title: Exchange coupling and magnetic anisotropy at Fe/FePt interfaces

abstract:
  We perform fully relativistic first principles calculations of the exchange
interactions and the magnetocrystalline anisotropy energy (MAE) in an
Fe/FePt/Fe sandwich system in order to elucidate how the presence of Fe/FePt
(soft/hard magnetic) interfaces impacts on the magnetic properties of
Fe/FePt/Fe multilayers. Throughout our study we make comparisons between a
geometrically unrelaxed system and a geometrically relaxed system. We observe
that the Fe layer at the Fe/FePt interface plays a crucial role inasmuch its
(isotropic) exchange coupling to the soft (Fe) phase of the system is
substantially reduced. Moreover, this interfacial Fe layer has a substantial
impact on the MAE of the system. We show that the MAE of the FePt slab,
including the contribution from the Fe/FePt interface, is dominated by
anisotropic inter-site exchange interactions. Our calculations indicate that
the change in the MAE of the FePt slab with respect to the corresponding bulk
value is negative, i.e., the presence of Fe/FePt interfaces appears to reduce
the perpendicular MAE of the Fe/FePt/Fe system. However, for the relaxed
system, this reduction is marginal. It is also shown that the relaxed system
exhibits a reduced interfacial exchange. Using a simple linear chain model we
demonstrate that the reduced exchange leads to a discontinuity in the
magnetisation structure at the interface.


title:
Mapping Between Nonlinear Sch\"odinger Equations with Real and Complex
  Potentials

abstract:
  A mapping between stationary solutions of nonlinear Sch\"odinger equations
with real and complex potentials is constructed and a set of exact solutions
with real energies are obtained for a large class of complex potentials. As
specific examples we consider the case of the damped dynamics of a quantum
harmonic oscillator and the case of dissipative periodic soliton solutions of
the nonlinear Schr\"odinger equation with complex potential.


title:
Optimal decay estimates for the general solution to a class of
  semi-linear dissipative hyperbolic equations

abstract:
  We consider a class of semi-linear dissipative hyperbolic equations in which
the operator associated to the linear part has a nontrivial kernel.
  Under appropriate assumptions on the nonlinear term, we prove that all
solutions decay to 0, as t -> +infinity, at least as fast as a suitable
negative power of t. Moreover, we prove that this decay rate is optimal in the
sense that there exists a nonempty open set of initial data for which the
corresponding solutions decay exactly as that negative power of t.
  Our results are stated and proved in an abstract Hilbert space setting, and
then applied to partial differential equations.


title:
Massless particles and arrow of time in relativistic quantum field
  theory

abstract:
  Introduction (in German) to a novel approach to sector analysis in theories
with long range forces which avoids notorious infrared problems; cf.
arXiv:1304.2794


title: 130 GeV Gamma Ray Signal in NMSSM by Internal Bremsstrahlung

abstract:
  There is a possible \gamma-ray signal at 130 GeV coming from the Galactic
Center as seen by Fermi-LAT experiment. We give a SUSY dark matter model to
explain this \gamma-ray feature in NMSSM. We show that in NMSSM, one can have a
benchmark set in which the \gamma-ray signal arises from final state \gamma's
in the $\chi\chi \to f \bar f \gamma $ annihilation of a 130 GeV bino dark
matter requiring a boost factor of ~590 to fit the \gamma-ray signal. In
addition, this benchmark set also gives the correct relic density, lightest
Higgs mass of 125 GeV and is consistent with constraints on SUSY from LHC. This
dark matter model evades the XENON100 constraint but is testable in a future
XENON1T experiment.


title:
Performance and Energy Efficiency of Mobile Data Offloading with
  Mobility Prediction and Prefetching

abstract:
  We present a detailed evaluation of procedures that exploit mobility
prediction and prefetching to enhance offloading of traffic from mobile
networks to WiFi hotspots, for both delay tolerant and delay sensitive traffic.
We consider empirical measurements and evaluate the percentage of offloaded
traffic, data transfer delay, and energy consumption of the proposed
procedures. Our results illustrate how various factors such as mobile, WiFi and
hotspot backhaul throughput, data size, number of hotspots, along with time and
throughput estimation errors, influence the performance and energy efficiency
of mobile data offloading enhanced with mobility prediction and prefetching.


title: Non-determinism in the limit of nonsmooth dynamics

abstract:
  Discontinuous time derivatives are used to model threshold-dependent
switching in such diverse applications as dry friction, electronic control, and
biological growth. In a continuous flow, a discon- tinuous derivative can
generate multiple outcomes from a single initial state. Here we show that well
defined solution sets exist for flows that become multi-valued due to grazing a
discontinuity. Loss of determinism is used to quantify dynamics in the limit of
infinite sensitivity to initial conditions, then applied to the dynamics of a
superconducting resonator and a negatively damped oscillator.


title: Iterative Plan Construction for the Workflow Satisfiability Problem

abstract:
  The \emph{Workflow Satisfiability Problem (WSP)} is a problem of practical
interest that arises whenever tasks need to be performed by authorized users,
subject to constraints defined by business rules. We are required to decide
whether there exists a \emph{plan} -- an assignment of tasks to authorized
users -- such that all constraints are satisfied. Several bespoke algorithms
have been constructed for solving the WSP, optimised to deal with constraints
(business rules) of particular types.
  It is natural to see the WSP as a subclass of the {\em Constraint
Satisfaction Problem (CSP)} in which the variables are tasks and the domain is
the set of users. What makes the WSP distinctive as a CSP is that we can assume
that the number of tasks is very small compared to the number of users. This is
in sharp contrast with traditional CSP models where the domain is small and the
number of variables is very large. As such, it is appropriate to ask for which
constraint languages the WSP is fixed-parameter tractable (FPT), parameterized
by the number of tasks. We have identified a new FPT constraint language,
user-independent constraint, that includes many of the constraints of interest
in business processing systems. We are also able to prove that the union of FPT
languages remains FPT if they satisfy a simple compatibility condition.
  In this paper we present our generic algorithm, in which plans are grouped
into equivalence classes, each class being associated with a \emph{pattern}. We
demonstrate that our generic algorithm has running time $O^*(2^{k\log k})$,
where $k$ is the number of tasks, for the language of user-independent
constraints. We also show that there is no algorithm of running time
$O^*(2^{o(k\log k)})$ for user-independent constraints unless the Exponential
Time Hypothesis fails.


title: Polynomial extensions of semistar operations

abstract:
  We provide a complete solution to the problem of extending arbitrary semistar
operations of an integral domain $D$ to semistar operations of the polynomial
ring $D[X]$. As an application, we show that one can reobtain the main results
of some previous papers concerning the problem in the special cases of stable
semistar operations of finite type or semistar operations defined by families
of overrings. Finally, we investigate the behavior of the polynomial extensions
of the most important and classical operations such as $d_D$, $v_D$, $t_D$,
$w_D$ and $b_D$ operations.


title: Modified gravitational collapse, or the wonders of the MOND

abstract:
  There are many hot discussions in the literature about two competing
paradigms in galactic and extra-galactic astronomy and cosmology, namely the
Dark Matter and the Modified Newtonian Dynamics (MOND). It is very difficult to
challenge MOND from the cosmological side because a full relativistic
realisation is needed in the first place, and any failure can then be
attributed to a particular model, and not to the MOND itself. We propose to
study non-relativistic stages of gravitational collapse in MOND which, we
argue, is a relevant task for this competition. Spherically symmetric dust
cloud collapse and intrinsic unavoidable non-linearities of the deep MOND
regime are discussed. We conclude that complicated, both numerical and
analytic, studies of modified gravitational dynamics are needed in order to
assess the viability of MOND.


title:
Zero-Field Fiske Resonance Coupled with Spin-waves in Ferromagnetic
  Josephson Junctions

abstract:
  AC Josephson current density in a Josephson junction with DC bias is
spatially modulated by an external magnetic field, and induces an
electromagnetic (EM) field inside the junction. The current-voltage ($I$-$V$)
curve exhibits peaks due to the resonance between the EM field and the
spatially modulated AC Josephson current density. This is called {\it Fiske
resonance}. Such a spatially modulated Josephson current density can be also
induced by a non-uniform insulating barrier and the Fiske resonance appears
without external magnetic field. This is called zero-field Fiske resonance
(ZFFR). In this paper, we theoretically study the ZFFR coupled with spin-waves
in a superconductor/ferromagnetic insulator/superconductor junction
(ferromagnetic Josephson junction) with a non-uniform ferromagnetic insulating
barrier. The resonant mode coupled with spin-waves can be induced without
external magnetic field. We find that the $I$-$V$ curve shows resonant peaks
associated with composite excitations of spin-waves and the EM field in the
junction. The voltage at the resonance is obtained as a function of the normal
modes of EM field. The ZFFRs coupled with spin-waves are found as peak
structures in the DC Josephson current density as a function of bias voltage.


title:
Searching for GeV-scale new Gauge Bosons in QGP thermal dilepton
  production

abstract:
  In this paper we propose to use the measurement of the thermal Quark-Gluon
Plasma (QGP) dilepton spectra in the Intermediate Mass Region (IMR) of
heavy-ion collisions, as a new method to search for GeV-scale dark gauge bosons
(gamma' or Z'). Such light mediators are a common feature of light (i.e. low
mass) dark matter scenarios, which have been invoked to explain puzzling
signals in dark matter indirect and direct detection experiments. First we show
that a light gamma' or Z' will generate a resonant enhancement of the dilepton
spectrum produced thermally by the QGP, at an energy corresponding to the dark
gauge boson mass. Secondly, using data from the PHENIX experiment, we are able
to set an upper limit on the combined coupling of this new gauge boson to
quarks and leptons (independently of their vectorial or axial nature) chi_q
chi_e < 10^(-3) at the 95% confidence level for a gauge boson mass in the range
1.5 - 2.5 GeV. This result complements previous searches for new light gauge
bosons and probes a new region of the parameter space, particularly interesting
in the case of non-universal couplings to quarks and leptons. Prospects for the
discovery of such a boson by the ALICE collaboration are also discussed.


title:
Optimal concentrating arbitrary partially entangled W states with linear
  optics

abstract:
  We propose two optimal entanglement concentration protocols (ECPs) for
arbitrary single-photon multi-mode W state and multi-photon polarization W
state, respectively. In both ECPs, we only require one pair of partially
entangled W state, and do not consume any auxiliary photon. Both ECPs are based
on the linear optics which can be easily realized. On the other hand, the
concentrated maximally entangled states can be remained, which are quite
different from the previous ECPs. Moreover, for the concentration of the
arbitrary single-photon N-mode W state or N-mode polarization W state, the
total success probability is equal to Nth the modulus square of the Schmidt
coefficient of the smallest magnitude. It makes both ECPs optimal than all the
previous ECPs. Our ECPs may be useful in current quantum communication fields.


title: The Murnaghan-Nakayama rule and some virtual S_n characters

abstract:
  We construct certain virtual characters for the symmetric groups, then
compute a formula which calculates the values of these virtual characters.


title: Space-time correlations in urban sprawl

abstract:
  Understanding demographic and migrational patterns constitutes a great
challenge. Millions of individual decisions, motivated by economic, political,
demographic, rational, and/or emotional reasons underlie the high complexity of
demographic dynamics. Significant advances in quantitatively understanding such
complexity have been registered in recent years, as those involving the growth
of cities [Bettencourt LMA, Lobo J, Helbing D, Kuehnert C, West GB (2007)
Growth,. Innovation, Scaling, and the Pace of Life in Cities, Proc Natl Acad
Sci USA 104 (17) 7301-7306] but many fundamental issues still defy
comprehension. We present here compelling empirical evidence of a high level of
regularity regarding time and spatial correlations in urban sprawl, unraveling
patterns about the inertia in the growth of cities and their interaction with
each other. By using one of the world's most exhaustive extant demographic data
basis ---that of the Spanish Government's Institute INE, with records covering
111 years and (in 2011) 45 million people, distributed amongst more than 8000
population nuclei--- we show that the inertia of city growth has a
characteristic time of 15 years, and its interaction with the growth of other
cities has a characteristic distance of 70 km. Distance is shown to be the main
factor that entangles two cities (a 60% of total correlations). We present a
mathematical model for population flows that i) reproduces all these
regularities and ii) can be used to predict the population-evolution of cities.
The power of our current social theories is thereby enhanced.


title:
Non-monotonic field dependence of Kondo conductance in a single-electron
  transistor driven by microwave field

abstract:
  The interplay between magnetic field and microwave applied in a
single-electron transistor(SET) has a profound influence on the Kondo effect,
as shown in a recent experiment[B. Hemingway, S. Herbert, M. Melloch and A.
Kogan, arXiv:1304.0037(2013)]. For a given microwave frequency, the Kondo
differential conductance shows a non-monotonic magnetic field dependence, and a
very sharp peak is observed for certain field applied. Additionally, the
microwave frequency is found to be larger of about one order than the
corresponding Zeeman energy. These two features are not understood in the
current theory. Here we propose a phenomenological mechanism to explain these
observations. When both magnetic field and microwave are applied in the SET, if
the frequency matches the (renormalized) Zeeman energy, it is assumed that the
microwave is able to induce spin-flip in the SET, which leads to two
consequences. One is the dot level shifts down and the other is the
renormalization of the Zeeman energy. This picture can not only explain
qualitatively the main findings in the experiment but also further stimulate
the related experimental study of the dynamic response of the Kondo effect in
out-of-equilibrium devices.


title:
Instabilities at Frictional Interfaces: Creep Patches, Nucleation and
  Rupture Fronts

abstract:
  The strength and stability of frictional interfaces, ranging from
tribological systems to earthquake faults, are intimately related to the
underlying spatially-extended dynamics. Here we provide a comprehensive
theoretical account, both analytic and numeric, of spatiotemporal interfacial
dynamics in a realistic rate-and-state friction model, featuring both
velocity-weakening and strengthening behaviors. Slowly extending, loading-rate
dependent, creep patches undergo a linear instability at a critical nucleation
size, which is nearly independent of interfacial history, initial stress
conditions and velocity-strengthening friction. Nonlinear propagating rupture
fronts -- the outcome of instability -- depend sensitively on the stress state
and velocity-strengthening friction. Rupture fronts span a wide range of
propagation velocities and are related to steady state fronts solutions.


title: On Astala's theorem for martingales and Fourier multipliers

abstract:
  We exhibit a large class of symbols $m$ on $\R^d$, $d\geq 2$, for which the
corresponding Fourier multipliers $T_m$ satisfy the following inequality. If
$D$, $E$ are measurable subsets of $\R^d$ with $E\subseteq D$ and $|D|<\infty$,
then $$ \int_{D\setminus E} |T_{m}\chi_E(x)|\mbox{d}x\leq \begin{cases}
|E|+|E|\ln\left(\frac{|D|}{2|E|}\right), & \mbox{if}|E|<|D|/2, |D\setminus
E|+\frac{1}{2}|D \setminus E|\ln \left(\frac{|E|}{|D\setminus E|}\right), &
\mbox{if}|E|\geq |D|/2. \end{cases}. $$ Here $|\cdot|$ denotes the Lebesgue
measure on $\bR^d$. When $d=2$, these multipliers include the real and
imaginary parts of the Beurling-Ahlfors operator $B$ and hence the inequality
is also valid for $B$ with the right-hand side multiplied by $\sqrt{2}$. The
inequality is sharp for the real and imaginary parts of $B$. This work is
motivated by K. Astala's celebrated results on the Gehring-Reich conjecture
concerning the distortion of area by quasiconformal maps. The proof rests on
probabilistic methods and exploits a family of appropriate novel sharp
inequalities for differentially subordinate martingales. These martingale
bounds are of interest on their own right.


title: Can we quantize Galois theory ?

abstract:
  We present a non-linear difference-differential equation whoes Galois group
is a non-commutative and non-co-comutative Hopf algebra.


title: Efimov Physics around the neutron rich Calcium-60 isotope

abstract:
  We calculate the neutron-Calcium-60 S-wave scattering phase shifts using
state of the art coupled-cluster theory combined with modern ab initio
interactions derived from chiral effective theory. Effects of three-nucleon
forces are included schematically as density dependent nucleon-nucleon
interactions. This information is combined with halo effective field theory in
order to investigate the Calcium-60-neutron-neutron system. We predict
correlations between different three-body observables and the two-neutron
separation energy of Calcium-62. This provides evidence of Efimov physics along
the Calcium isotope chain. Experimental key observables that facilitate a test
of our findings are discussed.


title: Quantum Renormalization Groups Based on Natural Orbitals

abstract:
  We propose a new concept upon the renormalization group (RG) procedure for an
interacting many-electron correlated system in the framework of natural
orbitals, and formulate an algorithm for this RG approach. To demonstrate its
effectiveness, we apply this new approach on a quantum cluster-impurity model
with four impurities in comparison with the exact diagonalization method. We
also find a shortcut to dramatically improving this RG algorithm. Further
discussion is presented with the cluster dynamical mean-field theory and
multi-impurity/orbital Kondo problems.

categories: cond-mat.str-el physics.chem-ph physics.comp-ph quant-ph


title:
Measurement of B meson production cross-sections in proton-proton
  collisions at sqrt(s)= 7 TeV

abstract:
  The production cross-sections of B mesons are measured in pp collisions at a
centre-of-mass energy of 7 TeV, using data collected with the LHCb detector
corresponding to a integrated luminosity of 0.36 fb-1. The B+, B0 and Bs0
mesons are reconstructed in the exclusive decays B+ -> J/psi K+, B0 -> J/psi
K*0 and Bs0 -> J/psi phi, with J/psi -> mu+ mu-, K*0 -> K+ pi- and phi -> K+
K-. The differential cross-sections are measured as functions of B meson
transverse momentum pT and rapidity y, in the range 0 < pT < 40 GeV/c and 2.0 <
y < 4.5. The integrated cross-sections in the same pT and y ranges, including
charge-conjugate states, are measured to be sigma(pp -> B+ + X) = 38.9 +- 0.3
(stat.) +- 2.5 (syst.) +- 1.3 (norm.) mub, sigma(pp -> B0 + X) = 38.1 +- 0.6
(stat.) +- 3.7 (syst.) +- 4.7 (norm.) mub, sigma(pp -> Bs0 + X) = 10.5 +- 0.2
(stat.) +- 0.8 (syst.) +- 1.0 (norm.) mub, where the third uncertainty arises
from the pre-existing branching fraction measurements.


title: Fault-tolerant Operations for Universal Blind Quantum Computation

abstract:
  Blind quantum computation is an appealing use of quantum information
technology because it can conceal both the client's data and the algorithm
itself from the server. However, problems need to be solved in the practical
use of blind quantum computation and fault-tolerance is a major challenge. On
an example circuit, the computational cost measured in T gates executed by the
client is 97 times more than performing the original computation directly,
without using the server, even before applying error correction. (The client
still benefits due to drastically reduced memory requirements.) Broadbent et
al. proposed running error correction over blind computation, but our first
protocol applies one layer of Steane's [[7,1,3]] code underneath instead. This
protocol has better fault tolerance, but still results in a substantial
overhead. We propose another protocol to reduce the client's computational load
by transferring the qubit preparation to the server. For each logical qubit
used in the computation, the client is only required to receive eight logical
qubits via teleportation then buffer two logical qubits before returning one.
This protocol also protects the client's fault-tolerant preparation of logical
qubits from a side-channel attack.


title:
Metallicity Dependent Transformations for Red Giants with Synthetic
  Colours of UBV and ugr

abstract:
  We present metallicity dependent transformation equations between UBV and
SDSS ugr colours for red giants with synthetic data. The ranges of the colours
used for the transformations are 0.400 $\leq(B-V)_{0}\leq$ 1.460, -0.085$\leq(U
- B)_{0}\leq$ 1.868, 0.291$\leq(g-r)_{0}\leq$ 1.326, and 1.030$\leq(u -
g)_{0}\leq$ 3.316 mag, and cover almost all the observational colours of red
giants. We applied the transformation equations to six clusters with different
metallicities and compared the resulting $(u - g)_{0}$ colours with the ones
estimated by the calibration of the fiducial sequences of the clusters. The
mean and standard deviation of the residuals for all clusters are $<\Delta(u -
g)_0> =$-0.01 and $\sigma(u - g)_{0} =$0.07 mag, respectively. We showed that
interstellar reddening plays an important role on the derived colours. The
transformations can be applied to clusters as well as to field stars. They can
be used to extend the colour range of the red giants in the clusters which are
restricted due to the saturation of SDSS data.


title:
On a Conjecture of Lan-Sheng-Zuo on Semistable Higgs Bundles: Rank 3
  Case

abstract:
  Let $X$ be a smooth projective curve of genus $g$ over an algebraically
closed field $k$ of characteristic $p>2$. We prove that any rank $3$ nilpotent
semistable Higgs bundle $(E,\theta)$ on $X$ is a strongly semistable Higgs
bundle. This gives a partially affirmative answer to a conjecture of
Lan-Sheng-Zuo \cite{LanShengZuo12ii}\footnotemark[1]. In addition, we prove a
tensor product theorem for strongly semistable Higgs bundles with $p$
satisfying some bounds (Theorem \ref{TensorTheorem}). From this we reprove a
tensor theorem for semistable Higgs bundles on the condition that the
Lan-Sheng-Zuo conjecture holds (Corollary \ref{TensorStableBundle}).


title: Observational study of the extremely slow nova V1280 Scorpii

abstract:
  We present multi-color light curves and optical spectra of V1280 Scorpii
obtained from 2007 to 2012. It is shown that V1280 Sco is the extremely slow
nova and the mass of white dwarf appears to be $\sim$ 0.6 M$\odot$ or lower.
Blue-shifted multiple absorption lines of Na {\sc i} D, Ca {\sc ii} HK, and He
{\sc i*} are detected on high-resolution spectra. We also discuss that an
approach using metastable He absorption lines is useful to investigate
structures of nova shells.


title:
Containment Counterexamples for ideals of various configurations of
  points in ${\bf P}^N$

abstract:
  When $I$ is the radical homogeneous ideal of a finite set of points in
projective $N$-space, ${\bf P}^N$, over a field $K$, it has been conjectured
that $I^{(rN-N+1)}$ should be contained in $I^r$ for all $r\geq 1$. Recent
counterexamples show that this can fail when N=r=2. We study properties of the
resulting ideals. We also show that failures occur for infinitely many $r$ in
every characteristic $p>2$ when N=2, and we find additional positive
characteristic failures when $N>2$.


title: Ergodic Multiplier Properties

abstract:
  In this article we will see some properties that guarantee that a product of
an ergodic non-singular action and a probability preserving ergodic action is
also an ergodic action. We will start by proving 'The multiplier theorem' for
locally compact abelian groups. Then we will show that for certain locally
compact Polish groups (Moore groups, and minimally weakly mixing groups), a
non-singular G action is weakly mixing if and only if any finite dimensional
G-invariant subspace of L_\infty is trivial. Finally, we will show that the
Gaussian action associated to the infinite dimensional irreducible
representation of the continuous Heisenberg group, H_3, is weakly mixing but
not mildly mixing.


title:
Silicon carbide grains of type C provide evidence for the production of
  the unstable isotope $^{32}$Si in supernovae

abstract:
  Carbon-rich grains are observed to condense in the ejecta of recent
core-collapse supernovae, within a year after the explosion. Silicon carbide
grains of type X are C-rich grains with isotpic signatures of explosive
supernova nucleosynthesis have been found in primitive meteorites. Much rarer
silicon carbide grains of type C are a special sub-group of SiC grains from
supernovae. They show peculiar abundance signatures for Si and S, isotopically
heavy Si and isotopically light S, which appear to to be in disagreement with
model predictions. We propose that C grains are formed mostly from C-rich
stellar material exposed to lower SN shock temperatures than the more common
type X grains. In this scenario, extreme $^{32}$S enrichments observed in C
grains may be explained by the presence of short-lived $^{32}$Si
($\tau$$_{1/2}$ = 153 years) in the ejecta, produced by neutron capture
processes starting from the stable Si isotopes. No mixing from deeper Si-rich
material and/or fractionation of Si from S due to molecular chemistry is needed
to explain the $^{32}$S enrichments. The abundance of $^{32}$Si in the grains
can provide constraints on the neutron density reached during the supernova
explosion in the C-rich He shell material. The impact of the large uncertainty
of the neutron capture cross sections in the $^{32}$Si region is discussed.


title: On Two Kinds of Differential Operators on General Smooth Surfaces

abstract:
  Two kinds of differential operators that can be generally defined on an
arbitrary smooth surface in a finite dimensional Euclid space are studied, one
is termed as surface gradient and the other one as Levi-Civita gradient. The
surface gradient operator is originated from the differentiability of a tensor
field defined on the surface. Some integral and differential identities have
been theoretically studied that play the important role in the studies on
continuous mediums whose geometrical configurations can be taken as surfaces
and on interactions between fluids and deformable boundaries. The definition of
Levi-Civita gradient is based on Levi-Civita connections generally defined on
Riemann manifolds. It can be used to set up some differential identities in the
intrinsic/coordiantes-independent form that play the essential role in the
theory of vorticity dynamics for two dimensional flows on general fixed smooth
surfaces.


title: Can planetesimals form by collisional fusion?

abstract:
  As a test bed for the growth of protoplanetary bodies in a turbulent
circumstellar disk we examine the fate of a boulder using direct numerical
simulations of particle seeded gas flowing around it. We provide an accurate
description of the flow by imposing no-slip and non-penetrating boundary
conditions on the boulder surface using the immersed boundary method pioneered
by Peskin (2002). Advected by the turbulent disk flow, the dust grains collide
with the boulder and we compute the probability density function (PDF) of the
normal component of the collisional velocity. Through this examination of the
statistics of collisional velocities we test the recently developed concept of
collisional fusion which provides a physical basis for a range of collisional
velocities exhibiting perfect sticking. A boulder can then grow sufficiently
rapidly to settle into a Keplerian orbit on disk evolution time scales.


title:
On weight modules of algebras of twisted differential operators on the
  projective space

abstract:
  We classify blocks of categories of weight and generalized weight modules of
algebras of twisted differential operators on P^n. Necessary and sufficient
conditions for these blocks to be tame and proofs that some of the blocks are
Koszul are provided. We also establish equivalences of categories between these
blocks and categories of bounded and generalized bounded weight sl(n+1)-modules
in the cases of nonintegral and singular central character.


title: Lengths of Monotone Subsequences in a Mallows Permutation

abstract:
  We study the length of the longest increasing and longest decreasing
subsequences of random permutations drawn from the Mallows measure. Under this
measure, the probability of a permutation pi in S_n is proportional to
q^{inv(pi)} where q is a real parameter and inv(pi) is the number of inversions
in pi. The case q=1 corresponds to uniformly random permutations. The Mallows
measure was introduced by Mallows in connection with ranking problems in
statistics.
  We determine the typical order of magnitude of the lengths of the longest
increasing and decreasing subsequences, as well as large deviation bounds for
them. We also provide a simple bound on the variance of these lengths, and
prove a law of large numbers for the length of the longest increasing
subsequence. Assuming without loss of generality that q<1, our results apply
when q is a function of n satisfying n(1-q) -> infty. The case that n(1-q)=O(1)
was considered previously by Mueller and Starr. In our parameter range, the
typical length of the longest increasing subsequence is of order n(1-q)^(1/2),
whereas the typical length of the longest decreasing subsequence has four
possible behaviors according to the precise dependence of n and q.
  We show also that in the graphical representation of a Mallows-distributed
permutation, most points are found in a symmetric strip around the diagonal
whose width is of order 1/(1-q). This suggests a connection between the longest
increasing subsequence in the Mallows model and the model of last passage
percolation in a strip.


title: Solar wind reflection from the lunar surface: The view from far and near

abstract:
  The Moon appears bright in the sky as a source of energetic neutral atoms
(ENAs). These ENAs have recently been imaged over a broad energy range both
from near the lunar surface, by India's Chandrayaan-1 mission (CH-1), and from
a much more distant Earth orbit by NASA's Interstellar Boundary Explorer (IBEX)
satellite. Both sets of observations have indicated that a relatively large
fraction of the solar wind is reflected from the Moon as energetic neutral
hydrogen. CH-1's angular resolution over different viewing angles of the lunar
surface has enabled measurement of the emission as a function of angle. IBEX in
contrast views not just a swath but a whole quadrant of the Moon as effectively
a single pixel, as it subtends even at the closest approach no more than a few
degrees on the sky. Here we use the scattering function measured by CH-1 to
model global lunar ENA emission and combine these with IBEX observations. The
deduced global reflection is modestly larger (by a factor of 1.25) when the
angular scattering function is included. This provides a slightly updated IBEX
estimate of AH = 0.11 +/- 0.06 for the global neutralized albedo, which is 25 %
larger than the previous values of 0.09 +/- 0.05, based on an assumed uniform
scattering distribution.


title: Diagonalizations of two classes of unbounded Hankel operators

abstract:
  We show that every Hankel operator $H$ is unitarily equivalent to a
pseudo-differential operator $A$ of a special structure acting in the space
$L^2 ({\Bbb R}) $. As an example, we consider integral operators $H$ in the
space $L^2 ({\Bbb R}_{+}) $ with kernels $P (\ln (t+s)) (t+s)^{-1}$ where
$P(x)$ is an arbitrary real polynomial of degree $K$. In this case, $A$ is a
differential operator of the same order $K$. This allows us to study spectral
properties of Hankel operators $H$ with such kernels. In particular, we show
that the essential spectrum of $H$ coincides with the whole axis for $K$ odd,
and it coincides with the positive half-axis for $K$ even. In the latter case
we additionally find necessary and sufficient conditions for the positivity of
$H$. We also consider Hankel operators whose kernels have a strong singularity
at some positive point. We show that spectra of such operators consist of the
zero eigenvalue of infinite multiplicity and eigenvalues accumulating to
$+\infty$ and $-\infty$. We find the asymptotics of these eigenvalues.


title: Optimal Blind Quantum Computation

abstract:
  Blind quantum computation allows a client with limited quantum capabilities
to interact with a remote quantum computer to perform an arbitrary quantum
computation, while keeping the description of that computation hidden from the
remote quantum computer. While a number of protocols have been proposed in
recent years, little is currently understood about the resources necessary to
accomplish the task. Here we present general techniques for upper and lower
bounding the quantum communication necessary to perform blind quantum
computation, and use these techniques to establish a concrete bounds for common
choices of the client's quantum capabilities. Our results show that the UBQC
protocol of Broadbent, Fitzsimons and Kashefi [1], comes within a factor of 8/3
of optimal when the client is restricted to preparing single qubits. However,
we describe a generalization of this protocol which requires exponentially less
quantum communication when the client has a more sophisticated device.


title:
Surface and Bulk Electronic Structure of the Strongly Correlated System
  SmB$_{6}$ and Implications for a Topological Kondo Insulator

abstract:
  Recent theoretical calculations and experimental results suggest that the
strongly correlated material SmB$_{6}$ may be a realization of a topological
Kondo insulator. We have performed an angle-resolved photoemission spectroscopy
study on SmB$_{6}$ in order to elucidate elements of the electronic structure
relevant to the possible occurrence of a topological Kondo insulator state. The
obtained electronic structure in the whole three-dimensional momentum space
reveals one electron-like 5d bulk band centred at the X point of the bulk
Brillouin zone that is hybridized with strongly correlated f electrons, as well
as the opening of a Kondo bandgap ($\Delta_B$ $\sim$ 20 meV) at low
temperature. In addition, we observe electron-like bands forming three Fermi
surfaces at the center $\bar{\Gamma}$ point and boundary $\bar{X}$ point of the
surface Brillouin zone. These bands are not expected from calculations of the
bulk electronic structure, and their observed dispersion characteristics are
consistent with surface states. Our results suggest that the unusual
low-temperature transport behavior of SmB$_{6}$ is likely to be related to the
pronounced surface states sitting inside the band hybridisation gap and/or the
presence of a topological Kondo insulating state.


title:
Fractional Order Fuzzy Control of Nuclear Reactor Power with
  Thermal-Hydraulic Effects in the Presence of Random Network Induced Delay and
  Sensor Noise having Long Range Dependence

abstract:
  Nonlinear state space modeling of a nuclear reactor has been done for the
purpose of controlling its global power in load following mode. The nonlinear
state space model has been linearized at different percentage of reactor powers
and a novel fractional order (FO) fuzzy proportional integral derivative (PID)
controller is designed using real coded Genetic Algorithm (GA) to control the
reactor power level at various operating conditions. The effectiveness of using
the fuzzy FOPID controller over conventional fuzzy PID controllers has been
shown with numerical simulations. The controllers tuned with the highest power
models are shown to work well at other operating conditions as well; over the
lowest power model based design and hence are robust with respect to the
changes in nuclear reactor operating power levels. This paper also analyzes the
degradation of nuclear reactor power signal due to network induced random
delays in shared communication network and due to sensor noise while being
fed-back to the Reactor Regulating System (RRS). The effect of long range
dependence (LRD) which is a practical consideration for the stochastic
processes like network induced delay and sensor noise has been tackled by
optimum tuning of FO fuzzy PID controllers using GA, while also taking the
operating point shift into consideration.


title:
Optimum Weight Selection Based LQR Formulation for the Design of
  Fractional Order PI{\lambda}D{\mu} Controllers to Handle a Class of
  Fractional Order Systems

abstract:
  A weighted summation of Integral of Time Multiplied Absolute Error (ITAE) and
Integral of Squared Controller Output (ISCO) minimization based time domain
optimal tuning of fractional-order (FO) PID or PI{\lambda}D{\mu} controller is
proposed in this paper with a Linear Quadratic Regulator (LQR) based technique
that minimizes the change in trajectories of the state variables and the
control signal. A class of fractional order systems having single non-integer
order element which show highly sluggish and oscillatory open loop responses
have been tuned with an LQR based FOPID controller. The proposed controller
design methodology is compared with the existing time domain optimal tuning
techniques with respect to change in the trajectory of state variables,
tracking performance for change in set-point, magnitude of control signal and
also the capability of load disturbance suppression. A real coded genetic
algorithm (GA) has been used for the optimal choice of weighting matrices while
designing the quadratic regulator by minimizing the time domain integral
performance index. Credible simulation studies have been presented to justify
the proposition.


title: Counting and zeta functions over F1

abstract:
  A new interpretation of zeta functions is given for F1-schemes which do not
satisfy Soul\'e's condition. Functional equations for reductive groups are
computed and a new definition of zeta functions attached to more general
counting functions is given which is based on regularization and puts on an
equal footing F1-theory on the one hand and spectral theory of Laplace
operators on manifolds on the other.


title:
Frequency Domain Design of Fractional Order PID Controller for AVR
  System Using Chaotic Multi-objective Optimization

abstract:
  A fractional order (FO) PID or FOPID controller is designed for an Automatic
Voltage Regulator (AVR) system with the consideration of contradictory
performance objectives. An improved evolutionary Non-dominated Sorting Genetic
Algorithm (NSGA-II), augmented with a chaotic Henon map is used for the
multi-objective optimization based design procedure. The Henon map as the
random number generator outperforms the original NSGA-II algorithm and its
Logistic map assisted version for obtaining a better design trade-off with an
FOPID controller. The Pareto fronts showing the trade-offs between the
different design objectives have also been shown for both the FOPID controller
and the conventional PID controller to enunciate the relative merits and
demerits of each. The design is done in frequency domain and hence stability
and robustness of the design is automatically guaranteed unlike the other time
domain optimization based controller design methods.


title:
Performance Comparison of Optimal Fractional Order Hybrid Fuzzy PID
  Controllers for Handling Oscillatory Fractional Order Processes with Dead
  Time

abstract:
  Fuzzy logic based PID controllers have been studied in this paper,
considering several combinations of hybrid controllers by grouping the
proportional, integral and derivative actions with fuzzy inferencing in
different forms. Fractional order (FO) rate of error signal and FO integral of
control signal have been used in the design of a family of decomposed hybrid FO
fuzzy PID controllers. The input and output scaling factors (SF) along with the
integro-differential operators are tuned with real coded genetic algorithm (GA)
to produce optimum closed loop performance by simultaneous consideration of the
control loop error index and the control signal. Three different classes of
fractional order oscillatory processes with various levels of relative
dominance between time constant and time delay have been used to test the
comparative merits of the proposed family of hybrid fractional order fuzzy PID
controllers. Performance comparison of the different FO fuzzy PID controller
structures has been done in terms of optimal set-point tracking, load
disturbance rejection and minimal variation of manipulated variable or smaller
actuator requirement etc. In addition, multi-objective Non-dominated Sorting
Genetic Algorithm (NSGA-II) has been used to study the Pareto optimal
trade-offs between the set point tracking and control signal, and the set point
tracking and load disturbance performance for each of the controller structure
to handle the three different types of processes.


title:
Design of Hybrid Regrouping PSO-GA based Sub-optimal Networked Control
  System with Random Packet Losses

abstract:
  In this paper, a new approach has been presented to design sub-optimal state
feedback regulators over Networked Control Systems (NCS) with random packet
losses. The optimal regulator gains, producing guaranteed stability are
designed with the nominal discrete time model of a plant using Lyapunov
technique which produces a few set of Bilinear Matrix Inequalities (BMIs). In
order to reduce the computational complexity of the BMIs, a Genetic Algorithm
(GA) based approach coupled with the standard interior point methods for LMIs
has been adopted. A Regrouping Particle Swarm Optimization (RegPSO) based
method is then employed to optimally choose the weighting matrices for the
state feedback regulator design that gets passed through the GA based stability
checking criteria i.e. the BMIs. This hybrid optimization methodology put
forward in this paper not only reduces the computational difficulty of the
feasibility checking condition for optimum stabilizing gain selection but also
minimizes other time domain performance criteria like expected value of the
set-point tracking error with optimum weight selection based LQR design for the
nominal system.


title:
Continuous Order Identification of PHWR Models Under Step-back for the
  Design of Hyper-damped Power Tracking Controller with Enhanced Reactor Safety

abstract:
  In this paper, discrete time higher integer order linear transfer function
models have been identified first for a 500 MWe Pressurized Heavy Water Reactor
(PHWR) which has highly nonlinear dynamical nature. Linear discrete time models
of the nonlinear nuclear reactor have been identified around eight different
operating points (power reduction or step-back conditions) with least square
estimator (LSE) and its four variants. From the synthetic frequency domain data
of these identified discrete time models, fractional order (FO) models with
sampled continuous order distribution are identified for the nuclear reactor.
This enables design of continuous order Proportional-Integral-Derivative (PID)
like compensators in the complex w-plane for global power tracking at a wide
range of operating conditions. Modeling of the PHWR is attempted with various
levels of discrete commensurate-orders and the achievable accuracies are also
elucidated along with the hidden issues, regarding modeling and controller
design. Credible simulation studies are presented to show the effectiveness of
the proposed reactor modeling and power level controller design. The controller
pushes the reactor poles in higher Riemann sheets and thus makes the closed
loop system hyper-damped which ensures safer reactor operation at varying
dc-gain while making the power tracking temporal response slightly sluggish;
but ensuring greater safety margin.


title:
Two-dimensional p-wave superconducting states with magnetic moments on a
  conventional s-wave superconductor

abstract:
  Unconventional superconductivity induced by the magnetic moments in a
conventional spin-singlet s-wave superconductor is theoretically studied. By
choosing the spin directions of these moments, one can design spinless pairing
states appearing within the s-wave superconducting energy gap. It is found that
the helix spins produce px + py-wave state while the skyrmion crystal
configuration px + ipy-wave like state. Nodes in the energy gap and the zero
energy flat band of Majorana edge states exist in the former one, while the
chiral Majorana channels along edges of the sample and the zero energy Majorana
bound state at the core of the vortex appear in the latter case.


title:
Local Interstellar Hydrogen's Disappearance at 1 Au: Four Years of IBEX
  in the Rising Solar Cycle

abstract:
  NASA's Interstellar Boundary Explorer (IBEX) mission has recently opened a
new window on the interstellar medium (ISM) by imaging neutral atoms. One
"bright" feature in the sky is the interstellar wind flowing into the solar
system. Composed of remnants of stellar explosions as well as primordial gas
and plasma, the ISM is by no means uniform. The interaction of the local ISM
with the solar wind shapes our heliospheric environment with hydrogen being the
dominant component of the very local ISM. In this paper, we report on direct
sampling of the neutral hydrogen of the local ISM over four years of IBEX
observations. The hydrogen wind observed at 1 AU has decreased and nearly
disappeared as the solar activity has increased over the last four years; the
signal at 1 AU has dropped off in 2012 by a factor of ~8 to near background
levels. The longitudinal offset has also increased with time presumably due to
greater radiation pressure deflecting the interstellar wind. We present
longitudinal and latitudinal arrival direction measurements of the bulk flow as
measured over four years beginning at near solar minimum conditions. The H
distribution we observe at 1 AU is expected to be different from that outside
the heliopause due to ionization, photon pressure, gravity, and filtration by
interactions with heliospheric plasma populations. These observations provide
an important benchmark for modeling of the global heliospheric interaction.
Based on these observations we suggest a further course of scientific action to
observe neutral hydrogen over a full solar cycle with IBEX.


title: On the Negative $K$-theory of Singular Varieties

abstract:
  Let $X$ be an $n$-dimensional variety over a field $k$ of characteristic
zero, regular in codimension 1 with singular locus $Z$. In this paper we study
the negative $K$-theory of $X$, showing that when $Z$ is sufficiently nice,
$K_{1-n}(X)$ is an extension of $KH_{1-n}(X)$ by a finite dimensional vector
space, which we compute explicitly. We also show that $KH_{1-n}(X)$ almost has
a geometric structure. Specifically, we give an explicit 1-motive $[L
\rightarrow G]$ and a map $G(k) \rightarrow KH_{1-n}(X)$ whose kernel and
cokernel are finitely generated abelian groups.


title: Geometry of rational helices and its applications

abstract:
  The present paper attempts to show an alternative approach with regards to
rational Pythagorean-hodograph (PH) curves and especially more natural approach
for rational PH helices (i.e. rational helices). It exploits geometric features
of rational helices to obtain a simpler construction of these curves and apply
this to related subjects. One of these applications is Geometric C1 Hermite
interpolation (i.e. interpolation of end points with associated unit tangents)
by rational helices. Furthermore, we investigate the existence of rational
rotation minimizing frames (RRMFs) on rational helices. A rational
approximation procedure to rotation minimizing frames (RMFs) is suggested.
Subsequently, we deploy the approximate frame for modeling a rational sweep
surface. The resulting algorithms are illustrated by several examples.


title:
Do semidefinite relaxations solve sparse PCA up to the information
  limit?

abstract:
  Estimating the leading principal components of data, assuming they are
sparse, is a central task in modern high-dimensional statistics. Many
algorithms were developed for this sparse PCA problem, from simple diagonal
thresholding to sophisticated semidefinite programming (SDP) methods. A key
theoretical question is under what conditions can such algorithms recover the
sparse principal components? We study this question for a single-spike model
with an $\ell_0$-sparse eigenvector, in the asymptotic regime as dimension $p$
and sample size $n$ both tend to infinity. Amini and Wainwright [Ann. Statist.
37 (2009) 2877-2921] proved that for sparsity levels $k\geq\Omega(n/\log p)$,
no algorithm, efficient or not, can reliably recover the sparse eigenvector. In
contrast, for $k\leq O(\sqrt{n/\log p})$, diagonal thresholding is consistent.
It was further conjectured that an SDP approach may close this gap between
computational and information limits. We prove that when
$k\geq\Omega(\sqrt{n})$, the proposed SDP approach, at least in its standard
usage, cannot recover the sparse spike. In fact, we conjecture that in the
single-spike model, no computationally-efficient algorithm can recover a spike
of $\ell_0$-sparsity $k\geq\Omega(\sqrt{n})$. Finally, we present empirical
results suggesting that up to sparsity levels $k=O(\sqrt{n})$, recovery is
possible by a simple covariance thresholding algorithm.


title: Equilateral non-Gaussianity from heavy fields

abstract:
  The effect of self-interactions of heavy scalar fields during inflation on
the primordial non-Gaussianity is studied. We take a specific constant-turn
quasi-single field inflation as an example. We derive an effective theory with
emphasis on non-linear self-interactions of heavy fields and calculate the
corresponding non-Gaussianity, which is of equilateral type and can be as
relevant as those computed previously in the literature. We also derive the
non-Gaussianity by directly using the in-in formalism, and verify the
equivalence of these two approaches.


title:
An open diachronic corpus of historical Spanish: annotation criteria and
  automatic modernisation of spelling

abstract:
  The IMPACT-es diachronic corpus of historical Spanish compiles over one
hundred books --containing approximately 8 million words-- in addition to a
complementary lexicon which links more than 10 thousand lemmas with
attestations of the different variants found in the documents. This textual
corpus and the accompanying lexicon have been released under an open license
(Creative Commons by-nc-sa) in order to permit their intensive exploitation in
linguistic research. Approximately 7% of the words in the corpus (a selection
aimed at enhancing the coverage of the most frequent word forms) have been
annotated with their lemma, part of speech, and modern equivalent. This paper
describes the annotation criteria followed and the standards, based on the Text
Encoding Initiative recommendations, used to the represent the texts in digital
form. As an illustration of the possible synergies between diachronic textual
resources and linguistic research, we describe the application of statistical
machine translation techniques to infer probabilistic context-sensitive rules
for the automatic modernisation of spelling. The automatic modernisation with
this type of statistical methods leads to very low character error rates when
the output is compared with the supervised modern version of the text.


title:
Message Passing Algorithms for Phase Noise Tracking Using Tikhonov
  Mixtures

abstract:
  In this work, a new low complexity iterative algorithm for decoding data
transmitted over strong phase noise channels is presented. The algorithm is
based on the Sum & Product Algorithm (SPA) with phase noise messages modeled as
Tikhonov mixtures. Since mixture based Bayesian inference such as SPA, creates
an exponential increase in mixture order for consecutive messages, mixture
reduction is necessary. We propose a low complexity mixture reduction algorithm
which finds a reduced order mixture whose dissimilarity metric is
mathematically proven to be upper bounded by a given threshold. As part of the
mixture reduction, a new method for optimal clustering provides the closest
circular distribution, in Kullback Leibler sense, to any circular mixture. We
further show a method for limiting the number of tracked components and further
complexity reduction approaches. We show simulation results and complexity
analysis for the proposed algorithm and show better performance than other
state of the art low complexity algorithms. We show that the Tikhonov mixture
approximation of SPA messages is equivalent to the tracking of multiple phase
trajectories, or also can be looked as smart multiple phase locked loops (PLL).
When the number of components is limited to one the result is similar to a
smart PLL.


title:
Experimental verification of reciprocity relations in quantum
  thermoelectric transport

abstract:
  Symmetry relations are manifestations of fundamental principles and
constitute cornerstones of modern physics. An example are the Onsager relations
between coefficients connecting thermodynamic fluxes and forces, central to
transport theory and experiments. Initially formulated for classical systems,
these reciprocity relations are also fulfilled in quantum conductors.
Surprisingly, novel relations have been predicted specifically for
thermoelectric transport. However, whereas these thermoelectric reciprocity
relations have to date not been verified, they have been predicted to be
sensitive to inelastic scattering, always present at finite temperature. The
question whether the relations exist in practice is important for
thermoelectricity: whereas their existence may simplify the theory of complex
thermoelectric materials, their absence has been shown to enable, in principle,
higher thermoelectric energy conversion efficiency for a given material
quality. Here we experimentally verify the thermoelectric reciprocity relations
in a four-terminal mesoscopic device where each terminal can be electrically
and thermally biased, individually. The linear response thermoelectric
coefficients are found to be symmetric under simultaneous reversal of magnetic
field and exchange of injection and emission contacts. Intriguingly, we also
observe the breakdown of the reciprocity relations as a function of increasing
thermal bias. Our measurements thus clearly establish the existence of the
thermoelectric reciprocity relations, as well as the possibility to control
their breakdown with the potential to enhance thermoelectric performance


title:
Symmetry-protected topological phases with charge and spin symmetries:
  response theory and dynamical gauge theory in 2D, 3D and the surface of 3D

abstract:
  A large class of symmetry-protected topological phases (SPT) in boson / spin
systems have been recently predicted by the group cohomology theory. In this
work, we consider SPT states at least with charge symmetry (U(1) or Z$_N$) or
spin $S^z$ rotation symmetry (U(1) or Z$_N$) in 2D, 3D, and the surface of 3D.
If both are U(1), we apply external electromagnetic field / `spin gauge field'
to study the charge / spin response. For the SPT examples we consider (i.e.
U$_c$(1)$\rtimes$Z$^T_2$, U$_s$(1)$\times$Z$^T_2$,
U$_c$(1)$\times$[U$_s$(1)$\rtimes$Z$_2$]; subscripts $c$ and $s$ are short for
charge and spin; Z$^T_2$ and Z$_2$ are time-reversal symmetry and
$\pi$-rotation about $S^y$, respectively), many variants of Witten effect in
the 3D SPT bulk and various versions of anomalous surface quantum Hall effect
are defined and systematically investigated. If charge or spin symmetry reduces
to Z$_N$ by considering charge-$N$ or spin-$N$ condensate, instead of the
linear response approach, we gauge the charge/spin symmetry, leading to a
dynamical gauge theory with some remaining global symmetry. The 3D dynamical
gauge theory describes a symmetry-enriched topological phase (SET), i.e. a
topologically ordered state with global symmetry which admits nontrivial ground
state degeneracy depending on spatial manifold topology. For the SPT examples
we consider, the corresponding SET states are described by dynamical
topological gauge theory with topological BF term and axionic $\Theta$-term in
3D bulk. And the surface of SET is described by the chiral boson theory with
quantum anomaly.


title: Bounding the norm of a log-concave vector via thin-shell estimates

abstract:
  Chaining techniques show that if X is an isotropic log-concave random vector
in R^n and Gamma is a standard Gaussian vector then E |X| < C n^{1/4} E |Gamma|
for any norm |*|, where C is a universal constant. Using a completely different
argument we establish a similar inequality relying on the thin-shell constant
sigma_n = sup ((var|X|^){1/2} ; X isotropic and log-concave on R^n).
  In particular, we show that if the thin-shell conjecture sigma_n = O(1)
holds, then n^{1/4} can be replaced by log (n) in the inequality.
  As a consequence, we obtain certain bounds for the mean-width, the dual
mean-width and the isotropic constant of an isotropic convex body.
  In particular, we give an alternative proof of the fact that a positive
answer to the thin-shell conjecture implies a positive answer to the slicing
problem, up to a logarithmic factor.


title:
Nuclear temperatures from the evaporation fragment spectra and observed
  anomalies

abstract:
  The extreme back-angle evaporation spectra of alpha, lithium, beryllium,
boron and carbon from different compound nuclei near A=100 (EX=76-210 MeV) have
been compared with the predictions of standard statistical model codes such as
'CASCADE' and 'GEMINI'. It was found that the shapes of the alpha spectra agree
well with the predictions of the statistical models. However the spectra of
lithium, beryllium, boron and carbon show significantly gentler slopes implying
higher temperature of the residual nuclei, even though the spectra satisfy all
other empirical criteria of statistical emissions. The observed slope anomaly
was found to be largest for lithium and decreases at higher excitation energy.
These results could not be understood by adjusting the parameters of the
statistical models or from reaction dynamics and might require examining the
statistical model from a quantum mechanical perspective.


title: The Johnson Cokernel and the Enomoto-Satoh invariant

abstract:
  We study the cokernel of the Johnson homomorphism for the mapping class group
of a surface with one boundary component. A graphical trace map simultaneously
generalizing trace maps of Enomoto-Satoh and Conant-Kassabov-Vogtmann is given,
and using technology from the author's work with Kassabov and Vogtmann, this is
is shown to detect a large family of representations which vastly generalizes
series due to Morita and Enomoto-Satoh. The Enomoto-Satoh trace is the rank 1
part of the new trace. The rank 2 part is also investigated.


title:
Existence of steady states for the Maxwell-Schr\"odinger-Poisson system:
  exploring the applicability of the concentration-compactness principle

abstract:
  This paper is intended to review recent results and open problems concerning
the existence of steady states to the Maxwell-Schr\"odinger system. A
combination of tools, proofs and results are presented in the framework of the
concentration--compactness method.


title: Contextuality in bosonic bunching

abstract:
  We show that under certain assumptions one can derive a variant of Specker's
non-contextual inequality for a system of three indistinguishable bosonic
particles. The inequality states that the sum of probabilities of three
pairwise exclusive events is bounded by one. This inequality cannot be violated
using standard quantum mechanical projectors. On the other hand, due to bosonic
properties this bound is violated up to 3/2. We also argue that the violation
of this inequality can be considered as a test of bosonic nature.


title:
Fast Star, Slow Star; Old Star, Young Star: Subgiant Rotation as a
  Population and Stellar Physics Diagnostic

abstract:
  Stellar rotation is a strong function of both mass and evolutionary state.
Missions such as Kepler and CoRoT provide tens of thousands of rotation
periods, drawn from stellar populations that contain objects at a range of
masses, ages, and evolutionary states. Given a set of reasonable starting
conditions and a prescription for angular momentum loss, we address the
expected range of rotation periods for cool field stellar populations. We find
that cool stars fall into three distinct regimes in rotation. Rapid rotators
with surface periods less than 10 days are either young low-mass main sequence
(MS) stars, or higher mass subgiants which leave the MS with high rotation
rates. Intermediate rotators (10-40 days) can be either cool MS dwarfs,
suitable for gyrochronology, or crossing subgiants at a range of masses.
Gyrochronology relations must therefore be applied cautiously, since there is
an abundant population of subgiant contaminants. The slowest rotators, at
periods greater than 40 days, are lower mass subgiants undergoing envelope
expansion. We identify additional diagnostic uses of rotation periods. There
exists a period-age relation for subgiants distinct from the MS period-age
relations. There is also a period-radius relation that can be used as a
constraint on the stellar radius, particularly in the interesting case of
planet host stars. The high-mass/low-mass break in the rotation distribution on
the MS persists onto the subgiant branch, and has potential as a diagnostic of
stellar mass. Finally, this set of theoretical predictions can be compared to
extensive datasets to motivate improved modeling.


title:
Exact band structures for 1D superlattices beyond the tight-binding
  approximation

abstract:
  The band structures describing non-interacting particles in one-dimensional
superlattices of arbitrary periodicity are obtained by an analytical
diagonalization of the Hamiltonian without adopting the popular tight-binding
approximation. The results are compared with those of the tight-binding
approximation. In this way, a quantitative prediction of the validity and
failure of the tight-binding approximation becomes possible. In particular, it
is demonstrated that in contrast to the prediction of the tight-binding
approximation the central energy bands do not touch for periodicities $\tau$ of
the lattice where $\tau=4n$ and $n$ is an integer.


title: Logical systems I: Lambda calculi through discreteness

abstract:
  This paper shows how internal models for polymorphic lambda calculi arise in
any 2-category with a notion of discreteness. We generalise to a 2-categorical
setting the famous theorem of Peter Freyd saying that there are no sufficiently
(co)complete non-degenerate categories. As a simple corollary, we obtain a
variant of Freyd theorem for categories internal to any tensored category.
Also, with help of introduced concept of an associated category, we prove a
representation theorem relating our internal models with well-studied
fibrational models for polymorphism.


title:
How interbank lending amplifies overlapping portfolio contagion: A case
  study of the Austrian banking network

abstract:
  In spite of the growing theoretical literature on cascades of failures in
interbank lending networks, empirical results seem to suggest that networks of
direct exposures are not the major channel of financial contagion. In this
paper we show that networks of interbank exposures can however significantly
amplify contagion due to overlapping portfolios. To illustrate this point, we
consider the case of the Austrian interbank network and perform stress tests on
it according to different protocols. We consider in particular contagion due to
(i) counterparty loss; (ii) roll-over risk; and (iii) overlapping portfolios.
We find that the average number of bankruptcies caused by counterparty loss and
roll-over risk is fairly small if these contagion mechanisms are considered in
isolation. Once portfolio overlaps are also accounted for, however, we observe
that the network of direct interbank exposures significantly contributes to
systemic risk.


title:
Wodzicki residue and minimal operators on a noncommutative 4-dimensional
  torus

abstract:
  We compute the Wodzicki residue of the inverse of a conformally rescaled
Laplace operator over a 4-dimensional noncommutative torus. We show that the
straightforward generalization of the Laplace-Beltrami operator to the
noncommutative case is not the minimal operator.


title:
Local case-control sampling: Efficient subsampling in imbalanced data
  sets

abstract:
  For classification problems with significant class imbalance, subsampling can
reduce computational costs at the price of inflated variance in estimating
model parameters. We propose a method for subsampling efficiently for logistic
regression by adjusting the class balance locally in feature space via an
accept-reject scheme. Our method generalizes standard case-control sampling,
using a pilot estimate to preferentially select examples whose responses are
conditionally rare given their features. The biased subsampling is corrected by
a post-hoc analytic adjustment to the parameters. The method is simple and
requires one parallelizable scan over the full data set. Standard case-control
sampling is inconsistent under model misspecification for the population
risk-minimizing coefficients $\theta^*$. By contrast, our estimator is
consistent for $\theta^*$ provided that the pilot estimate is. Moreover, under
correct specification and with a consistent, independent pilot estimate, our
estimator has exactly twice the asymptotic variance of the full-sample MLE -
even if the selected subsample comprises a miniscule fraction of the full data
set, as happens when the original data are severely imbalanced. The factor of
two improves to $1+\frac{1}{c}$ if we multiply the baseline acceptance
probabilities by $c>1$ (and weight points with acceptance probability greater
than 1), taking roughly $\frac{1+c}{2}$ times as many data points into the
subsample. Experiments on simulated and real data show that our method can
substantially outperform standard case-control subsampling.


title: Low latency via redundancy

abstract:
  Low latency is critical for interactive networked applications. But while we
know how to scale systems to increase capacity, reducing latency --- especially
the tail of the latency distribution --- can be much more difficult. In this
paper, we argue that the use of redundancy is an effective way to convert extra
capacity into reduced latency. By initiating redundant operations across
diverse resources and using the first result which completes, redundancy
improves a system's latency even under exceptional conditions. We study the
tradeoff with added system utilization, characterizing the situations in which
replicating all tasks reduces mean latency. We then demonstrate empirically
that replicating all operations can result in significant mean and tail latency
reduction in real-world systems including DNS queries, database servers, and
packet forwarding within networks.


title: Mechanical separation of chiral dipoles by chiral light

abstract:
  We calculate optical forces and torques exerted on a chiral dipole by chiral
light fields and reveal genuinely chiral forces in combining the chiral
contents of both light field and dipolar matter. Here, the optical chirality is
characterized in a general way through the definition of optical chirality
density and chirality flow. We show in particular that both terms have
mechanical effects associated respectively with reactive and dissipative
components of the chiral forces. Remarkably, these chiral force components are
directly related to standard observables: optical rotation for the reactive
component and circular dichroism for the dissipative one. As a consequence, the
resulting forces and torques are dependent on the enantiomeric form of the
chiral dipole. This suggests promising strategies for using chiral light forces
to mechanically separate chiral objects according to their enantiomeric form.


title: A library of near-infrared integral field spectra of young M-L dwarfs

abstract:
  We present a library of near-infrared (1.1-2.45 microns) medium-resolution
(R~1500-2000) integral field spectra of 15 young M6-L0 dwarfs, composed of
companions with known ages and of isolated objects. We use it to (re)derive the
NIR spectral types, luminosities and physical parameters of the targets, and to
test (BT-SETTL, DRIFT-PHOENIX) atmospheric models. We derive infrared spectral
types L0+-1, L0+-1, M9.5+-0.5, M9.5+-0.5, M9.25+-0.25, M8+0.5-0.75, and
M8.5+-0.5 for AB Pic b, Cha J110913-773444, USco CTIO 108B, GSC 08047-00232 B,
DH Tau B, CT Cha b, and HR7329B, respectively. BT-SETTL and DRIFT-PHOENIX
models yield close Teff and log g estimates for each sources. The models seem
to evidence a 600-300+600 K drop of the effective temperature at the M-L
transition. Assuming the former temperatures are correct, we derive new mass
estimates which confirm that DH Tau B, USco CTIO 108B, AB Pic b, KPNO Tau 4,
OTS 44, and Cha1109 lay inside or at the boundary of the planetary mass range.
We combine the empirical luminosities of the M9.5-L0 sources to the Teff to
derive semi-empirical radii estimates that do not match "hot-start"
evolutionary models predictions at 1-3 Myr. We use complementary data to
demonstrate that atmospheric models are able to reproduce the combined optical
and infrared spectral energy distribution, together with the near-infrared
spectra of these sources simultaneously. But the models still fail to represent
the dominant features in the optical. This issue casts doubts on the ability of
these models to predict correct effective temperatures from near-infrared
spectra alone. We advocate the use of photometric and spectroscopic data
covering a broad range of wavelengths to study the properties of very low mass
young companions to be detected with the planet imagers (Subaru/SCExAO,
LBT/LMIRCam, Gemini/GPI, VLT/SPHERE).


title: Symmetric Two-User MIMO BC and IC with Evolving Feedback

abstract:
  Extending recent findings on the two-user MISO broadcast channel (BC) with
imperfect and delayed channel state information at the transmitter (CSIT), the
work here explores the performance of the two user MIMO BC and the two user
MIMO interference channel (MIMO IC), in the presence of feedback with evolving
quality and timeliness. Under standard assumptions, and in the presence of M
antennas per transmitter and N antennas per receiver, the work derives the DoF
region, which is optimal for a large regime of sufficiently good (but
potentially imperfect) delayed CSIT. This region concisely captures the effect
of having predicted, current and delayed-CSIT, as well as concisely captures
the effect of the quality of CSIT offered at any time, about any channel. In
addition to the progress towards describing the limits of using such imperfect
and delayed feedback in MIMO settings, the work offers different insights that
include the fact that, an increasing number of receive antennas can allow for
reduced quality feedback, as well as that no CSIT is needed for the direct
links in the IC.


title:
Riemann Hypothesis: Architecture of a conjecture "along" the lines of
  P\'olya. From trivial zeros and Harmonic Oscillator to information about
  non-trivial zeros of the Riemann zeta-function

abstract:
  We propose an architecture of a conjecture concerning the Riemann Hypothesis
in the form of an "alternative" to the P\'olya strategy: we construct a
Hamiltonian H_Polya whose spectrum coincides exactly with that of the Harmonic
Oscillator Hamiltonian H_osc if and only if the Riemann Hypothesis holds true.
In other words, it can be said that we formulate the Riemann Hypothesis by
means of a non-commutative structure on the real axis, viz., that of the
Harmonic Oscillator, by an equation of the type H_Polya(H_osc) = H_osc: the
Harmonic Oscillator operator, if viewed as an argument of H_Polya, reproduces
itself.


title: Principal subspaces for quantum affine algebra $U_q(A_n^{(1)})$

abstract:
  We consider principal subspace W({\Lambda}) of integrable highest weight
module L({\Lambda}) for quantum affine algebra
$U_q(\hat{\mathfrak{sl}}_{n+1})$. We introduce quantum analogues of the
quasi-particles associated with the principal subspaces for
$\hat{\mathfrak{sl}}_{n+1}$ and discover certain relations among them. By using
these relations we find, for certain highest weight {\Lambda}, combinatorial
bases of principal subspace W({\Lambda}) in terms of monomials of quantum
quasi-particles.


title:
The eigenpairs of a Sylvester-Kac type matrix associated with a simple
  model for one-dimensional deposition and evaporation

abstract:
  A straightforward model for deposition and evaporation on discrete cells of a
finite array of any dimension leads to a matrix equation involving a
Sylvester-Kac type matrix. The eigenvalues and eigenvectors of the general
matrix are determined for an arbitrary number of cells. A variety of models to
which this solution may be applied are discussed.


title:
An approach to first principles electronic structure calculation by
  symbolic-numeric computation

abstract:
  This article is an introduction to a new approach to first principles
electronic structure calculation. The starting point is the
Hartree-Fock-Roothaan equation, in which molecular integrals are approximated
by polynomials by way of Taylor expansion with respect to atomic coordinates
and other variables. It leads to a set of polynomial equations whose solutions
are eigenstate, which is designated as algebraic molecular orbital equation.
Symbolic computation, especially, Gr\"obner bases theory, enables us to rewrite
the polynomial equations into more trimmed and tractable forms with identical
roots, from which we can unravel the relationship between physical parameters
(wave function, atomic coordinates, and others) and numerically evaluate them
one by one in order. Furthermore, this method is a unified way to solve the
electronic structure calculation, the optimization of physical parameters, and
the inverse problem as a forward problem.


title: Sharp diameter estimates for compact manifold with boundary

abstract:
  Let $(N,g)$ be an $n$-dimensional complete Riemannian manifold with nonempty
boundary $\pt N$. Assume that the Ricci curvature of $N$ has a negative lower
bound $Ric\geq -(n-1)c^2$ for some $c>0$, and the mean curvature of the
boundary $\pt N$ satisfies $H\geq (n-1)c_0>(n-1)c$ for some $c_0>c>0$. Then a
known result (see \cite{LN}) says that $\sup_{x\in N}d(x,\pt N)\leq \frac
1c\coth^{-1}\frac{c_0}c$. In this paper, we prove that if the boundary $\pt N$
is compact, then the equality holds if and only if $N$ is isometric to the
geodesic ball of radius $\frac 1c\coth^{-1}\frac{c_0}c$ in an $n$-dimensional
hyperbolic space $\mathbb{H}^n(-c^2)$ of constant sectional curvature $-c^2$.
Moreover, we also prove an analogous result for manifold with nonempty boundary
and with $m$-Bakry-\'{E}mery Ricci curvature bounded below by a negative
constant.


title: Artin--Schreier and Cyclotomic Extensions

abstract:
  In this paper we prove that any Artin--Schreier extension of a congruence
rational function field is contained in the composite of a cyclotomic function
field and a constant field extension that are explicitly prescribed.


title:
Performance Analysis for Physical Layer Security in Multi-Antenna
  Downlink Networks with Limited CSI Feedback

abstract:
  Channel state information (CSI) at the transmitter is of importance to the
performance of physical layer security based on multi-antenna networks.
Specifically, CSI is not only beneficial to improve the capacity of the
legitimate channel, but also can be used to degrade the performance of the
eavesdropper channel. Thus, the secrecy rate increases accordingly. This letter
focuses on the quantitative analysis of the ergodic secrecy sum-rate in terms
of feedback amount of the CSI from the legitimate users in multiuser
multi-antenna downlink networks. Furthermore, the asymptotic characteristics of
the ergodic secrecy sum-rate in two extreme cases is investigated in some
detail. Finally, our theoretical claims are confirmed by the numerical results.


title: Fluctuations From Edge Defects in Superconducting Resonators

abstract:
  Superconducting resonators, used in astronomy and quantum computation, couple
strongly to microscopic two-level defects. We monitor the microwave response of
superconducting resonators and observe fluctuations in dissipation and
resonance frequency. We present a unified model where the observed dissipative
and dispersive effects can be explained as originating from a bath of
fluctuating two-level systems. From these measurements, we quantify the number
and distribution of the defects.


title:
Energy spectra of three electrons in SiGe/Si/SiGe laterally coupled
  triple quantum dots

abstract:
  We investigate the energy spectra of three electrons in SiGe/Si/SiGe
equilateral triangular and symmetric linear triple quantum dots in the presence
of magnetic (in either Faraday or Voigt configuration) and electric fields with
single valley approximation by using the real-space configuration interaction
method. The strong electron-electron Coulomb interaction, which is crucial to
the energy spectra, is explicitly calculated whereas the weak spin-orbit
coupling is treated perturbatively. In both equilateral triangular and
symmetric linear triple quantum dots, we find doublet-quartet transition of
ground-state spin configuration by varying dot size or interdot distance in the
absence of external fields. This transition has not been reported in the
literature on triple quantum dots. In the magnetic-field (Faraday
configuration) dependence of energy spectra, we find anticrossings with large
energy splittings between the energy levels with the same spin state in the
absence of the spin-orbit coupling. This anticrossing behavior originates from
the triple quantum dot confinement potential. In addition, with the inclusion
of the spin-orbit coupling, we find that all the intersections shown in the
equilateral triangular case become anticrossing whereas only part of the
intersections in symmetric linear case show anticrossing behavior in the
presence of magnetic field in either the Faraday or Voigt configuration. All
the anticrossing behaviors are analyzed based on symmetry consideration.
Moreover, we show that the electric field can effectively influence the energy
levels and the charge configurations.


title:
Population trapping and inversion in ultracold Fermi gases by excitation
  of the optical lattice - Non-equilibrium Floquet-Keldysh description

abstract:
  A gas of ultracold interacting quantum degenerate Fermions is considered in a
three dimensional optical lattice which is externally modulated in the fre-
quency and the amplitude. This theoretical study utilizes the Keldysh formalism
to account for the system being out of thermodynamical equilibrium. A dynamical
mean field theory, extended to non-equilibrium, is presented to calculate
characteristic quantities such as the local density of states and the
non-equilibrium distribution function. A dynamics Franz-Keldysh splitting is
found which accounts for the non-equilibrium modification of the underlying
bandstructure. The found characteristic Floquet-fan like bandstructure accounts
for the quantized nature of the effect over all frequency space.


title: Online Alternating Direction Method (longer version)

abstract:
  Online optimization has emerged as powerful tool in large scale optimization.
In this pa- per, we introduce efficient online optimization algorithms based on
the alternating direction method (ADM), which can solve online convex
optimization under linear constraints where the objective could be non-smooth.
We introduce new proof techniques for ADM in the batch setting, which yields a
O(1/T) convergence rate for ADM and forms the basis for regret anal- ysis in
the online setting. We consider two scenarios in the online setting, based on
whether an additional Bregman divergence is needed or not. In both settings, we
establish regret bounds for both the objective function as well as constraints
violation for general and strongly convex functions. We also consider inexact
ADM updates where certain terms are linearized to yield efficient updates and
show the stochastic convergence rates. In addition, we briefly discuss that
online ADM can be used as projection- free online learning algorithm in some
scenarios. Preliminary results are presented to illustrate the performance of
the proposed algorithms.


title: A new parameter space study of cosmological microlensing

abstract:
  Cosmological gravitational microlensing is a useful technique for
understanding the structure of the inner parts of a quasar, especially the
accretion disk and the central supermassive black hole. So far, most of the
cosmological microlensing studies have focused on single objects from ~90
currently known lensed quasars. However, present and planned all-sky surveys
are expected to discover thousands of new lensed systems. Using a graphics
processing unit (GPU) accelerated ray-shooting code, we have generated 2550
magnification maps uniformly across the convergence ({\kappa}) and shear
({\gamma}) parameter space of interest to microlensing. We examine the effect
of random realizations of the microlens positions on map properties such as the
magnification probability distribution (MPD). It is shown that for most of the
parameter space a single map is representative of an average behaviour. All of
the simulations have been carried out on the GPU-Supercomputer for Theoretical
Astrophysics Research (gSTAR).


title:
Magnetar Giant Flares and Their Precursors --- Flux Rope Eruptions with
  Current Sheets

abstract:
  We propose a catastrophic magnetospheric model for magnetar precursors and
their successive giant flares. Axisymmetric models of the magnetosphere, which
contain both a helically twisted flux rope and a current sheet, are established
based on force-free field configurations. In this model, the helically twisted
flux rope would lose its equilibrium and erupt abruptly in response to the slow
and quasi-static variations at the ultra-strongly magnetized neutron star's
surface. In a previous model without current sheets, only one critical point
exists in the flux rope equilibrium curve. New features show up in the
equilibrium curves for the flux rope when current sheets appear in the
magnetosphere. The causal connection between the precursor and the giant flare,
as well as the temporary re-entry of the quiescent state between the precursor
and the giant flare, can be naturally explained. Magnetic energy would be
released during the catastrophic state transitions. The detailed energetics of
the model are also discussed. The current sheet created by the catastrophic
loss of equilibrium of the flux rope provides an ideal place for magnetic
reconnection. We point out the importance of magnetic reconnection for further
enhancement of the energy release during eruptions.


title:
A fixed point theorem for closed-graphed decomposable-valued
  correspondences

abstract:
  We prove a fixed point theorem for closed-graphed, decomposable-valued
correspondences whose domain and range is a decomposable set of functions from
an atomless measure space to a topological space. One consequence is an
improvement of the fixed point theorem in Cellina, Colombo, and Fonda (1986).


title: Stability of Schwarzschild black holes in fourth-order gravity revisited

abstract:
  We revisit the classical stability of Schwarzschild black hole in
fourth-order theories of gravity. On the contrary of the stability of this
black hole, it turns out that the linearized perturbations exhibit unstable
modes featuring the Gregory-Laflamme instability of five-dimensional black
string. This shows clearly an instability of black hole in fourth-order gravity
with $\alpha=-\beta/3$.


title: Automatic functions, linear time and learning

abstract:
  The present work determines the exact nature of {\em linear time computable}
notions which characterise automatic functions (those whose graphs are
recognised by a finite automaton). The paper also determines which type of
linear time notions permit full learnability for learning in the limit of
automatic classes (families of languages which are uniformly recognised by a
finite automaton). In particular it is shown that a function is automatic iff
there is a one-tape Turing machine with a left end which computes the function
in linear time where the input before the computation and the output after the
computation both start at the left end. It is known that learners realised as
automatic update functions are restrictive for learning. In the present work it
is shown that one can overcome the problem by providing work tapes additional
to a resource-bounded base tape while keeping the update-time to be linear in
the length of the largest datum seen so far. In this model, one additional such
work tape provides additional learning power over the automatic learner model
and two additional work tapes give full learning power. Furthermore, one can
also consider additional queues or additional stacks in place of additional
work tapes and for these devices, one queue or two stacks are sufficient for
full learning power while one stack is insufficient.


title: A note on scheduling with low rank processing times

abstract:
  We consider the classical minimum makespan scheduling problem, where the
processing time of job $j$ on machine $i$ is $p_{ij}$, and the matrix
$P=(p_{ij})_{m\times n}$ is of a low rank. It is proved in (Bhaskara et al.,
SODA 2013) that rank 7 scheduling is NP-hard to approximate to a factor of
$3/2-\epsilon$, and rank 4 scheduling is APX-hard (NP-hard to approximate
within a factor of $1.03-\epsilon$). We improve this result by showing that
rank 4 scheduling is already NP-hard to approximate within a factor of
$3/2-\epsilon$, and meanwhile rank 3 scheduling is APX-hard.


title:
Entanglement Structure of an Open System of $N$ Quantum Oscillators: II.
  Strong Disparate Couplings N=3

abstract:
  In this paper we study a system of $N$ coupled quantum oscillators
interacting with each other directly with varying coupling strengths and
indirectly through linear couplings to a scalar massless quantum field as its
environment. The influence of the quantum field on the system is calculated
with the use of the influence functional formalism. We take the direct route of
seeking solutions to the evolutionary operator of the reduced density matrix
for the derivation of the correlation functions. They are then used to
construct the covariance matrix which we use to perform an analysis of the
structure of quantum entanglement in the open system at a stationary state. To
see the physical features more explicitly we specialize to a system of three
quantum coupled oscillators placed at the vertices of a equilateral triangle
and allowed to have disparate pairwise couplings. We analyze the entanglement
between one oscillator and the other two with equal (symmetric) and unequal
(asymmetric) coupling strengths. As an illustration we use the results for
these two different configurations to address two representative issues in
macroscopic quantum phenomena. We also mention possible extensions of our work
and applications of our analysis and results to issues in some current areas of
research in quantum thermodynamics and mesoscopic quantum systems.


title: Spectral Experts for Estimating Mixtures of Linear Regressions

abstract:
  Discriminative latent-variable models are typically learned using EM or
gradient-based optimization, which suffer from local optima. In this paper, we
develop a new computationally efficient and provably consistent estimator for a
mixture of linear regressions, a simple instance of a discriminative
latent-variable model. Our approach relies on a low-rank linear regression to
recover a symmetric tensor, which can be factorized into the parameters using a
tensor power method. We prove rates of convergence for our estimator and
provide an empirical evaluation illustrating its strengths relative to local
optimization (EM).


title:
The structure of massive quiescent galaxies at z~3 in the CANDELS-COSMOS
  field

abstract:
  In this letter, we use a two-color (J-L) vs. (V-J) selection criteria to
search massive, quiescent galaxy candidates at 2.5<z<4.0 in the CANDELS-COSMOS
field. We construct a H-selected catalogue and complement it with public
auxiliary data. We finally obtain 19 passive VJL-selected (hereafter pVJL)
galaxies as the possible massive quiescent galaxy candidates at z~3 by several
constrains. We find the sizes of our pVJL galaxies are on average 3-4 times
smaller than those of local ETGs with analogous stellar mass. The compact size
of these z~3 galaxies can be modelled by assuming their formation at z ~ 4-6
according to the dissipative collapse of baryons. Up to z<4, the
mass-normalized size evolution can be described by $r_e\propto (1+z)^{-1.0}$.
Low Sersic index and axis ratio, with median values n~1.5 and b/a~0.65
respectively, indicate most of pVJL galaxies are disk-dominated. Despite large
uncertainty, the inner region of the median mass profile of our pVJL galaxies
is similar to those of quiescent galaxies (QGs) at 0.5<z<2.5 and local
Early-type galaxies (ETGs). It indicates local massive ETGs have been formed
according to an inside-out scenario: the compact galaxies at high redshift make
up the cores of local massive ETGs and then build up the outskirts according to
dissipationless minor mergers.


title:
Sharp low energy feature in single-particle spectra due to forward
  scattering in $d$-wave cuprate superconductors

abstract:
  There is an enormous interest in renormalization of quasi-particle (qp)
dispersion relation of cuprate superconductors both below and above the
critical temperature $T_c$ because it enables determination of the fluctuation
spectrum to which the qps are coupled. A remarkable discovery by angle-resolved
photoemission spectroscopy (ARPES) is a sharp low energy feature (LEF) in qp
spectra well below the superconducting energy gap but with its energy
increasing in proportion to $T_c$ and its intensity increasing sharply below
$T_c$. This unexpected feature needs to be reconciled with $d$-wave
superconductivity. Here, we present a quantitative analysis of ARPES data from
Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ (Bi2212) using Eliashberg equations to show
that the qp scattering rate due to the forward scattering impurities far from
the Cu-O planes is modified by the energy gap below $T_c$ and shows up as the
LEF. This is also a necessary step to analyze ARPES data to reveal the spectrum
of fluctuations promoting superconductivity.


title:
Multiplicative Modeling of Children's Growth and Its Statistical
  Properties

abstract:
  We develop a numerical growth model which can predict the statistical
properties of the height distribution of Japanese children. Our previous
studies have clarified that the height distribution of schoolchildren shows a
transition from the lognormal to the normal distribution during puberty period.
In this paper, we demonstrate by our simulations that the transition occurs
owing to the variability of the onset of the puberty period.


title:
Polarization of photons scattered by electrons in any spectral
  distribution

abstract:
  Based on the quantum electrodynamics, we present a generic formalism of the
polarization for beamed monochromatic photons scattered by electrons in any
spectral distribution. The formulae reduce to the components of the Fano matrix
when electrons are at rest. We mainly investigate the polarization in three
scenarios, i.e., electrons at rest, isotropic electrons with a power law
spectrum and thermal electrons. If the incident beam is polarized, the
polarization is reduced significantly by isotropic electrons at large viewing
angles, and the degree of polarization due to thermal electrons is about one
times less than that of electrons in a power law. If the incident bean is
unpolarized, soft $\gamma$-rays can lead to about 15% polarization at viewing
angles around $\pi/4$. For isotropic electrons, one remarkable feature is that
the polarization as a function of the incident photon energy always peaks
roughly at 1 MeV, this is valid for both the thermal and power law cases. This
feature can be used to distinguish the model of the inverse Compton scattering
from that of the synchrotron radiation.


title:
A confirmative spin-parity assignment for the key 6.15 MeV state in
  $^{18}$Ne of astrophysical importance

abstract:
  Proton resonant states in $^{18}$Ne have been investigated by the resonant
elastic scattering of $^{17}$F+$p$. The $^{17}$F beam was separated by the CNS
radioactive ion beam separator (CRIB), and bombarded a thick H$_2$ gas target
at 3.6 MeV/nucleon. The recoiled light particles were measured by using three
sets of ${\Delta}$E-E Si telescope at scattering angles of
$\theta$$_{lab}$$\approx 3^\circ$, 10$^\circ$ and 18$^\circ$, respectively.
Four resonances, {\it i.e.}, at $E_{x}$=6.15, 6.30, 6.85, and 7.05 MeV, were
observed clearly. By $R$-matrix analysis of the excitation functions,
$J^{\pi}$=1$^-$ was firmly assigned to the 6.15 MeV state which is a key state
in calculating the reaction rate of $^{14}$O($\alpha$,$p$)$^{17}$F reaction.
This reaction was thought to be one of the most probable key reactions for the
breakout from the hot-CNO cycle to the $rp$-process in type I x-ray bursts In
addition, a new excited state observed at $E_{x}$=6.85 MeV was tentatively
assigned as 0$^{-}$, which could be the analog state of 6.880 MeV, 0$^{-}$ in
mirror $^{18}$O.


title: Global Well-posedness for the Generalized Navier-Stokes System

abstract:
  In this paper we investigate well-posedness of the Cauchy problem of the
three dimensional generalized Navier-Stokes system. We first establish local
well-posedness of the GNS system for any initial data in the Fourier-Herz space
$\chi^{-1}$. Then we show that if the $\chi^{-1}$ norm of the initial data is
smaller than C$\nu$ in the GNS system where $\nu$ is the viscosity coefficient,
the corresponding solution exists globally in time. Moreover, we prove global
well-posedness of the Navier-Stokes system without norm restrictions on the
corresponding solutions provided the $\chi^{-1}$ norm of the initial data is
less than $\nu.$ Our obtained results cover and improve recent results in
\cite{Zhen Lei,wu}.


title: The local cohomology of the jacobian ring

abstract:
  We study the 0-th local cohomology module of the jacobian ring of a singular
reduced complex projective hypersurface X, by relating it to the sheaf of
logarithmic vector field along X. We investigate the analogies between the
local cohomology and the well known properties of the jacobian ring of a
nonsingular hypersurface. In particular we study self-duality, Hodge theoretic
and Torelli type questions.


title:
Classical Mechanical Systems with one-and-a-half Degrees of Freedom and
  Vlasov Kinetic Equation

abstract:
  We consider non-stationary dynamical systems with one-and-a-half degrees of
freedom. We are interested in algorithmic construction of rich classes of
Hamilton's equations with the Hamiltonian H=p^2/2+V(x,t) which are Liouville
integrable. For this purpose we use the method of hydrodynamic reductions of
the corresponding one-dimensional Vlasov kinetic equation.
  Also we present several examples of such systems with first integrals with
non-polynomial dependencies w.r.t. to momentum.
  The constructed in this paper classes of potential functions {$V(x,t)$} which
give integrable systems with one-and-a-half degrees of freedom are
parameterized by arbitrary number of constants.


title:
A coevolving model based on preferential triadic closure for social
  media networks

abstract:
  The dynamical origin of complex networks, i.e., the underlying principles
governing network evolution, is a crucial issue in network study. In this
paper, by carrying out analysis to the temporal data of Flickr and
Epinions--two typical social media networks, we found that the dynamical
pattern in neighborhood, especially the formation of triadic links, plays a
dominant role in the evolution of networks. We thus proposed a coevolving
dynamical model for such networks, in which the evolution is only driven by the
local dynamics--the preferential triadic closure. Numerical experiments
verified that the model can reproduce global properties which are qualitatively
consistent with the empirical observations.


title: Approximation Algorithms for Movement Repairmen

abstract:
  In the {\em Movement Repairmen (MR)} problem we are given a metric space $(V,
d)$ along with a set $R$ of $k$ repairmen $r_1, r_2, ..., r_k$ with their start
depots $s_1, s_2, ..., s_k \in V$ and speeds $v_1, v_2, ..., v_k \geq 0$
respectively and a set $C$ of $m$ clients $c_1, c_2, ..., c_m$ having start
locations $s'_1, s'_2, ..., s'_m \in V$ and speeds $v'_1, v'_2, ..., v'_m \geq
0$ respectively. If $t$ is the earliest time a client $c_j$ is collocated with
any repairman (say, $r_i$) at a node $u$, we say that the client is served by
$r_i$ at $u$ and that its latency is $t$. The objective in the (\smr{}) problem
is to plan the movements for all repairmen and clients to minimize the sum
(average) of the clients latencies. The motivation for this problem comes, for
example, from Amazon Locker Delivery \cite{amazon} and USPS gopost
\cite{gopost}. We give the first $O(\log n)$-approximation algorithm for the
\smr{} problem.