title:
Elastic and inelastic collisions of $^2\Sigma$ molecules in a magnetic
  field

abstract:
  We calculate the cross sections for elastic scattering and Zeeman relaxation
in binary collisions of molecules in the ro-vibrational ground state of a
$^2\Sigma$ electronic state and the Zeeman state with the electron spin
projection $M_S=1/2$ on the magnetic field axis. This is the lowest-energy
state of $^2\Sigma$ molecules confined in a magnetic trap. The results are
averaged over calculations with multiple molecule - molecule interaction
potentials, which yields the expectation intervals for the cross sections and
the elastic-to-inelastic cross section ratios. We find that the
elastic-to-inelastic cross section ratios under conditions corresponding to
trapped molecular ensembles at $T \sim 10^{-3}$ K exceed 100 for the majority
of $^2\Sigma$ molecules. The range of $^2\Sigma$ molecules expected to be
collisionally unstable in magnetic traps at $T < 10^{-3}$ K is limited to
molecules with the spin-rotation interaction constant $\gamma_{\rm SR} > 0.5$
cm$^{-1}$ and the rotational constant $B_e < 4$ cm$^{-1}$.


title: Experimental Review of Structures in the $J/\psi\phi$ Mass Spectrum

abstract:
  The discovery of numerous new charmonium-like structures since 2003 have
revitalized interest in exotic meson spectroscopy. These structures do not fit
easily into the conventional charmonium model, and proposals like four-quark
states, hybrids, and re-scattering effects have been suggested as explanations.
Since 2009, several new structures were reported in the $J/\psi\phi$ mass
spectrum with the following characteristics: they are the first ones reported
decaying into two heavy mesons which contain both a $c\bar{c}$ pair and a
$s\bar{s}$ pair; and their masses are well beyond the open charm pair
threshold. Conventional $c\bar{c}$ states with a mass beyond the $J/\psi\phi$
threshold are not expected to decay into this channel and the width is expected
to be large, thus they are good candidates for exotic mesons. My focus in this
article is to review the recent developments on the structures in the
$J/\psi\phi$ mass spectrum from CDF, Belle and LHCb.


title: Network versus portfolio structure in financial systems

abstract:
  The question of how to stabilize financial systems has attracted considerable
attention since the global financial crisis of 2007-2009. Recently, Beale et
al. ("Individual versus systemic risk and the regulator's dilemma", Proc Natl
Acad Sci USA 108: 12647-12652, 2011) demonstrated that higher portfolio
diversity among banks would reduce systemic risk by decreasing the risk of
simultaneous defaults at the expense of a higher likelihood of individual
defaults. In practice, however, a bank default has an externality in that it
undermines other banks' balance sheets. This paper explores how each of these
different sources of risk, simultaneity risk and externality, contributes to
systemic risk. The results show that the allocation of external assets that
minimizes systemic risk varies with the topology of the financial network as
long as asset returns have negative correlations. In the model, a well-known
centrality measure, PageRank, reflects an appropriately defined "infectiveness"
of a bank. An important result is that the most infective bank need not always
be the safest bank. Under certain circumstances, the most infective node should
act as a firewall to prevent large-scale collective defaults. The introduction
of a counteractive portfolio structure will significantly reduce systemic risk.


title: Efficient Data Augmentation in Dynamic Models for Binary and Count Data

abstract:
  Dynamic linear models with Gaussian observations and Gaussian states lead to
closed-form formulas for posterior simulation. However, these closed-form
formulas break down when the response or state evolution ceases to be Gaussian.
Dynamic, generalized linear models exemplify a class of models for which this
is the case, and include, amongst other models, dynamic binomial logistic
regression and dynamic negative binomial regression. Finding and appraising
posterior simulation techniques for these models is important since modeling
temporally correlated categories or counts is useful in a variety of
disciplines, including ecology, economics, epidemiology, medicine, and
neuroscience. In this paper, we present one such technique, P\'olya-Gamma data
augmentation, and compare it against two competing methods. We find that the
P\'olya-Gamma approach works well for dynamic logistic regression and for
dynamic negative binomial regression when the count sizes are small.
Supplementary files are provided for replicating the benchmarks.


title:
A Unified Approach to Convex and Convexified Generalized Differentiation
  of Nonsmooth Functions and Set-Valued Mappings

abstract:
  In the early 1960's, Moreau and Rockafellar introduced a concept of called
\emph{subgradient} for convex functions, initiating the developments of
theoretical and applied convex analysis. The needs of going beyond convexity
motivated the pioneer works by Clarke considering generalized differentiation
theory of Lipschitz continuous functions. Although Clarke generalized
differentiation theory is applicable for nonconvex functions, convexity still
plays a crucial role in Clarke subdifferential calculus. In the mid 1970's,
Mordukhovich developed another generalized differentiation theory for nonconvex
functions and set-valued mappings in which the "umbilical cord with convexity"
no longer exists. The primary goal of this paper is to present a unified
approach and shed new light on convex and Clarke generalized differentiation
theories using the concepts and techniques from Mordukhovich's developments.


title:
Dynamic Approximate All-Pairs Shortest Paths: Breaking the O(mn) Barrier
  and Derandomization

abstract:
  We study dynamic $(1+\epsilon)$-approximation algorithms for the all-pairs
shortest paths problem in unweighted undirected $n$-node $m$-edge graphs under
edge deletions. The fastest algorithm for this problem is a randomized
algorithm with a total update time of $\tilde O(mn/\epsilon)$ and constant
query time by Roditty and Zwick [FOCS 2004]. The fastest deterministic
algorithm is from a 1981 paper by Even and Shiloach [JACM 1981]; it has a total
update time of $O(mn^2)$ and constant query time. We improve these results as
follows: (1) We present an algorithm with a total update time of $\tilde
O(n^{5/2}/\epsilon)$ and constant query time that has an additive error of $2$
in addition to the $1+\epsilon$ multiplicative error. This beats the previous
$\tilde O(mn/\epsilon)$ time when $m=\Omega(n^{3/2})$. Note that the additive
error is unavoidable since, even in the static case, an $O(n^{3-\delta})$-time
(a so-called truly subcubic) combinatorial algorithm with $1+\epsilon$
multiplicative error cannot have an additive error less than $2-\epsilon$,
unless we make a major breakthrough for Boolean matrix multiplication [Dor et
al. FOCS 1996] and many other long-standing problems [Vassilevska Williams and
Williams FOCS 2010]. The algorithm can also be turned into a
$(2+\epsilon)$-approximation algorithm (without an additive error) with the
same time guarantees, improving the recent $(3+\epsilon)$-approximation
algorithm with $\tilde O(n^{5/2+O(\sqrt{\log{(1/\epsilon)}/\log n})})$ running
time of Bernstein and Roditty [SODA 2011] in terms of both approximation and
time guarantees. (2) We present a deterministic algorithm with a total update
time of $\tilde O(mn/\epsilon)$ and a query time of $O(\log\log n)$. The
algorithm has a multiplicative error of $1+\epsilon$ and gives the first
improved deterministic algorithm since 1981. It also answers an open question
raised by Bernstein [STOC 2013].


title:
A testing based extraction algorithm for identifying significant
  communities in networks

abstract:
  A common and important problem arising in the study of networks is how to
divide the vertices of a given network into one or more groups, called
communities, in such a way that vertices of the same community are more
interconnected than vertices belonging to different ones. We propose and
investigate a testing based community detection procedure called Extraction of
Statistically Significant Communities (ESSC). The ESSC procedure is based on
$p$-values for the strength of connection between a single vertex and a set of
vertices under a reference distribution derived from a conditional
configuration network model. The procedure automatically selects both the
number of communities in the network and their size. Moreover, ESSC can handle
overlapping communities and, unlike the majority of existing methods,
identifies "background" vertices that do not belong to a well-defined
community. The method has only one parameter, which controls the stringency of
the hypothesis tests. We investigate the performance and potential use of ESSC
and compare it with a number of existing methods, through a validation study
using four real network data sets. In addition, we carry out a simulation study
to assess the effectiveness of ESSC in networks with various types of community
structure, including networks with overlapping communities and those with
background vertices. These results suggest that ESSC is an effective
exploratory tool for the discovery of relevant community structure in complex
network systems. Data and software are available at
\urlhttp://www.unc.edu/~jameswd/research.html.


title: Resolution of degenerate mirror families via toric morphisms

abstract:
  This paper continues the study of two examples of extremal transitions
between families of Calabi-Yau threefolds. In a previous paper we suggested
that the "mirror transition" between mirror families predicted by Morrison
could be achieved naturally by combining a toric morphism with the
Batyrev-Borisov construction. This was carried out for a particular example of
a conifold transition. In this paper we show that similar methods work for
another extremal transition involving more complicated singularities. We also
study how the resolution is related to geometry of the ambient toric varieties,
and discuss the connection with recent work by Doran and Harder.


title:
p-adic Cohomology and classicality of overconvergent Hilbert modular
  forms

abstract:
  Let $F$ be a totally real field in which $p$ is unramified. We prove that, if
a cuspidal overconvergent Hilbert cuspidal form has small slopes under
$U_p$-operators, then it is classical. Our method follows the original
cohomological approach of Coleman. The key ingredient of the proof is giving an
explicit description of the Goren-Oort stratification of the special fiber of
the Hilbert modular variety. A byproduct of the proof is to show that, at least
when $p$ is inert, of the rigid cohomology of the ordinary locus has the same
image as the classical forms in the Grothendieck group of Hecke modules.


title: Symmetrically complete ordered sets, abelian groups and fields

abstract:
  We characterize and construct linearly ordered sets, abelian groups and
fields that are {\emph symmetrically complete}, meaning that the intersection
over any chain of closed bounded intervals is nonempty. Such ordered abelian
groups and fields are important because generalizations of Banach's Fixed Point
Theorem hold in them. We prove that symmetrically complete ordered abelian
groups and fields are divisible Hahn products and real closed power series
fields, respectively. We show how to extend any given ordered set, abelian
group or field to one that is symmetrically complete. A main part of the paper
establishes a detailed study of the cofinalities in cuts.


title: Coherent control of total transmission of light through disordered media

abstract:
  We demonstrate order of magnitude coherent control of total transmission of
light through random media by shaping the wavefront of the input light. To
understand how the finite illumination area on a wide slab affects the maximum
values of total transmission, we develop a model based on random matrix theory
that reveals the role of long-range correlations. Its predictions are confirmed
by numerical simulations and provide physical insight into the experimental
results.


title:
Young walls and graded dimension formulas for finite quiver Hecke
  algebras of type $A^{(2)}_{2\ell}$ and $D^{(2)}_{\ell+1}$

abstract:
  We study graded dimension formulas for finite quiver Hecke algebras
$R^{\Lambda_0}(\beta)$ of type $A^{(2)}_{2\ell}$ and $D^{(2)}_{\ell+1}$ using
combinatorics of Young walls. We introduce the notion of standard tableaux for
proper Young walls and show that the standard tableaux form a graded poset with
lattice structure. We next investigate Laurent polynomials associated with
proper Young walls and their standard tableaux arising from the Fock space
representations consisting of proper Young walls. Then we prove the graded
dimension formulas described in terms of the Laurent polynomials. When
evaluating at $q=1$, the graded dimension formulas recover the dimension
formulas for $R^{\Lambda_0}(\beta)$ described in terms of standard tableaux of
strict partitions.


title: Generic A-family of exponential sums

abstract:
  In this paper we construct a generating polynomial over the rationals for the
generic Newton polygon for the L function of exponential sums of the family of
f = x^d+ a x^s parameterized by a, and prove some of its key properties. The
generating polynomial encodes information of and determines the generic Newton
polygon at each prime p when p is large enough, and vice versa.


title:
Nonlinear waves of polarization in two-component Bose-Einstein
  condensates

abstract:
  Waves with different symmetries exist in two-component Bose-Einstein
condensates (BECs) whose dynamics is described by a system of coupled
Gross-Pitaevskii (GP) equations. A first type of waves corresponds to
excitations for which the motion of both components is locally in phase. In the
second type of waves the two components have a counter-phase local motion. In
the case of different values of inter- and intra-component interaction
constants, the long wave-length behavior of these two modes corresponds to two
types of sound with different velocities. In the limit of weak nonlinearity and
small dispersion the first mode is described by the well-known Korteweg-de
Vries (KdV) equation. We show that in the same limit the second mode can be
described by the Gardner (modified KdV) equation, if the intra-component
interaction constants have close enough values. This leads to a rich
phenomenology of nonlinear excitations (solitons, kinks, algebraic solitons,
breathers) which does not exist in the KdV description.


title:
On the relative importance of second-order terms in relativistic
  dissipative fluid dynamics

abstract:
  In Denicol et al., Phys. Rev. D 85, 114047 (2012), the equations of motion of
relativistic dissipative fluid dynamics were derived from the relativistic
Boltzmann equation. These equations contain a multitude of terms of second
order in Knudsen number, in inverse Reynolds number, or their product. Terms of
second order in Knudsen number give rise to non-hyperbolic (and thus acausal)
behavior and must be neglected in (numerical) solutions of relativistic
dissipative fluid dynamics. The coefficients of the terms which are of the
order of the product of Knudsen and inverse Reynolds numbers have been
explicitly computed in the above reference, in the limit of a massless
Boltzmann gas. Terms of second order in inverse Reynolds number arise from the
collision term in the Boltzmann equation, upon expansion to second order in
deviations from the single-particle distribution function in local
thermodynamical equilibrium. In this work, we compute these second-order terms
for a massless Boltzmann gas with constant scattering cross section.
Consequently, we assess their relative importance in comparison to the terms
which are of the order of the product of Knudsen and inverse Reynolds numbers.


title: Content Distribution Strategies in Opportunistic Networks

abstract:
  This paper describes a mechanism for content distribution through
opportunistic contacts between subscribers. A subset of subscribers in the
network are seeded with the content. The remaining subscribers obtain the
information through opportunistic contact with a user carrying the updated
content. We study how the rate of content retrieval by subscribers is affected
by the number of initial seeders in the network. We also study the rate of
content retrieval by the subscribers under coding strategies (Network Coding,
Erasure Coding) and under Flooding, Epidemic Routing.


title: Computing equivariant characteristic classes of singular varieties

abstract:
  The paper is based on a talk. Complete exposition is given in "Equivariant
Hirzebruch class for singular varieties".
  Starting from the classical theory we describe Hirzebruch class and the
related Todd genus of a complex singular algebraic varieties. When the variety
is equipped with an action of an algebraic torus we localize the Hirzebruch
class at the fixed points of the action. We give some examples of computations.


title: Equivariant Hirzebruch class for singular varieties

abstract:
  The Hirzebruch $td_y(X)$ class of a complex manifold X is a formal
combination of Chern characters of the sheaves of differential forms multiplied
by the Todd class. The related $\chi_y$-genus admits a generalization for
singular complex algebraic varieties. The equivariant version of the Hirzebruch
class can be developed as well. The general theory applied in the situation
when a torus acts on a singular variety allows to apply powerful tools as the
Localization Theorem of Atiyah and Segal for equivariant K-theory and
Berline-Vergne formula for equivariant cohomology. We obtain a meaningful
invariant of a germ of singularity. When it is made explicit it turns out to be
just a polynomial in characters of the torus. We discuss a relation of the
properties of a singularity germ with its local Hirzebruch class. The issue of
positivity of coefficients in a certain expansion remains mysterious. The
quotient singularities, toric singularities, the singularities of Schubert
varieties are of special interest.


title: Complete sets and completion of sets in Banach spaces

abstract:
  In this paper we study properties of complete sets and of completions of sets
in Banach spaces. We consider the family of completions of a given set and its
size; we also study in detail the relationships concerning diameters, radii,
and centers. The results are illustrated by several examples.


title: On Goren-Oort stratification for quaternionic Shimura varieties

abstract:
  Let $F$ be a totally real field in which $p$ is unramified. We study the
Goren-Oort stratification of the special fibers of quaternionic Shimura
varieties over a place above $p$. We show that each stratum is a
$(\mathbb{P}^1)^N$-bundle over other quaternionic Shimura varieties (for some
appropriate $N$).


title: Illuminating and covering convex bodies

abstract:
  Covering numbers of convex bodies based on homothetical copies and related
illumination numbers are well-known in combinatorial geometry and, for example,
related to Hadwiger's famous covering problem. Similar numbers can be defined
by using proper translates instead of homothets, and even more related concepts
make sense. On these lines we introduce some new covering and illumination
numbers of convex bodies, present their properties and compare them with each
other as well as with already known numbers. Finally, some suggestive examples
illustrate that these new illumination numbers are interesting and non-trivial.


title: A Natural Higgs Mass in Supersymmetry from Non-Decoupling Effects

abstract:
  The Higgs mass implies fine-tuning for minimal theories of weak scale
supersymmetry (SUSY). Non-decoupling effects can boost the Higgs mass when new
states interact with the Higgs, but new sources of SUSY breaking that accompany
such extensions threaten naturalness. We show that two singlets with a Dirac
mass can increase the Higgs mass while maintaining naturalness in the presence
of large SUSY breaking in the singlet sector. We explore the modified Higgs
phenomenology of this scenario, which we call the "Dirac NMSSM."


title:
Real time imaging of quantum and thermal fluctuations: the case of a
  two-level system

abstract:
  A quantum system in contact with a heat bath undergoes quantum transitions
between energy levels upon absorption or emission of energy quanta by the bath.
These transitions remain virtual unless the energy of the system is measured
repeatedly, even continuously in time. Isolating the two indispensable
mechanisms in competition, we describe in a synthetic way the main physical
features of thermally activated quantum jumps. Using classical tools of
stochastic analysis, we compute in the case of a two-level system the complete
statistics of jumps and transition times in the limit when the typical
measurement time is small compared to the thermal relaxation time. The emerging
picture is that quantum trajectories are similar to those of a classical
particle in a noisy environment, subject to transitions a la Kramer in a
multi-well landscape, but with a large multiplicative noise.


title: Shungite as loosely packed fractal nets of graphene-based quantum dots

abstract:
  The current paper presents the first attempt to recreate the origin of
shungite carbon at microscopic level basing on knowledge accumulated by
graphene science. The main idea of our approach is that different efficacy of
chemical transformation of primarily generated graphene flakes (aromatic
lamellae in geological literature), subjected to oxidation/reduction reactions
in aqueous environment, lays the foundation of the difference in graphite and
shungite derivation under natural conditions. Low-efficient reactions in the
case of graphite do not prevent from the formation of large graphite layers
while high-efficient oxidation/reduction transforms the initial graphene flakes
into those of reduced graphene oxide of ~1nm in size. Multistage aggregation of
these basic structural units, attributed to graphene quantum dots of shungite,
leads to the fractal structure of shungite carbon thus exhibiting it as a new
allotrope of natural carbon. The suggested microscopic view has finds a
reliable confirmation when analyzing the available empirical data.


title: The Economic and Sustainability Future of Cellular Networks

abstract:
  Global data traffic is expected to grow exponentially in the next few years
with video and smartphone applications driving data growth. Many mobile network
providers in the UK have either deployed or planning to deploy 4th generation
Long-Term-Evolution (LTE) mobile technology as the solution to meet capacity
demands. This study evaluates the technological improvements in 4G LTE in
comparison to 3G High Speed Packet Access (HSPA) and further conducts a
techno-economic analysis using primary researched tariff data to determine
network operator profitability and mobile tariff strategy to meet user demand.
To ensure holistic analysis, the study also considers the environmental impacts
of LTE by determining the annual carbon emission for a network operator. The
study results shows LTE will prove profitable; however a trade-off has to be
made by network operators between meeting consumer tariff demands or increasing
profitability. Analysis also shows a 63% reduced in carbon emissions is
possible with migration to 4G services with implication of further financial
benefits for network operators as a result.


title: Symmetric Representation Rings are $\lambda$-Rings

abstract:
  The representation ring of an affine algebraic group scheme can be endowed
with the structure of a (special) $\lambda$-ring. We show that the same is true
for the ring of symmetric representations, i.e. for the Grothendieck-Witt ring
of the representation category, for any affine algebraic group scheme over a
field of characteristic not two.


title: H-Infinity-Optimal Fractional Delay Filters

abstract:
  Fractional delay filters are digital filters to delay discrete-time signals
by a fraction of the sampling period. Since the delay is fractional, the
intersample behavior of the original analog signal becomes crucial. In contrast
to the conventional designs based on the Shannon sampling theorem with the
band-limiting hypothesis, the present paper proposes a new approach based on
the modern sampled-data H-infinity optimization that aims at restoring the
intersample behavior beyond the Nyquist frequency. By using the lifting
transform or continuous-time blocking the design problem is equivalently
reduced to a discrete-time H-infinity optimization, which can be effectively
solved by numerical computation softwares. Moreover, a closed-form solution is
obtained under an assumption on the original analog signals. Design examples
are given to illustrate the advantage of the proposed method.


title:
Lineage specific reductions in genome size in salamanders are associated
  with increased rates of mutation

abstract:
  Very low levels of genetic diversity have been reported in vertebrates with
large genomes, notably salamanders and lungfish [1-3]. Interpreting differences
in heterozygosity, which reflects genetic diversity in a population, is
complicated because levels of heterozygosity vary widely between conspecific
populations, and correlate with many different physiological and demographic
variables such as body size and effective population size. Here we return to
the question of genetic variability in salamanders and report on the
relationship between evolutionary rates and genome sizes in five different
salamander families. We found that rates of evolution are exceptionally low in
salamanders as a group. Evolutionary rates are as low as those reported for
cartilaginous fish, which have the slowest rates recorded so far in vertebrates
[4]. We also found that, independent of life history, salamanders with the
smallest genomes (14 pg) are evolving at rates two to three times faster than
salamanders with the largest genomes (>50 pg). After accounting for
evolutionary duration, we conclude that more recently evolved species have
correspondingly smaller genomes compared to older taxa and concomitantly higher
rates of mutation and evolution.


title: Compressive Sampling for Remote Control Systems

abstract:
  In remote control, efficient compression or representation of control signals
is essential to send them through rate-limited channels. For this purpose, we
propose an approach of sparse control signal representation using the
compressive sampling technique. The problem of obtaining sparse representation
is formulated by cardinality-constrained L2 optimization of the control
performance, which is reducible to L1-L2 optimization. The low rate random
sampling employed in the proposed method based on the compressive sampling, in
addition to the fact that the L1-L2 optimization can be effectively solved by a
fast iteration method, enables us to generate the sparse control signal with
reduced computational complexity, which is preferable in remote control systems
where computation delays seriously degrade the performance. We give a
theoretical result for control performance analysis based on the notion of
restricted isometry property (RIP). An example is shown to illustrate the
effectiveness of the proposed approach via numerical experiments.


title:
In vitro toxicity of nanoceria: effect of coating and stability in
  biofluids

abstract:
  Due to the increasing use of nanometric cerium oxide in applications,
concerns about the toxicity of these particles have been raised and have
resulted in a large number of investigations. We report here on the
interactions between 7 nm anionically charged cerium oxide particles and living
mammalian cells. By a modification of the particle coating including
low-molecular weight ligands and polymers, two generic behaviors are compared:
particles coated with citrate ions that precipitate in biofluids and particles
coated with poly(acrylic acid) that are stable and remain nanometric. We find
that nanoceria covered with both coating agents are taken up by mouse
fibroblasts and localized into membrane-bound compartments. However, flow
cytometry and electron microscopy reveal that as a result of their
precipitation, citrate-coated particles interact more strongly with cells. At
cerium concentration above 1 mM, only citrate-coated nanoceria (and not
particles coated with poly(acrylic acid)) display toxicity and moderate
genotoxicity. The results demonstrate that the control of the surface chemistry
of the particles and its ability to prevent aggregation can affect the toxicity
of nanomaterials.


title: Spectral Sequences, Exact Couples and Persistent Homology of filtrations

abstract:
  In this paper we study the relationship between a very classical algebraic
object associated to a filtration of spaces, namely a spectral sequence
introduced by Leray in the 1940's, and a more recently invented object that has
found many applications -- namely, its persistent homology groups. We show the
existence of a long exact sequence of groups linking these two objects and
using it derive formulas expressing the dimensions of each individual groups of
one object in terms of the dimensions of the groups in the other object. The
main tool used to mediate between these objects is the notion of exact couples
first introduced by Massey in 1952.


title: Nitsche's method for two and three dimensional NURBS patch coupling

abstract:
  A Nitche's method is presented to couple non-conforming two and three
dimensional NURBS (Non Uniform Rational B-splines) patches in the context of
isogeometric analysis (IGA). We present results for elastic stress analyses
under the static condition of two and three dimensional NURBS geometries. The
contribution fills the gap in the literature and enlarges the applicability of
NURBS-based isogeometric analysis.


title:
Cooling molecular vibrations with shaped laser pulses: Optimal control
  theory exploiting the timescale separation between coherent excitation and
  spontaneous emission

abstract:
  Laser cooling of molecules employing broadband optical pumping involves a
timescale separation between laser excitation and spontaneous emission. Here,
we optimize the optical pumping step using shaped laser pulses. We derive two
optimization functionals to drive population into those excited state levels
that have the largest spontaneous emission rates to the target state. We show
that, when using optimal control, laser cooling of molecules works even if the
Franck-Condon map governing the transitions is preferential to heating rather
than cooling. Our optimization functional is also applicable to the laser
cooling of other degrees of freedom provided the cooling cycle consists of
coherent excitation and dissipative deexcitation steps whose timescales are
separated.


title:
Multi-channel scattering problems: Analytical approach for exact
  solution using Green's functions

abstract:
  We have proposed an analytical approach for exact solution of multi-channel
scattering problems, in presence of Dirac Delta function couplings. Our
solution is quite general and is valid for any set of potentials, if the
Green's functions of the uncoupled potentials are known at the crossing point.
Using our model, it is possible to express N-channel problem by N independent
`single' channel problems and hence one can have a realistic solution of
multi-channel scattering problem. In this paper we have shown that transition
probability from first diabatic potential to any other potential can be easily
evaluated using a very simple analytical formula - which only require value of
eigenfunction of first uncoupled potential and value of Green's function of
other uncoupled potential, at the crossing.


title: Numerical Simulation of Asymmetric Merging Flow in a Rectangular Channel

abstract:
  The steady, asymmetric and two-dimensional flow of viscous, incompressible,
and Newtonian fluid through a rectangular channel with splitter plate parallel
to walls is investigated numerically. In the past, the position of the splitter
plate was taken as a centerline of channel but here we consider its different
positions which cause the asymmetric behaviour of the flow field. The geometric
parameter that controls the position of splitter is defined as splitter
position parameter {\alpha}. The plane Poiseuille flow is considered far from
upstream and downstream of the splitter. The fourth order method Mancera [11],
followed by special finite-method Dennis [5] is used to solve in our purpose.
This numerical scheme transforms the governing equations to system of
finite-difference equations which are solved by point S.O.R. iterative method.
Moreover, the results obtained are further refined and upgraded by Richardson
Extrapolation method Jain [18]. This scheme yields the sixth order accurate
solution. The results are compared with those of Badr et al [1] for symmetric
case (when {\alpha}=0) for velocity, vorticity and skin friction distributions.
The comparison is very favourable.


title:
A comparison of old and new definitions of the geometric measure of
  entanglement

abstract:
  Several inequivalent definitions of the geometric measure of entanglement
(GM) have been introduced and studied in the past. Here we review several known
and new definitions, with the qualifying criterion being that for pure states
the measure is a linear or logarithmic function of the maximal fidelity with
product states. The entanglement axioms and properties of the measures are
studied, and qualitative and quantitative comparisons are made between all
definitions. Streltsov et al. [New J. Phys 12 123004 (2010)] proved the
equivalence of two linear definitions of GM, whereas we show that the
corresponding logarithmic definitions are distinct. Certain classes of states
such as "maximally correlated states" and isotropic states are particularly
valuable for this analysis. A little-known GM definition is found to be the
first one to be both normalized and weakly monotonous, thus being a prime
candidate for future studies of multipartite entanglement. We also find that a
large class of graph states, which includes all cluster states, have a
"universal" closest separable state that minimizes the quantum relative
entropy, the Bures distance and the trace distance.


title: Stratified Labelings for Abstract Argumentation

abstract:
  We introduce stratified labelings as a novel semantical approach to abstract
argumentation frameworks. Compared to standard labelings, stratified labelings
provide a more fine-grained assessment of the controversiality of arguments
using ranks instead of the usual labels in, out, and undecided. We relate the
framework of stratified labelings to conditional logic and, in particular, to
the System Z ranking functions.


title:
Limit to the radio emission from a putative central compact source in
  SN1993J

abstract:
  SN1993J in M81 is the best studied young radio-luminous supernova in the
Northern Hemisphere. We recently reported results from the analysis of a
complete set of VLBI observations of this supernova at 1.7, 2.3, 5.0, and 8.4
GHz, covering a time baseline of more than one decade. Those reported results
were focused on the kinematics of the expanding shock, the particulars of its
evolving non-thermal emission, the density profile of the circumstellar medium,
and the evolving free-free opacity by the supernova ejecta. In the present
paper, we complete our analysis by performing a search for any possible signal
from a compact source (i.e., a stellar-mass black hole or a young pulsar
nebula) at the center of the expanding shell. We have performed a stacking of
all our VLBI images at each frequency, after subtraction of our best-fit shell
model at each epoch, and measured the peak intensity in the stacked residual
image. Given the large amount of available global VLBI observations, the
stacking of all the residual images allows us to put upper limits to the
eventual emission of a putative compact central source at the level of
$\sim102$ $\mu$Jy at 5 GHz (or, more conservatively, $\sim192$ $\mu$Jy, if we
make a further correction for the ejecta opacity) and somewhat larger at other
wavelengths.


title: Improved Nucleon Properties in the Extended Quark Sigma Model

abstract:
  The quark sigma model describes the quarks interacting via exchange the pions
and sigma meson fields. A new version of mesonic potential is suggested in the
frame of some aspects of the quantum chromodynamics (QCD). The field equations
have been solved in the mean-field approximation for the hedgehog baryon state.
The obtained results are compared with previous works and other models. We
conclude that the suggested mesonic potential successfully calculates nucleon
properties.


title: Risk-consistency of cross-validation with lasso-type procedures

abstract:
  The lasso and related sparsity inducing algorithms have been the target of
substantial theoretical and applied research. Correspondingly, many results are
known about their behavior for a fixed or optimally chosen tuning parameter
specified up to unknown constants. In practice, however, this oracle tuning
parameter is inaccessible so one must use the data to select one. Common
statistical practice is to use a variant of cross-validation for this task.
However, little is known about the theoretical properties of the resulting
predictions with such data-dependent methods. We consider the high-dimensional
setting with random design wherein the number of predictors $p$ grows with the
number of observations $n$. Under typical assumptions on the data generating
process, similar to those in the literature, we recover oracle rates up to a
log factor when choosing the tuning parameter with cross-validation. Under
weaker conditions, when the true model is not necessarily linear, we show that
the lasso remains risk consistent relative to its linear oracle. We also
generalize these results to the group lasso and square-root lasso and
investigate the predictive and model selection performance of cross-validation
via simulation.


title: Limitations on the number of plasmons in nanoparticles

abstract:
  In this letter, we address the thermal processes occurring in plasmonic
nanoparticles. We determine constrains imposed upon the plasmonic excitation in
such nanoparticle by the resulting heat generation. Taking into account
temperature dependence of the metal losses, we predict the existence of the
critical number of plasmons in the nanoparticle. We also allow for the
temperature dependencies of the thermal-conductivity coefficient of the
environment and the Kapitza heat boundary resistance. We show that the latter
can dominate the overall heat resistance in the system. Strength limitations
caused by the action of electric forces are also considered. Obtained results
provide instruments for the heat and strength management in the plasmonic
engineering.


title:
Fermi Condensation Near van Hove Singularities Within the Hubbard Model
  on the Triangular Lattice

abstract:
  The proximity of the Fermi surface to van Hove singularities drastically
enhances interaction effects and leads to essentially new physics. In this work
we address the formation of flat bands ("Fermi condensation") within the
Hubbard model on the triangular lattice and provide a detailed analysis from an
analytical and numerical perspective. To describe the effect we consider both
weak-coupling and strong-coupling approaches, namely the renormalization group
and dual fermion methods. It is shown that the band flattening is driven by
correlations and is well pronounced even at sufficiently high temperatures, of
the order of 0.1-0.2 of the hopping parameter. The effect can therefore be
probed in experiments with ultracold fermions in optical lattices.


title: Multi-agent Systems with Compasses

abstract:
  This paper investigates agreement protocols over cooperative and
cooperative--antagonistic multi-agent networks with coupled continuous-time
nonlinear dynamics. To guarantee convergence for such systems, it is common in
the literature to assume that the vector field of each agent is pointing inside
the convex hull formed by the states of the agent and its neighbors, given that
the relative states between each agent and its neighbors are available. This
convexity condition is relaxed in this paper, as we show that it is enough that
the vector field belongs to a strict tangent cone based on a local supporting
hyperrectangle. The new condition has the natural physical interpretation of
requiring shared reference directions in addition to the available local
relative states. Such shared reference directions can be further interpreted as
if each agent holds a magnetic compass indicating the orientations of a global
frame. It is proven that the cooperative multi-agent system achieves
exponential state agreement if and only if the time-varying interaction graph
is uniformly jointly quasi-strongly connected. Cooperative--antagonistic
multi-agent systems are also considered. For these systems, the relation has a
negative sign for arcs corresponding to antagonistic interactions. State
agreement may not be achieved, but instead it is shown that all the agents'
states asymptotically converge, and their limits agree componentwise in
absolute values if and in general only if the time-varying interaction graph is
uniformly jointly strongly connected.


title: Distinct distances from three points

abstract:
  Let $p_1,p_2,p_3$ be three non-collinear points in the plane, and let $P$ be
a set of $n$ other points in the plane. We show that the number of distinct
distances between $p_1,p_2,p_3$ and the points of $P$ is $\Omega(n^{6/11})$,
improving the lower bound $\Omega(n^{0.502})$ of Elekes and Szab\'o \cite{ESz}
(and considerably simplifying the analysis).


title:
Solving a two-electron quantum dot model in terms of polynomial
  solutions of a Biconfluent Heun Equation

abstract:
  The effects on the non-relativistic dynamics of a system compound by two
electrons interacting by a Coulomb potential and with an external harmonic
oscillator potential, confined to move in a two dimensional Euclidean space,
are investigated. In particular, it is shown that it is possible to determine
exactly and in a closed form a finite portion of the energy spectrum and the
associated eigeinfunctions for the Schr\"odinger equation describing the
relative motion of the electrons, by putting it into the form of a biconfluent
Heun equation. In the same framework, another set of solutions of this type can
be straightforwardly obtained for the case when the two electrons are submitted
also to an external constant magnetic field.

categories: quant-ph cond-mat.mes-hall cond-mat.str-el math-ph math.MP


title: Higgs Vacuum Stability in $B-L$ extended Standard Model

abstract:
  We study vacuum stability of B-L extension of the Standard Model (SM) and its
supersymmetric version. We show that the generation of non-vanishing neutrino
masses through TeV inverse seesaw mechanism leads to a cutoff scale of SM Higgs
potential stability of order 10^5 GeV. However, in the non-supersymmetric B-L
model, we find that the mixing between the SM-like Higgs and the B-L Higgs
plays a crucial role in alleviating the vacuum stability problem. We also
provide the constraints of stabilizing the Higgs potential in the
supersymmetric B-L model.


title: Characterization of ellipsoids as K-dense sets

abstract:
  Let K\subset R^N be any convex body containing the origin. A measurable set
G\subset R^N with finite and positive Lebesgue measure is said to be K-dense
if, for any fixed r>0, the measure of G\cap (x+r K) is constant when x varies
on the boundary of G (here, x+r K denotes a translation of a dilation of K). In
[6], we proved for the case in which N=2 that if G is K-dense, then both G and
K must be homothetic to the same ellipse. Here, we completely characterize
K-dense sets in R^N: if G is K-dense, then both G and K must be homothetic to
the same ellipsoid. Our proof, by building upon results obtained in [6], relies
on an asymptotic formula for the measure of G\cap (x+r K) for large values of
the parameter r and a classical characterization of ellipsoids due to C.M.
Petty [9].


title: Effects of Individual Success on Globally Distributed Team Performance

abstract:
  Necessity of different competencies with high level of knowledge makes it
inevitable that software development is a team work. With the today's
technology, teams can communicate both synchronously and asynchronously using
different online collaboration tools throughout the world. Researches indicate
that there are many factors that affect the team success and in this paper,
effect of individual success on globally distributed team performance will be
analyzed. Student team projects undertaken by other researchers will be used to
analyze collected data and conclusions will be drawn for further analysis.


title: Entanglement Temperature in Non-conformal Cases

abstract:
  Potential reconstruction can be used to find various analytical asymptotical
AdS solutions in Einstein dilation system generally. We have generated two
simple solutions without physical singularity called zero temperature
solutions. We also proposed a numerical way to obtain black hole solution in
Einstein dilaton system with special dilaton potential. By using this method,
we obtain the corresponding black hole solutions numerically and investigate
the thermal stability of the black hole by comparing the free energy of thermal
gas and the corresponding black hole. In two groups of non-conformal gravity
solutions obtained in this paper, we find that the two thermal gas solutions
are more unstable than black hole solutions respectively. Finally, we consider
black hole solutions as a thermal state of zero temperature solutions to check
that the first thermal dynamical law exists in entanglement system from
holographic point of view.


title: Anisotropy studies with the Pierre Auger Observatory

abstract:
  We report recent results from the Pierre Auger Observatory about the study of
the anisotropy in the arrival directions of ultra-high energy cosmic rays. We
present the results of the search for a dipolar anisotropy at the EeV energy
scale. Measurements of the phase and the amplitude of the first harmonic
modulation in the right-ascension distribution are discussed. For cosmic rays
with energies above 55 EeV, we present an update of the search for correlations
between their arrival directions and the positions of active galactic nuclei
from the Veron-Cetty and Veron catalog. We also discuss the results of
correlation analyses applied to other populations of extragalactic objects.
Finally we present the search for anisotropies in the data without the usage of
astronomical catalogues.


title:
Dendritic signal transmission induced by intracellular charge
  inhomogeneities

abstract:
  Signal propagation in neuronal dendrites represents the basis for interneuron
communication and information processing in the brain. Here we take into
account charge inhomogeneities arising in the vicinity of ion channels in
cytoplasm and obtained a modified cable equation. We show that the charge
inhomogeneities acting on the millisecond time scale can lead to the appearance
of propagating waves with wavelengths of hundreds of micrometers. They
correspond to a certain frequency band predicting the appearance of resonant
properties in brain neuron signalling.


title: Standing Sound Waves in a tube: Approach analysis \& sugestions

abstract:
  In this paper we attempt to present some questions with respect to the
approach used in some brazilian mid-level textbooks on the topic of stationary
sound waves in tubes. In addition to ranking the textbooks within a set of
criteria, we also present some suggestions for further discussions of this
topic. We suggest the use of gifs and animations and the use of two experiments
that allow you to view the profiles of variation of pressure and air
displacement for the harmonic modes of vibration.


title:
Vector Chiral Phases in the Frustrated 2D XY Model and Quantum Spin
  Chains

abstract:
  The phase diagram of the frustrated 2D classical and 1D quantum XY models is
calculated analytically. Four transitions are found: the vortex unbinding
transitions triggered by strong fluctuations occur above and below the chiral
transition temperature. Vortex interaction is short range on small and
logarithmic on large scales. The chiral transition, though belonging to the
Ising universality class by symmetry, has different critical exponents due to
nonlocal interaction. In a narrow region close to the Lifshitz point a
reentrant phase transition between paramagnetic and quasiferromagnetic phase
appears. Applications to antiferromagnetic quantum spin chains and
multiferroics are discussed.

categories: cond-mat.stat-mech cond-mat.mtrl-sci cond-mat.other cond-mat.str-el quant-ph


title: Secure Authentication of Cloud Data Mining API

abstract:
  Cloud computing is a revolutionary concept that has brought a paradigm shift
in the IT world. This has made it possible to manage and run businesses without
even setting up an IT infrastructure. It offers multi-fold benefits to the
users moving to a cloud, while posing unknown security and privacy issues. User
authentication is one such growing concern and is greatly needed in order to
ensure privacy and security in a cloud computing environment. This paper
discusses the security at different levels viz. network, application and
virtualization, in a cloud computing environment. A security framework based on
one-time pass key mechanism has been proposed. The uniqueness of the proposed
security protocol lies in the fact, that it provides security to both the
service providers as well the users in a highly conflicting cloud environment.


title:
Growth and fragmentation of centimetre-sized dust aggregates: the
  dependence on aggregate size and porosity

abstract:
  We carry out three-dimensional Smoothed Particle Hydrodynamics simulations of
spherical homogeneous SiO2 dust aggregates to investigate how the mass and the
porosity of the aggregates affects their ability to survive an impact at
various different collision velocities (between 1 - 27.5m/s). We explore how
the threshold velocities for fragmentation vary with these parameters.
Crucially, we find that the porosity plays a part of utmost importance in
determining the outcome of collisions. In particular, we find that aggregates
with filling factors >37% are significantly weakened and that the velocity
regime in which the aggregates grow is reduced or even non-existent (instead,
the aggregates either rebound off each other or break apart). At filling
factors less than ~37% we find that more porous objects are weaker but not as
weak as highly compact objects with filling factors >37%. In addition we find
that (for a given aggregate density) collisions between very different mass
objects have higher threshold velocities than those between very similar mass
objects. We find that fragmentation velocities are higher than the typical
values of 1m/s and that growth can even occur for velocities as high as
27.5m/s. Therefore, while the growth of aggregates is more likely if collisions
between different sized objects occurs or if the aggregates are porous with
filling factor <37%, it may also be hindered if the aggregates become too
compact.


title:
Elemental Topological Insulator with a Tunable Fermi Level: Strained
  \alpha-Sn on InSb(001)

abstract:
  We report on the epitaxial fabrication and electronic properties of a
topological phase in strained \alpha-Sn on InSb. The topological surface state
forms in the presence of an unusual band order not based on direct spin-orbit
coupling, as shown in density functional and GW slab-layer calculations.
Angle-resolved photoemission including spin detection probes experimentally how
the topological spin-polarized state emerges from the second bulk valence band.
Moreover, we demonstrate the precise control of the Fermi level by dopants.


title: Immersion in four-edge-connected graphs

abstract:
  Fix g>1. Every graph of large enough tree-width contains a g x g grid as a
minor; but here we prove that every four-edge-connected graph of large enough
tree-width contains a g x g grid as an immersion (and hence contains any fixed
graph with maximum degree at most four as an immersion). This result has a
number of applications.


title: Signatures in the conductance for phase transitions in excitonic systems

abstract:
  We analyse two phase transitions in exciton bilayer systems: a topological
phase transition to a phase which hosts Majorana fermions and a phase
transition to a Wigner crystal. Using generic simple models for the different
phases we discuss the conductance properties of the latter when contacted to
metallic leads and demonstrate the possibility to observe the different phase
transitions by simple conductance measurements.


title:
Parametric Study of Flow Patterns behind the Standing Accretion Shock
  Wave for Core-Collapse Supernovae

abstract:
  In this study, we conduct three-dimensional hydrodynamic simulations
systematically to investigate the flow patterns behind the accretion shock
waves that are commonly formed in the post-bounce phase of core-collapse
supernovae. Adding small perturbations to spherically symmetric, steady,
shocked accretion flows, we compute the subsequent evolutions to find what flow
pattern emerges as a consequence of hydrodynamical instabilities such as
convection and standing accretion shock instability (SASI) for different
neutrino luminosities and mass accretion rates. Depending on these two
controlling parameters, various flow patterns are indeed realized. We classify
them into three basic patterns and two intermediate ones; the former includes
sloshing motion (SL), spiral motion (SP) and multiple buoyant bubble formation
(BB); the latter consists of spiral motion with buoyant-bubble formation (SPB)
and spiral motion with pulsationally changing rotational velocities (SPP).
Although the post-shock flow is highly chaotic, there is a clear trend in the
pattern realization. The sloshing and spiral motions tend to be dominant for
high accretion rates and low neutrino luminosities, and multiple buoyant
bubbles prevail for low accretion rates and high neutrino luminosities. It is
interesting that the dominant pattern is not always identical between the
semi-nonlinear and nonlinear phases near the critical luminosity; the
intermediate cases are realized in the latter case. Running several simulations
with different random perturbations, we confirm that the realization of flow
pattern is robust in most cases.


title: Effect of Magnetic Misalignment on Protobinary Evolution

abstract:
  The majority of solar-type stars reside in multiple systems, especially
binaries. They form in dense cores of molecular clouds that are observed to be
significantly magnetized. Our previous study shows that magnetic braking can
tighten the binary separation during the protostellar mass accretion phase by
removing the angular momentum of the accreting material. Recent numerical
calculations of single star formation have shown that misalignment between the
magnetic field and rotation axis may weaken both magnetic braking and the
associated magnetically driven outflows. These two effects allow for disk
formation even in strongly magnetized cores. Here we investigate the effects of
magnetic field misalignment on the properties of protobinaries. Somewhat
surprisingly, the misaligned magnetic field is more efficient at tightening the
binary orbit compared to the aligned field. The main reason is that the
misalignment weakens the magnetically-driven outflow, which allows more
material to accrete onto the binary. Even though the specific angular momentum
of this inner material is higher than in the aligned case, it is insufficient
to compensate for the additional mass. A corollary of this result is that a
weaker field is required to achieve the same degree of inward migration when
the field is tilted relative to the rotation axis. Large field misalignment
also helps to produce rotationally-supported circumbinary disks even for
relatively strong magnetic fields, by weakening the magnetically-dominated
structure close to the binary. Our result may provide an explanation for the
circumbinary disks detected in recent SMA and ALMA observations.


title: Quantum noise eater for a single photonic qubit

abstract:
  We propose a quantum noise eater for a single qubit and experimentally verify
its performance for recovery of a superposition carried by a dual-rail photonic
qubit. We consider a case when only one of the rails (e.g., one of
interferometric arms) is vulnerable to noise. A coherent but randomly arriving
photon penetrating into this single rail causes a change of its state, which
results in an error in a subsequent quantum information processing. We
theoretically prove and experimentally demonstrate a conditional full recovery
of the superposition by this quantum noise eater.


title: Hodge-Teichmueller planes and finiteness results for Teichmueller curves

abstract:
  We prove that there are only finitely many algebraically primitive
Teichmueller curves in the minimal stratum in each prime genus at least 3. The
proof is based on the study of certain special planes in the first cohomology
of a translation surface which we call Hodge-Teichmueller planes.
  We also show that algebraically primitive Teichmueller curves are not dense
in any connected component of any stratum in genus at least 3; the closure of
the union of all such curves (in a fixed stratum) is equal to a finite union of
affine invariant submanifolds with unlikely properties. Results of this type
hold even without the assumption of algebraic primitivity.
  Combined with work of Nguyen and the second author, a corollary of our
results is that there are at most finitely many non-arithmetic Teichmueller
curves in H(4)^hyp.


title: Data Structures in Classical and Quantum Computing

abstract:
  This survey summarizes several results about quantum computing related to
(mostly static) data structures. First, we describe classical data structures
for the set membership and the predecessor search problems: Perfect Hash tables
for set membership by Fredman, Koml\'{o}s and Szemer\'{e}di and a data
structure by Beame and Fich for predecessor search. We also prove results about
their space complexity (how many bits are required) and time complexity (how
many bits have to be read to answer a query). After that, we turn our attention
to classical data structures with quantum access. In the quantum access model,
data is stored in classical bits, but they can be accessed in a quantum way: We
may read several bits in superposition for unit cost. We give proofs for lower
bounds in this setting that show that the classical data structures from the
first section are, in some sense, asymptotically optimal - even in the quantum
model. In fact, these proofs are simpler and give stronger results than
previous proofs for the classical model of computation. The lower bound for set
membership was proved by Radhakrishnan, Sen and Venkatesh and the result for
the predecessor problem by Sen and Venkatesh. Finally, we examine fully quantum
data structures. Instead of encoding the data in classical bits, we now encode
it in qubits. We allow any unitary operation or measurement in order to answer
queries. We describe one data structure by de Wolf for the set membership
problem and also a general framework using fully quantum data structures in
quantum walks by Jeffery, Kothari and Magniez.


title:
Observational constraints on non-flat dynamical dark energy cosmological
  models

abstract:
  We constrain two non-flat time-evolving dark energy cosmological models by
using Hubble parameter data, Type Ia supernova apparent magnitude measurements,
and baryonic acoustic oscillation peak length scale observations. The inclusion
of space curvature as a free parameter in the analysis results in a significant
broadening of the allowed range of values of the parameter that governs the
time evolution of the dark energy density in these models. While consistent
with the "standard" spatially-flat $\Lambda$CDM cosmological model, these data
are also consistent with a range of mildly non-flat, slowly time-varying dark
energy models. After marginalizing over all other parameters, these data
require the averaged magnitude of the curvature density parameter
$|\Omega_{k0}| \lesssim 0.15$ at 1$\sigma$ confidence.


title: On the Construction of Simply Connected Solvable Lie Groups

abstract:
  Let $\omega_\mathfrak{g}$ be a Lie algebra valued differential $1$-form on a
manifold $M$ satisfying the structure equations $d \omega_\mathfrak{g} +
\frac{1}{2} \omega_\mathfrak{g}\wedge \omega_\mathfrak{g}=0$ where
$\mathfrak{g}$ is solvable. We show that the problem of finding a smooth map
$\rho:M\to G$, where $G$ is an $n$-dimensional solvable Lie group with Lie
algebra $\mathfrak{g}$ and left invariant Maurer-Cartan form $\tau$, such that
$\rho^* \tau= \omega_\mathfrak{g}$ can be solved by quadratures and the matrix
exponential. In the process we give a closed form formula for the vector fields
in Lie's third theorem for solvable Lie algebras. A further application
produces the multiplication map for a simply connected $n$-dimensional solvable
Lie group using only the matrix exponential and $n$ quadratures. Applications
to finding first integrals for completely integrable Pfaffian systems with
solvable symmetry algebras are also given.


title: Warm Dark Matter in B-L Inverse Seesaw

abstract:
  We show that a standard model gauge singlet fermion field, with mass of order
keV or larger, and involved in the inverse seesaw mechanism of light neutrino
mass generation, can be a good warm dark matter candidate. Our framework is
based on B-L extension of the Standard Model. The construction ensures the
absence of any mixing between active neutrinos and the aforementioned dark
matter field. This circumvents the usual constraints on the mass of warm dark
matter imposed by X-ray observations. We show that over-abundance of thermally
produced warm dark matter (which nevertheless do not reach chemical
equilibrium) can be reduced to an acceptable range in the presence of a moduli
field decaying into radiation --- though only when the reheat temperature is
low enough. Our warm dark matter candidate can also be produced directly from
the decay of the moduli field during reheating. In this case, obtaining the
right amount of relic abundance, while keeping the reheat temperature high
enough as to be consistent with Big Bang nucleosynthesis bounds, places
constraints on the branching ratio for the decay of the moduli field into dark
matter.


title: Phase statistics of the WMAP 7 year data

abstract:
  We performed a comprehensive statistical analysis using complex phases of the
a_lm coefficients computed from the most recent data of the Wilkinson Microwave
Anisotropy Probe (WMAP). Our aim was to confirm or constrain the presence of
non-Gaussianities in the data. We found phase correlations - that suggest
non-Gaussianity - at high-l in a_lm coefficients by applying various
statistical tests. Most of all, we detected a non-Gaussian signal reaching a
significance of 4.7 sigma using random walk statistics and simulations.
However, our conclusion is that the non-Gaussian behavior is due to
contamination from galactic foregrounds that show up in small scales only. When
masked out the contaminated regions, we found no significant non-Gaussianity.
Furthermore, we constrained the f_NL parameter using CMB simulations that mimic
primordial non-Gaussianity. Our estimate is f_NL=40 +/- 200, in agreement with
previous measurements and inflationary expectations.


title: Restrictions of SL_3 Maass forms to maximal flat subspaces

abstract:
  Let \psi be a Hecke-Maass form on a cubic division algebra over \Q. We apply
arithmetic amplification to improve the local bound for the L^2 norm of \psi
restricted to maximal flat subspaces.


title: Pairing Correlations Near a Kondo-Destruction Quantum Critical Point

abstract:
  Motivated by the unconventional superconductivity observed in heavy-fermion
metals, we investigate pairing susceptibilities near a continuous quantum phase
transition of the Kondo-destruction type. We solve two-impurity Bose-Fermi
Anderson models with Ising and Heisenberg forms of the interimpurity exchange
interaction using continuous-time quantum Monte-Carlo and numerical
renormalization-group methods. Each model exhibits a Kondo-destruction quantum
critical point separating Kondo-screened and local-moment phases. For
antiferromagnetic interimpurity exchange interactions, singlet pairing is found
to be enhanced in the vicinity of the transition. Implications of this result
for heavy-fermion superconductivity are discussed.


title: Designing Parity Preserving Reversible Circuits

abstract:
  Making a reversible circuit fault-tolerant is much more difficult than
classical circuit and there have been only a few works in the area of
parity-preserving reversible logic design. Moreover, all of these designs are
ad hoc, based on some pre-defined parity preserving reversible gates as
building blocks. In this paper, we for the first time propose a novel and
systematic approach towards parity preserving reversible circuits design. We
provide some related theoretical results and give two algorithms, one from
reversible specification to parity preserving reversible specification and
another from irreversible specification to parity preserving reversible
specification. We also evaluate the effectiveness of our approach by extensive
experimental results.


title: Cost Minimization in Multiple IaaS Clouds: A Double Auction Approach

abstract:
  IaaS clouds invest substantial capital in operating their data centers.
Reducing the cost of resource provisioning, is their forever pursuing goal.
Computing resource trading among multiple IaaS clouds provide a potential for
IaaS clouds to utilize cheaper resources to fulfill their jobs, by exploiting
the diversities of different clouds' workloads and operational costs. In this
paper, we focus on studying the IaaS clouds' cost reduction through computing
resource trading among multiple IaaS clouds. We formulate the global cost
minimization problem among multiple IaaS clouds under cooperative scenario
where each individual cloud's workload and cost information is known. Taking
into consideration jobs with disparate lengths, a non-preemptive approximation
algorithm for leftover job migration and new job scheduling is designed. Given
to the selfishness of individual clouds, we further design a randomized double
auction mechanism to elicit clouds' truthful bidding for buying or selling
virtual machines. We evaluate our algorithms using trace-driven simulations.


title: A compact entanglement distillery using realistic quantum memories

abstract:
  We adopt the beam splitter model for losses to analyse the performance of a
recent compact continuous-variable entanglement distillation protocol [Phys.
Rev. Lett. 108, 060502, (2012)] implemented using realistic quantum memories.
We show that the decoherence undergone by a two-mode squeezed state while
stored in a quantum memory can strongly modify the results of the preparatory
step of the protocol. We find that the well-known method for locally increasing
entanglement, phonon subtraction, may not result in entanglement gain when
losses are taken into account. Thus, we investigate the critical number $m_c$
of phonon subtraction attempts from the matter modes of the quantum memory. If
the initial state is not de-Gaussified within $m_c$ attempts, the protocol
should be restarted to obtain any entanglement increase. Moreover, the
condition $m_c>1$ implies an additional constraint on the subtraction beam
splitter interaction transmissivity, viz. it should be about 50% for a wide
range of protocol parameters. Additionally, we consider the average
entanglement rate, which takes into account both the unavoidable probabilistic
nature of the protocol and its possible failure as a result of a large number
of unsuccessful subtraction attempts. We find that a higher value of the
average entanglement can be achieved by increasing the subtraction beam
splitter interaction transmissivity. We conclude that the compact distillation
protocol with the practical constraints coming from realistic quantum memories
allows a feasible experimental realization within existing technologies.


title:
Snowmass Energy Frontier Simulations using the Open Science Grid (A
  Snowmass 2013 whitepaper)

abstract:
  Snowmass is a US long-term planning study for the high-energy community by
the American Physical Society's Division of Particles and Fields. For its
simulation studies, opportunistic resources are harnessed using the Open
Science Grid infrastructure. Late binding grid technology, GlideinWMS, was used
for distributed scheduling of the simulation jobs across many sites mainly in
the US. The pilot infrastructure also uses the Parrot mechanism to dynamically
access CvmFS in order to ascertain a homogeneous environment across the nodes.
This report presents the resource usage and the storage model used for
simulating large statistics Standard Model backgrounds needed for Snowmass
Energy Frontier studies.


title: On monotonicity-preserving perturbations of $M$-matrices

abstract:
  We obtain an explicit analytical sufficient condition on $E$ that ensures the
monotonicity of the matrix $M+E$, where $M$ is an $M$-matrix.


title: Multi-Lepton Signals of Top-Higgs Associated Production

abstract:
  We evaluate the potential to measure ttbar H associated production at the LHC
using non-resonant multi-lepton final states in conjunction with two or more
b-tags. The multi-lepton ttbar H signal arises predominantly from H to tau tau
and H to WW^* alongside the semi-leptonic or fully leptonic decay of the ttbar
pair. We demonstrate the power of a multi-lepton search for ttbar H associated
production by recasting the CMS b-tagged multi-lepton search with 19.5 fb^-1 of
8 TeV data to obtain an observed (expected) limit of 4.7 (6.6) times the
Standard Model rate, comparable to ongoing searches in 4b and bb gamma gamma
final states. Sensitivity can be further improved by the addition of exclusive
channels involving same-sign dileptons. We recast the CMS b-tagged same-sign
dilepton search with 10.5 fb^-1 of 8 TeV data to set limits on ttbar H
associated production, and approximately combine the two searches by
calculating the fraction of same-sign dilepton signal events which do not
satisfy multi-lepton selection criteria. We estimate an expected total
non-resonant leptonic reach of mu < 5.0 times the Standard Model rate in 20
fb^-1 of 8 TeV data, with improvements possible.


title: Studying the Supernova Remnant G31.9+0.0 in Gamma and X-Rays

abstract:
  G31.9+0.0 (3C 391) is a Galactic mixed-morphology supernova remnant observed
in GeV gamma rays by Fermi Gamma Ray Space Telescope's LAT (Fermi-LAT), as well
as in the 0.3-10 keV X-ray band by Suzaku. In this paper, we will present the
analysis results of X- and gamma-ray data of 3C 391 taken with Suzaku and
Fermi-LAT. The X-ray spectrum of 3C 391 was fitted to a single-temperature
variable abundance non-equilibrium ionization model with an electron
temperature of kTe ~ 0.57 keV, an absorbing column density of NH ~ 3.1 x
10^{22} cm^{-2} and a very high ionization age (\tau > 10^{12} cm^{-3} s),
which suggest that the plasma has reached ionization equilibrium. The spectrum
shows clearly detected emission lines of Mg, Si, and S. 3C 391 was detected in
GeV gamma rays with a significance of ~ 13 sigma. The spectrum was fitted with
a log-parabola function, where the spectral index and beta parameters were
found to be \alpha = 2.35 +- 0.07 and \beta = 0.366 +- 0.339. The integrated
flux above 200 MeV was found as F = (2.34 +- 0.37) x 10^{-8} ph cm^{-2} s^{-1}.
These results are in agreement with the Fermi-LAT results given in the 2nd
Fermi-LAT catalog.


title: The DESI Experiment, a whitepaper for Snowmass 2013

abstract:
  The Dark Energy Spectroscopic Instrument (DESI) is a massively multiplexed
fiber-fed spectrograph that will make the next major advance in dark energy in
the timeframe 2018-2022. On the Mayall telescope, DESI will obtain spectra and
redshifts for at least 18 million emission-line galaxies, 4 million luminous
red galaxies and 3 million quasi-stellar objects, in order to: probe the
effects of dark energy on the expansion history using baryon acoustic
oscillations (BAO), measure the gravitational growth history through
redshift-space distortions, measure the sum of neutrino masses, and investigate
the signatures of primordial inflation. The resulting 3-D galaxy maps at z<2
and Lyman-alpha forest at z>2 will make 1%-level measurements of the distance
scale in 35 redshift bins, thus providing unprecedented constraints on
cosmological models.


title:
Variations of Landau's theorem for p-regular and p-singular conjugacy
  classes

abstract:
  The well-known Landau's theorem states that, for any positive integer $k$,
there are finitely many isomorphism classes of finite groups with exactly $k$
(conjugacy) classes. We study variations of this theorem for $p$-regular
classes as well as $p$-singular classes. We prove several results showing that
the structure of a finite group is strongly restricted by the number of
$p$-regular classes or the number of $p$-singular classes of the group. In
particular, if $G$ is a finite group with $O_p(G)=1$ then $|G/F(G)|_{p'}$ is
bounded in terms of the number of $p$-regular classes of $G$. However, it is
not possible to prove that there are finitely many groups with no nontrivial
normal $p$-subgroup and $k$ $p$-regular classes without solving some extremely
difficult number-theoretic problems (for instance, we would need to show that
the number of Fermat primes is finite).


title: Power-Broadening-Free Correlation Spectroscopy in Cold Atoms

abstract:
  We report a detailed investigation on the properties of correlation spectra
for cold atoms under the condition of Electromagnetically Induced Transparency
(EIT). We describe the transition in the system from correlation to
anti-correlation as the intensity of the fields increases. Such transition
occurs for laser frequencies around the EIT resonance, which is characterized
by a correlation peak. The transition point between correlation and
anti-correlation is independent of power broadening and provides directly the
ground-state coherence time. We introduce a method to extract in real time the
correlation spectra of the system. The experiments were done in two distinct
magneto-optical traps (MOT), one for cesium and the other for rubidium atoms,
employing different detection schemes. A simplified theory is introduced
assuming three-level atoms in $\Lambda$ configuration interacting with a laser
with stochastic phase fluctuations, providing a good agreement with the
experimental observations.


title: Generating Sequences With Recurrent Neural Networks

abstract:
  This paper shows how Long Short-term Memory recurrent neural networks can be
used to generate complex sequences with long-range structure, simply by
predicting one data point at a time. The approach is demonstrated for text
(where the data are discrete) and online handwriting (where the data are
real-valued). It is then extended to handwriting synthesis by allowing the
network to condition its predictions on a text sequence. The resulting system
is able to generate highly realistic cursive handwriting in a wide variety of
styles.


title:
Global and local existence for the dissipative critical SQG equation
  with small oscillations

abstract:
  This article is devoted to the study of the critical dissipative surface
quasi-geostrophic $(SQG)$ equation in $\mathbb{R}^2$. For any initial data
$\theta_{0}$ belonging to the space $\Lambda^{s} ( H^{s}_{uloc}(\mathbb{R}^2))
\cap L^\infty(\mathbb{R}^2)$, we show that the critical (SQG) equation has at
least one global weak solution in time for all $1/4\leq s \leq 1/2$ and at
least one local weak solution in time for all $0<s<1/4$. The proof for the
global existence is based on a new energy inequality which improves the one
obtain in \cite{Laz} whereas the local existence uses more refined energy
estimates based on Besov space techniques.


title: Interaction and decay of Kelvin waves in the Gross-Pitaevskii model

abstract:
  By solving numerically the governing Gross-Pitaevskii equation, we study the
dynamics of Kelvin waves on a superfluid vortex. After determining the
dispersion relation, we monitor the turbulent decay of Kelvin waves with energy
initially concentrated at large length scales. At intermediate length scales,
we find that the decay is consistent with scaling predictions of theoretical
models. Finally we report the unexpected presence of large-length scale phonons
in the system.


title: Refined Sobolev inequalities on manifolds with ends

abstract:
  By considering a suitable Besov type norm, we obtain refined Sobolev
inequalities on a family of Riemannian manifolds with (possibly exponentially
large) ends. The interest is twofold: on one hand, these inequalities are
stable by multiplication by rapidly oscillating functions, much as the original
ones \cite{GMO}, and on the other hand our Besov space is stable by spectral
localization associated to the Laplace-Beltrami operator (while $ L^p $ spaces,
with $ p \ne 2 $, are in general not preserved by such localizations on
manifolds with exponentially large ends). We also prove an abstract version of
refined Sobolev inequalities for any selfadjoint operator on a measure space
(Proposition \ref{general}).


title: Rank-Level duality and Conformal Block divisors

abstract:
  We describe new relations among conformal block divisors in
$\operatorname{Pic}(\bar{\operatorname{M}}_{0,n})$. These relations appear from
various rank-level dualities of conformal blocks on $\mathbb{P}^1$ with $n$
marked points. We also give a coordinate free description of rank-level duality
maps on $\overline{\mathcal{M}}_{g,n}$.


title: Legendre Drinfeld modules and universal supersingular polynomials

abstract:
  We introduce a certain family of Drinfeld modules that we propose as
analogues of the Legendre normal form elliptic curves. We exhibit explicit
formulas for a certain period of such Drinfeld modules as well as formulas for
the supersingular locus in that family, establishing a connection between these
two kinds of formulas. Lastly, we also provide a closed formula for the
supersingular polynomial in the $\jmath$-invariant for generic Drinfeld
modules.


title: On equivariant homotopy theory for model categories

abstract:
  We introduce and compare two approaches to equivariant homotopy theory in a
topological or ordinary Quillen model category. For the topological model
category of spaces, we generalize Piacenza's result that the categories of
topological presheaves indexed by the orbit category of a fixed topological
group $G$ and the category of $G$-spaces can be endowed with Quillen equivalent
model category structures. We prove an analogous result for any cofibrantly
generated model category and discrete group $G$, under certain conditions on
the fixed point functors of the subgroups of $G$. These conditions hold in many
examples, though not in the category of chain complexes, where we nevertheless
establish and generalize to collections an equivariant Whitehead Theorem \`{a}
la Kropholler and Wall for the normalized chain complexes of simplicial
$G$-sets.


title: Tracing the Orphan Stream to 55 kpc with RR Lyrae Stars

abstract:
  We report positions, velocities and metallicities of 50 ab-type RR Lyrae
(RRab) stars observed in the vicinity of the Orphan stellar stream. Using about
30 RRab stars classified as being likely members of the Orphan stream, we study
the metallicity and the spatial extent of the stream. We find that RRab stars
in the Orphan stream have a wide range of metallicities, from -1.5 dex to -2.7
dex. The average metallicity of the stream is -2.1 dex, identical to the value
obtained by Newberg et al. (2010) using blue horizontal branch stars. We find
that the most distant parts of the stream (40-50 kpc from the Sun) are about
0.3 dex more metal-poor than the closer parts (within ~30 kpc), suggesting a
possible metallicity gradient along the stream's length. We have extended the
previous studies and have mapped the stream up to 55 kpc from the Sun. Even
after a careful search, we did not identify any more distant RRab stars that
could plausibly be members of the Orphan stream. If confirmed with other
tracers, this result would indicate a detection of the end of the leading arm
of the stream. We have compared the distances of Orphan stream RRab stars with
the best-fit orbits obtained by Newberg et al. (2010). We find that model 6 of
Newberg et al. (2010) cannot explain the distances of the most remote Orphan
stream RRab stars, and conclude that the best fit to distances of Orphan stream
RRab stars and to the local circular velocity is provided by potentials where
the total mass of the Galaxy within 60 kpc is M_{60}~2.7x10^{11} Msun, or about
60% of the mass found by previous studies. More extensive modelling that would
consider non-spherical potentials and the possibility of misalignment between
the stream and the orbit, is highly encouraged.


title: Convective Equations and a Generalized Cole-Hopf Transformation

abstract:
  Differential equations with convective terms such as the Burger's equation
appear in many applications and have been the subject of intense research. In
this paper we use a generalized form of Cole-Hopf transformation to relate the
solutions of some of these nonlinear equations to the solutions of linear
equations. In particular we consider generalized forms of Burger's equation and
second order nonlinear ordinary differential equations with convective terms
which can represent steady state one-dimensional convection.


title:
The convergence Newton polygon of a $p$-adic differential equation III :
  global decomposition and controlling graphs

abstract:
  We deal with locally free $\mathcal{O}_X$-modules with connection over a
Berkovich curve $X$. As a main result we prove local and global decomposition
theorems of such objects by the radii of convergence of their solutions. We
also derive a bound of the number of edges of the controlling graph, in terms
of the geometry of the curve and the rank of the equation. As an application we
provide a classification result of such equations over elliptic curves.


title:
Nonbaryonic dark matter and scalar field coupled with a transversal
  interaction plus decoupled radiation

abstract:
  We analyze a universe filled with interacting dark matter, a scalar field
accommodated as dark radiation along with dark energy plus a decoupled
radiation term within the framework of spatially flat
Friedmann-Robertson-Walker (FRW) spacetime. We work in a three-dimensional
internal space spanned by the interaction vector and use a transversal
interaction $\mathbf{Q_t}$ for solving the source equation in order to find all
the interacting component energy densities. We asymptotically reconstruct the
scalar field and potential from an early radiation era to the late dominate
dark energy one, passing through an intermediate epoch dominated by dark
matter. We apply the $\chi^{2}$ method to the updated observational Hubble data
for constraining the cosmic parameters, contrast with the Union 2 sample of
supernovae, and analyze the amount of dark energy in the radiation era. It
turns out that our model fulfills the severe bound of $\Omega_{\rm
\phi}(z\simeq 1100)<0.018$ at $2\sigma$ level, is consistent with the recent
analysis that includes cosmic microwave background anisotropy measurements from
the Atacama Cosmology Telescope and the South Pole Telescope along with the
future constraints achievable by Planck and CMBPol experiments, and satisfies
the stringent bound $\Omega_{\rm \phi}(z\simeq 10^{10})<0.04$ at $2\sigma$
level in the big-bang nucleosynthesis epoch.

categories: gr-qc astro-ph.CO hep-ph hep-th physics.space-ph


title: Bounds of incidences between points and algebraic curves

abstract:
  We prove new bounds on the number of incidences between points and higher
degree algebraic curves. The key ingredient is an improved initial bound, which
is valid for all fields. Then we apply the polynomial method to obtain global
bounds on $\mathbb{R}$ and $\mathbb{C}$.


title:
Some boundedness properties of solutions to the Vafa-Witten equations on
  closed four-manifolds

abstract:
  We consider a set of gauge-theoretic equations on closed oriented
four-manifolds, which was introduced by Vafa and Witten. The equations involve
a triple consisting of a connection and extra fields associated to a principal
bundle over a closed oriented four-manifold. They are similar to Hitchin's
equations over compact Riemann surfaces, and as part of the resemblance, there
is no $L^2$-bound on the curvature without an $L^2$-bound on the extra fields.
In this article, however, we observe that under the particular circumstance
where the curvature does not become concentrated and the limiting connection is
not locally reducible, one obtains an $L^2$-bound on the extra fields.


title: The partial r-Bell polynomials

abstract:
  In this paper, we show that the r-Stirling numbers of both kinds, the
r-Whitney numbers of both kinds, the r-Lah numbers and the r-Whitney-Lah
numbers form particular cases of family of polynomials forming a generalization
of the partial Bell polynomials. We deduce the generating functions of several
restrictions of these numbers. In addition, a new combinatorial interpretations
is presented for the r-Whitney numbers and the r-Whitney-Lah numbers.


title: Quasi-dynamic Traffic Light Control for a Single Intersection

abstract:
  We address the traffic light control problem for a single intersection by
viewing it as a stochastic hybrid system and developing a Stochastic Flow Model
(SFM) for it. We adopt a quasi-dynamic control policy based on partial state
information defined by detecting whether vehicle backlog is above or below a
certain threshold, without the need to observe an exact vehicle count. The
policy is parameterized by green and red cycle lengths which depend on this
partial state information. Using Infinitesimal Perturbation Analysis (IPA), we
derive online gradient estimators of an average traffic congestion metric with
respect to these controllable green and red cycle lengths when the vehicle
backlog is above or below the threshold. The estimators are used to iteratively
adjust light cycle lengths so as to improve performance and, in conjunction
with a standard gradient-based algorithm, to seek optimal values which adapt to
changing traffic conditions. Simulation results are included to illustrate the
approach and quantify the benefits of quasidynamic traffic light control over
earlier static approaches.


title:
Doping evolution of Zhang-Rice singlet spectral weight: a comprehensive
  examination by x-ray absorption spectroscopy

abstract:
  The total spectral weight \textit{S} of the emergent low-energy quasipaticles
in high-temperature superconductors is explored by x-ray absorption
spectroscopy. In order to examine the applicability of the Hubbard model,
regimes that cover from zero doping to overdoping are investigated. In contrast
to mean field theory, we found that \textit{S} deviates from linear dependence
on the doping level \textit{p}. The slope of \textit{S} versus \textit{p}
changes continuously throughout the whole doping range with no sign of
saturation up to \textit{p} = 0.23. Therefore, the picture of Zhang-Rice
singlet remains intact within the most prominent doping regimes of HTSC's.


title: Negative differential transmission in graphene

abstract:
  By using the Kubo linear response theory with the Keldysh Green function
approach, we investigate the mechanism leading to the negative differential
transmission in system with the equilibrium electron density much smaller than
the photon-excited one. It is shown that the negative differential transmission
can appear at low probe-photon energy (in the order of the scattering rate) or
at high energy (much larger than the scattering rate). For the low probe-photon
energy case, the negative differential transmission is found to come from the
increase of the intra-band conductivity due to the large variation of electron
distribution after the pumping. As for the high probe-photon energy case, the
negative differential transmission is shown to tend to appear with the
hot-electron temperature being closer to the equilibrium one and the chemical
potential higher than the equilibrium one but considerably smaller than half of
the probe-photon energy. We also show that this negative differential
transmission can come from both the inter- and the intra-band components of the
conductivity. Especially, for the inter-band component, its contribution to the
negative differential transmission is shown to come from both the Hartree-Fock
self-energy and the scattering. Furthermore, the influence of the Coulomb-hole
self-energy is also addressed.


title:
A Survey of Spline-based Volumetric Data Modeling Framework and Its
  Applications

abstract:
  The rapid advances in 3D scanning and acquisition techniques have given rise
to the explosive increase of volumetric digital models in recent years. This
dissertation systematically trailblazes a novel volumetric modeling framework
to represent 3D solids. The need to explore more efficient and robust 3D
modeling framework has gained the prominence. Although the traditional surface
representation (e.g., triangle mesh) has many attractive properties, it is
incapable of expressing the interior space and materials. Such a serious
drawback overshadows many potential modeling and analysis applications.
Consequently volumetric modeling techniques become the well-known solution to
this problem. Nevertheless, many unsolved research issues remain when
developing an efficient modeling paradigm for existing 3D models: complex
geometry (fine details and extreme concaveness), arbitrary topology,
heterogenous materials, large-scale data storage and processing, etc.


title:
Unifying Amplitude and Phase Analysis: A Compositional Data Approach to
  Functional Multivariate Mixed-Effects Modeling of Mandarin Chinese

abstract:
  Mandarin Chinese is characterized by being a tonal language; the pitch (or
$F_0$) of its utterances carries considerable linguistic information. However,
speech samples from different individuals are subject to changes in amplitude
and phase which must be accounted for in any analysis which attempts to provide
a linguistically meaningful description of the language. A joint model for
amplitude, phase and duration is presented which combines elements from
Functional Data Analysis, Compositional Data Analysis and Linear Mixed Effects
Models. By decomposing functions via a functional principal component analysis,
and connecting registration functions to compositional data analysis, a joint
multivariate mixed effect model can be formulated which gives insights into the
relationship between the different modes of variation as well as their
dependence on linguistic and non-linguistic covariates. The model is applied to
the COSPRO-1 data set, a comprehensive database of spoken Taiwanese Mandarin,
containing approximately 50 thousand phonetically diverse sample $F_0$ contours
(syllables), and reveals that phonetic information is jointly carried by both
amplitude and phase variation.


title: A Spline-based Volumetric Data Modeling Framework and Its Applications

abstract:
  In this dissertation, we concentrate on the challenging research issue of
developing a spline-based modeling framework, which converts the conventional
data (e.g., surface meshes) to tensor-product trivariate splines. This
methodology can represent both boundary/volumetric geometry and real volumetric
physical attributes in a compact and continuous fashion. The regular
tensor-product structure enables our new developed methods to be embedded into
the industry standard seamlessly. These properties make our techniques highly
preferable in many physically-based applications including mechanical analysis,
shape deformation and editing, virtual surgery training, etc.


title: On Interference Networks over Finite Fields

abstract:
  We present a framework to study linear deterministic interference networks
over finite fields. Unlike the popular linear deterministic models introduced
to study Gaussian networks, we consider networks where the channel coefficients
are general scalars over some extension field $\FF_{p^m}$ (scalar $m$-th
extension-field models), $m \times m$ diagonal matrices over $\FF_p$
($m$-symbol extension ground-field models), and $m \times m$ general
non-singular matrices (MIMO ground field models). We use the companion matrix
representation of the extension field to convert $m$-th extension scalar models
into MIMO ground-field models where the channel matrices have special algebraic
structure. For such models, we consider the $2 \times 2 \times 2$ topology
(two-hops two-flow) and the 3-user interference network topology. We derive
achievability results and feasibility conditions for certain schemes based on
the Precoding-Based Network Alignment (PBNA) approach, where intermediate nodes
use random linear network coding (i.e., propagate random linear combinations of
their incoming messages) and non-trivial precoding/decoding is performed only
at the network edges, at the sources and destinations. Furthermore, we apply
this approach to the scalar $2\times 2\times 2$ complex Gaussian IC with fixed
channel coefficients, and show two competitive schemes outperforming other
known approaches at any SNR, where we combine finite-field linear
precoding/decoding with lattice coding and the Compute and Forward approach at
the signal level. As a side result, we also show significant advantages of
vector linear network coding both in terms of feasibility probability (with
random coding coefficients) and in terms of coding latency, with respect to
standard scalar linear network coding, in PBNA schemes.


title: Quantifying resolving power in astronomical spectra

abstract:
  The spectral resolving power R = lambda / delta lambda is a key property of
any spectrograph, but its definition is vague because the `smallest resolvable
wavelength difference' delta lambda does not have a consistent definition.
Often the FWHM is used, but this is not consistent when comparing the
resolution of instruments with different forms of spectral line spread
function. Here two methods for calculating resolving power on a consistent
scale are given. The first is based on the principle that two spectral lines
are just resolved when the mutual disturbance in fitting the fluxes of the
lines reaches a threshold (here equal to that of sinc^2 profiles at the
Rayleigh criterion). The second criterion assumes that two spectrographs have
equal resolving powers if the wavelength error in fitting a narrow spectral
line is the same in each case (given equal signal flux and noise power). The
two criteria give similar results, and give rise to scaling factors which can
be applied to bring resolving power calculated using the FWHM on to a
consistent scale. The differences among commonly encountered Line Spread
Functions are substantial, with a Lorentzian profile (as produced by an imaging
Fabry-Perot interferometer) being a factor of two worse than the boxy profile
from a projected circle (as produced by integration across the spatial
dimension of a multi-mode fibre) when both have the same FWHM. The projected
circle has a larger FWHM in comparison with its true resolution, so using FWHM
to characterise the resolution of a spectrograph which is fed by multi-mode
fibres significantly underestimates its true resolving power if it has small
aberrations and a well-sampled profile.


title: On limit periodicity of discrete time stochastic processes

abstract:
  We consider a discrete time dynamic system described by a difference equation
with periodic coefficients and with additive stochastic noise. We investigate
the possibility of the periodicity for the solution. In particular, we found
sufficient conditions for existence of a periodic process such that the
solution converges to it, including almost surely convergence.


title:
Vacancy trapping behaviors of hydrogen atoms in Ti3SiC2: a
  first-principles study

abstract:
  The behaviors of hydrogen (H) in MAX phase material Ti3SiC2 have been
investigated using first-principles method. We show that a single H atom
prefers to stay 1.01 {\AA} down of the Si vacancy with solution energy of about
-4.07 eV, lowerthan that in bulk Ti3SiC2. Multi H atoms exhibit a repulsive
interaction at the Si vacancy. And up to five H atoms can be trapped by a Si
vacancy without H2 molecules formation. These results suggest the strong
vacancy trapping characteristic of H atoms in Ti3SiC2.
  Meanwhile, the barrier for H diffusion from an interstitial site to a vacancy
is 1.17 eV, which is much larger than that in metals, indicating that to some
extent H atoms can not easily migrate or aggregate to form bubble in Ti3SiC.


title:
The Generalization of the Decomposition of Functions by Energy operators
  (Part II) and some Applications

abstract:
  This work introduces the families of generalized energy operators
$([[.]^p]_k^+)_{k\in\mathbb{Z}}$ and $([[.]^p]_k^-)_{k\in\mathbb{Z}}$ ($p$ in
$\mathbb{Z}^+$). One shows that with Lemma 1, the successive derivatives of
$\big ([[$f$]^{p-1}]_1^+ \big)^n$ ($n$ in $\mathbb{Z}$, $n\neq 0$) can be
decomposed with the generalized energy operators $\big
([[.]^p]_k^+\big)_{k\in\mathbb{Z}}$ when $f$ is in the subspace
$\mathbf{S}_p^-(\mathbb{R})$. With Theorem 1 and $f$ in
$\mathbf{s}_p^-(\mathbb{R})$, one can decompose uniquely the successive
derivatives of $\big ([[$f$]^{p-1}]_1^+ \big)^n$ ($n$ in $\mathbb{Z}$, $n\neq
0$) with the generalized energy operators $\big
([[.]^p]_k^+\big)_{k\in\mathbb{Z}}$ and $\big
([[.]^p]_k^-\big)_{k\in\mathbb{Z}}$. $\mathbf{S}_p^-(\mathbb{R})$ and
$\mathbf{s}_p^-(\mathbb{R})$ ($p$ in $\mathbb{Z}^+$) are subspaces of the
Schwartz space $\mathbf{S}^-(\mathbb{R})$. These results generalize the work of
[arxiv:1208.3385]. The second fold of this work is the application of the
generalized energy operator families onto the solutions of linear partial
differential equations. The solutions are functions of two variables and
defined in subspaces of $\mathbf{S}^-(\mathbb{R}^2)$. The theory is then
applied to the Helmholtz equation. In this specific case, the use of
generalized energy operators in the general solution of this PDE extends the
results of [montilletIMF45-48-2010]. This work ends with some numerical
examples. We also underline that this theory could possibly open some
applications in astrophysics and aeronautics.