a variant of the min-max fair nucleolus.
  We consider two types of routing games based on the agents' Performance
Objectives, namely bottleneck routing games and additive routing games. For
bottleneck games we establish that the core includes all system-optimal flow
profiles and that the nucleolus is system-optimal or disadvantageous for the
smallest agent in the system. Moreover, we describe an interesting set of
scenarios for which the nucleolus is always system-optimal. For additive games,
we focus on the fundamental load balancing game of routing over parallel links.
We establish that, in contrary to bottleneck games, not all system-optimal flow
profiles lie in the core. However, we describe a specific system-optimal flow
profile that does lie in the core and, under assumptions of symmetry, is equal
to the nucleolus.


title: A topological group of extensions of $\Q$ by $\Z$

abstract:
  The group of extensions (as in the title), endowed with something like a
connection at Archimedean infinity, is isomorphic to the ad\'ele-class group of
$\Q$: which is a topological group with interesting Haar measure.}


title:
Distributed Control of Multiagent Systems under Unknown Persistent
  Disturbances

abstract:
  This paper focuses on the consensus and formation problems of multiagent
systems under unknown persistent disturbances. Specifically, we propose a novel
method that combines an existing consensus (or formation) algorithm with a new
controller. The new controller has an integral action that produces a control
input based on an error signal locally projected onto the column space of the
graph Laplacian. This action allows agents to achieve a consensus or a
predetermined formation objective under constant or time-varying disturbances.
This study has analyzed the stability properties of this architecture and
provides several illustrative examples to demonstrate the proposed approach.


title: The sandpile groups of graphs of classes CH_n (a_1, ..., a_n)

abstract:
  The article considers the procedure of connection of graphs to the edges of a
cyclic graph and its influence on the sandpile group of the graph thus
obtained. A series of classes of graphs CH_n(a_1,...,a_n) is defined. Recurrent
and non-recurrent formulas for calculating the sandpile groups of all graphs of
classes CH_n (a_1, ..., a_n) are proposed.


title:
Momentum-Resolved Electronic Relaxation Dynamics in D-wave
  Superconductors

abstract:
  Motivated by recent development in time-resolved angle-resolved photoemission
spectroscopy (trARPES) for d-wave superconductors, we analyze the
non-equilibrium relaxation dynamics of the laser pulse excited sample within
the scenario of two-temperature model. It is shown that the main features
reported in the trARPES technique may be understood within this
phenomenological picture. The momentum dependence of the excited quasiparticle
density and the relaxation rate is associated with the dynamics of the nodal
d-wave superconducting gap, and the fluence dependence of the relaxation rate
is related to the recombination process of quasiparticles into Cooper pairs.


title:
Predicting Social Links for New Users across Aligned Heterogeneous
  Social Networks

abstract:
  Online social networks have gained great success in recent years and many of
them involve multiple kinds of nodes and complex relationships. Among these
relationships, social links among users are of great importance. Many existing
link prediction methods focus on predicting social links that will appear in
the future among all users based upon a snapshot of the social network. In
real-world social networks, many new users are joining in the service every
day. Predicting links for new users are more important. Different from
conventional link prediction problems, link prediction for new users are more
challenging due to the following reasons: (1) differences in information
distributions between new users and the existing active users (i.e., old
users); (2) lack of information from the new users in the network. We propose a
link prediction method called SCAN-PS (Supervised Cross Aligned Networks link
prediction with Personalized Sampling), to solve the link prediction problem
for new users with information transferred from both the existing active users
in the target network and other source networks through aligned accounts. We
proposed a within-target-network personalized sampling method to process the
existing active users' information in order to accommodate the differences in
information distributions before the intra-network knowledge transfer. SCAN-PS
can also exploit information in other source networks, where the user accounts
are aligned with the target network. In this way, SCAN-PS could solve the cold
start problem when information of these new users is total absent in the target
network.


title: Instabilities by ionic bombardment

abstract:
  This fluid dynamics video is an entry for the Gallery of Fluid Motion of the
66th Annual Meeting of the APS-DFD. This work reveals new types of interfacial
instabilities that occur during forced-spreading of dielectric films subjected
to ionic bombardment. We demonstrated that keeping the ionic bombardment
strength constant, the appearance of instability patterns dramatically changes
by varying viscosity of the bombarded droplet.


title:
On a new method for calculation of the number of prime numbers in the
  given interval

abstract: Definition of the number of prime numbers in the given interval


title:
Type-Ia Supernova Rates to Redshift 2.4 from CLASH: the Cluster Lensing
  And Supernova survey with Hubble

abstract:
  We present the supernova (SN) sample and Type-Ia SN (SN Ia) rates from the
Cluster Lensing And Supernova survey with Hubble (CLASH). Using the Advanced
Camera for Surveys and the Wide Field Camera 3 on the Hubble Space Telescope
(HST), we have imaged 25 galaxy-cluster fields and parallel fields of
non-cluster galaxies. We report a sample of 27 SNe discovered in the parallel
fields. Of these SNe, ~13 are classified as SN Ia candidates, including four SN
Ia candidates at redshifts z > 1.2. We measure volumetric SN Ia rates to
redshift 1.8 and add the first upper limit on the SN Ia rate in the range 1.8 <
z < 2.4. The results are consistent with the rates measured by the HST/GOODS
and Subaru Deep Field SN surveys. We model these results together with previous
measurements at z < 1 from the literature. The best-fitting SN Ia delay-time
distribution (DTD; the distribution of times that elapse between a short burst
of star formation and subsequent SN Ia explosions) is a power law with an index
of -1.00 +0.06(0.09) -0.06(0.10) (statistical) +0.12 -0.08 (systematic), where
the statistical uncertainty is a result of the 68% and 95% (in parentheses)
statistical uncertainties reported for the various SN Ia rates (from this work
and from the literature), and the systematic uncertainty reflects the range of
possible cosmic star-formation histories. We also test DTD models produced by
an assortment of published binary population synthesis (BPS) simulations. The
shapes of all BPS double-degenerate DTDs are consistent with the volumetric SN
Ia measurements, when the DTD models are scaled up by factors of 3-9. In
contrast, all BPS single-degenerate DTDs are ruled out by the measurements at a
>99% significance level.


title:
Dissipative length scale estimates for turbulent flows - a Wiener
  algebra approach

abstract:
  In this paper, a lower bound estimate on the uniform radius of spatial
analyticity is established for solutions to the incompressible, forced
Navier-Stokes system on an n-torus. This estimate improves or matches
previously known estimates provided that certain bounds on the initial data are
satisfied. It is argued that for 2D or 3D turbulent flows, the initial data is
guaranteed to satisfy these hypothesized bounds on a significant portion of the
2D global attractor or the 3D weak attractor. In these scenarios, the estimate
obtained for 3D generalizes and improves upon that of [Doering-Titi], while in
2D, the estimate matches the best known one found in [Kukavica]. A key feature
in the approach taken here is the choice of the Wiener algebra as the phase
space, i.e., the Banach algebra of functions with absolutely convergent Fourier
series, whose structure is suitable for the use of the so-called Gevrey norms.


title:
Herschel observations: contraints on dust attenuation and star formation
  histories at high redshift

abstract:
  SPICA is one of the key projects for the future. Not only its instrument
suite will open up a discovery window but they will also allow to physically
understand some of the phenomena that we still do not understand in the
high-redshift universe. Using new homogeneous luminosity functions (LFs) in the
Far-Ultraviolet (FUV) from VVDS and in the Far-Infrared (FIR) from Herschel/PEP
and Herschel/HerMES, we studied the evolution of the dust attenuation with
redshift. With this information, we are able to estimate the redshift evolution
of the total (FUV + FIR) star formation rate density (SFRD_TOT). Our main
conclusions are that: 1) the dust attenuation A_FUV is found to increase from z
= 0 to $z \sim 1.2 and then starts to decrease until our last data point at z =
3.6; 2) the estimated SFRD confirms published results to z \sim 2. At z > 2, we
observe either a plateau or a small increase up to z \sim 3 and then a likely
decrease up to z = 3.6; 3) the peak of A_FUV is delayed with respect to the
plateau of SFRD_TOT but the origin of this delay is not understood yet, and
SPICA instruments will provide clues to move further in the physical
understanding of this delay but also on the detection and redshift measurements
of galaxies at higher redshifts. This work is further detailed in Burgarella et
al. (2013).


title:
New Ways to Promote Sustainability and Social Well-Being in a Complex,
  Strongly Interdependent World: The FuturICT Approach

abstract:
  FuturICT is one of six proposals currently being considered for support
within the European Commission's Flagship Initiative (see Box 1). The vision of
the FuturICT project is to develop new science and new information and
communication systems that will promote social self-organization,
self-regulation, well-being, sustainability, and resilience. One of the main
aims of the approach is to increase individual opportunities for social,
economic and political participation, combined with the creation of collective
awareness of the impact that human actions have on our world. This requires us
to mine large datasets ("Big Data") and to develop new methods and tools: a
Planetary Nervous System (PNS) to answer "What is (the state of the world)..."
questions, a Living Earth Simulator (LES) to study "What ... if ..." scenarios,
and a Global Participatory Platform (GPP) for social exploration and
interaction.


title: Forecasting of Events by Tweet Data Mining

abstract:
  This paper describes the analysis of quantitative characteristics of frequent
sets and association rules in the posts of Twitter microblogs related to
different event discussions. For the analysis, we used a theory of frequent
sets, association rules and a theory of formal concept analysis. We revealed
the frequent sets and association rules which characterize the semantic
relations between the concepts of analyzed subjects. The support of some
frequent sets reaches its global maximum before the expected event but with
some time delay. Such frequent sets may be considered as predictive markers
that characterize the significance of expected events for blogosphere users. We
showed that the time dynamics of confidence in some revealed association rules
can also have predictive characteristics. Exceeding a certain threshold may be
a signal for corresponding reaction in the society within the time interval
between the maximum and the probable coming of an event. In this paper, we
considered two types of events: the Olympic tennis tournament final in London,
2012 and the prediction of Eurovision 2013 winner.


title: Can Twitter Predict Royal Baby's Name ?

abstract:
  In this paper, we analyze the existence of possible correlation between
public opinion of twitter users and the decision-making of persons who are
influential in the society. We carry out this analysis on the example of the
discussion of probable name of the British crown baby, born in July, 2013. In
our study, we use the methods of quantitative processing of natural language,
the theory of frequent sets, the algorithms of visual displaying of users'
communities. We also analyzed the time dynamics of keyword frequencies. The
analysis showed that the main predictable name was dominating in the spectrum
of names before the official announcement. Using the theories of frequent sets,
we showed that the full name consisting of three component names was the part
of top 5 by the value of support. It was revealed that the structure of
dynamically formed users' communities participating in the discussion is
determined by only a few leaders who influence significantly the viewpoints of
other users.


title: High-frequency capillary waves excited by oscillating microbubbles

abstract:
  This fluid dynamics video shows high-frequency capillary waves excited by the
volumetric oscillations of microbubbles near a free surface. The frequency of
the capillary waves is controlled by the oscillation frequency of the
microbubbles, which are driven by an ultrasound field. Radial capillary waves
produced by single bubbles and interference patterns generated by the
superposition of capillary waves from multiple bubbles are shown.


title:
Jahn-Teller distortion induced magnetic phase transition in cubic
  BaFeO$_{3}$

abstract:
  Using density functional theory (DFT) with local density approximation (LDA)
and generalized gradient approximation (GGA) correlation functionals, the
electronic and magnetic structures of cubic BaFeO$_{3}$ in the ferromagnetic
(FM) and antiferromagnetic (AFM) states are studied. Our LDA/GGA and
LDA$+U$/GGA$+U$ results show that cubic BFO has a FM ground state, in agreement
with recent experimental works. Two types of Jahn-Teller (JT) distortions,
denoted as JT1 and JT2, are considered. We find FM to ferrimagnetic (FIM) and
FM to AFM magnetic phase transitionn in the JT1 and JT2 type of distortions,
respectively. Larger strains are required for the FM-AFM transition as compared
to the FM-FIM. DFT$+U$ calculations also show that the magnetic moments
dramatically decrease at large strains due to strong overlapping between the Fe
and O atoms. The origins of these transitions is discussed in terms of a
competition between double exchange and superexchange interactions. Oxygen and
Fe displacements are therefore responsible for the magnetic phase transitions
and the reduction of the magnetic moments.


title: A Remark on Unconditional Uniqueness in the Chern-Simons-Higgs Model

abstract:
  The solution of the Chern-Simons-Higgs model in Lorenz gauge with data for
the potential in $H^{s-1/2}$ and for the Higgs field in $H^s \times H^{s-1}$ is
shown to be unique in the natural space $C([0,T];H^{s-1/2} \times H^s \times
H^{s-1})$ for $s \ge 1$, where $s=1$ corresponds to finite energy. Huh and Oh
recently proved local well-posedness for $s > 3/4$, but uniqueness was obtained
only in a proper subspace $Y^s$ of Bourgain type. We prove that any solution in
$C([0,T];H^{1/2} \times H^1 \times L^2)$ must in fact belong to the space
$Y^{3/4+\epsilon}$, hence it is the unique solution obtained by Huh and Oh.


title: On the fundamental group of certain polyhedral products

abstract:
  Let $K$ be a finite simplicial complex, and $(X,A)$ be a pair of spaces. The
purpose of this article is to study the fundamental group of the polyhedral
product denoted $Z_K(X,A)$, which denotes the moment-angle complex of
Buchstaber-Panov in the case $(X,A) = (D^2, S^1)$, with extension to arbitrary
pairs in [2] as given in Definition 2.2 here.
  For the case of a discrete group $G$, we give necessary and sufficient
conditions on the abstract simplicial complex $K$ such that the polyhedral
product denoted by $Z_K(\underline{BG})$ is an Eilenberg-Mac Lane space. The
fundamental group of $Z_K(\underline{BG})$ is shown to depend only on the
1-skeleton of $K$. Further special examples of polyhedral products are also
investigated.
  Finally, we use polyhedral products to study an extension problem related to
transitively commutative groups, which are given in Definition 5.2.


title: Effective Field Theory calculations of $NN\to NN\pi$

abstract:
  In this review we present the recent advances for calculations of the
reactions $NN\to NN\pi$ using chiral effective field theory. Discussed are the
next-to-next-to leading order loop contributions with nucleon and Delta-isobar
for near threshold s-wave pion production. Results of recent experimental
pion-production data for energies close to the threshold are analyzed. Several
particular applications are discussed: (i) it is shown how the measured charge
symmetry violating pion-production reaction can be used to extract the
strong-interaction contribution to the proton-neutron mass difference; (ii) the
role of $NN\to NN\pi$ for the extraction of the pion-nucleon scattering lengths
from pionic atoms data is illuminated.


title: Geometry of Rational Curves on Low degree Complete Intersections

abstract:
  For a smooth complete intersection X, we consider a general fiber \mathbb{F}
of the evaluation map ev of Kontsevich moduli space
\bar{M}_{0,m}(X,m)\rightarrow X^m and the forgetful functor F : \mathbb{F}
\rightarrow \bar{M}_{0,m}. We prove that a general fiber of the map $F$ is a
smooth complete intersection if $X$ is of low degree. The result sheds some
light on the arithmetic and geometry of Fano complete intersections.


title: On the Separated Bumps Conjecture for Calderon-Zygmund Operators

abstract:
  We study the `separated bump conjecture' of Cruz-Uribe & Perez, and
Cruz-Uribe & Reznikov & Volberg. In the L^p setting, we formulate a stronger
version of this conjecture, and show that under it, a two weight inequality
holds for all CZOs. When p=2, this is the result of Nazarov & Reznikov &
Volberg (1306.2653). Our argument is based on stopping time arguments and the
extra hypothesis is used in a clear-cut and seemingly essential way. This
argument could be of some help in searching for a counterexample to the
conjecture.


title: Using Twisted Alexander Polynomials to Detect Fiberdness

abstract:
  In this paper we use twisted Alexander polynomials to prove that the exterior
of a particular graph knot is not fibered. Then we build three 2-component
graph links out of this knot, and use similar techniques to discuss their
fiberedness.


title:
Bounds on self-interacting fermion dark matter from observations of old
  neutron stars

abstract:
  The existence of old neutron stars deeply constrains self-interacting fermion
dark matter, which can form star-killing black holes. We quantify this
constraint on dark matter-nucleon scattering, considering collapse scenarios
that broaden bounds over intermediate masses. We then find the self- and
co-annihilation rates necessary to lift these dark matter-nucleon scattering
bounds. For Yukawa-coupled dark matter that fits dwarf galaxy halo profiles
with a coupling $\alpha = 10^{-1}-10^{-4}$, a scalar mediator mass $m_\phi =
1-500$ MeV, and DM mass $m_X = 0.1-10^7$ GeV, we show that fermion dark matter
is unconstrained if it self-annihilates at a rate greater than $10^{-40} ~
\rm{cm^3/s}$ or co-annihilates with baryons at a rate greater than $10^{-50} ~
\rm{cm^3/s}$.


title: Fission of Halving Edges Graphs

abstract:
  In this paper we discuss an operation on halving edges graph that we call
fission. Fission replaces each point in a given configuration with a small
cluster of k points. The operation interacts nicely with halving edges, so we
examine its properties in detail.


title:
Spin-wave-induced corrections to the electronic density of states in
  metallic ferromagnets

abstract:
  We calculate the correction to the electronic density of states in a
disordered ferromagnetic metal induced by spin-wave mediated interaction
between the electrons. Our calculation is valid for the case that the exchange
splitting in the ferromagnet is much smaller than the Fermi energy, but we make
no assumption on the relative magnitude of the exchange splitting and the
elastic electronic scattering time. In the "clean limit", where the exchange
splitting is much larger than the electronic scattering rate, we find a
correction with a T^{d/2} temperature dependence, where d is the effective
dimensionality of the ferromagnet. In the opposite "dirty limit" the
density-of-states correction is a non-monotonous function of energy and
temperature.


title: Vibration Isolation Design for the Micro-X Rocket Payload

abstract:
  Micro-X is a NASA-funded, sounding rocket-borne X-ray imaging spectrometer
that will allow high precision measurements of velocity structure, ionization
state and elemental composition of extended astrophysical systems. One of the
biggest challenges in payload design is to maintain the temperature of the
detectors during launch. There are several vibration damping stages to prevent
energy transmission from the rocket skin to the detector stage, which causes
heating during launch. Each stage should be more rigid than the outer stages to
achieve vibrational isolation. We describe a major design effort to tune the
resonance frequencies of these vibration isolation stages to reduce heating
problems prior to the projected launch in the summer of 2014.


title:
Classical density functional theory for associating fluids in orienting
  external fields

abstract:
  We develop a classical density functional theory (DFT) for two site
associating fluids in spatially uniform external fields which exhibit
orientational inhomogeneities. The Helmholtz free energy functional is obtain
using Wertheim's thermodynamic perturbation theory and the orientational
distribution function is obtained using DFT in the canonical ensemble. It is
shown that an orienting field significantly enhances association by ordering
the molecules thereby reducing the entropic penalty of association. It is also
shown that association enhances orientational order for fixed field strength.


title:
Existence of globally attracting fixed points of viscous Burgers
  equation with constant forcing. A computer assisted proof

abstract:
  We present a computer assisted method for proving the existence of globally
attracting fixed points of dissipative PDEs. An application to the viscous
Burgers equation with periodic boundary conditions and a forcing function
constant in time is presented as a case study. We establish the existence of a
locally attracting fixed point by using rigorous numerics techniques. To prove
that the fixed point is, in fact, globally attracting we introduce a technique
relying on a construction of an absorbing set, capturing any sufficiently
regular initial condition after a finite time. Then the absorbing set is
rigorously integrated forward in time to verify that any sufficiently regular
initial condition is in the basin of attraction of the fixed point.


title: Operators on Symmetric Polynomials

abstract:
  We provide a brief survey of a certain algebra of operators on symmetric
polynomials, and collect a number of previously known results in the field.


title:
Inverse Elastic Scattering for Multiscale Rigid Bodies with A Single
  Far-field Pattern

abstract:
  We develop three inverse elastic scattering schemes for locating multiple
small, extended and multiscale rigid bodies, respectively. There are some
salient and promising features of the proposed methods. The cores of those
schemes are certain indicator functions, which are obtained by using only a
single far-field pattern of the pressure (longitudinal) wave, or the shear
(transversal) wave, or the total wave field. Though the inverse scattering
problem is known to be nonlinear and ill-posed, the proposed reconstruction
methods are totally "direct" and there are no inversions involved. Hence, the
methods are very efficient and robust against noisy data. Both rigorous
mathematical justifications and numerical simulations are presented in our
study.


title:
Superconducting gap in LiFeAs from three-dimensional spin-fluctuation
  pairing calculations

abstract:
  The lack of nesting of the electron and hole Fermi-surface sheets in the
Fe-based superconductor LiFeAs, with a critical temperature of 18 K, has led to
questions as to whether the origin of superconductivity in this material might
be different from other Fe-based superconductors. Both angle-resolved
photoemission and quasiparticle interference experiments have reported fully
gapped superconducting order parameters with significant anisotropy. The system
is also of interest because relatively strong correlations seem to be
responsible for significant renormalization of the hole bands. Here we present
calculations of the superconducting gap and pairing in the random-phase
approximation using Fermi surfaces derived from measured photoemission spectra.
The qualitative features of the gaps obtained in these calculations are shown
to be different from previous two-dimensional theoretical works, and in good
agreement with experiment on the main Fermi surface pockets. We analyze the
contributions to the pairing vertex thus obtained and show that the scattering
processes between electron and hole pockets that are believed to dominate the
pairing in other Fe-based superconductors continue to do so in LiFeAs despite
the lack of nesting, leading to gaps with anisotropic $s_\pm$ structure. Some
interesting differences relating to the enhanced $d_{xy}$ orbital content of
the LiFeAs Fermi surface are noted.


title: Non-identifiability of identity coefficients at biallelic loci

abstract:
  Shared genealogies introduce allele dependencies in diploid genotypes, as
alleles within an individual or between different individuals will likely match
when they originate from a recent common ancestor. At a locus shared by a pair
of diploid individuals, there are nine combinatorially distinct modes of
identity-by-descent (IBD), capturing all possible combinations of coancestry
and inbreeding. A distribution over the IBD modes is described by the nine
associated probabilities, known as (Jacquard's) identity coefficients. The
genetic relatedness between two individuals can be succinctly characterized by
the identity coefficients corresponding to the joint genealogy. The identity
coefficients (together with allele frequencies) determine the distribution of
joint genotypes at a locus. At a locus with two possible alleles, identity
coefficients are not identifiable because different coefficients can generate
the same genotype distribution.
  We analyze precisely how different IBD modes combine into identical genotype
distributions at diallelic loci. In particular, we describe IBD mode mixtures
that result in identical genotype distributions at all allele frequencies,
implying the non-identifiability of the identity coefficients from independent
loci. Our analysis yields an exhaustive characterization of relatedness
statistics that are always identifiable. Importantly, we show that identifiable
relatedness statistics include the kinship coefficient (probability that a
random pair of alleles are identical by descent between individuals) and
inbreeding-related measures, which can thus be estimated from genotype
distributions at independent loci.


title: A remark on the simple cuspidal representations of GL(n, F)

abstract:
  Let $F$ be a non-archimedean local field of residue characteristic $p$, $G$
be the group $GL(n, F)$. In this note, under the assumption $(n, p)=1$, we show
a simple cuspidal representation $\pi$ (that with normalized level
$\frac{1}{n}$) of $G$ is determined uniquely up to isomorphism by the local
constants of $\chi\circ \text{det}\otimes \pi$ for all characters $\chi$ of
$F^\times$.


title: The minimum rank of a sign pattern matrix with a 1-separation

abstract:
  A sign pattern matrix is a matrix whose entries are from the set $\{+,-,0\}$.
If $A$ is an $m\times n$ sign pattern matrix, the qualitative class of $A$,
denoted $Q(A)$, is the set of all real $m\times n$ matrices $B=[b_{i,j}]$ with
$b_{i,j}$ positive (respectively, negative, zero) if $a_{i,j}$ is +
(respectively, $-$, 0). The minimum rank of a sign pattern matrix $A$, denoted
$\mr(A)$, is the minimum of the ranks of the real matrices in $Q(A)$.
Determination of the minimum rank of a sign pattern matrix is a longstanding
open problem.
  For the case that the sign pattern matrix has a 1-separation, we present a
formula to compute the minimum rank of a sign pattern matrix using the minimum
ranks of certain generalized sign pattern matrices associated with the
1-separation.


title: Platform Competition as Network Contestability

abstract:
  Recent research in industrial organisation has investigated the essential
place that middlemen have in the networks that make up our global economy. In
this paper we attempt to understand how such middlemen compete with each other
through a game theoretic analysis using novel techniques from decision-making
under ambiguity. We model a purposely abstract and reduced model of one
middleman who pro- vides a two-sided platform, mediating surplus-creating
interactions between two users. The middleman evaluates uncertain outcomes
under positional ambiguity, taking into account the possibility of the
emergence of an alternative middleman offering intermediary services to the two
users. Surprisingly, we find many situations in which the middleman will
purposely extract maximal gains from her position. Only if there is relatively
low probability of devastating loss of business under competition, the
middleman will adopt a more competitive attitude and extract less from her
position.


title:
Deconfinement in N=1 super Yang-Mills theory on R^3 x S^1 via
  dual-Coulomb gas and "affine" XY-model

abstract:
  We study finite-temperature N=1 SU(2) super Yang-Mills theory, compactified
on a spatial circle of size L with supersymmetric boundary conditions. In the
semiclassical small-L regime, a deconfinement transition occurs at T_c <<1/L.
The transition is due to a competition between non-perturbative topological
"molecules"---magnetic and neutral bion-instantons---and electrically charged
W-bosons and superpartners. Compared to deconfinement in non-supersymmetric
QCD(adj) arXiv:1112.6389, the novelty is the relevance of the light modulus
scalar field. It mediates interactions between neutral bions (and W-bosons),
serves as an order parameter for the Z_2^{L} center symmetry associated with
the non-thermal circle, and explicitly breaks the electric-magnetic
(Kramers-Wannier) duality enjoyed by non-supersymmetric QCD(adj) near T_c. We
show that deconfinement can be studied using an effective two-dimensional gas
of electric and magnetic charges with (dual) Coulomb and Aharonov-Bohm
interactions, or, equivalently, via an XY-spin model with a symmetry-breaking
perturbation, where each system couples to the scalar field. To study the
realization of the discrete R-symmetry and the Z_2^{beta} thermal and Z_2^{L}
non-thermal center symmetries, we perform Monte Carlo simulations of both
systems. The dual-Coulomb gas simulations are a novel way to analyze
deconfinement and provide a new venue to study the phase structure of a class
of two-dimensional condensed matter models that can be mapped into dual-Coulomb
gases. Our results indicate a continuous deconfinement transition, with Z_2^{L}
remaining unbroken at the transition. Thus, the SYM transition appears similar
to the one in SU(2) QCD(adj) arXiv:1112.6389 and is also likely to be
characterized by continuously varying critical exponents.

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


title: Underwater Gas Expansion and Deflagration

abstract:
  The underwater combustion of a propane-air mixture in an acrylic cylinder is
captured on video from multiple angles. This experiment is designed to provide
visual data and pressure time-histories for future CFD validation studies.


title: What the Timing of Millisecond Pulsars Can Teach us about Their Interior

abstract:
  The cores of compact stars reach the highest densities in nature and
therefore could consist of novel phases of matter. We demonstrate via a
detailed analysis of pulsar evolution that precise pulsar timing data can
constrain the star's composition, through unstable global oscillations
(r-modes) whose damping is determined by microscopic properties of the
interior. If not efficiently damped, these modes emit gravitational waves that
quickly spin down a millisecond pulsar. As a first application of this general
method, we find that ungapped interacting quark matter is consistent with both
the observed radio and x-ray data, whereas for ordinary nuclear matter some
additional enhanced damping mechanism is required.


title:
Optically-driven nuclear-spin-selective Rabi oscillations of single
  electron spins in diamond

abstract:
  Optically-driven Rabi oscillations of single electron spins in a diamond
nitrogen vacancy center are realized with two Raman-resonant optical pulses
that are detuned from the respective dipole optical transitions. The Rabi
oscillations are nuclear-spin selective and are robust against rapid
decoherence of the underlying optical transitions, opening the door to
generating phonon-mediated spin entanglement in an optically-driven spin-phonon
system. A direct comparison between the Rabi oscillations and simulated Raman
adiabatic passage along with a detailed theoretical analysis provide a wealth
of information on the coherent spin dynamics and in particular reveal that
decoherence and environmental fluctuations associated with the optical
transitions affect the fidelity of the Rabi oscillations through relatively
large jumps in the transition frequencies.


title: Cycles in Random Bipartite Graphs

abstract:
  In this paper we study cycles in random bipartite graph $G(n,n,p)$. We prove
that if $p\gg n^{-2/3}$, then $G(n,n,p)$ a.a.s. satisfies the following. Every
subgraph $G'\subset G(n,n,p)$ with more than $(1+o(1))n^2p/2$ edges contains a
cycle of length $t$ for all even $t\in[4,(1+o(1))n/30]$. Our theorem
complements a previous result on bipancyclicity, and is closely related to a
recent work of Lee and Samotij.


title:
Enrichments of Boolean Algebras: a uniform treatment of some classical
  and some novel examples

abstract:
  We give a unified treatment of the model theory of various enrichments of
infinite atomic Boolean algebras, with special attention to
quantifier-eliminations, complete axiomatizations and decidability. A classical
example is the enrichment by a predicate for the ideal of finite sets, and a
novel one involves predicates giving congruence conditions on the cardinality
of finite sets. We focus on three examples, and classify them by expressive
power.


title: Evolution and Controllability of Cancer Networks: a Boolean Perspective

abstract:
  Cancer forms a robust system and progresses as stages over time typically
with increasing aggressiveness and worsening prognosis. Characterizing these
stages and identifying the genes driving transitions between them is critical
to understand cancer progression and to develop effective anti-cancer
therapies. Here, we propose a novel model of the 'cancer system' as a Boolean
state space in which a Boolean network, built from protein interaction and
gene-expression data from different stages of cancer, transits between Boolean
satisfiability states by "editing" interactions and "flipping" genes. The
application of our model (called BoolSpace) on three case studies - pancreatic
and breast tumours in human and post spinal-cord injury in rats - reveals
valuable insights into the phenomenon of cancer progression. In particular, we
notice that several of the genes flipped are serine/threonine kinases which act
as natural cellular switches and that different sets of genes are flipped
during the initial and final stages indicating a pattern to tumour progression.
We hypothesize that robustness of cancer partly stems from "passing of the
baton" between genes at different stages, and therefore an effective therapy
should target a "cover set" of these genes. A C/C++ implementation of BoolSpace
is freely available at: http://www.bioinformatics.org.au/tools-data


title:
On the origin of long-range azimuthal correlations in hadronic
  collisions

abstract:
  We review the models suggested, to date, as an explanation for the so called
"ridge" phenomenon, an elongation in rapidity of 2-particle correlations seen
at RHIC and LHC energies. We argue that these models can be divided into two
phenomenologically distinct classes: "Hotspot+flow" driven correlations, where
initial state correlations created by structures local in configuration space
are collimated by transverse flow, and models where the azimuthal correlation
is created through local partonic interactions in a high gluon density initial
state.
  We further argue that the key to distinguish these two scenarios is to
experimentally examine the role flow plays in the ridge. The measurement of a
strong double ridge in $pA$ and $dA$ collisions allows a good opportunity to
understand the ridge's origin. In this sense, particle-identified correlations
are particularly promising way of testing the assumptions at the base of either
of the two models above.
  The successful fit of the pA ridge by hydrodynamic models \cite{us},
therefore, suggests that the ridge is primarily a "final state effect"
generated by radial expansion, although its scaling across system sizes is
non-trivial to reconcile with hydrodynamic expectations. We close by discussing
experimental observables capable of clarifying the situation.


title: Symmetric Extension of Two-Qubit States

abstract:
  Quantum key distribution uses public discussion protocols to establish shared
secret keys. In the exploration of ultimate limits to such protocols, the
property of symmetric extendibility of underlying bipartite states $\rho_{AB}$
plays an important role. A bipartite state $\rho_{AB}$ is symmetric extendible
if there exits a tripartite state $\rho_{ABB'}$, such that the $AB$ marginal
state is identical to the $AB'$ marginal state, i.e. $\rho_{AB'}=\rho_{AB}$.
For a symmetric extendible state $\rho_{AB}$, the first task of the public
discussion protocol is to break this symmetric extendibility. Therefore to
characterize all bi-partite quantum states that possess symmetric extensions is
of vital importance. We prove a simple analytical formula that a two-qubit
state $\rho_{AB}$ admits a symmetric extension if and only if
$\tr(\rho_B^2)\geq \tr(\rho_{AB}^2)-4\sqrt{\det{\rho_{AB}}}$. Given the
intimate relationship between the symmetric extension problem and the quantum
marginal problem, our result also provides the first analytical necessary and
sufficient condition for the quantum marginal problem with overlapping
marginals.


title: Factorial moments of point processes

abstract:
  We derive joint factorial moment identities for point processes with
Papangelou intensities. Our proof simplifies previous approaches to related
moment identities and includes the setting of Poisson point processes.
Applications are given to random transformations of point processes and to
their distribution invariance properties.


title: Oscillatory behavior of the domain wall fermions revisited

abstract:
  In the generic domain wall fermion formulation of chiral fermions on the
lattice, the zero modes of the four-dimensional Wilson fermion operator with
the negative mass parameter $-M_5$ introduce unphysical massive modes
propagating in the four-dimensional spacetime. In the free fermion case, the
pole mass of this kind of unphysical modes is given by $\tilde{E}=\ln(1-M_5)$,
which acquires an imaginary part, $i\pi$, when $M_5>1$ and results in an
oscillatory behavior of the domain wall fermion propagator in time. The
existence of the unphysical modes in the presence of gauge fields is
investigated in the mean field approximation, and their physical consequences
are discussed. In addition, we also give a semiquantitative criterion for
tuning $M_5$ in the realistic numerical study.


title:
All-order calculations of the spectra of Ba II, Ra II, Fr I and
  superheavy elements E119 I and E120 II

abstract:
  A technique based on summation of dominating classes of correlation diagrams
to all orders in Coulomb interaction is used to calculate the energies of the
lowest $s,p$ and $d$ states of Ba II, Ra II, Fr I, E119 I and E120 II. Breit
and quantum electrodynamic corrections are also included. Comparison with
experiment for Ba II, Ra II and Fr I demonstrates that the accuracy of the
calculations is on the level of 0.1%. The technique has been applied to predict
the spectra of superheavy elements E119 and E120$^+$. The role of the {\em
ladder diagrams} (V. A. Dzuba, Phys. Rev. A {\bf 78}, 042502 (2008)) which is
the most recent addition to the method has been emphasised. Their inclusion
significantly improves the accuracy of the calculations and expands the
applicability of the method.


title: On the GIT Quotient Space of Quintic Surfaces

abstract:
  We describe the GIT compactification for the moduli space of smooth quintic
surfaces in projective space. In particular, we show that a normal quintic
surface with at worst an isolated double point or a minimal elliptic
singularity is stable. We also describe the boundary of the GIT quotient, and
we discuss the stability of the non-normal surfaces.


title: Cyclic spectroscopy of The Millisecond Pulsar, B1937+21

abstract:
  Cyclic spectroscopy is a signal processing technique that was originally
developed for engineering applications and has recently been introduced into
the field of pulsar astronomy. It is a powerful technique with many attractive
features, not least of which is the explicit rendering of information about the
relative phases in any filtering imposed on the signal, thus making holography
a more straightforward proposition. Here we present methods for determining
optimum estimates of both the filter itself and the statistics of the
unfiltered signal, starting from a measured cyclic spectrum. In the context of
radio pulsars these quantities tell us the impulse response of the interstellar
medium and the intrinsic pulse profile. We demonstrate our techniques by
application to 428 MHz Arecibo data on the millisecond pulsar B1937+21,
obtaining the pulse profile free from the effects of interstellar scattering.
As expected, the intrinsic profile exhibits main- and inter-pulse components
that are narrower than they appear in the scattered profile; it also manifests
some weak, but sharp features that are revealed for the first time at low
frequency. We determine the structure of the received electric-field envelope
as a function of delay and Doppler-shift. Our delay-Doppler image has a high
dynamic-range and displays some pronounced, low-level power concentrations at
large delays. These concentrations imply strong clumpiness in the ionized
interstellar medium, on AU size-scales, which must adversely affect the timing
of B1937+21.


title:
Symmetry Protected Topological Charge in Symmetry Broken Phase:
  Spin-Chern, Spin-Valley-Chern and Mirror-Chern Numbers

abstract:
  The Chern number is a genuine topological number. On the other hand, a
symmetry protected topological (SPT) charge is a topological number only when a
symmetry exists. We propose a formula for the SPT charge as a derivative of the
Chern number in terms of the Green function in such a way that it is valid and
related to the associated Hall current even when the symmetry is broken. We
estimate the amount of deviation from the quantized value as a function of the
strength of the broken symmetry. We present two examples. First, we consider
Dirac electrons with the spin-orbit coupling on honeycomb lattice, where the
SPT charges are given by the spin-Chern, valley-Chern and spin-valley-Chern
numbers. Though the spin-Chern charge is not quantized in the presence of the
Rashba coupling, the deviation is estimated to be $10^{-7}$ in the case of
silicene, a silicon cousin of graphene. Second, we analyze the effect of the
mirror-symmetry breaking of the mirror-Chern number in a thin-film of
topological crystalline insulator.


title: Integral models of P^1 and analytic distribution algebras for GL_2

abstract:
  In the first part of the paper we show that the ring of global sections of
arithmetic differential operators on the formal projective line over Zp is
isomorphic to the analytic distribution algebra of the 'wide open' congruence
subgroup of level zero of GL(2,Zp). In the second part we study rings of
logarithmic differential operators on semistable integral models of the
projective line over Zp and we relate these to analytic distribution algebra of
'wide open' congruence subgroups of higher level.


title: Uncovering MIT wind myths through micro-climatological CFD analysis

abstract:
  Popular campus myths of unusually strong pedestrian level winds are
investigated with a Computational Fluid Dynamics (CFD) approach. The numerical
simulations confirm the existence of the reported phenomena and provide a
qualitative explanation of their physical mechanisms.

categories: physics.ao-ph physics.comp-ph physics.flu-dyn physics.pop-ph


title: Discrete Symmetry in Relativistic Quantum Mechanics

abstract:
  EPR experiment on $K^0-\bar{K}^0$ system in 1998\cite{1} strongly hints that
one should use operators $\hat{E}_c=-i\hbar\frac{\partial}{\partial t}$ and
$\hat{\bf p}_c=i\hbar\nabla$ for the wavefunction (WF) of antiparticle. Further
analysis on Klein-Gordon (KG) equation reveals that there is a discrete
symmetry hiding in relativistic quantum mechanics (RQM) that ${\cal P}{\cal
T}={\cal C}$. Here ${\cal P}{\cal T}$ means the (newly defined) combined
space-time inversion (with ${\bf x}\to -{\bf x}, t\to-t$), while ${\cal C}$ the
transformation of WF $\psi$ between particle and its antiparticle whose
definition is just residing in the above symmetry. After combining with
Feshbach-Villars (FV) dissociation of KG equation ($\psi=\phi+\chi$)\cite{2},
this discrete symmetry can be rigorously reformulated by the invariance of
coupling equation of $\phi$ and $\chi$ under either the combined space-time
inversion ${\cal P}{\cal T}$ or the mass inversion ($m\to -m$), which makes the
KG equation a self-consistent theory. Dirac equation is also discussed
accordingly. Various applications of this discrete symmetry are discussed,
including the prediction of antigravity between matter and antimatter as well
as the reason why we believe neutrinos are likely the tachyons.


title:
Sensitive dependence of isotope and isobar distribution of limiting
  temperatures on symmetry energy

abstract:
  The mass, isotope, and isobar distributions of limiting temperatures for
finite nuclei are investigated by using a thermodynamics approach together with
the Skyrme energy density functional.
  The relationship between the width of the isotope (isobar) distribution of
limiting temperatures and the stiffness of the density dependence of the
symmetry energy clearly is observed.
  The nuclear symmetry energy with smaller slope parameter $L_{\rm{sym}}$
causes a wider the isotope (isobar) distribution of limiting temperatures.
  The widths of the isotope (isobar) distributions of limiting temperatures
could be useful observables for exploring the information of the density
dependence of the nuclear symmetry energy at finite temperatures.


title: The ultraviolet and infrared perturbative finiteness of massless QED$_3$

abstract:
  The massless QED$_3$ is ultraviolet and infrared perturbatively finite,
parity and infrared anomaly free to all orders in perturbation theory.


title: Unbounded Weighted Composition Operators in L2-Spaces

abstract:
  Bounded and unbounded weighted composition operators on $L^2$ spaces over
$\sigma$-finite measure spaces are investigated. A variety of questions related
to seminormality of such operators are discussed.


title: Flavor revolution at ICECUBE horizons?

abstract:
  Recently (May-November 2013) highest energy neutrino events have been
presented by ICECUBE. Most (21) of all these (28) events are cascades shower
whose flux exhibits a sharp hardening respect other lower energy atmospheric
neutrino component, events suggesting an injection of extraterrestrial
neutrino, mostly nu e, nu tau, making cascades. ICECUBE claimed that a
component (10:6+5:0 3:6), a third, of these events must be a trace of expected
downward muons and-or atmospheric neutrinos (muon track dominated): The
probability that this scenario occurs is very poor, about 0.1- 0.5%. The
paradox might be mitigate as we suggest if nearly all of the 28 events are
originated by extraterrestrial sources arriving to us in de-coherent states. At
first sight also a partial solution may rise if highest energy events at E nu >
60 TeV ( 17 showering versus 4 muon tracks) are mostly of extraterrestrial
nature. However this solution leaves problematic the earlier 30 - 60 TeV energy
region, whose 8 showers versus 3 tracks is in tension with most nearby
atmospheric neutrino signals, by a sharp difference at TeV energy ruled (as
shown in Deep Core) by ten over one neutrino (muon) events over showers. This
puzzling (fast) flavor transition from atmospheric nu muon flux at TeV to tens
TeV showers and muon neutrino absence has deep consequences. Few cascades
shower events in Antares might also test the nu flavor changes above TeVs up to
a rare one at few tens TeV signal. Higher energy EeV tau air-shower induced by
UHE nu tau within mountains or Earth skin while skimming terrestrial ground as
AUGER arrays might be still rare, but the correlated horizontal upward PeVs tau
air-shower may soon shine into ASHRA crown telescopes at mountain edges by
their Cherenkov flashes.


title:
Optical rogue waves in the generalized inhomogeneous higher-order
  nonlinear Schrodinger equation with modulating coefficients

abstract:
  The higher-order dispersive and nonlinear effects (alias {\it the
perturbation terms}) like the third-order dispersion, the self-steepening, and
the self-frequency shift play important roles in the study of the ultra-short
optical pulse propagation. We consider optical rogue wave solutions and
interactions for the generalized higher-order nonlinear Schr\"odinger (NLS)
equation with space- and time-modulated parameters. A proper transformation is
presented to reduce the generalized higher-order NLS equation to the integrable
Hirota equation with constant coefficients. This transformation allows us to
relate certain class of exact solutions of the generalized higher-order NLS
equation to the variety of solutions of the integrable Hirota equation. In
particular, we illustrate the approach in terms of two lowest-order rational
solutions of the Hirota equation as seeding functions to generate rogue wave
solutions localized in time that have complicated evolution in space with or
without the differential gain or loss term. We simply analyze the physical
mechanisms of the obtained optical rogue waves on the basis of these
constraints. Finally, The stability of the obtained rogue-wave solutions is
addressed numerically. The obtained rogue wave solutions may raise the
possibility of relative experiments and potential applications in nonlinear
optics and other fields of nonlinear science as Bose-Einstein condensates and
ocean

categories: nlin.SI math-ph math.MP physics.class-ph physics.optics


title:
Gamma-Ray Emission in Dissipative Pulsar Magnetospheres: From Theory to
  Fermi Observations

abstract:
  We compute the patterns of $\gamma$-ray emission due to curvature radiation
in dissipative pulsar magnetospheres. Our ultimate goal is to construct
macrophysical models that are able to reproduce the observed $\gamma$-ray
light-curve phenomenology recently published in the Second Fermi Pulsar
Catalog. We apply specific forms of Ohm's law on the open field lines using a
broad range for the macroscopic conductivity values that result in solutions
ranging, from near-vacuum to near Force-Free. Using these solutions, we
generate model $\gamma$-ray light curves by calculating realistic trajectories
and Lorentz factors of radiating particles, under the influence of both the
accelerating electric fields and curvature radiation-reaction. We further
constrain our models using the observed dependence of the phase-lags between
the radio and $\gamma$-ray emission on the $\gamma$-ray peak-separation. We
perform a statistical comparison of our model radio-lag vs peak-separation
diagram and the one obtained for the Fermi standard pulsars. We find that for
models of uniform conductivity over the entire open magnetic field line region,
agreement with observations favors higher values of this parameter. We find,
however, significant improvement in fitting the data with models that employ a
hybrid form of conductivity; specifically, infinite conductivity interior to
the light-cylinder and high but finite conductivity on the outside. In these
models the $\gamma$-ray emission is produced in regions near the equatorial
current sheet but modulated by the local physical properties. These models have
radio-lags near the observed values and statistically best reproduce the
observed light-curve phenomenology. Additionally, these models produce GeV
photon cut-off energies.


title:
Formal degrees of unipotent discrete series representations and the
  exotic Fourier transform

abstract:
  We introduce a notion of elliptic fake degrees for unipotent elliptic
representations of a semisimple p-adic group. We conjecture, and verify in some
cases, that the relation between the formal degrees of unipotent discrete
series representations of a semisimple p-adic group and the elliptic fake
degrees is given by the exotic Fourier transform matrix introduced by Lusztig
in the study of representations of finite groups of Lie type.


title: Transient Current-Current Correlations and Noise Spectra

abstract:
  In this paper, we present an exact formalism for transient current-current
correlations and transient noise spectra. The exact solution of transient
current correlations in both the time domain and the frequency domain are
obtained. Without taking the wide band limit, we investigate transient
current-current correlations with different bias voltages and different finite
temperatures. Transient noise spectra over the whole frequency range are
calculated and that in the steady-state limit are also reproduced. From
transient current-current correlations and noise spectra, we analyze the
frequency-dependence of electron transport for the system evolving far away
from equilibrium to the steady state. Various time scales associated with the
energy structure of the nanosystem are also obtained from the transient
current-current correlations and transient noise spectra.


title: Grothendieck classes of quiver cycles as iterated residues

abstract:
  In the case of Dynkin quivers we establish a formula for the Grothendieck
class of a quiver cycle as the iterated residue of a certain rational function,
for which we provide an explicit combinatorial construction. Moreover, we
utilize a new definition of the double stable Grothendieck polynomials due to
Rimanyi and Szenes in terms of iterated residues to exhibit how the computation
of quiver coefficients can be reduced to computing coefficients in Laurent
expansions of certain rational functions.


title: Puzzling the 120-cell

abstract:
  We introduce Quintessence: a family of burr puzzles based on the geometry and
combinatorics of the 120-cell. We discuss the regular polytopes, their
symmetries, the dodecahedron as an important special case, the three-sphere,
and the quaternions. We then construct the 120-cell, giving an illustrated
survey of its geometry and combinatorics. This done, we describe the pieces out
of which Quintessence is made. The design of our puzzle pieces uses a drawing
technique of Leonardo da Vinci; the paper ends with a catalogue of new puzzles.