title:
Studies on the UV to IR Evolution of Gauge Theories and Quasiconformal
  Behavior

abstract:
  We describe recent results from our studies of the UV to IR evolution of
asymptotically free vectorial gauge theories and quasiconformal behavior. These
include higher-loop calculations of the IR zero of the beta function and of the
anomalous dimension of the fermion bilinear. Effects of scheme-dependence of
higher-loop results are assessed in detail. Applications to models with
dynamical electroweak symmetry breaking are discussed.


title:
Correcting self-intersecting polygons using minimal memory A simple and
  efficient algorithm and thoughts on line-segment intersection algorithms

abstract:
  While well-known methods to list the intersections of either a list of
segments or a complex polygon aim at achieving optimal time-complexity they
often do so at the cost of memory comsumption and complex code. Real-life
software optimisation however lies in optimising at the same time speed and
memory usage as well as keeping code simple. This paper first presents some
thoughts on the available algorithms in terms of memory usage leading to a very
simple scan-line-based algorithm aiming at answering that challenge. Although
sub-optimal in terms of speed it is optimal if both speed and memory space are
taken together and is very easy to implement. For N segments and k
intersections it uses only N additional integers and lists the intersections in
O(N^1.26) or corrects them in O((N+k) N^0.26) at most in average, with a high
probability of a much lower exponent around 0.16 and even as low as 0.1. It is
therefore well adapted for inclusion in larger software and seems like a good
compromise. Worst-case is in O(N^2). Then the paper will focus on differences
between available methods and the brute-force algorithm and a solution is
proposed. Although sub-optimal its applications could mainly be to answer in a
fast way a number of scattered unrelated intersection queries using minimal
complexity and additional resources.


title:
Reverberation and photoionization estimates of the Broad Line Region
  Radius in Low-z Quasars

abstract:
  Black Hole Mass (M_BH) estimation in quasars, especially at high redshift,
involves use of single epoch spectra with s/n and resolution that permit
accurate measurement of the width of a broad line assumed to be a reliable
virial estimator. Coupled with an estimate of the radius of the broad line
region this yields M_BH. The radius of the broad line region (BLR) may be
inferred from an extrapolation of the correlation between source luminosity and
reverberation derived r_BLR measures (the so-called Kaspi relation involving
about 60 low z sources). We are exploring a different method for estimating
r_BLR directly from inferred physical conditions in the BLR of each source. We
report here on a comparison of r_BLR estimates that come from our method and
from reverberation mapping. Our "photoionization" method employs diagnostic
line intensity ratios in the rest-frame range 1400-2000 A
(AlIII1860/SiIII]1892, CIV1549/AlIII1860) that enable derivation of the product
of density and ionization parameter with the BLR distance derived from the
definition of the ionization parameter. We find good agreement between our
estimates of the density, ionization parameter and r_BLR and those from
reverberation mapping. We suggest empirical corrections to improve the
agreement between individual photoionization-derived r_BLR values and those
obtained from reverberation mapping. The results in this paper can be exploited
to estimate M_BH for large samples of high-z quasars using an appropriate
virial broadening estimator. We show that the width of the UV intermediate
emission lines are consistent with the width of H beta, therefore providing a
reliable virial broadening estimator that can be measured in large samples of
high-z quasars.


title:
Multichannel parametrization of $\bar K N$ scattering amplitudes and
  extraction of resonance parameters

abstract:
  We present results of a new multichannel partial-wave analysis for $\bar K N$
scattering in the c.m.\ energy range 1480 to 2100 MeV. Resonance parameters
were extracted by fitting partial-wave amplitudes from all considered channels
using a multichannel parametrization that is consistent with $S$-matrix
unitarity. The resonance parameters are generally in good agreement with
predictions of the Koniuk-Isgur quark model.


title: Physics Pedagogy and Assessment in Secondary Schools in the U.S.

abstract:
  The objective of this project is to compare the effectiveness of teaching
styles used in high school physics classes and the methods used to assess them.
We would like to determine those approaches to physics at the high schools that
work and those that do not work for students from different demographics. We
sent out a survey to high school physics teachers in the U.S. Midwest states,
inquiring about student preparation, pedagogy in the classroom, assessment and
professional development. We found that there are differences in the practices
of physics teachers in all of these areas, depending on the school location, be
it rural, suburban or urban. Our results enable us to report on the most common
successful practices in physics courses for these demographic areas.


title:
Ground States of Fermionic lattice Hamiltonians with Permutation
  Symmetry

abstract:
  We study the ground states of lattice Hamiltonians that are invariant under
permutations, in the limit where the number of lattice sites, N -> \infty. For
spin systems, these are product states, a fact that follows directly from the
quantum de Finetti theorem. For fermionic systems, however, the problem is very
different, since mode operators acting on different sites do not commute, but
anti-commute. We construct a family of fermionic states, \cal{F}, from which
such ground states can be easily computed. They are characterized by few
parameters whose number only depends on M, the number of modes per lattice
site. We also give an explicit construction for M=1,2. In the first case,
\cal{F} is contained in the set of Gaussian states, whereas in the second it is
not. Inspired by that constructions, we build a set of fermionic variational
wave functions, and apply it to the Fermi-Hubbard model in two spatial
dimensions, obtaining results that go beyond the generalized Hartree-Fock
theory.


title: On Topological Lattices and an Application to First Submodules

abstract:
  We introduce the notion of a (strongly) topological lattice
$\mathcal{L}=(L,\wedge ,\vee)$ with respect to a subset $X\subsetneqq L;$
aprototype is the lattice of (two-sided) ideals of a ring $R,$ which
is(strongly) topological with respect to the prime spectrum of $R.$ We
investigate and characterize (strongly) topological lattices. Given a non-zero
left $R$-module $M,$ we introduce and investigate the spectrum
$\mathrm{Spec}^{\mathrm{f}}(M)$ of \textit{first submodules} of $M.$ We
topologize $\mathrm{Spec}^{\mathrm{f}}(M)$ and investigate the algebraic
properties of $_{R}M$ by passing to the topological properties of the
associated space.


title: Josephson surface plasmons in spatially confined cuprate superconductors

abstract:
  In this work, we generalize the theory of localized surface plasmons to the
case of high-Tc cuprate superconductors, spatially confined in the form of
small spherical particles. At variance from ordinary metals, cuprate
superconductors are characterized by a low-energy bulk excitation known as the
Josephson plasma wave (JPW), arising from interlayer tunneling of the
condensate along the c-axis. The effect of the JPW is revealed in a
characteristic spectrum of surface excitations, which we call Josephson surface
plasmons. Our results, which apply to any material with a strongly anisotropic
electromagnetic response, are worked out in detail for the case of multilayered
superconductors supporting both low-frequency (acoustic) and transverse-optical
JPW. Spatial confinement of the Josephson plasma waves may represent a new
degree of freedom to engineer their frequencies and to explore the link between
interlayer tunnelling and high-Tc superconductivity.


title: Reconstruction and Repair Degree of Fractional Repetition Codes

abstract:
  Given a Fractional Repetition code, finding the reconstruction and repair
degree in a distributed storage system is an important problem. In this work,
we present algorithms for computing the reconstruction and repair degree of
fractional repetition codes.


title:
The Unique Games Conjecture, Integrality Gap for Cut Problems and
  Embeddability of Negative Type Metrics into $\ell_1$

abstract:
  In this paper, we disprove a conjecture of Goemans and Linial; namely, that
every negative type metric embeds into $\ell_1$ with constant distortion. We
show that for an arbitrarily small constant $\delta> 0$, for all large enough
$n$, there is an $n$-point negative type metric which requires distortion at
least $(\log\log n)^{1/6-\delta}$ to embed into $\ell_1.$
  Surprisingly, our construction is inspired by the Unique Games Conjecture
(UGC) of Khot, establishing a previously unsuspected connection between
probabilistically checkable proof systems (PCPs) and the theory of metric
embeddings. We first prove that the UGC implies a super-constant hardness
result for the (non-uniform) Sparsest Cut problem. Though this hardness result
relies on the UGC, we demonstrate, nevertheless, that the corresponding PCP
reduction can be used to construct an "integrality gap instance" for Sparsest
Cut. Towards this, we first construct an integrality gap instance for a natural
SDP relaxation of Unique Games. Then we "simulate" the PCP reduction and
"translate" the integrality gap instance of Unique Games to an integrality gap
instance of Sparsest Cut. This enables us to prove a $(\log \log
n)^{1/6-\delta}$ integrality gap for Sparsest Cut, which is known to be
equivalent to the metric embedding lower bound.


title: Causal Dynamical Triangulations without Preferred Foliation

abstract:
  We introduce a generalized version of the Causal Dynamical Triangulations
(CDT) formulation of quantum gravity, in which the regularized, triangulated
path integral histories retain their causal properties, but do not have a
preferred proper-time foliation. An extensive numerical study of the associated
nonperturbative path integral in 2+1 dimensions shows that it can nevertheless
reproduce the emergence of an extended de Sitter universe on large scales, a
key feature of CDT quantum gravity. This suggests that the preferred foliation
normally used in CDT is not a crucial (albeit convenient) part of its
background structure.


title: Parallel Coordinates Guided High Dimensional Transfer Function Design

abstract:
  High-dimensional transfer function design is widely used to provide
appropriate data classification for direct volume rendering of various
datasets. However, its design is a complicated task. Parallel coordinate plot
(PCP), as a powerful visualization tool, can efficiently display
high-dimensional geometry and accurately analyze multivariate data. In this
paper, we propose to combine parallel coordinates with dimensional reduction
methods to guide high-dimensional transfer function design. Our pipeline has
two major advantages: (1) combine and display extracted high-dimensional
features in parameter space; and (2) select appropriate high-dimensional
parameters, with the help of dimensional reduction methods, to obtain
sophisticated data classification as transfer function for volume rendering. In
order to efficiently design high-dimensional transfer functions, the
combination of both parallel coordinate components and dimension reduction
results is necessary to generate final visualization results. We demonstrate
the capability of our method for direct volume rendering using various CT and
MRI datasets.


title: Functional Package Management with Guix

abstract:
  We describe the design and implementation of GNU Guix, a purely functional
package manager designed to support a complete GNU/Linux distribution. Guix
supports transactional upgrades and roll-backs, unprivileged package
management, per-user profiles, and garbage collection. It builds upon the
low-level build and deployment layer of the Nix package manager. Guix uses
Scheme as its programming interface. In particular, we devise an embedded
domain-specific language (EDSL) to describe and compose packages. We
demonstrate how it allows us to benefit from the host general-purpose
programming language while not compromising on expressiveness. Second, we show
the use of Scheme to write build programs, leading to "two-tier" programming
system.


title: The Dip Effect under Integer Quantized Hall Conditions

abstract:
  In this work we investigate an unusual transport phenomenon observed in
two-dimensional electron gas under integer quantum Hall effect conditions. Our
calculations are based on the screening theory, using a semi-analytical model.
The transport anomalies are \emph{dip} and overshoot effects, where the Hall
resistance decreases (or increases) unexpectedly at the quantized resistance
plateaus intervals. We report on our numerical findings of the \emph{dip}
effect in the Hall resistance, considering GaAs/AlGaAs heterostructures in
which we investigated the effect under different experimental conditions. We
show that, similar to overshoot, the amplitude of the dip effect is strongly
influenced by the edge reconstruction due to electrostatics. It is observed
that the steep potential variation close to the physical boundaries of the
sample results in narrower incompressible strips, hence, the experimental
observation of the dip effect is limited by the properties of these current
carrying strips. By performing standard Hall resistance measurements on gate
defined narrow samples, we demonstrate that the predictions of the screening
theory is in well agreement with our experimental findings.


title: Certifying The Quantumness of A Generalized Coherent Control Scenario

abstract:
  We consider the role of quantum mechanics in a specific coherent control
scenario, designing a "coherent control interferometer" as the essential tool
that links coherent control to quantum fundamentals. Building upon this allows
us to rigorously display the genuinely quantum nature of a generalized
weak-field coherent control scenario (utilizing 1 vs. 2 photon excitation) via
a Bell-CHSH test. Specifically, we propose an implementation of "quantum
delayed-choice" in a bichromatic alkali atom photoionization experiment. The
experimenter can choose between two complementary situations, which are
characterized by a random photoelectron spin polarization with particle-like
behaviour on the one hand, and by spin controllability and wave-like nature on
the other. Because these two choices are conditioned coherently on states of
the driving fields, it becomes physically unknowable, prior to measurement,
whether there is control over the spin or not.


title: 2HDM confronting LHC data

abstract:
  Almost all data collected at the LHC during the 7 and 8 TeV runs has now been
analysed by the ATLAS and CMS collaborations. Its consistency with the Standard
Model (SM) predictions has cornered the CP-conserving two-Higgs doublet model
(2HDM) into the SM limit, sin (\beta -\alpha) = 1. However, there are still
allowed regions of the 2HDM parameter space away from this limit. In this work
we discuss how the 2HDM is performing in view of the LHC data together with the
remaining available experimental and theoretical constraints.


title: SU(3) Landau - Zener Interferometry

abstract:
  We consider a general theory of Landau-Zener transitions in a three-level
system. Based on a classification of three level crossings we express the
Landau - Zener Hamiltonians in terms of two bases: i) spin S=1 SU(2) operators
and ii) SU(3) Gell - Mann matrices. We show that the generic Hamiltonians being
non-linear in terms of the SU(2) group generators become linear in the SU(3)
basis. If the diabatic states of the SU(3) Landau - Zener Hamiltonian form a
triangle, the interference between two paths results in formation of "beats"
and "steps" pattern in the time-dependent transition probability. The
characteristic time scales describing the "beats" and "steps" depend on a dwell
time through the triangle. These scales are related to the geometric size of
the interferometer. We formulate the SU(3) Landau - Zener problem in terms of
Bloch dynamics of a unit vector and find a solution of eight-dimensional Bloch
equations in the limit of a non-adiabatic transition. Possible experiments in
triangular and linearly arranged triple quantum dots where Landau - Zener
interferometry can be used for finding manifestations of SU(3) symmetry are
discussed.


title:
Projective limits of quantum symmetry groups and the doubling
  construction for Hopf algebras

abstract:
  The quantum symmetry group of the inductive limit of C*-algebras equipped
with orthogonal filtrations is shown to be the projective limit of the quantum
symmetry groups of the C*-algebras appearing in the sequence. Some explicit
examples of such projective limits are studied, including the case of quantum
symmetry groups of the duals of finite symmetric groups, which do not fit
directly into the framework of the main theorem and require further specific
study. The investigations reveal a deep connection between quantum symmetry
groups of discrete group duals and the doubling construction for Hopf algebras.


title:
Nearby M, L, and T Dwarfs Discovered by the Wide-field Infrared Survey
  Explorer (WISE)

abstract:
  In our effort to complete the census of low-mass stars and brown dwarfs in
the immediate Solar Neighborhood, we present spectra, photometry, proper
motions, and distance estimates for forty-two low-mass star and brown dwarf
candidates discovered by the Wide-field Infrared Survey Explorer (WISE). We
also present additional follow-up information on twelve candidates selected
using WISE data but previously published elsewhere. The new discoveries include
fifteen M dwarfs, seventeen L dwarfs, five T dwarfs, and five objects of other
type. Among these discoveries is a newly identified "unusually red L dwarf"
(WISE J223527.07+451140.9), four peculiar L dwarfs whose spectra are most
readily explained as unresolved L+T binary systems, and a T9 dwarf (WISE
J124309.61+844547.8). We also show that the recently discovered red L dwarf
WISEP J004701.06+680352.1 (Gizis et al. 2012) may be a low-gravity object and
hence young and potentially low mass (< 25 MJup).


title:
Protecting Information Against Computational Errors and Quantum Erasures
  via Concatenation

abstract:
  In this work, we introduce a new concatenation scheme which aims at
protecting information against the occurrence of both computational errors and
quantum erasures. According to our scheme, the internal code must be a quantum
loss-correcting code that does not perform measurements, while the external
code must be a quantum error-correcting code. We illustrate the concatenation
proposed with an example in which one qubit of information is protected against
the occurrence of two erasures and one computational error.


title:
A new method based on noise counting to monitor the frontend electronics
  of the LHCb muon detector

abstract:
  A new method has been developed to check the correct behaviour of the
frontend electronics of the LHCb muon detector. This method is based on the
measurement of the electronic noise rate at different thresholds of the
frontend discriminator. The method was used to choose the optimal discriminator
thresholds. A procedure based on this method was implemented in the detector
control system and allowed the detection of a small percentage of frontend
channels which had deteriorated. A Monte Carlo simulation has been performed to
check the validity of the method.


title: Odd-frequency superconducting pairing in multi-band superconductors

abstract:
  We point out that essentially all multi-band superconductors have an
odd-frequency pairing component, as follows from a general symmetry analysis of
even- and odd-frequency pairing states. We show that odd-frequency
superconducting pairing requires only a finite band hybridization, or
scattering, and non-identical intraband order parameters, of which only one
band needs to be superconducting. Under these conditions odd-frequency
odd-interband pairing is always present. From a symmetry analysis we establish
a complete reciprocity between parity in band-index and frequency.


title:
Quench Dynamics in Bose condensates in the Presence of a Bath: Theory
  and Experiment

abstract:
  In this paper we study the transient dynamics of a Bose superfluid subsequent
to an interaction quench. Essential for equilibration is a source of
dissipation which we include following the approach of Caldeira and Leggett.
Here we solve the equations of motion exactly by integrating out an
environmental bath. We thereby derive precisely the time dependent density
correlation functions with the appropriate analytic and asymptotic properties.
The resulting structure factor exhibits the expected damping and thereby
differs from that of strict Bogoliubov theory. These damped sound modes, which
reflect the physics beyond mean field approaches, are characterized and the
structure factors are found to compare favorably with experiment.


title: $C$ is not equivalent to $C^-$ in its Jacobian: a tropical point of view

abstract:
  We show that the Abel-Jacobi image of a tropical curve $C$ in its Jacobian
$J(C)$ is not algebraically equivalent to its reflection by using a simple
calculation in tropical homology.


title:
Self-dual Continuous Series of Representations for U_q(sl(2)) and
  U_q(osp(1|2))

abstract:
  We determine the Clebsch-Gordan and Racah-Wigner coefficients for continuous
series of representations of the quantum deformed algebras U_q(sl(2)) and
U_q(osp(1|2)). While our results for the former algebra reproduce formulas by
Ponsot and Teschner, the expressions for the orthosymplectic algebra are new.
Up to some normalization factors, the associated Racah-Wigner coefficients are
shown to agree with the fusing matrix in the Neveu-Schwarz sector of N=1
supersymmetric Liouville field theory.


title:
Constraining the parameter space of the one-zone
  synchrotron-self-Compton model for GeV-TeV detected BL Lac objects

abstract:
  The one-zone synchrotron-self-Compton (SSC) model aims to describe the
spectral energy distribution (SED) of BL Lac objects via synchrotron emission
by a non-thermal population of electrons and positrons in a single homogeneous
emission region, partially upscattered to gamma-rays by the particles
themselves. The model is usually considered as degenerate, given that the
number of free parameters is higher than the number of observables. It is thus
common to model the SED by choosing a single set of values for the SSC-model
parameters that provide a good description of the data, without studying the
entire parameter space. We present here a new numerical algorithm which permits
us to find the complete set of solutions, using the information coming from the
detection in the GeV and TeV energy bands. The algorithm is composed of three
separate steps: we first prepare a grid of simulated SEDs and extract from each
SED the values of the observables; we then parametrize each observable as a
function of the SSC parameters; we finally solve the system for a given set of
observables. We iteratively solve the system to take into account uncertainties
in the values of the observables, producing a family of solutions. We present a
first application of our algorithm to the typical high-frequency-peaked BL Lac
object 1RXS J101015.9-311909, provide constraints on the SSC parameters, and
discuss the result in terms of our understanding of the blazar emitting region.


title: Non-Abelian Lie algebroids over jet spaces

abstract:
  We associate Hamiltonian homological evolutionary vector fields --which are
the non-Abelian variational Lie algebroids' differentials-- with Lie
algebra-valued zero-curvature representations for partial differential
equations.


title: Adaptive Complex Contagions and Threshold Dynamical Systems

abstract:
  A broad range of nonlinear processes over networks are governed by threshold
dynamics. So far, existing mathematical theory characterizing the behavior of
such systems has largely been concerned with the case where the thresholds are
static. In this paper we extend current theory of finite dynamical systems to
cover dynamic thresholds. Three classes of parallel and sequential dynamic
threshold systems are introduced and analyzed. Our main result, which is a
complete characterization of their attractor structures, show that sequential
systems may only have fixed points as limit sets whereas parallel systems may
only have period orbits of size at most two as limit sets. The attractor states
are characterized for general graphs and enumerated in the special case of
paths and cycle graphs; a computational algorithm is outlined for determining
the number of fixed points over a tree. We expect our results to be relevant
for modeling a broad class of biological, behavioral and socio-technical
systems where adaptive behavior is central.


title: Worst-Case Results For Positive Semidefinite Rank

abstract:
  This paper presents various worst-case results on the positive semidefinite
(psd) rank of a nonnegative matrix, primarily in the context of polytopes. We
prove that the psd rank of a generic n-dimensional polytope with v vertices is
at least (nv)^(1/4) improving on previous lower bounds. For polygons with v
vertices, we show that psd rank cannot exceed 4ceil(v/6) which in turn shows
that the psd rank of a p by q matrix of rank three is at most
4ceil(min{p,q}/6). In general, a nonnegative matrix of rank (k+1 choose 2) has
psd rank at least k and we pose the problem of deciding whether the psd rank is
exactly k. Using geometry and bounds on quantifier elimination, we show that
this decision can be made in polynomial time when k is fixed.


title:
Two-photon ladder climbing and transition to autoresonance in a chirped
  oscillator

abstract:
  The two-photon ladder climbing (successive two-photon Landau-Zener-type
transitions) in a chirped quantum nonlinear oscillator and its classical limit
(subharmonic autoresonance) are discussed. An isomorphism between the chirped
quantum-mechanical one and two-photon resonances in the system is used in
calculating the threshold for the phase-locking transition in both the
classical and quantum limits. The theory is tested by solving the Schrodinger
equation in the energy basis and illustrated via the Wigner function in phase
space.


title: Demonstration of mid-infrared waveguide photonic crystal cavities

abstract:
  We have demonstrated what we believe to be the first waveguide photonic
crystal cavity operating in the mid-infrared. The devices were fabricated from
Ge23Sb7S70 chalcogenide glass on CaF2 substrates by combing photolithographic
patterning and focus ion beam milling. The waveguide-coupled cavities were
characterized using a fiber end fire coupling method at 5.2 {\mu}m wavelength,
and a loaded quality factor of ~ 2,000 was measured near the critical coupling
regime.


title: Trapping of waves and null geodesics for rotating black holes

abstract:
  We present dynamical properties of linear waves and null geodesics valid for
Kerr and Kerr-de Sitter black holes and their stationary perturbations. The two
are intimately linked by the geometric optics approximation. For the
nullgeodesic flow the key property is the r-normal hyperbolicity of the trapped
set and for linear waves it is the distribution of quasi-normal modes: the
exact quantization conditions do not hold for perturbations but the bounds on
decay rates and the statistics of frequencies are still valid.


title: Higher-spin correlators

abstract:
  We analyze the properly normalized three-point correlator of two protected
scalar operators and one higher spin twist-two operator in N=4 super
Yang-Mills, in the limit of large spin j. The relevant structure constant can
be extracted from the OPE of the four-point correlator of protected scalar
operators. We show that crossing symmetry of the four point correlator plus a
judicious guess for the perturbative structure of the three-point correlator,
allow to make a prediction for the structure constant at all loops in
perturbation theory, up to terms that remain finite as the spin becomes large.
Furthermore, the expression for the structure constant allows to propose an
expression for the all loops four-point correlator G(u,v), in the limit u,v ->
0. Our predictions are in perfect agreement with the large j expansion of
results available in the literature.


title:
Conformal symmetry limit of QED and QCD and identities between
  perturbative contributions to deep-inelastic scattering sum rules

abstract:
  Conformal symmetry-based relations between concrete perturbative QED and QCD
approximations for the Bjorken, the Ellis-Jaffe sum rules of polarized lepton-
nucleon deep-inelastic scattering (DIS), the Gross-Llewellyn Smith sum rules of
neutrino-nucleon DIS, and for the Adler functions of axial-vector and vector
channels are derived. They result from the application of the operator product
expansion to three triangle Green functions, constructed from the non-singlet
axial-vector, and two vector currents, the singlet axial-vector and two
non-singlet vector currents and the non-singlet axial-vector, vector and
singlet vector currents in the limit, when the conformal symmetry of the gauge
models with fermions is considered unbroken. We specify the perturbative
conditions for this symmetry to be valid in the case of the $U(1)$ and
$SU(N_c)$ models. The all-order perturbative identity following from the
conformal invariant limit between the concrete contributions to the Bjorken,
the Ellis-Jaffe and the Gross-Llewellyn Smith sum rules is proved. The
analytical and numerical $O(\alpha^4)$ and $O(\alpha_s^2)$ conformal symmetry
based approximations for these sum rules and for the Adler function of the
non-singlet vector currents are summarized. Possible theoretical applications
of the results presented are discussed.


title:
Antiferromagnetic Ising model saturation field entropies: ladders and
  kagome lattice

abstract:
  Saturation field entropies of antiferromagnetic Ising models on quasi
one-dimensional lattices (ladders) and the kagome lattice are calculated. The
former is evaluated exactly by constructing the corresponding transfer
matrices, while the latter calculation uses Binder's algorithm for efficiently
and exactly computing the partition function of over 1300 spins to give, in
Boltzmann's units, S = 0.393589(6). We comment on the relation of the kagome
lattice to the experimental situation in the spin-ice compound dysprosium
titanium oxide.


title: Functorial Factorizations in Pro Categories

abstract:
  In this paper we prove a few propositions concerning factorizations of
morphisms in pro categories, the most important of which solves an open problem
of Isaksen concerning the existence of certain types of functorial
factorizations. On our way we explain and correct an error in one of the
standard references on pro categories.


title: Tracer Applications of Noble Gas Radionuclides in the Geosciences

abstract:
  The noble gas radionuclides, including 81Kr (half-life = 229,000 yr), 85Kr
(11 yr), and 39Ar (269 yr), possess nearly ideal chemical and physical
properties for studies of earth and environmental processes. Recent advances in
Atom Trap Trace Analysis (ATTA), a laser-based atom counting method, have
enabled routine measurements of the radiokrypton isotopes, as well as the
demonstration of the ability to measure 39Ar in environmental samples. Here we
provide an overview of the ATTA technique, and a survey of recent progress made
in several laboratories worldwide. We review the application of noble gas
radionuclides in the geosciences and discuss how ATTA can help advance these
fields, specifically determination of groundwater residence times using 81Kr,
85Kr, and 39Ar; dating old glacial ice using 81Kr; and an 39Ar survey of the
main water masses of the oceans, to study circulation pathways and estimate
mean residence times. Other scientific questions involving deeper circulation
of fluids in the Earth's crust and mantle also are within the scope of future
applications. We conclude that the geoscience community would greatly benefit
from an ATTA facility dedicated to this field, with instrumentation for routine
measurements, as well as for research on further development of ATTA methods.


title: Superconductivity from repulsive interaction

abstract:
  The BCS theory of superconductivity named electron-phonon interaction as a
glue that overcomes Coulomb repulsion and binds fermions into pairs which then
condense and superconduct. We review recent and not so recent works aiming to
understand whether a nominally repulsive Coulomb interaction can by itself give
rise to a superconductivity. We first discuss a generic scenario of the pairing
by electron-electron interaction, put forward by Kohn and Luttinger back in
1965, and then turn to modern studies of the electronic mechanism of
superconductivity in the lattice models for the cuprates, the Fe-pnictides, and
the doped graphene. We show that the pairing in all three classes of materials
can be viewed as lattice version of Kohn-Luttinger physics, despite that the
pairing symmetries are different. We discuss under what conditions the pairing
occurs and rationalize the need to do parquet renormalization-group analysis.
We also discuss the interplay between superconductivity and
density-instabilities.


title: On the Optimality of Treating Interference as Noise

abstract:
  It is shown that in the K-user interference channel, if for each user the
desired signal strength is no less than the sum of the strengths of the
strongest interference from this user and the strongest interference to this
user (all values in dB scale), then the simple scheme of using point to point
Gaussian codebooks with appropriate power levels at each transmitter and
treating interference as noise at every receiver (in short, TIN scheme)
achieves all points in the capacity region to within a constant gap. The
generalized degrees of freedom (GDoF) region under this condition is a
polyhedron, which is shown to be fully achieved by the same scheme, without the
need for time-sharing. The results are proved by first deriving a polyhedral
relaxation of the GDoF region achieved by TIN, then providing a dual
characterization of this polyhedral region via the use of potential functions,
and finally proving the optimality of this region in the desired regime.


title:
Exclusive photoproduction of J/psi and psi(2S) states in proton-proton
  collisions at the CERN LHC

abstract:
  In this work we investigate the exclusive photoproduction of J/psi and the
radially excited psi(2S) state off nucleon in proton-proton collisions. The
theoretical framework considered in the analysis is the light-cone dipole
formalism and predictions are done for proton-proton collisions at the CERN-LHC
energy of 7 TeV. The theoretical uncertainties are investigated and comparison
is done to the recent LHCb Collaboration data for the exclusive charmonium
production.


title:
Three-terminal semiconductor junction thermoelectric devices: improving
  performance

abstract:
  A three-terminal thermoelectric device based on a $p$-$i$-$n$ semiconductor
junction is proposed, where the intrinsic region is mounted onto a, typically
bosonic, thermal terminal. Remarkably, the figure of merit of the device is
governed also by the energy distribution of the {\em bosons} participating in
the transport processes, in addition to the electronic one. An enhanced figure
of merit can be obtained when the relevant distribution is narrow and the
electron-boson coupling is strong (such as for optical phonons). We study the
conditions for which the figure of merit of the three-terminal junction can be
greater than those of the usual thermoelectric devices made of the same
material. A possible setup with a high figure of merit, based on
Bi$_2$Te$_3$/Si superlattices, is proposed.


title: A Maximum Likelihood Approach to Estimating Correlation Functions

abstract:
  We define a Maximum Likelihood (ML for short) estimator for the correlation
function, {\xi}, that uses the same pair counting observables (D, R, DD, DR,
RR) as the standard Landy and Szalay (1993, LS for short) estimator. The ML
estimator outperforms the LS estimator in that it results in smaller
measurement errors at any fixed random point density. Put another way, the ML
estimator can reach the same precision as the LS estimator with a significantly
smaller random point catalog. Moreover, these gains are achieved without
significantly increasing the computational requirements for estimating {\xi}.
We quantify the relative improvement of the ML estimator over the LS estimator,
and discuss the regimes under which these improvements are most significant. We
present a short guide on how to implement the ML estimator, and emphasize that
the code alterations required to switch from a LS to a ML estimator are
minimal.


title: Note on a proposed proof of the Riemann Hypothesis by Jin Gyu Lee

abstract:
  This is a reformulation and refutation of a proposed proof of the Riemann
hypothesis published in 2013 (arXiv:1305.0323) and in 2014 (arXiv:1402.2822).
Proceeding by contradiction, the author wants to prove that if zeta(s)=0 where
1/2<Re s<1, then zeta(2s)=0, which is known to be impossible. We show that both
versions of the proof are incomplete.


title: Exotic iterated Dehn twists

abstract:
  Consider cotangent bundles of exotic spheres, with their canonical symplectic
structure. They admit automorphisms which preserve the part at infinity of one
fibre, and which are analogous to the square of a Dehn twist. Pursuing that
analogy, we show that they have infinite order up to isotopy (inside the group
of all automorphisms with the same behaviour).


title: Fractional Hardy inequalities and visibility of the boundary

abstract:
  We prove fractional order Hardy inequalities on open sets under a combined
fatness and visibility condition on the boundary. We demonstrate by
counterexamples that fatness conditions alone are not sufficient for such Hardy
inequalities to hold. In addition, we give a short exposition of various
fatness conditions related to our main result, and apply fractional Hardy
inequalities in connection to the boundedness of extension operators for
fractional Sobolev spaces.


title:
High Angular Resolution Stellar Imaging with Occultations from the
  Cassini Spacecraft I: Observational Technique

abstract:
  We present novel observations utilising the Cassini spacecraft to conduct an
observing campaign for stellar astronomy from a vantage point in the outer
solar system. By exploiting occultation events in which Mira passed behind the
Saturnian ring plane as viewed by Cassini, parametric imaging data were
recovered spanning the near-infrared. From this, spatial information at
extremely high angular resolution was recovered enabling a study of the stellar
atmospheric extension across a spectral bandpass spanning the 1 - 5 {\mu}m
spectral region in the near-infrared. The resulting measurements of the angular
diameter of Mira were found to be consistent with existing observations of its
variation in size with wavelength. The present study illustrates the validity
of the technique; more detailed exploration of the stellar physics obtained by
this novel experiment will be the subject of forthcoming papers.


title: Sharp conditional bounds for moments of the Riemann zeta function

abstract:
  We prove, assuming the Riemann Hypothesis, that \int_{T}^{2T}
|\zeta(1/2+it)|^{2k} dt \ll_{k} T log^{k^{2}} T for any fixed k \geq 0 and all
large T. This is sharp up to the value of the implicit constant.
  Our proof builds on well known work of Soundararajan, who showed, assuming
the Riemann Hypothesis, that \int_{T}^{2T} |\zeta(1/2+it)|^{2k} dt
\ll_{k,\epsilon} T log^{k^{2}+\epsilon} T for any fixed k \geq 0 and \epsilon >
0. Whereas Soundararajan bounded \log|\zeta(1/2+it)| by a single Dirichlet
polynomial, and investigated how often it attains large values, we bound
\log|\zeta(1/2+it)| by a sum of many Dirichlet polynomials and investigate the
joint behaviour of all of them. We also work directly with moments throughout,
rather than passing through estimates for large values.


title: Bohmian quantum trajectories from coherent states

abstract:
  We find that real and complex Bohmian quantum trajectories resulting from
well-localized Klauder coherent states in the quasi-Poissonian regime possess
qualitatively the same type of trajectories as those obtained from a purely
classical analysis of the corresponding Hamilton-Jacobi equation. In the
complex cases treated the quantum potential results to a constant, such that
the agreement is exact. For the real cases we provide conjectures for
analytical solutions for the trajectories as well as the corresponding quantum
potentials. The overall qualitative behaviour is governed by the Mandel
parameter determining the regime in which the wavefunctions evolve as soliton
like structures. We demonstrate these features explicitly for the harmonic
oscillator and the Poeschl-Teller potential.


title:
Scale choice & collinear contributions to Mueller-Navelet jets at LHC
  energies

abstract:
  We investigate the stability under variation of the renormalization,
factorization and energy scales entering the calculation of the cross section,
at next-to-leading order in the BFKL formalism, for the production of
Mueller-Navelet jets at the Large Hadron Collider, following the experimental
cuts on the tagged jets. To find optimal values for the scales involved in this
observable it is possible to look for regions of minimal sensitivity to their
variation. We show that the scales found with this logic are more natural, in
the sense of being more similar to the squared transverse momenta of the tagged
jets, when the BFKL kernel is improved with a resummation of collinear
contributions than when the treatment is at a purely next-to-leading order. We
also discuss the good perturbative convergence of the ratios of azimuthal angle
correlations, which are quite insensitive to collinear resummations and well
described by the original BFKL framework.


title:
Fibonacci-like unimodal inverse limit spaces and the core Ingram
  conjecture

abstract:
  We study the structure of inverse limit space of so-called Fibonacci-like
tent maps. The combinatorial constraints implied by the Fibonacci-like
assumption allow us to introduce certain chains that enable a more detailed
analysis of symmetric arcs within this space than is possible in the general
case. We show that link-symmetric arcs are always symmetric or a
well-understood concatenation of quasi-symmetric arcs. This leads to the proof
of the Ingram Conjecture for cores of Fibonacci-like unimodal inverse limits.


title: Mathematical modeling of the metastatic process

abstract:
  Mathematical modeling in cancer has been growing in popularity and impact
since its inception in 1932. The first theoretical mathematical modeling in
cancer research was focused on understanding tumor growth laws and has grown to
include the competition between healthy and normal tissue, carcinogenesis,
therapy and metastasis. It is the latter topic, metastasis, on which we will
focus this short review, specifically discussing various computational and
mathematical models of different portions of the metastatic process, including:
the emergence of the metastatic phenotype, the timing and size distribution of
metastases, the factors that influence the dormancy of micrometastases and
patterns of spread from a given primary tumor.


title: Updates on Hirzebruch's 1954 Problem List

abstract:
  We present updates to the problems on Hirzebruch's 1954 problem list
focussing on open problems, and on those where substantial progress has been
made in recent years. We discuss some purely topological problems, as well as
geometric problems about (almost) complex structures, both algebraic and
non-algebraic, about contact structures, and about (complementary pairs of)
foliations.


title: Interaction of light with gravitational waves

abstract:
  The physical properties of electromagnetic waves in the presence of a
gravitational plane wave are analyzed. Formulas for the Stokes parameters
describing the polarization of light are obtained in closed form. The
particular case of a constant amplitude gravitational wave is worked out
explicitly.


title: W-WIMP Annihilation as a Source of the Fermi Bubbles

abstract:
  The Fermi Gamma-ray Space Telescope discovered two \gamma-ray emitting
bubble-shaped structures that extend nearly symmetrically on either side of our
Galaxy and appear morphologically connected to the Galactic center. The origin
of the emission is still not entirely clear. It was recently shown that the
spectral shape of the emission from the Fermi bubbles is well described by an
approximately 50 GeV dark matter particle annihilating to b \bar b, with a
normalization corresponding to a velocity average annihilation cross section of
< \sigma_b v > ~ 8 \times 10^{-27} cm^3/s. We study the minimal hidden sector
recently introduced by Weinberg and examine to what extent its
weakly-interacting massive particles (W-WIMPs) are capable of accommodating
both the desired effective annihilation rate into quarks and the observed relic
density.


title: Absolutely \gamma-Summing Multilinear Operators

abstract:
  In this paper we introduce an abstract approach to the notion of absolutely
summing multilinear operators. We show that several previous results on
different contexts (absolutely summing, almost summing, Cohen summing) are
particular cases of our general results.


title: Restoration of Quantum State in Dephasing Channel

abstract:
  In this paper, we propose an explicit scheme to fully recover a
multiple-qubit state subject to a phase damping noise. We establish the
theoretical framework and the operational procedure to restore an unknown
initial quantum state for an N-qubit model interacting with either individual
baths or a common bath. We give an explicit construction of the random unitary
(RU) Kraus decomposition for an N-qubit model interacting with a common bath.
We also demonstrate how to use only one unitary reversal operation to restore
an arbitrary state with phase damping noise. In principle, the initial state
can always be recovered with a success probability of 1. Interestingly, we
found that non-RU decomposition can also be used to restore some particular
entangled states. This may open a new path to restore a quantum state beyond
the standard RU scheme.


title:
Estimation of Lateral Distribution Function in Extensive Air Showers by
  Using AIRES Simulation System

abstract:
  In this work the estimation of the lateral distribution function in Extensive
Air showers was performed by using a system for air shower simulations which is
called AIRES version 2.6 for different hadronic models like (QGSJET99, SIBYLL
and SIBYLL1.6). The simulation was fulfilled in the high energy range
(10^15-10^19 eV) for different primary particles like (gamma, protons and iron
nuclei) for vertical showers. This simulation can be used to reconstruct the
type and energy of the particle that generated Extensive Air showers for
charged particles that registered with different arrays.


title: Generalized P-Reducible Finsler Metrics

abstract:
  In this paper, we study a class of Finsler metrics which contains the class
of P-reducible metrics. Finsler metrics in this class are called generalized
P-reducible metrics. We consider generalized P-reducible metrics with scalar
flag curvature and find a condition under which these metrics reduce to
C-reducible metrics. This generalize Matsumotos theorem, which describes the
equivalency of C-reducibility and P-reducibility on Finsler manifolds with
scalar curvature. Then we show that generalized P-reducible metrics with
vanishing stretch curvature are C-reducible.


title:
A Topological Extension of General Relativity to Explore the Nature of
  Quantum Space-time, Dark Energy and Inflation

abstract:
  General Relativity is extended into the quantum domain. A thought experiment
is explored to derive a specific topological build-up for Planckian space-time.
The presented arguments are inspired by Feynman's path integral for
superposition and Wheeler's quantum foam of Planck mass mini black
holes/wormholes. Paths are fundamental and prime 3-manifolds like T^3, S^1xS^2
and S^3 are used to construct quantum space-time. A physical principle is
formulated that causes observed paths to multiply: It takes one to know one. So
topological fluctuations on the Planck scale take the form of multiple copies
of any homeomorphically distinct path through quantum space-time. The discrete
time equation of motion for this topological quantum gravity is derived by
counting distinct paths globally. The equation of motion is solved to derive
some properties of dark energy and inflation. The dark energy density depends
linearly on the number of macroscopic black holes in the universe and is time
dependent in a manner consistent with current astrophysical observations,
having an effective equation of state w=-1.1 for redshifts smaller than unity.
Inflation driven by mini black holes proceeds over n=55 e-foldings, without
strong inhomogeneity, a scalar-to-tensor ratio r=ln(7)/n=0.036 and a spectral
index n_s=1-r=0.964. A discrete time effect visible in the cosmic microwave
background is suggested.


title:
Symmetry Group Analysis for perfect fluid Inhomogeneous Cosmological
  Models in General Relativity

abstract:
  In this paper, we have searched the existence of the similarity solution for
plane symmetric inhomogeneous cosmological models in general relativity. The
matter source consists of perfect fluid with proportionality relation between
expansion scalar and shear scalar. The isovector fields of Einstein's field
equation for the models under consideration are derived. A new class of exact
solutions of Einstein's field equation have been obtained for inhomogeneous
space-time. The physical behaviors and geometric aspects of the derived models
have been discussed in detail.


title:
The Process of Mobile Spectrum Allocation and its impact on Electronic
  Commerce and Mobile Commerce

abstract:
  Spectrum being a very scarce natural resource of a country has to be
judicially used for the purpose of nation building and the allocation process
to telecom operators should be very transparent and ethical. There are various
ways of how spectrum can be allocated and there is no best way that can be
adopted universally. The market situation, Government policies, competition etc
determine the price of the spectrum and this is purely a regulatory or a
government decision to sell spectrum to telecom companies. The different
allocation methods, their implications with case studies across the globe is
analysed and presented in this paper. The reason why spectrum allocation should
be fair and transparent and the cost should be reasonable is analysed and
described.


title: Evolution of Giant Molecular Clouds in Nearby Galaxies

abstract:
  Studies of GMC evolution in galactic disks were limited to local,
predominantly atom-rich small galaxies in the past, but have now been expanded
to typical spiral galaxies with a rich molecular content. The evolution appears
quite different between the two environments. GMCs exist almost exclusively
along HI spiral arms and filaments in the disks of local small galaxies (LMC,
M33), suggesting that GMCs form and end their short lives there. However, in a
more molecular-rich environment (MW, M51), GMCs are present everywhere
independent of HI structures. Indeed, the molecular gas fraction remains high
and almost constant during arm passage into the next inter-arm region. The gas
remains molecular, presumably in GMCs, for a long time. A transitional case has
been found recently in the central region of the atom-rich galaxy M33 - GMCs do
not coincide with HI there. Evolution of the physical conditions of molecular
gas from spiral arms to inter-arm regions is also being revealed in
molecule-rich galaxies. An increase of the CO J=2-1 and 1-0 line ratio in
spiral arms in M51 suggests density and/or temperature increases by a factor of
2-3 in GMCs in the arms, compared to their counterparts in the inter-arm
regions. An analysis of high-resolution Milky Way survey data revealed that the
fraction of dense (or warm) clumps increases dramatically in the spiral arms.


title:
Turbovelocity Stars: Kicks Resulting From the Tidal Disruption of
  Solitary Stars

abstract:
  The centers of most known galaxies host supermassive black holes (SMBHs). In
orbit around these black holes are a centrally-concentrated distribution of
stars, both in single and in binary systems. Occasionally, these stars are
perturbed onto orbits that bring them close to the SMBH. If the star is in a
binary system, the three-body interaction with the SMBH can lead to large
changes in orbital energy, depositing one of the two stars on a tightly-bound
orbit, and its companion into a hyperbolic orbit that may escape the galaxy. In
this Letter, we show that the disruption of solitary stars can also lead to
large positive increases in orbital energy. The kick velocity depends on the
amount of mass the star loses at pericenter, but not on the ratio of black hole
to stellar mass, and are at most the star's own escape velocity. We find that
these kicks are usually too small to result in the ejection of stars from the
Milky Way, but can eject the stars from the black hole's sphere of influence,
reducing their probability of being disrupted again. We estimate that ~10^5
stars, ~1% of all stars within 10 pc of the galactic center, are likely to have
had mass removed by the central black hole through tidal interaction, and
speculate that these "turbovelocity" stars will at first be redder, but
eventually bluer, and always brighter than their unharrassed peers.


title: Higgs Couplings after Moriond

abstract:
  Performing fits to all publicly available data, we analyze the extent to
which the latest results from the LHC and Tevatron (including new results
presented at the Rencontres de Moriond) constrain the couplings of the Higgs
boson-like state at ~ 125 GeV, as well as possible decays into invisible
particles.


title: Relativity violations and beta decay

abstract:
  In some quantum theories of gravity, deviations from the laws of relativity
could be comparatively large while escaping detection to date. In the neutrino
sector, precision experiments with beta decay yield new and improved
constraints on these countershaded relativity violations. Existing data are
used to extract bounds of $3 \times 10^{-8}$ GeV on the magnitudes of two of
the four possible coefficients, and estimates are provided of future attainable
sensitivities in a variety of experiments.


title:
WISE TF: A Mid-infrared, 3.4-micron Extension of the Tully-Fisher
  Relation Using WISE Photometry

abstract:
  We present a mid-infrared Tully-Fisher (TF) relation using photometry from
the 3.4-micron W1 band of the Wide-field Infrared Survey Explorer (WISE)
satellite. The WISE TF relation is formed from 568 galaxies taken from the
all-sky 2MASS Tully-Fisher (2MTF) galaxy catalog, spanning a range of
environments including field, group, and cluster galaxies. This constitutes the
largest mid-infrared TF relation constructed, to date. After applying a number
of corrections to galaxy magnitudes and line widths, we measure a master TF
relation given by M_corr = -22.24 - 10.05[log(W_corr) - 2.5], with an average
dispersion of sigma_WISE = 0.686 magnitudes. There is some tension between WISE
TF and a preliminary 3.6-micron relation, which has a shallower slope and
almost no intrinsic dispersion. However, our results agree well with a more
recent relation constructed from a large sample of cluster galaxies. We
additionally compare WISE TF to the near-infrared 2MTF template relations,
finding a good agreement between the TF parameters and total dispersions of
WISE TF and the 2MTF K-band template. This fact, coupled with typical galaxy
colors of (K - W1) ~ 0, suggests that these two bands are tracing similar
stellar populations, including the older, centrally-located stars in the
galactic bulge which can (for galaxies with a prominent bulge) dominate the
light profile.


title: Higgs bundles and (A,B,A)-branes

abstract:
  Through the action of anti-holomorphic involutions on a compact Riemann
surface, we construct families of (A,B,A)-branes in the moduli spaces of
G_c-Higgs bundles on the Riemann surface. We study the geometry of these
(A,B,A)-branes in terms of spectral data and show they have the structure of
real integrable systems.


title:
The Anticorrelated Nature of the Primary and Secondary Eclipse Timing
  Variations for the Kepler Contact Binaries

abstract:
  We report on a study of eclipse timing variations in contact binary systems,
using long-cadence lightcurves in the Kepler archive. As a first step,
'observed minus calculated' (O-C) curves were produced for both the primary and
secondary eclipses of some 2000 Kepler binaries. We find ~390 short-period
binaries with O-C curves that exhibit (i) random-walk like variations or
quasi-periodicities, with typical amplitudes of +/- 200-300 seconds, and (ii)
anticorrelations between the primary and secondary eclipse timing variations.
We present a detailed analysis and results for 32 of these binaries with
orbital periods in the range of 0.35 +/- 0.05 days. The anticorrelations
observed in their O-C curves cannot be explained by a model involving mass
transfer, which among other things requires implausibly high rates of ~0.01
M_sun per year. We show that the anticorrelated behavior, the amplitude of the
O-C delays, and the overall random-walk like behavior can be explained by the
presence of a starspot that is continuously visible around the orbit and slowly
changes its longitude on timescales of weeks to months. The quasi-periods of
~50-200 days observed in the O-C curves suggest values for k, the coefficient
of the latitude dependence of the stellar differential rotation, of
~0.003-0.013.


title: Time Fluctuations in Isolated Quantum Systems of Interacting Particles

abstract:
  Numerically, we study the time fluctuations of few-body observables after
relaxation in isolated dynamical quantum systems of interacting particles. Our
results suggest that they decay exponentially with system size in both regimes,
integrable and chaotic. The integrable systems considered are solvable with the
Bethe ansatz and have a highly nondegenerate spectrum. This is in contrast with
integrable Hamiltonians mappable to noninteracting ones. We show that the
coefficient of the exponential decay depends on the level of delocalization of
the initial state with respect to the energy shell.


title:
Third-Epoch Magellanic Cloud Proper Motions II: The Large Magellanic
  Cloud Rotation Field in Three Dimensions

abstract:
  We present the first detailed assessment of the large-scale rotation of any
galaxy based on full three-dimensional velocity measurements. We do this for
the LMC by combining our HST average proper motion (PM) measurements for stars
in 22 fields, with existing line-of-sight (LOS) velocity measurements for 6790
individual stars. We interpret these data with a model of circular rotation in
a flat disk. The PM and LOS data paint a consistent picture of the LMC rotation
and their combination yields several new insights. The PM data imply a stellar
dynamical center that coincides with the HI dynamical center, and a rotation
curve amplitude consistent with that inferred from LOS velocity studies. The
implied disk viewing angles agree with the range of values found in the
literature, but continue to indicate variations with stellar population and/or
radius. Young (RSG) stars rotate faster than old (RGB/AGB) stars due to
asymmetric drift. Outside the central region, the circular velocity is
approximately flat at Vcirc = 91.7 +/- 18.8 km/s. This is consistent with the
baryonic Tully-Fisher relation, and implies an enclosed mass M(8.7 kpc) = (1.7
+/- 0.7) x 10^10 solar masses. The virial mass is larger and depends on the
full extent of the dark halo. The tidal radius is 22.3 +/- 5.2 kpc (24.0 +/-
5.6 degrees). Combination of the PM and LOS data yields kinematic distance
estimates for the LMC, but these are not yet competitive with other methods.


title:
One-point remapping of Lagrangian perturbation theory in the mildly
  non-linear regime of cosmic structure formation

abstract:
  On the smallest scales, three-dimensional large-scale structure surveys
contain a wealth of cosmological information which cannot be trivially
extracted due to the non-linear dynamical evolution of the density field.
Lagrangian perturbation theory (LPT) is widely applied to the generation of
mock halo catalogs and data analysis. In this work, we compare topological
features of the cosmic web such as voids, sheets, filaments and clusters, in
the density fields predicted by LPT and full numerical simulation of
gravitational large-scale structure formation. We propose a method designed to
improve the correspondence between these density fields, in the mildly
non-linear regime. We develop a computationally fast and flexible tool for a
variety of cosmological applications. Our method is based on a remapping of the
approximately-evolved density field, using information extracted from N-body
simulations. The remapping procedure consists of replacing the one-point
distribution of the density contrast by one which better accounts for the full
gravitational dynamics. As a result, we obtain a physically more pertinent
density field on a point-by-point basis, while also improving higher-order
statistics predicted by LPT. We quantify the approximation error in the power
spectrum and in the bispectrum as a function of scale and redshift. Our
remapping procedure improves one-, two- and three-point statistics at scales
down to 8 Mpc/h.


title:
The imperfect Bose gas in d dimensions: critical behavior and Casimir
  forces

abstract:
  We consider the d-dimensional imperfect (mean-field) Bose gas confined in a
slit-like geometry and subject to periodic boundary conditions. Within an exact
analytical treatment we first extract the bulk critical properties of the
system at Bose-Einstein condensation and identify the bulk universality class
to be the one of the classical d-dimensional spherical model. Subsequently we
consider finite slit width D and analyze the excess surface free energy and the
related Casimir force acting between the slit boundaries. Above the bulk
condensation temperature (T>T_c) the Casimir force decays exponentially as a
function of D with the bulk correlation length determining the relevant length
scale. For T=T_c and for T<T_c its decay is algebraic. The magnitude of the
Casimir forces at T_c and for T<T_c is governed by the universal Casimir
amplitudes. We extract the relevant values for different d and compute the
scaling functions describing the crossover between the critical and
low-temperature asymptotics of the Casimir force. The scaling function is
monotonous at any d\in (2,4) and becomes constant for d>4 and T\leq T_c.


title:
Activity in Galactic Nuclei of Compact Group Galaxies in the Local
  Universe

abstract:
  We study the nuclear activity of galaxies in local compact groups. We use a
spectroscopic sample of 238 galaxies in 58 compact groups from the Sloan
Digital Sky Survey data release 7 to estimate the fraction of AGN-host galaxies
in compact groups, and to compare it with those in cluster and field regions.
We use emission-line ratio diagrams to identify AGN-host galaxies, and find
that the AGN fraction of compact group galaxies is 17-42% depending on the AGN
classification method. The AGN fraction in compact groups is not the highest
among the galaxy environments. This trend remains even if we use several
subsamples segregated by galaxy morphology and optical luminosity. The AGN
fraction for early-type galaxies decreases with increasing galaxy number
density, but the fraction for late-type galaxies changes little. We find no
mid-infrared detected AGN-host galaxies in our sample of compact groups using
Wide-field Infrared Survey Explorer data. These results suggest that the
nuclear activity of compact group galaxies (mostly early types) is not strong
because of lack of gas supply even though they may experience frequent
galaxy-galaxy interactions and mergers that could trigger nuclear activity.


title:
Large-time behavior of a two-scale semilinear reaction-diffusion system
  for concrete sulfatation

abstract:
  We study the large-time behavior of (weak) solutions to a two-scale
reaction-diffusion system coupled with a nonlinear ordinary differential
equations modeling the partly dissipative corrosion of concrete (/cement)-based
materials with sulfates. We prove that as $t\to\infty$ the solution to the
original two-scale system converges to the corresponding two-scale stationary
system. To obtain the main result we make use essentially of the theory of
evolution equations governed by subdifferential operators of time-dependent
convex functions developed combined with a series of two-scale energy-like
time-independent estimates.


title: Quantum Fluctuations and Long-Range Order in Molecular Magnets

abstract:
  We review our studies of the effect of transverse fields on the
susceptibility and magnetization of single crystals of the prototype single
molecule magnet (SMM), Mn$_{12}$-acetate, and of a new high-symmetry variant,
Mn$_{12}$-acetate-MeOH. SMM single crystals can exhibit long range
ferromagnetic order associated with intermolecular dipole interactions.
Transverse fields increase quantum spin fluctuation and quantum tunneling of
the magnetization suppressing long range order. However, we have found that
suppression of the Curie temperature by a transverse field in Mn$_{12}$-acetate
is far more rapid than predicted by the Transverse-Field Ising Ferromagnetic
Model (TFIFM). It appears that solvent disorder in Mn$_{12}$-acetate that
results in an intrinsic distribution of small discrete tilts of the molecular
magnetic easy axis from the global easy axis of the crystal ($\approx \pm
1^\circ$) gives rise to a distribution of random-fields that further suppresses
long-range order. Semiquantitative agreement with the predictions of a
Random-Field Ising Ferromagnet Model is found. Subsequent susceptibility
studies we have conducted of the high symmetry Mn$_{12}$ variant,
Mn$_{12}$-acetate-MeOH, with the same spin structure and similar lattice
constants but without the same solvent disorder as Mn$_{12}$-acetate, agrees
with the TFIFM. An important implication of our studies is that long-range
order in these two chemically very similar SMMs are described by distinct
physical models.


title:
On Wald entropy of black holes: logarithmic corrections and trace
  anomaly

abstract:
  Quantum effects due to conformal matter in a black hole background result in
universal logarithmic corrections to black-hole entropy. The universality
resides in the connection of the log term coefficient with those of type-A and
type-B Weyl anomalies, regularization-scheme independent quantities. We
presently study the case of extremal black holes within Wald's Noether charge
formalism. In the conformal class of flat metrics, we are again able to unveil
the log term in the entropy from the horizon value of the solution to the
Q-curvature uniformization problem. Beyond conformally flat backgrounds, type-B
Weyl anomaly becomes an obstruction to considering flat space as the fiducial
metric and the search for a metric of constant Q-curvature remains open.
Notwithstanding, by a uniform scaling argument we show that the results based
on heat kernel and euclidean computations (namely entropy function and conical
defect) can also be derived as Wald entropy, that is, as Noether charge of the
integrated anomaly or conformal index. We finally comment on the relation with
entanglement entropy.


title: Interacting epidemics and coinfection on contact networks

abstract:
  The spread of certain diseases can be promoted, in some cases substantially,
by prior infection with another disease. One example is that of HIV, whose
immunosuppressant effects significantly increase the chances of infection with
other pathogens. Such coinfection processes, when combined with nontrivial
structure in the contact networks over which diseases spread, can lead to
complex patterns of epidemiological behavior. Here we consider a mathematical
model of two diseases spreading through a single population, where infection
with one disease is dependent on prior infection with the other. We solve
exactly for the sizes of the outbreaks of both diseases in the limit of large
population size, along with the complete phase diagram of the system. Among
other things, we use our model to demonstrate how diseases can be controlled
not only by reducing the rate of their spread, but also by reducing the spread
of other infections upon which they depend.


title: Graphene physics and insulator-metal transition in compressed hydrogen

abstract:
  Compressed hydrogen passes through a series of layered structures in which
the layers can be viewed as distorted graphene sheets. The electronic
structures of these layered structures can be understood by studying simple
model systems- an ideal single hydrogen graphene sheet and three-dimensional
model lattices consisting of such sheets. The energetically stable structures
result from structural distortions of model graphene-based systems due to
electronic instabilities towards Peierls or other distortions associated with
the opening of a band gap. Two factors play crucial roles in the metallization
of compressed hydrogen: (i) crossing of conduction and valence bands in
hexagonal or graphene-like layers due to topology and (ii) formation of bonding
states with $2p_z$ $\pi$ character.


title: A parallel butterfly algorithm

abstract:
  The butterfly algorithm is a fast algorithm which approximately evaluates a
discrete analogue of the integral transform \int K(x,y) g(y) dy at large
numbers of target points when the kernel, K(x,y), is approximately low-rank
when restricted to subdomains satisfying a certain simple geometric condition.
In d dimensions with O(N^d) quasi-uniformly distributed source and target
points, when each appropriate submatrix of K is approximately rank-r, the
running time of the algorithm is at most O(r^2 N^d log N). A parallelization of
the butterfly algorithm is introduced which, assuming a message latency of
\alpha and per-process inverse bandwidth of \beta, executes in at most O(r^2
N^d/p log N + \beta r N^d/p + \alpha)log p) time using p processes. This
parallel algorithm was then instantiated in the form of the open-source
DistButterfly library for the special case where K(x,y)=exp(i \Phi(x,y)), where
\Phi(x,y) is a black-box, sufficiently smooth, real-valued phase function.
Experiments on Blue Gene/Q demonstrate impressive strong-scaling results for
important classes of phase functions. Using quasi-uniform sources, hyperbolic
Radon transforms and an analogue of a 3D generalized Radon transform were
respectively observed to strong-scale from 1-node/16-cores up to
1024-nodes/16,384-cores with greater than 90% and 82% efficiency, respectively.


title:
Hardware Impairments in Large-scale MISO Systems: Energy Efficiency,
  Estimation, and Capacity Limits

abstract:
  The use of large-scale antenna arrays has the potential to bring substantial
improvements in energy efficiency and/or spectral efficiency to future wireless
systems, due to the greatly improved spatial beamforming resolution. Recent
asymptotic results show that by increasing the number of antennas one can
achieve a large array gain and at the same time naturally decorrelate the user
channels; thus, the available energy can be focused very accurately at the
intended destinations without causing much inter-user interference. Since these
results rely on asymptotics, it is important to investigate whether the
conventional system models are still reasonable in the asymptotic regimes. This
paper analyzes the fundamental limits of large-scale multiple-input
single-output (MISO) communication systems using a generalized system model
that accounts for transceiver hardware impairments. As opposed to the case of
ideal hardware, we show that these practical impairments create finite ceilings
on the estimation accuracy and capacity of large-scale MISO systems.
Surprisingly, the performance is only limited by the hardware at the
single-antenna user terminal, while the impact of impairments at the
large-scale array vanishes asymptotically. Furthermore, we show that an
arbitrarily high energy efficiency can be achieved by reducing the power while
increasing the number of antennas.


title:
Quasi-exact solution to the Dirac equation for the hyperbolic secant
  potential

abstract:
  We analyze bound modes of two-dimensional massless Dirac fermions confined
within a hyperbolic secant potential, which provides a good fit for potential
profiles of existing top-gated graphene structures. We show that bound states
of both positive and negative energies exist in the energy spectrum and that
there is a threshold value of the characteristic potential strength for which
the first mode appears. Analytical solutions are presented in several limited
cases and supercriticality is discussed.


title: A non-concentration estimate for partially rectangular billiards

abstract:
  We consider quasimodes on planar domains with a partially rectangular
boundary. We prove that for any $\epsilon_0>0$, an $\O(\lambda^{-\epsilon_0})$
quasimode must have $L^2$ mass in the "wings" bounded below by
$\lambda^{-2-\delta}$ for any $\delta>0$. The proof uses the author's recent
work on 0-Gevrey smooth domains to approximate quasimodes on $C^{1,1}$ domains.
There is an improvement for $C^{2,\alpha}$ domains.


title: $\gamma$ gravity: Steepness control

abstract:
  We investigate a simple generalization of the metric exponential $f(R)$
gravity theory that is cosmologically viable and compatible with solar system
tests of gravity. We show that, as compared to other viable $f(R)$ theories,
its steep dependence on the Ricci scalar $R$ facilitates agreement with
structure constraints, opening the possibility of $f(R)$ models with
equation-of-state parameter that could be differentiated from a cosmological
constant ($w_{de}=-1$) with future surveys at both background and perturbative
levels.


title: Formation of Massive Molecular Cloud Cores by Cloud-cloud Collision

abstract:
  Recent observations of molecular clouds around rich massive star clusters
including NGC3603, Westerlund 2, and M20 revealed that the formation of massive
stars could be triggered by a cloud-cloud collision. By using
three-dimensional, isothermal, magnetohydrodynamics simulations with the effect
of self-gravity, we demonstrate that massive, gravitationally unstable,
molecular cloud cores are formed behind the strong shock waves induced by the
cloud-cloud collision. We find that the massive molecular cloud cores have
large effective Jeans mass owing to the enhancement of the magnetic field
strength by shock compression and turbulence in the compressed layer. Our
results predict that massive molecular cloud cores formed by the cloud-cloud
collision are filamentary and threaded by magnetic fields perpendicular to the
filament.


title: Origin of Radially Aligned Magnetic Fields in Young Supernova Remnants

abstract:
  It has been suggested by radio observations of polarized synchrotron
emissions that downstream magnetic field in some young supernova remnants are
oriented radially. We study magnetic field distribution of turbulent supernova
remnant driven by the Richtmyer-Meshkov instability -- in other words, the
effect of rippled shock -- by using three-dimensional magnetohydrodynamics
simulations. We find that the induced turbulence has radially biased
anisotropic velocity dispersion that leads to a selective amplification of the
radial component of the magnetic field. The Richtmyer-Meshkov instability is
induced by the interaction between the shock and upstream density fluctuations.
Future high-resolution polarization observations can distinguish the following
candidates responsible for the upstream density fluctuations: (i) inhomogeneity
caused by the cascade of large-scale turbulence in the ISM so-called the
big-power-law-in-the-sky, (ii) structures generated by the Drury instability in
the cosmic-ray modified shock, and (iii) fluctuations induced by the non-linear
feedback of the cosmic-ray streaming instability.


title:
Beam studies of novel THGEM-based potential sampling elements for
  Digital Hadron Calorimetry

abstract:
  Beam studies of thin single- and double-stage THGEM-based detectors are
presented. Several 10 x 10 cm^2 configurations with a total thickness of 5-6 mm
(excluding readout electronics), with 1 x 1 cm^2 pads inductively coupled
through a resistive layer to APV-SRS readout electronics, were investigated
with muons and pions. Detection efficiencies in the 98% range were recorded
with an average pad-multiplicity of ~1.1. The resistive anode resulted in
efficient discharge damping, with few-volt potential drops; discharge
probabilities were ~10^{-7} for muons and 10^{-6} for pions in the double-stage
configuration, at rates of a few kHz/cm^2. These results, together with the
robustness of THGEM electrodes against spark damage and their suitability for
economic production over large areas make THGEM-based detectors highly
competitive compared to the other technologies considered for the SiD-DHCAL.


title: Feedback control of optical beam spatial profiles using thermal lensing

abstract:
  A method for active control of the spatial profile of a laser beam using
adaptive thermal lensing is described. A segmented electrical heater was used
to generate thermal gradients across a transmissive optical element, resulting
in a controllable thermal lens. The segmented heater also allows the generation
of cylindrical lenses, and provides the capability to steer the beam in both
horizontal and vertical planes. Using this device as an actuator, a feedback
control loop was developed to stabilize the beam size and position.


title: Superfuidity in neutron-star matter

abstract:
  Correlated basis function perturbation theory and the formalism of cluster
expansions have been recently employed to obtain an effective interaction from
a state-of-the-art nuclear Hamiltonian. We report the results of a study of the
superfluid gap in pure neutron matter, associated with formation of Cooper
pairs in the $^1S_0$ sector. The calculations have been carried out using an
improved version of the CBF effective interaction, in which three-nucleon
forces are taken into account using a realistic microscopic model. Our results
show that the superfluid transition occurs at densities corresponding to the
neutron star inner crust, and that inclusion of three-nucleon interactions
leads to a sizable reduction of the energy gap at the Fermi surface.


title:
The Burst Cluster: Dark Matter in a Cluster Merger Associated with the
  Short Gamma Ray Burst, GRB 050509B

abstract:
  We have identified a merging galaxy cluster with evidence of two distinct
sub-clusters. The X-ray and optical data suggest that the subclusters are
moving away from each other after closest approach. This cluster merger was
discovered from observations of the well localized short-duration gamma-ray
burst (GRB), GRB 050509B. The Swift/Burst Alert Telescope (BAT) source position
is coincident with a cluster of galaxies ZwCl 1234.0+02916. The subsequent
Swift/X-Ray Telescope (XRT) localization of the X-ray afterglow found the GRB
coincident with 2MASX J12361286+2858580, a giant red elliptical galaxy in the
cluster. Deep multi-epoch optical images were obtained to constrain the
evolution of the GRB afterglow, including a 27480s exposure in the F814W band
with Hubble Space Telescope Advanced Camera for Surveys (ACS), among the
deepest imaging ever obtained towards a known galaxy cluster in a single
passband. We perform a weak gravitational lensing analysis, including mapping
the total mass distribution of the merger system. Combined with Chandra X-ray
Observatory and Swift/XRT observations, we investigate the dynamical state of
the merger to probe the nature of the dark matter component. Our weak
gravitational lensing measurements reveal a separation of the X-ray centroid of
the western subcluster from the center of the mass and galaxy light
distributions, similar to that of the famous "Bullet cluster". We conclude that
the "Burst cluster" is another candidate merger system for determining the
nature of dark matter and for studying the environment of short GRBs. We
discuss connections between the cluster dynamical state and/or matter
composition and compact object mergers, the leading model for the origin of
short GRBs. Finally, we present results from a weak lensing survey based on
archival Very Large Telescope (VLT) images in the areas of 5 other short GRBs.


title: A combinatorial non-positive curvature I: weak systolicity

abstract:
  We introduce the notion of weakly systolic complexes and groups, and initiate
regular studies of them. Those are simplicial complexes with
nonpositive-curvature-like properties and groups acting on them geometrically.
We characterize weakly systolic complexes as simply connected simplicial
complexes satisfying some local combinatorial conditions. We provide several
classes of examples --- in particular systolic groups and CAT(-1) cubical
groups are weakly systolic. We present applications of the theory, concerning
Gromov hyperbolic groups, Coxeter groups and systolic groups.


title:
The complement of a point subset in a projective space and a Grassmann
  space

abstract:
  In a projective space we fix some set of points, a horizon, and investigate
the complement of that horizon. We prove, under some assumptions on the size of
lines, that the ambient projective space, together with its horizon, both can
be recovered in that complement. Then we apply this result to show something
similar for Grassmann spaces.


title:
The age structure of stellar populations in the solar vicinity. Clues of
  a two-phase formation history of the Milky Way disk

abstract:
  We analyze high quality abundances data of solar neighborhood stars and show
that there are two distinct regimes of [alpha/Fe] versus age which we identify
as the epochs of the thick and thin disk formation. A tight correlation between
metallicity and [alpha/Fe] versus age is clearly identifiable on thick disk
stars, implying that this population formed from a well mixed ISM, over a time
scale of 4-5 Gyr. Thick disk stars vertical velocity dispersion correlate with
age, with the youngest objects having as small scale heights as those of thin
disk stars. A natural consequence of these two results is that a vertical
metallicity gradient is expected in this population. We suggest that the thick
disk set the initial conditions for the formation of the inner thin disk. This
provides also an explanation of the apparent coincidence between the step in
metallicity at 7-10 kpc in the thin disk and the confinment of the thick disk
at about R<10 kpc. We suggest that the outer thin disk developped outside the
influence of the thick disk, but also that the high alpha-enrichment of the
outer regions may originate from a primordial pollution by the gas expelled
from the thick disk. Local metal-poor thin disk stars, whose properties are
best explained by an origin in the outer disk, are shown to be as old as the
youngest thick disk (9-10 Gyr), implying that the outer thin disk started to
form while the thick disk formation was still on-going in the inner Galaxy. We
point out that, given the tight age-abundance relations in the thick disk, an
inside-out process would give rise to a radial gradient in abundances in this
population which is not observed. Finally, we argue that the data discussed
here leave little room for radial migration, either to have contaminated the
solar vicinity, or, to have redistributed stars in significant proportion
across the solar annulus.


title:
Scalar Field Perturbations with Arbitrary Potentials in Quantum
  Backgrounds

abstract:
  In this paper it is shown how to obtain, without ever using the background
classical equations of motion, a simple second order Hamiltonian involving the
Mukhanov-Sasaki variable describing quantum linear scalar perturbations for the
case of scalar fields with arbitrary potentials and arbitrary spacelike
hyper-surfaces. It is a generalization of previous works, where the scalar
field potential was absent and the spacelike hypersurfaces were flat. This was
possible due to the implementation of a new method, together with the
Faddeev-Jackiw procedure for the constraint reduction. The resulting
Hamiltonian can then be used to study the evolution of quantum cosmological
perturbations in quantum backgrounds.


title: Emergent Horava gravity in graphene

abstract:
  First of all, we reconsider the tight - binding model of monolayer graphene,
in which the variations of the hopping parameters are allowed. We demonstrate
that the emergent 2D Weitzenbock geometry as well as the emergent U(1) gauge
field appear. The emergent gauge field is equal to the linear combination of
the components of the zweibein. Therefore, we actually deal with the gauge
fixed version of the emergent 2+1 D teleparallel gravity. In particular, we
work out the case, when the variations of the hopping parameters are due to the
elastic deformations, and relate the elastic deformations with the emergent
zweibein. Next, we investigate the tight - binding model with the varying
intralayer hopping parameters for the multilayer graphene with the ABC
stacking. In this case the emergent 2D Weitzenbock geometry and the emergent
U(1) gauge field appear as well, the emergent low energy effective field theory
has the anisotropic scaling.


title: Intrinsic lifetime of Dirac plasmons in graphene

abstract:
  Dirac plasmons in a doped graphene sheet have recently been shown to enable
confinement of light to ultrasmall volumes. In this work we calculate the
intrinsic lifetime of a Dirac plasmon in a doped graphene sheet by analyzing
the role of electron-electron interactions beyond the random phase
approximation. The damping mechanism at work is intrinsic since it operates
also in disorder-free samples and in the absence of lattice vibrations. We
demonstrate that graphene's sublattice-pseudospin degree of freedom suppresses
intrinsic plasmon losses with respect to those that occur in ordinary
two-dimensional electron liquids. We relate our findings to a microscopic
calculation of the homogeneous dynamical conductivity at energies below the
single-particle absorption threshold.


title: On the intersection forms of spin four-manifolds with boundary

abstract:
  We prove Furuta-type bounds for the intersection forms of spin cobordisms
between homology 3-spheres. The bounds are in terms of a new numerical
invariant of homology spheres, obtained from Pin(2)-equivariant Seiberg-Witten
Floer K-theory. In the process we introduce the notion of a Floer K_G-split
homology sphere; this concept may be useful in an approach to the 11/8
conjecture.


title:
Canonical tree-decompositions of finite graphs I. Existence and
  algorithms

abstract:
  We construct tree-decompositions of graphs that distinguish all their
k-blocks and tangles of order k, for any fixed integer k. We describe a family
of algorithms to construct such decompositions, seeking to maximize their
diversity subject to the requirement that they commute with graph isomorphisms.
In particular, all the decompositions constructed are invariant under the
automorphisms of the graph.


title: Parsimonious mixtures of multivariate contaminated normal distributions

abstract:
  A mixture of multivariate contaminated normal distributions is developed for
model-based clustering. In addition to the parameters of the classical normal
mixture, our contaminated mixture has, for each cluster, a parameter
controlling the proportion of mild outliers and one specifying the degree of
contamination. Crucially, these parameters do not have to be specified a
priori, adding a flexibility to our approach. Parsimony is introduced via
eigen-decomposition of the component covariance matrices, and sufficient
conditions for the identifiability of all the members of the resulting family
are provided. An expectation-conditional maximization algorithm is outlined for
parameter estimation and various implementation issues are discussed. Using a
large scale simulation study, the behaviour of the proposed approach is
investigated and comparison with well-established finite mixtures is provided.
The performance of this novel family of models is also illustrated on
artificial and real data.


title:
How many quantum phase transitions exist inside the superconducting dome
  of the iron pnictides?

abstract:
  Recent experiments on two iron-pnictide families suggest the existence of a
single quantum phase transition (QPT) inside the superconducting dome despite
the fact that two separate transition lines - magnetic and nematic - cross the
superconducting dome at $T_{c}$. Here we argue that these two observations are
actually consistent. We show, using a microscopic model, that each order
coexists with superconductivity for a wide range of parameters, and both
transition lines continue into the superconducting dome below $T_{c}$. However,
at some $T_{\mathrm{merge}}<T_{c}$, the two transitions merge and continue down
to T=0 as a single simultaneous first-order nematic/magnetic transition. We
show that superconductivity has a profound effect on the character of this
first-order transition, rendering it weakly first-order and allowing strong
fluctuations to exist near the QPT.


title: Not all entangled states violate Leggett's crypto-nonlocality

abstract:
  This note is a reply to M. Navascu\'es' claim that "all entangled states
violate Leggett's crypto-nonlocality" [arXiv:1303.5124v2]. I argue that such a
conclusion can only be reached if one introduces additional assumptions that
further restrict Leggett's notion of "crypto-nonlocality". If a contrario one
sticks only to Leggett's original axioms, there exist entangled states whose
correlations are always compatible with Leggett's crypto-nonlocality---which is
thus a genuinely different concept from quantum separability. I clarify in this
note the relation between these two notions, together also with Bell's
assumption of local causality.


title: Exploring Quantum Control Landscape Structure

abstract:
  A common goal of quantum control is to maximize a physical observable through
the application of a tailored field. The observable value as a function of the
field constitutes a quantum control landscape. Previous works have shown, under
specified conditions, that the quantum control landscape should be free of
suboptimal critical points. This favorable landscape topology is one factor
contributing to the efficiency of climbing the landscape. An additional,
complementary factor is the landscape \textit{structure}, which constitutes all
non-topological features. If the landscape's structure is too complex, then
climbs may be forced to take inefficient convoluted routes to finding optimal
controls. This paper provides a foundation for understanding control landscape
structure by examining the linearity of gradient-based optimization
trajectories through the space of control fields. For this assessment, a metric
$R\geq 1$ is defined as the ratio of the path length of the optimization
trajectory to the Euclidean distance between the initial control field and the
resultant optimal control field that takes an observable from the bottom to the
top of the landscape. Computational analyses for simple model quantum systems
are performed to ascertain the relative abundance of nearly straight control
trajectories encountered when optimizing a state-to-state transition
probability. The collected results indicate that quantum control landscapes
have very simple structural features. The favorable topology and the
complementary simple structure of the control landscape provide a basis for
understanding the generally observed ease of optimizing a state-to-state
transition probability.


title: Decomposition of fluctuating initial conditions and flow harmonics

abstract:
  Collective flow observed in heavy ion collisions is largely attributed to
initial geometrical fluctuations, and it is the hydrodynamic evolution of the
system that transforms those initial spatial irregularities into final state
momentum anisotropies. Cumulant analysis provides a mathematical tool to
decompose those initial fluctuations in terms of radial and azimuthal
components. It is usually thought that a specified order of azimuthal cumulant,
for the most part, linearly produces flow harmonic of the same order. In this
work, we carry out a systematic study on the connection between cumulants and
flow harmonics using a hydrodynamic code called NeXSPheRIO. We conduct three
types of calculations, by explicitly decomposing the initial conditions into
components corresponding to a given eccentricity and studying the out-coming
flow through hydrodynamic evolution. It is found that for initial conditions
deviating significantly from Gaussian, such as those from NeXuS, the linearity
between eccentricities and flow harmonics partially breaks down. Combining with
the effect of coupling between cumulants of different orders, it causes the
production of extra flow harmonics of higher orders. We argue that these
results can be seen as a natural consequence of the non-linear nature of
hydrodynamics, and they can be understood intuitively in terms of the
peripheral-tube model.


title: The 'Higgs' amplitude mode in weak ferromagnetic metals

abstract:
  Using Ferromagnetic Fermi liquid theory, Bedell and Blagoev derived the
collective low-energy excitations of a weak ferromagnet. They obtained the
well-known magnon (Nambu-Goldstone) mode and found a new gapped mode that was
never studied in weak ferromagnetic metals. In this article we have identified
this mode as the Higgs boson (amplitude mode) of a ferromagnetic metal. This is
identified as the Higgs since it can be show that it corresponds to a
fluctuation of the amplitude of the order parameter. We use this model to
describe the itinerant-electron ferromagnetic material MnSi. By fitting the
model with the existing experimental results, we calculate the dynamical
structure function and see well-defined peaks contributed from the magnon and
the Higgs. Our estimates of the relative intensity of the Higgs amplitude mode
suggest that it can be seen in neutron scattering experiments on MnSi.


title: Algorithms for Self-Healing Networks

abstract:
  Many modern networks are \emph{reconfigurable}, in the sense that the
topology of the network can be changed by the nodes in the network. For
example, peer-to-peer, wireless and ad-hoc networks are reconfigurable. More
generally, many social networks, such as a company's organizational chart;
infrastructure networks, such as an airline's transportation network; and
biological networks, such as the human brain, are also reconfigurable. Modern
reconfigurable networks have a complexity unprecedented in the history of
engineering, resembling more a dynamic and evolving living animal rather than a
structure of steel designed from a blueprint. Unfortunately, our mathematical
and algorithmic tools have not yet developed enough to handle this complexity
and fully exploit the flexibility of these networks.
  We believe that it is no longer possible to build networks that are scalable
and never have node failures. Instead, these networks should be able to admit
small, and maybe, periodic failures and still recover like skin heals from a
cut. This process, where the network can recover itself by maintaining key
invariants in response to attack by a powerful adversary is what we call
\emph{self-healing}.
  Here, we present several fast and provably good distributed algorithms for
self-healing in reconfigurable dynamic networks. Each of these algorithms have
different properties, a different set of gaurantees and limitations. We also
discuss future directions and theoretical questions we would like to answer.
%in the final dissertation that this document is proposed to lead to.


title:
Kinetic Decoupling and Small-Scale Structure in Effective Theories of
  Dark Matter

abstract:
  The size of the smallest dark matter collapsed structures, or protohalos, is
set by the temperature at which dark matter particles fall out of kinetic
equilibrium. The process of kinetic decoupling involves elastic scattering of
dark matter off of Standard Model particles in the early universe, and the
relevant cross section is thus closely related to the cross section for dark
matter scattering off of nuclei (direct detection) but also, via crossing
symmetries, for dark matter pair production at colliders and for pair
annihilation. In this study, we employ an effective field theoretic approach to
calculate constraints on the kinetic decoupling temperature, and thus on the
size of the smallest protohalos, from a variety of direct, indirect and
collider probes of particle dark matter.