title: SPICA as a probe of cosmic reionization

abstract:
  Current data indicate that the reionization of the Universe was complete by
redshift z~6-7, and while the sources responsible for this process have yet to
be identified, star-forming galaxies are often considered the most likely
candidates. However, the contribution from z>6 galaxies to cosmic reionization
critically depends on the fraction of ionizing (Lyman continuum, LyC) photons
escaping from these objects and into the intergalactic medium. At z<4, the
escaping LyC flux can be measured directly, but the opacity of the neutral
intergalactic medium precludes such measurements at higher redshifts. In a
recent paper, we argue that since the LyC escape fraction regulates the
contribution of nebular emission to the rest-frame optical/UV spectra of
galaxies, the James Webb Space Telescope should be able to indirectly assess
the LyC escape fraction for galaxies at z~6-9. JWST can, on the other hand, not
constrain the fraction of LyC photons directly absorbed by dust, and this is
where SPICA comes in. The dust continuum emission from gravitationally lensed
LyC-leakers at z=6 may in principle be detectable with SPICA, thereby
constraining the level of LyC extinction in these objects.


title:
Lower Bounds on the Communication Complexity of Binary Local Quantum
  Measurement Simulation

abstract:
  We consider the problem of the classical simulation of quantum measurements
in the scenario of communication complexity. Regev and Toner (2007) have
presented a 2-bit protocol which simulates one particular correlation function
arising from binary projective quantum measurements on arbitrary state, and in
particular does not preserve local averages. The question of simulating other
correlation functions using a protocol with bounded communication, or
preserving local averages, has been posed as an open one. Within this paper we
resolve it in the negative: we show that any such protocol must have unbounded
communication for some subset of executions. In particular, we show that for
any protocol, there exist inputs for which the random variable describing the
number of communicated bits has arbitrarily large variance.


title: Heavy-flavor azimuthal correlations of D mesons

abstract:
  Observables of heavy-quark azimuthal correlations in heavy-ion collisions are
a new and promising tool for the investigation of the in-medium energy loss. We
explore the potential of these observables to discriminate the collisional and
radiative contributions within a hybrid EPOS+MC@sHQ transport approach.


title: Tilings of the Sphere by Congruent Pentagons I

abstract:
  We show that there are no edge-to-edge tilings of the sphere by congruent
pentagons beyond the minimal dodecahedron tiling, such that there is a tile
with all vertices having degree 3 and the edge length combinations are three of
the five possibilities.


title:
Geometrization of Econophysics : An Alternative Approach for Measuring
  Elements of Risk Management of an Economic System

abstract:
  The relationship between micro-structure and macro-structure of complex
systems using information geometry has been dealt by several authors. From this
perspective, we are going to apply it as a geometrical structure connecting
both microeconomics and macroeconomics . The results lead us to introduce new
modified quantities into both micro-macro economics that enable us to describe
the link between them. The importance of such a scheme is to find out -with
some accuracy- a new method can be introduced for examining the stability of an
economic system. This type of requirement is expressed by examining the
stability of the equations of path deviations for some economic systems as
described in a statistical manifold. Such a geometization scheme of economic
systems is an important step toward identifying risk management factors and so
contributes to the growing literature of econophysics.


title:
Suppressing the loss of ultracold molecules via the continuous quantum
  Zeno effect

abstract:
  We investigate theoretically the suppression of two-body losses when the
on-site loss rate is larger than all other energy scales in a lattice. This
work quantitatively explains the recently observed suppression of chemical
reactions between two rotational states of fermionic KRb molecules confined in
one-dimensional tubes with a weak lattice along the tubes [Yan et al., Nature
501, 521-525 (2013)]. New loss rate measurements performed for different
lattice parameters but under controlled initial conditions allow us to show
that the loss suppression is a consequence of the combined effects of lattice
confinement and the continuous quantum Zeno effect. A key finding, relevant for
generic strongly reactive systems, is that while a single-band theory can
qualitatively describe the data, a quantitative analysis must include multiband
effects. Accounting for these effects reduces the inferred molecule filling
fraction by a factor of five. A rate equation can describe much of the data,
but to properly reproduce the loss dynamics with a fixed filling fraction for
all lattice parameters we develop a mean-field model and benchmark it with
numerically exact time-dependent density matrix renormalization group
calculations.


title: Photonic Crystal Cavities in Cubic (3C) Polytype Silicon Carbide Films

abstract:
  We present the design, fabrication, and characterization of high quality
factor and small mode volume planar photonic crystal cavities from cubic (3C)
thin films (thickness ~ 200 nm) of silicon carbide (SiC) grown epitaxially on a
silicon substrate. We demonstrate cavity resonances across the
telecommunications band, with wavelengths from 1,250 - 1,600 nm. Finally, we
discuss possible applications in nonlinear optics, optical interconnects, and
quantum information science.


title: Theory of magnetic oscillations in Weyl semimetals

abstract:
  Weyl semimetals are a new class of Dirac material that posses bulk energy
nodes in three dimensions. In this paper, we study a Weyl semimetal subject to
an applied magnetic field. We derive expressions for the density of states,
electronic specific heat, and the quantum oscillations of the magnetization, DC
conductivity, and thermal conductivity. We find phase shifts in the quantum
oscillations that distinguish the Weyl semimetal from conventional three
dimensional Schr\"odinger Fermions.


title: Electromagnetic properties of thin metallic films

abstract:
  We compute the electromagnetic fluctuations due to evanescent-wave Johnson
noise in the vicinity of a thin conducting film, such as a metallic gate or a
2-dimensional electron gas. This noise can decohere a nearby qubit and it is
also responsible for Casimir forces. We have improved on previous calculations
by including the nonlocal dielectric response of the film, which is an
important correction at short distances. Remarkably, the fluctuations
responsible for decoherence of charge qubits from a thin film are greatly
enhanced over the case of a conducting half space. The decoherence times can be
reduced by over an order of magnitude by decreasing the film thickness. This
appears to be due to the leakage into the vacuum of modes that are well
localized in the perpendicular direction. There is no corresponding effect for
spin qubits (magnetic field fluctuations). We also show that a nonlocal
dielectric function naturally removes the divergence in the Casimir force at
vanishing separation between two metallic sheets or halfspaces. In the
separation regime where a local and nonlocal treatment are noticeably distinct,
the Casimir attraction between two thin sheets and two halfspaces are
practically indistinguishable for any physical film thickness.


title:
Trajectories in interlaced integral pencils of 3-dimensional analytic
  vector fields are o-minimal

abstract:
  Let X be an analytic vector field defined in a neighborhood of the origin of
R^3, and let I be an analytically non-oscillatory integral pencil of X; that
is, I is a maximal family of analytically non-oscillatory trajectories of X at
the origin all sharing the same iterated tangents. We prove that if I is
interlaced, then for any trajectory T in I, the expansion of the structure
generated over the real field by T and all globally subanalytic sets is
model-complete, o-minimal and polynomially bounded.


title: Hard diffraction at CDF

abstract:
  We present a CDF measurement of diffractive dijet production in $\bar{p}p$
collisions at 1.96 TeV at the Fermilab Tevatron Collider using data from an
integrated luminosity of $\approx 310$ pb$^{-1}$ collected by triggering on a
high transverse momentum jet in coincidence with a recoil antiproton detected
in a roman pot spectrometer. We report final results for 4-momentum transfer
squared $t>-4$ GeV$^2$, antiproton-momentum-loss fraction within 0.03-0.09,
Bjorken-x of the interacting parton in the antiproton in the range 0.001-0.1,
and jet transverse energies from 10 to 100 GeV.


title:
Effects of moderate noise on a limit cycle oscillator: Counter rotation
  and bistability

abstract:
  The effects of noise on the dynamics of nonlinear systems is known to lead to
many counter-intuitive behaviors. Using simple planar limit cycle oscillators,
we show that the addition of moderate noise leads to qualitatively different
dynamics. In particular, the system can appear bistable, rotate in the opposite
direction of the deterministic limit cycle, or cease oscillating altogether.
Utilizing standard techniques from stochastic calculus and recently developed
stochastic phase reduction methods, we elucidate the mechanisms underlying the
different dynamics and verify our analysis with the use of numerical
simulations. Lastly, we show that similar bistable behavior is found when
moderate noise is applied to the more biologically realistic FitzHugh-Nagumo
model.


title: Turbulence analysis of an experimental flux rope plasma

abstract:
  We have previously generated elongated Taylor double-helix flux rope plasmas
in the SSX MHD wind tunnel. These plasmas are remarkable in their rapid
relaxation (about one Alfv\'en time) and their description by simple analytical
Taylor force-free theory despite their high plasma beta and high internal flow
speeds. We report on the turbulent features observed in these plasmas including
frequency spectra, autocorrelation function, and probability distribution
functions of increments. We discuss here the possibility that the turbulence
facilitating access to the final state supports coherent structures and
intermittency revealed by non-Gaussian signatures in the statistics.
Comparisons to a Hall-MHD simulation of the SSX MHD wind tunnel show similarity
in several statistical measures.


title: Fundamental elements of an affine Weyl group

abstract:
  Fundamental elements are certain special elements of affine Weyl groups
introduced by Gortz, Haines, Kottwitz and Reuman. They play an important role
in the study of affine Deligne-Lusztig varieties. In this paper, we obtain
characterizations of the fundamental elements and their natural
generalizations. We also derive an inverse to a version of "Newton-Hodge
decomposition" in affine flag varieties. As an application, we obtain a
group-theoretic generalization of Oort's results on minimal p-divisible groups,
and we show that, in certain good reduction reduction of PEL Shimura datum,
each Newton stratum contains a minimal Ekedahl-Oort stratum. This generalizes a
result of Viehmann and Wedhorn.


title:
Universal Suppression of Heavy Quarkonium Production in pA Collisions at
  Low Transverse Momentum

abstract:
  The nuclear suppression of heavy quarkonium production at low transverse
momentum in pA collisions in high energy scatterings is investigated in the
small-x factorization formalism. A universal suppression is found in the large
Nc limit between the two formalisms to describe the heavy quarkonium
production: the non-relativistic QCD (NRQCD) and the color-evaporation model
(CEM). This provides an important probe to the saturation momentum at small-x
in big nucleus. We also comment on the phenomenological applications of our
results.


title:
Evidence of s-channel Single Top Quark Production in Events with one
  Charged Lepton and Bottom Quark Jets at CDF

abstract:
  We report an evidence of \textit{s}-channel single top quark production in
$p\bar{p}$ collision at $\sqrt{s}= 1.96 \mathrm{TeV}$ using data with
integrated luminosity of $9.4 \mathrm{fb}^{-1}$ collected by the Collider
Detector at Fermilab (CDF). We select events with one charged lepton, large
missing transverse energy and two bottom quark jets. The observed significance
of the result is 3.8 standard deviation from background only prediction. We
measure the inclusive cross section to be
$1.41^{+0.44}_{-0.42}\mathrm{(stat+syst)} \mathrm{pb}$ assuming $m_t = 172.5
\mathrm{GeV}/c^2$.


title:
A Comparative Study of the Signal-to-Noise Ratios of Different
  Representations for Symbolic Sequences

abstract:
  Based on the numerical representations by T basic vectors of a symbolic
sequence consisting of T symbols, first, we prove mathematical that the total
Fourier spectrum of the sequence is the square of the length of the sequence.
In the meantime, we define the indicator sequences vector. Using the orthogonal
or row orthogonal transformations of the indicator sequences vector, we
construct some special numerical representations of the symbolic sequence and
characterize the signal-to-noise ratios of the power spectrum of the numerical
representations. After calculating the discrete Fourier transform of those
special numerical representations, the signal-to-noise ratios of them can be
figured out. Mathematical theorems prove that the signal-to-noise ratio of the
Fourier spectrum of those special representations of the symbolic sequence is
T/(T-1) times the signal-to-noise ratio of the representation by T base
vectors. The results are applied in analyzing the properties of the DNA
sequences or protein sequences in the frequency domain, if one uses the
signal-to-noise ratios of special representations as the distinguishing
criterion, the distinguishing results only depend upon the distribution of the
symbols in the symbolic sequence and their mathematical constructions of
representations, but do not relate to the chemical or biological meanings of
the representations.


title: Irreducible components of deformation spaces: wild 2-adic exercises

abstract:
  We prove that the irreducible components of the space of framed deformations
of the trivial 2-dimensional mod 2 representation of the absolute Galois group
of Q_2 are in natural bijection with those of the trivial character, confirming
a conjecture of B\"ockle. We deduce from this result that crystalline points
are Zariski dense in that space: this provides the missing ingredient for the
surjectivity of the p-adic local Langlands correspondence for GL_2(Q_p) in the
case p=2 (the result was already known for p\geq 3).


title: New critical point for QCD in a magnetic field

abstract:
  We provide a general argument for the possible existence of a new critical
point associated with a deconfinement phase transition in QCD at finite
temperature $T$ and in a magnetic field $B$ with zero chemical potential. This
is the first example of a QCD critical point in a physical external parameter
region that can be studied using lattice QCD simulations without suffering from
a sign problem.


abstract:
  The p-adic local Langlands correspondence for GL_2(Q_p) is given by an exact
functor from unitary Banach representations of GL_2(Q_p) to representations of
the absolute Galois group G_{Q_p} of Q_p. We prove, using characteristic 0
methods, that this correspondence induces a bijection between absolutely
irreducible non-ordinary representations of GL_2(Q_p) and absolutely
irreducible 2-dimensional representations of G_{Q_p}. This had already been
proved, by characteristic p methods, but only for p\geq 5.


title: Analysis of AneuRisk65 data: warped logistic discrimination

abstract:
  We analyze the AneuRisk65 curvature functions using a likelihood-based
warping method for sparsely sampled curves, and combine it with logistic
regression in order to discriminate subjects with aneurysms at or after the
terminal bifurcation of the internal carotid artery (the most life-threatening)
from subjects with no aneurysms or aneurysms along the carotid artery (the less
serious). Significantly lower misclassification rates are obtained when the
warping functions are included in the logistic discrimination model, rather
than being treated as mere nuisance parameters.


title: Relative Resolution and Its Applications

abstract:
  We present an introduction to the derived and relative resolutions of the
moduli of stable maps. We discuss one application and mention a few problems.


title: Electron gun system for NSC KIPT linac

abstract:
  In NSC KIPT linac, a neutron source based on a subcritical assembly driven by
a 100MeV/100kW electron linear accelerator is under design and development. The
linear accelerator needs a new high current electron gun. In this paper, the
physical design, mechanical fabrication and beam test of this new electron gun
are described. The emission current is designed to be higher than 2A for the
pulse width of 3us with repetition rate of 50 Hz. The gun will operate with a
DC high voltage power supply which can provide a high voltage up to 150 kV. .
Computer simulations and optimizations have been carried out in the design
stage, including the gun geometry and beam transport line. The test results of
high voltage conditioning and beam test are presented. The operation status of
the electron gun system is also included. The basic test results show that the
design, manufacture and operation of the new electron system are basically
successful.


title:
Mergers and Mass Accretion for Infalling Halos Both End Well Outside
  Cluster Virial Radii

abstract:
  We find that infalling dark matter halos (i.e., the progenitors of satellite
halos) begin losing mass well outside the virial radius of their eventual host
halos. The peak mass occurs at a range of clustercentric distances, with median
and 68th percentile range of 1.8 +2.3/-1.0 R_(vir,host) for progenitors of z=0
satellites. The peak circular velocity for infalling halos occurs at
significantly larger distances (3.7 +3.3/-2.2 R_(vir,host) at z=0). This
difference arises because different physical processes set peak circular
velocity (typically, ~1:5 and larger mergers which cause transient circular
velocity spikes) and peak mass (typically, smooth accretion) for infalling
halos. We find that infalling halos also stop having significant mergers well
before they enter the virial radius of their eventual hosts. Mergers larger
than a 1:40 ratio in halo mass end for infalling halos at similar
clustercentric distances (~ 1.9 R_(vir,host)) as the end of overall mass
accretion. However, mergers larger than 1:3 typically end for infalling halos
at more than 4 virial radial away from their eventual hosts. This limits the
ability of mergers to affect quenching and morphology changes in clusters. We
also note that the transient spikes which set peak circular velocity may lead
to issues with abundance matching on that parameter, including unphysical
galaxy stellar mass growth profiles near clusters; we propose a simple
observational test to check if a better halo proxy for galaxy stellar mass
exists.


title: Colored Kauffman Homology and Super-A-polynomials

abstract:
  We study the structural properties of colored Kauffman homologies of knots.
Quadruple-gradings play an essential role in revealing the differential
structure of colored Kauffman homology. Using the differential structure, the
Kauffman homologies carrying the symmetric tensor products of the vector
representation for the trefoil and the figure-eight are determined. In
addition, making use of relations from representation theory, we also obtain
the HOMFLY homologies colored by rectangular Young tableaux with two rows for
these knots. Furthermore, the notion of super-A-polynomials is extended in
order to encompass two-parameter deformations of PSL(2,C) character varieties.


title:
The Man Behind the Curtain: X-rays Drive the UV through NIR Variability
  in the 2013 AGN Outburst in NGC 2617

abstract:
  After the All-Sky Automated Survey for SuperNovae (ASAS-SN) discovered a
significant brightening of the inner region of NGC 2617, we began a ~70 day
photometric and spectroscopic monitoring campaign from the X-ray through
near-infrared (NIR) wavelengths. We report that NGC 2617 went through a
dramatic outburst, during which its X-ray flux increased by over an order of
magnitude followed by an increase of its optical/ultraviolet (UV) continuum
flux by almost an order of magnitude. NGC 2617, classified as a Seyfert 1.8
galaxy in 2003, is now a Seyfert 1 due to the appearance of broad optical
emission lines and a continuum blue bump. Such "changing look Active Galactic
Nuclei (AGN)" are rare and provide us with important insights about AGN
physics. Based on the Hbeta line width and the radius-luminosity relation, we
estimate the mass of central black hole to be (4 +/- 1) x 10^7 M_sun. When we
cross-correlate the light curves, we find that the disk emission lags the
X-rays, with the lag becoming longer as we move from the UV (2-3 days) to the
NIR (6-9 days). Also, the NIR is more heavily temporally smoothed than the UV.
This can largely be explained by a simple model of a thermally emitting thin
disk around a black hole of the estimated mass that is illuminated by the
observed, variable X-ray fluxes.


title: Thermal Conduction and Multiphase Gas in Cluster Cores

abstract:
  We examine the role of thermal conduction and magnetic fields in cores of
galaxy clusters through global simulations of the intracluster medium (ICM). In
particular, we study the influence of thermal conduction, both isotropic and
anisotropic, on the condensation of multiphase gas in cluster cores. Previous
hydrodynamic simulations have shown that cold gas condenses out of the hot ICM
in thermal balance only when the ratio of the cooling time ($t_{\rm cool}$) and
the free-fall time ($t_{\rm ff}$) is less than $\approx 10$. Since thermal
conduction is significant in the ICM and it suppresses local cooling at small
scales, it is imperative to include thermal conduction in such studies. We find
that anisotropic (along local magnetic field lines) thermal conduction does not
influence the condensation criterion for a general magnetic geometry, even if
thermal conductivity is large. However, with isotropic thermal conduction cold
gas condenses only if conduction is suppressed (by a factor $\lesssim 0.3$)
with respect to the Spitzer value.


title: Detecting Dark Matter Substructures around the Milky Way with Gaia

abstract:
  Cold Dark Matter (CDM) theory, a pillar of modern cosmology and astrophysics,
predicts the existence of a large number of starless dark matter halos
surrounding the Milky Way (MW). However, clear observational evidence of these
"dark" substructures remains elusive. Here, we present a detection method based
on the small, but detectable, velocity changes that an orbiting substructure
imposes on the stars in the MW disk. Using high-resolution numerical
simulations we estimate that the new space telescope Gaia should detect the
kinematic signatures of a few starless substructures provided the CDM paradigm
holds. Such a measurement will provide unprecedented constraints on the
primordial matter power spectrum at low-mass scales and offer a new handle onto
the particle physics properties of dark matter.


title:
Detailed Investigations of the Dimmest Bursts from Two Magnetars, SGR
  J0501+4516 and SGR J1550-5418

abstract:
  We applied the Bayesian blocks representation technique to search for the
dimmest bursts from two magnetars: we identified 320 events from SGR J0501+4516
using a deep XMM-Newton observation and 404 bursts from SGR J1550-5418 using
two Swift/XRT pointings. The fluence level of our sample for both sources are
about 1-2 orders of magnitude lower than earlier studies. We systematically
investigated morphological characteristics and duration distributions of these
bursts, as these properties are directly obtained from their Bayesian blocks
profiles. We also studied the spectral behavior of the dimmest bursts, which
were grouped based on the morphological types and fluences. Our results helped
us further differentiate the spectral nature of very dim bursts from that of
the persistent emission, both fitted with physically motivated continuum
emission models. Moreover, we generated the differential burst fluence
distribution for these two magnetars in the lowest fluence regime.


title: IRC-10414: a bow-shock-producing red supergiant star

abstract:
  Most runaway OB stars, like the majority of massive stars residing in their
parent clusters, go through the red supergiant (RSG) phase during their
lifetimes. Nonetheless, although many dozens of massive runaways were found to
be associated with bow shocks, only two RSG bow-shock-producing stars,
Betelgeuse and \mu Cep, are known to date. In this paper, we report the
discovery of an arc-like nebula around the late M-type star IRC-10414 using the
SuperCOSMOS H-alpha Survey. Our spectroscopic follow-up of IRC-10414 with the
Southern African Large Telescope (SALT) showed that it is a M7 supergiant,
which supports previous claims on the RSG nature of this star based on
observations of its maser emission. This was reinforced by our new radio- and
(sub)millimeter-wavelength molecular line observations made with the Atacama
Pathfinder Experiment (APEX) 12 meter telescope and the Effelsberg 100 m radio
telescope, respectively. The SALT spectrum of the nebula indicates that its
emission is the result of shock excitation. This finding along with the
arc-like shape of the nebula and an estimate of the space velocity of IRC-10414
(\approx 70\pm20 km/s) imply the bow shock interpretation for the nebula. Thus,
IRC-10414 represents the third case of a bow-shock-producing RSG and the first
one with a bow shock visible at optical wavelengths. We discuss the smooth
appearance of the bow shocks around IRC-10414 and Betelgeuse and propose that
one of the necessary conditions for stability of bow shocks generated by RSGs
is the ionization of the stellar wind. Possible ionisation sources of the wind
of IRC-10414 are proposed and discussed.


title:
Light-cone effect and supersonic correlations in one- and
  two-dimensional bosonic superfluids

abstract:
  We study the spreading of density-density correlations in Bose-Hubbard models
after a quench of the interaction strength, using time-dependent variational
Monte Carlo simulations. It gives access to unprecedented long propagation
times and to dimensions higher than one. In both one and two dimensions, we
find ballistic light-cone spreading of correlations and extract accurate values
of the light-cone velocity in the superfluid regime. We show that the spreading
of correlations is generally supersonic, with a light-cone propagating faster
than sound modes but slower than the maximum group velocity of density
excitations, except at the Mott transition, where all the characteristic
velocities are equal. Further, we show that in two dimensions the correlation
spreading is highly anisotropic and presents nontrivial interference effects.


title: Superfluid Kubo Formulas from Partition Function

abstract:
  Linear response theory relates hydrodynamic transport coefficients to
equilibrium retarded correlation functions of the stress-energy tensor and
global symmetry currents in terms of Kubo formulas. Some of these transport
coefficients are non-dissipative and affect the fluid dynamics at equilibrium.
We present an algebraic framework for deriving Kubo formulas for such thermal
transport coefficients by using the equilibrium partition function. We use the
framework to derive Kubo formulas for all such transport coefficients of
superfluids, as well as to rederive Kubo formulas for various normal fluid
systems.


title:
Impersonating the Standard Model Higgs Boson: Alignment without
  Decoupling

abstract:
  In models with an extended Higgs sector there exists an alignment limit, in
which the lightest CP-even Higgs boson mimics the Standard Model Higgs. The
alignment limit is commonly associated with the decoupling limit, where all
non-standard scalars are significantly heavier than the $Z$ boson. However,
alignment can occur irrespective of the mass scale of the rest of the Higgs
sector. In this work we discuss the general conditions that lead to "alignment
without decoupling", therefore allowing for the existence of additional
non-standard Higgs bosons at the weak scale. The values of $\tan\beta$ for
which this happens are derived in terms of the effective Higgs quartic
couplings in general two-Higgs-doublet models as well as in supersymmetric
theories, including the MSSM and the NMSSM. Moreover, we study the information
encoded in the variations of the SM Higgs-fermion couplings to explore regions
in the $m_A - \tan\beta$ parameter space.


title:
New observational Constraints on the Growth of the First Supermassive
  Black Holes

abstract:
  We constrain the total accreted mass density in supermassive black holes at
z>6, inferred via the upper limit derived from the integrated X-ray emission
from a sample of photometrically selected galaxy candidates. Studying galaxies
obtained from the deepest Hubble Space Telescope images combined with the
Chandra 4 Msec observations of the Chandra Deep Field South, we achieve the
most restrictive constraints on total black hole growth in the early Universe.
We estimate an accreted mass density <1000Mo Mpc^-3 at z~6, significantly lower
than the previous predictions from some existing models of early black hole
growth and earlier prior observations. These results place interesting
constraints on early black growth and mass assembly by accretion and imply one
or more of the following: (1) only a fraction of the luminous galaxies at this
epoch contain active black holes; (2) most black hole growth at early epochs
happens in dusty and/or less massive - as yet undetected - host galaxies; (3)
there is a significant fraction of low-z interlopers in the galaxy sample; (4)
early black hole growth is radiatively inefficient, heavily obscured and/or is
due to black hole mergers as opposed to accretion or (5) the bulk of the black
hole growth occurs at late times. All of these possibilities have important
implications for our understanding of high redshift seed formation models.


title: Global gravitational anomaly cancellation for five-branes

abstract:
  We show that the global mixed gauge-gravitational anomaly of the worldvolume
theory of the M5-brane vanishes, when the anomaly inflow from the bulk is taken
into account. This result extends to the type IIA and heterotic $E_8 \times
E_8$ five-branes. As a by-product, we provide a definition of the chiral
fermionic fields for generic non-spin M5-brane worldvolume and determine the
coupling between the self-dual field and the M-theory C-field.


title:
Hubble constant and dark energy inferred from free-form determined time
  delay distances

abstract:
  Time delays between multiple images of lensed sources can probe the geometry
of the universe. We propose a novel method based on free-form modelling of
gravitational lenses to estimate time-delay distances and, in turn,
cosmological parameters. This approach does not suffer from the degeneracy
between the steepness of the profile and the cosmological parameters. We apply
the method to 18 systems having time delay measurements and find
H_0=69+-6(stat.)+-4(syst.) km s^{-1}Mpc^{-1}. In combination with WMAP9, the
constraints on dark energy are Omega_w=0.68+-0.05 and w=-0.86+-0.17 in a flat
model with constant equation-of-state.


title:
Kramers-Wannier Duality of Statistical Mechanics Applied to the Boolean
  Satisfiability Problem of Computer Science

abstract:
  We present a novel application of the Kramers-Wannier duality on one of the
most important problems of computer science, the Boolean satisfiability problem
(SAT). More specifically, we focus on sharp-SAT or equivalently #SAT - the
problem of counting the number of solutions to a Boolean satisfaction formula.
#SAT can be cast into a statistical-mechanical language, where it reduces to
calculating the partition function of an Ising spin Hamiltonian with multi-spin
interactions. We show that Kramers-Wannier duality can be generalized to apply
to such multi-connected spin networks. We present an exact dual partner to #SAT
and explicitly verify their equivalence with a few simple examples. It is shown
that the NP-completeness of the original problem maps on the complexity of the
dual problem of enumerating the number of non-negative solutions to a
Diophantine system of equations. We discuss the implications of this duality
and the prospects of similar dualities applied to computer science problems.


title:
A Budget and Accounting of Metals at z~0: Results from the COS-Halos
  Survey

abstract:
  We present a budget and accounting of metals in and around star-forming
galaxies at $z\sim 0$. We combine empirically derived star formation histories
with updated supernova and AGB yields and rates to estimate the total mass of
metals produced by galaxies with present-day stellar mass of
$10^{9.3}$--$10^{11.6} M_{\odot}$. On the accounting side of the ledger, we
show that a surprisingly constant 20--25% mass fraction of produced metals
remain in galaxies' stars, interstellar gas and interstellar dust, with little
dependence of this fraction on the galaxy stellar mass (omitting those metals
immediately locked up in remnants). Thus, the bulk of metals are outside of
galaxies, produced in the progenitors of today's $L^*$ galaxies. The COS-Halos
survey is uniquely able to measure the mass of metals in the circumgalactic
medium (to impact parameters of $< 150$ kpc) of low-redshift $\sim L^*$
galaxies. Using these data, we map the distribution of CGM metals as traced by
both the highly ionized OVI ion and a suite of low-ionization species; combined
with constraints on circumgalactic dust and hotter X-ray emitting gas out to
similar impact parameters, we show that $\sim 40$% of metals produced by
$M_{\star}\sim 10^{10}M_{\odot}$ galaxies can be easily accounted for out to
150 kpc. With the current data, we cannot rule out a constant mass of metals
within this fixed physical radius. This census provides a crucial boundary
condition for the eventual fate of metals in galaxy evolution models.


title: Stable Commutator Length in Amalgamated Free Products

abstract:
  We show that stable commutator length is rational on free products of free
Abelian groups amalgamated over $\mathbb{Z}^k$, a class of groups containing
the fundamental groups of all torus knot complements. We consider a geometric
model for these groups and parameterize all surfaces with specified boundary
mapping to this space. Using this work we provide a topological algorithm to
compute stable commutator length in these groups. Further, we use the methods
developed to show that in free products of cyclic groups the stable commutator
length of a fixed varies quasirationally in the orders of the free factors.


title:
The imprint of dark matter haloes on the size and velocity dispersion
  evolution of early-type galaxies

abstract:
  Early-type galaxies (ETGs) are observed to be more compact, on average, at $z
\gtrsim 2$ than at $z\simeq 0$, at fixed stellar mass. Recent observational
works suggest that such size evolution could reflect the similar evolution of
the host dark matter halo density as a function of the time of galaxy
quenching. We explore this hypothesis by studying the distribution of halo
central velocity dispersion ($\sigma_0$) and half-mass radius ($r_{\rm h}$) as
functions of halo mass $M$ and redshift $z$, in a cosmological $\Lambda$-CDM
$N$-body simulation. In the range $0\lesssim z\lesssim 2.5$, we find
$\sigma_0\propto M^{0.31-0.37}$ and $r_{\rm h}\propto M^{0.28-0.32}$, close to
the values expected for homologous virialized systems. At fixed $M$ in the
range $10^{11} M_\odot \lesssim M\lesssim 5.5 \times 10^{14} M_\odot$ we find
$\sigma_0\propto(1+z)^{0.35}$ and $r_{\rm h}\propto(1+z)^{-0.7}$. We show that
such evolution of the halo scaling laws is driven by individual haloes growing
in mass following the evolutionary tracks $\sigma_0\propto M^{0.2}$ and $r_{\rm
h}\propto M^{0.6}$, consistent with simple dissipationless merging models in
which the encounter orbital energy is accounted for. We compare the $N$-body
data with ETGs observed at $0\lesssim z\lesssim3$ by populating the haloes with
a stellar component under simple but justified assumptions: the resulting
galaxies evolve consistently with the observed ETGs up to $z \simeq 2$, but the
model has difficulty reproducing the fast evolution observed at $z\gtrsim 2$.
We conclude that a substantial fraction of the size evolution of ETGs can be
ascribed to a systematic dependence on redshift of the dark matter haloes
structural properties.


title:
Two-loop fermionic electroweak corrections to the Z-boson width and
  production rate

abstract:
  Improved predictions for the Z-boson decay width and the hadronic Z-peak
cross-section within the Standard Model are presented, based on a complete
calculation of electroweak two-loop corrections with closed fermion loops.
Compared to previous partial results, the predictions for the Z width and
hadronic cross-section shift by about 0.6 MeV and 0.004 nb, respectively.
Compact parametrization formulae are provided, which approximate the full
results to better than 4 ppm.


title:
WISE J233237.05-505643.5: a Double-Peaked Broad-Lined AGN with
  Spiral-Shaped Radio Morphology

abstract:
  We present radio continuum mapping, optical imaging and spectroscopy of the
newly discovered double-peaked broad-lined AGN WISE J233237.05-505643.5 at
redshift z = 0.3447. This source exhibits an FR-I and FR-II hybrid-morphology,
characterized by bright core, jet, and Doppler-boosted lobe structures in ATCA
continuum maps at 1.5, 5.6, and 9 GHz. Unlike most FR-II objects, W2332-5056 is
hosted by a disk-like galaxy. The core has a projected 5" linear radio feature
that is perpendicular to the curved primary jet, hinting at unusual and complex
activity within the inner 25 kpc. The multi-epoch optical-near-IR photometric
measurements indicate significant variability over a 3-20 year baseline from
the AGN component. Gemini-South optical data shows an unusual double-peaked
emission-line features: the centroids of the broad-lined components of H-alpha
and H-beta are blueshifted with respect to the narrow lines and host galaxy by
~ 3800 km/s. We examine possible cases which involve single or double
supermassive black holes in the system, and discuss required future
investigations to disentangle the mystery nature of this system.


title: Inflaton as an auxiliary topological field in a QCD-like system

abstract:
  We propose a new scenario for early cosmology, where inflationary de Sitter
phase dynamically occurs. The effect emerges as a result of dynamics of the
topologically nontrivial sectors in expanding universe. Technically the effect
can be described in terms of the auxiliary fields which effectively describe
the dynamics of the topological sectors in a gauge theory. Inflaton in this
framework is an auxiliary topological non-propagating field with no canonical
kinetic term, similar to known topologically ordered phases in condensed matter
systems. We explain many deep questions in this framework using the so-called
weakly coupled "deformed QCD" toy model.While this theory is weakly coupled
gauge theory, it preserves all the crucial elements of strongly interacting
gauge theory, including confinement, nontrivial $\theta$ dependence, degeneracy
of the topological sectors, etc. We discuss a specific realization of these
ideas using a scaled up version of QCD, coined as \qcd, with the scale
M_{PL}\gg \Lbar\gg \sqrt[3]{M_{EW}^2M_{PL}}\sim 10^8 {\mathrm{GeV}}. If no
other fields are present in the system de Sitter phase will be the final
destination of evolution of the universe. If other interactions are present in
the system, the inflationary de Sitter phase lasts for a finite period of time.
The inflation starts from the thermal equilibrium state long after the \qcd
-confinement phase transition at temperature T_{i}\sim
\Lbar\sqrt{\frac{\Lbar}{M_{PL}}}. The end of inflation is triggered by the
coupling with gauge bosons from the Standard Model. The corresponding
interaction is unambiguously fixed by the triangle anomaly. Number of e-folds
in the \qcd-inflation framework is determined by the gauge coupling constant at
the moment of inflation, and estimated as N_{\rm inf}\sim \alpha_s^{-2}\sim
10^2.


title:
SweetSpot: Near-Infrared Observations of Thirteen Type Ia Supernovae
  from a New NOAO Survey Probing the Nearby Smooth Hubble Flow

abstract:
  We present 13 Type Ia supernovae (SNe Ia) observed in the restframe
near-infrared (NIR) from 0.02 < z < 0.09 with the WIYN High-resolution Infrared
Camera (WHIRC) on the WIYN 3.5-m telescope. With only 1-3 points per light
curve and a prior on the time of maximum from the spectrum used to type the
object we measure an H-band dispersion of spectroscopically normal SNe Ia of
0.164 mag. These observations continue to demonstrate the improved standard
brightness of SNe Ia in H-band even with limited data. Our sample includes two
SNe Ia at z ~ 0.09, which represent the most distant restframe NIR H-band
observations published to date.
  This modest sample of 13 NIR SNe Ia represent the pilot sample for
"SweetSpot" - a three-year NOAO Survey program that will observe 144 SNe Ia in
the smooth Hubble flow. By the end of the survey we will have measured the
relative distance to a redshift of z ~ 0.05 to 1%. Nearby Type Ia supernova (SN
Ia) observations such as these will test the standard nature of SNe Ia in the
restframe NIR, allow insight into the nature of dust, and provide a critical
anchor for future cosmological SN Ia surveys at higher redshift.


title:
A boundary integral equation with the generalized Neumann kernel for the
  Ahlfors map

abstract:
  This paper presents a uniquely solvable boundary integral equation with the
generalized Neumann kernel for the Ahlfors map of bounded multiply connected
regions.


title: F-zeta geometry, Tate motives, and the Habiro ring

abstract:
  In this paper we propose different notions of F_zeta-geometry, for zeta a
root of unity, generalizing notions of F_1-geometry (geometry over the "field
with one element") based on the behavior of the counting functions of points
over finite fields, the Grothendieck class, and the notion of torification. We
relate F_zeta-geometry to formal roots of Tate motives, and to functions in the
Habiro ring, seen as counting functions of certain ind-varieties. We
investigate the existence of F_zeta-structures in examples arising from general
linear groups, matrix equations over finite fields, and some quantum modular
forms.


title:
A characterization of Hardy spaces associated with certain Schr\"odinger
  operators

abstract:
  Let $\{K_t\}_{t>0}$ be the semigroup of linear operators generated by a
Schr\"odinger operator $-L=\Delta - V(x)$ on $\mathbb R^d$, $d\geq 3$, where
$V(x)\geq 0$ satisfies $\Delta^{-1} V\in L^\infty$. We say that an
$L^1$-function $f$ belongs to the Hardy space $H^1_L$ if the maximal function
$\mathcal M_L f(x) = \sup_{t>0} |K_tf(x)|$ belongs to $L^1(\mathbb R^d) $. We
prove that the operator $(-\Delta)^{1\slash 2} L^{-1\slash 2}$ is an
isomorphism of the space $H^1_L$ with the classical Hardy space $H^1(\mathbb
R^d)$ whose inverse is $L^{1\slash 2} (-\Delta)^{-1\slash 2}$. As a corollary
we obtain that the space $H^1_L$ is characterized by the Riesz transforms
$R_j=\frac{\partial}{\partial x_j}L^{-1\slash 2}$.


title:
Quasiholes of 1/3 and 7/3 quantum Hall states: size estimates via exact
  diagonalization and density-matrix renormalization group

abstract:
  We determine the size of the elementary quasihole in $\nu=1/3$ and $\nu=7/3$
quantum Hall states via exact-diagonalization and density-matrix
renormalization group calculations on the sphere and cylinder, using a variety
of short- and long-range pinning potentials. The size of the quasihole at
filling factor $\nu=1/3$ is estimated to be $\approx 4\ell_B$, and that of
$\nu=7/3$ is $\approx 7\ell_B$, where $\ell_B$ is the magnetic length. In
contrast, the size of the Laughlin quasihole, expected to capture the basic
physics in these two states, is around $\approx 2.5\ell_B$. Our work supports
the earlier findings that the quasihole in the first excited Landau level is
significantly larger than in the lowest Landau level.


title:
Application of compressed sensing to genome wide association studies and
  genomic selection

abstract:
  We show that the signal-processing paradigm known as compressed sensing (CS)
is applicable to genome-wide association studies (GWAS) and genomic selection
(GS). The aim of GWAS is to isolate trait-associated loci, whereas GS attempts
to predict the phenotypic values of new individuals on the basis of training
data. CS addresses a problem common to both endeavors, namely that the number
of genotyped markers often greatly exceeds the sample size. We show using CS
methods and theory that all loci of nonzero effect can be identified (selected)
using an efficient algorithm, provided that they are sufficiently few in number
(sparse) relative to sample size. For heritability h2 = 1, there is a sharp
phase transition to complete selection as the sample size is increased. For
heritability values less than one, complete selection can still occur although
the transition is smoothed. The transition boundary is only weakly dependent on
the total number of genotyped markers. The crossing of a transition boundary
provides an objective means to determine when true effects are being recovered;
we discuss practical methods for detecting the boundary. For h2 = 0.5, we find
that a sample size that is thirty times the number of nonzero loci is
sufficient for good recovery.


title:
Optical Birefringence and Dichroism of Cuprate Superconductors in the
  THz regime

abstract:
  The presence of optical polarization anisotropies, such as Faraday/Kerr
effects, linear birefringence, and magnetoelectric birefringence are evidence
for broken symmetry states of matter. The recent discovery of a Kerr effect
using near-IR light in the pseudogap phase of the cuprates can be regarded as a
strong evidence for a spontaneous symmetry breaking and the existence of an
anomalous long-range ordered state. In this work we present a high precision
study of the polarimetry properties of the cuprates in the THz regime. While no
Faraday effect was found in this frequency range to the limits of our
experimental uncertainty (1.3 milli-radian or 0.07$^\circ$), a small but
significant polarization rotation was detected that derives from an anomalous
linear dichroism. In YBa$_2$Cu$_3$O$_y$ the effect has a temperature onset that
mirrors the pseudogap temperature T$^*$ and is enhanced in magnitude in
underdoped samples. In $x=1/8$ La$_{2-x}$Ba$_{x}$CuO$_4$, the effect onsets
above room temperature, but shows a dramatic enhancement near a temperature
scale known to be associated with spin and charge ordered states. These
features are consistent with a loss of both C$_4$ rotation and mirror symmetry
in the electronic structure of the CuO$_2$ planes in the pseudogap state.


title: MAIA, a three-channel imager for asteroseismology: instrument design

abstract:
  MAIA, an acronym for Mercator Advanced Imager for Asteroseismology, is a
three-channel instrument that targets fast-cadence three-colour photometry,
installed at the 1.2-m Mercator telescope at the Roque de los Muchachos at La
Palma (Canary Islands, Spain). This instrument observes a 9.4x14.1arcmin2
Field-of-View simultaneously in three wavelength bands on three large
frame-transfer CCDs. These detectors were developed for ESA's cancelled
Eddington space mission and were offered on permanent loan to the Institute of
Astronomy (KU Leuven, Belgium). MAIA uses its own ugr photometric system that
is a crude approximation of the SDSS system. The instrument is designed to
perform multi-colour observations for asteroseismology, with specific emphasis
on subdwarf and white dwarf single and binary stars. We describe the design of
the instrument, discuss key components, and report on its performance and first
results.


title: A Partial Derandomization of PhaseLift using Spherical Designs

abstract:
  The problem of retrieving phase information from amplitude measurements alone
has appeared in many scientific disciplines over the last century. PhaseLift is
a recently introduced algorithm for phase recovery that is computationally
efficient, numerically stable, and comes with rigorous performance guarantees.
PhaseLift is optimal in the sense that the number of amplitude measurements
required for phase reconstruction scales linearly with the dimension of the
signal. However, it specifically demands Gaussian random measurement vectors -
a limitation that restricts practical utility and obscures the specific
properties of measurement ensembles that enable phase retrieval. Here we
present a partial derandomization of PhaseLift that only requires sampling from
certain polynomial size vector configurations, called t-designs. Such
configurations have been studied in algebraic combinatorics, coding theory, and
quantum information. We prove reconstruction guarantees for a number of
measurements that depends on the degree t of the design. If the degree is
allowed to to grow logarithmically with the dimension, the bounds become tight
up to polylog-factors. Beyond the specific case of PhaseLift, this work
highlights the utility of spherical designs for the derandomization of data
recovery schemes.


title: Self-Similar Graphs

abstract:
  For any graph $G$ on $n$ vertices and for any {\em symmetric} subgraph $J$ of
$K_{n,n}$, we construct an infinite sequence of graphs based on the pair
$(G,J)$. The First graph in the sequence is $G$, then at each stage replacing
every vertex of the previous graph by a copy of $G$ and every edge of the
previous graph by a copy of $J$ the new graph is constructed. We call these
graphs {\em self-similar} graphs. We are interested in delineating those pairs
$(G,J)$ for which the chromatic numbers of the graphs in the sequence are
bounded. Here we have some partial results. When $G$ is a complete graph and
$J$ is a special matching we show that every graph in the resulting sequence is
an {\em expander} graph.


title: Spin squeezing and entanglement for arbitrary spin

abstract:
  A complete set of generalized spin-squeezing inequalities is derived for an
ensemble of particles with an arbitrary spin. Our conditions are formulated
with the first and second moments of the collective angular momentum
coordinates. A method for mapping the spin-squeezing inequalities for spin-1/2
particles to entanglement conditions for spin-j particles is also presented. We
apply our mapping to obtain a generalization of the original spin-squeezing
inequality to higher spins. We show that, for large particle numbers, a
spin-squeezing parameter for entanglement detection based on one of our
inequalities is strictly stronger than the original spin-squeezing parameter
defined in [A. Sorensen et al., Nature 409, 63 (2001)]. We present a coordinate
system independent form of our inequalities that contains, besides the
correlation and covariance tensors of the collective angular momentum
operators, the nematic tensor appearing in the theory of spin nematics.
Finally, we discuss how to measure the quantities appearing in our inequalities
in experiments.


title: Hyperbolic manifolds of small volume

abstract:
  We conjecture that for every dimension n not equal 3 there exists a
noncompact hyperbolic n-manifold whose volume is smaller than the volume of any
compact hyperbolic n-manifold. For dimensions n at most 4 and n=6 this
conjecture follows from the known results. In this paper we show that the
conjecture is true for arithmetic hyperbolic n-manifolds of dimension n at
least 30.


title:
Steering the optimization pathway in the control landscape using
  constraints

abstract:
  We show how additional constraints, restricting the spectrum of the optimized
pulse or confining the system dynamics, can be used to steer optimization in
quantum control towards distinct solutions. Our examples are multi-photon
excitation in atoms and vibrational population transfer in molecules. We show
that a spectral constraint is most effective in enforcing non-resonant
two-photon absorption pathways in atoms and avoiding unnecessarily broad
spectra in Raman transitions in molecules. While a constraint restricting the
system to stay in an allowed subspace is also capable of identifying
non-resonant excitation pathways, it does not avoid spurious peaks in the pulse
spectrum. Both constraints are compatible with monotonic convergence but imply
different additional numerical costs.


title: Spontaneously broken mass

abstract:
  The Galilei group involves mass as a central charge. We show that the
associated superselection rule is incompatible with the observed phenomenology
of superfluid helium 4: this is recovered only under the assumption that mass
is spontaneously broken. This remark is somewhat immaterial for the real world,
where the correct space-time symmetries are encoded by the Poincar\'e group,
which has no central charge. Yet it provides an explicit example of how
superselection rules can be experimentally tested. We elaborate on what
conditions must be met for our ideas to be generalizable to the relativistic
case of the integer/half-integer angular momentum superselection rule.


title:
Semidefinite Programming Based Preconditioning for More Robust
  Near-Separable Nonnegative Matrix Factorization

abstract:
  Nonnegative matrix factorization (NMF) under the separability assumption can
provably be solved efficiently, even in the presence of noise, and has been
shown to be a powerful technique in document classification and hyperspectral
unmixing. This problem is referred to as near-separable NMF and requires that
there exists a cone spanned by a small subset of the columns of the input
nonnegative matrix approximately containing all columns. In this paper, we
propose a preconditioning based on semidefinite programming making the input
matrix well-conditioned. This in turn can improve significantly the performance
of near-separable NMF algorithms which is illustrated on the popular successive
projection algorithm (SPA). The new preconditioned SPA is provably more robust
to noise, and outperforms SPA on several synthetic data sets. We also show how
an active-set method allow us to apply the preconditioning on large-scale
real-world hyperspectral images.


title:
Accounting for Secondary Uncertainty: Efficient Computation of Portfolio
  Risk Measures on Multi and Many Core Architectures

abstract:
  Aggregate Risk Analysis is a computationally intensive and a data intensive
problem, thereby making the application of high-performance computing
techniques interesting. In this paper, the design and implementation of a
parallel Aggregate Risk Analysis algorithm on multi-core CPU and many-core GPU
platforms are explored. The efficient computation of key risk measures,
including Probable Maximum Loss (PML) and the Tail Value-at-Risk (TVaR) in the
presence of both primary and secondary uncertainty for a portfolio of property
catastrophe insurance treaties is considered. Primary Uncertainty is the the
uncertainty associated with whether a catastrophe event occurs or not in a
simulated year, while Secondary Uncertainty is the uncertainty in the amount of
loss when the event occurs.
  A number of statistical algorithms are investigated for computing secondary
uncertainty. Numerous challenges such as loading large data onto hardware with
limited memory and organising it are addressed. The results obtained from
experimental studies are encouraging. Consider for example, an aggregate risk
analysis involving 800,000 trials, with 1,000 catastrophic events per trial, a
million locations, and a complex contract structure taking into account
secondary uncertainty. The analysis can be performed in just 41 seconds on a
GPU, that is 24x faster than the sequential counterpart on a fast multi-core
CPU. The results indicate that GPUs can be used to efficiently accelerate
aggregate risk analysis even in the presence of secondary uncertainty.


title: A pointwise inequality for the fourth order Lane-Emden equation

abstract:
  We prove that the following pointwise inequality holds
  \begin{equation*} -\Delta u \ge \sqrt\frac{2}{(p+1)-c_n} |x|^{\frac{a}{2}}
u^{\frac{p+1}{2}} + \frac{2}{n-4} \frac{|\nabla u|^2}{u} \ \ \text{in}\ \
\mathbb{R}^n
  \end{equation*}
  where $c_n:=\frac{8}{n(n-4)}$, for positive bounded solutions of the fourth
order H\'{e}non equation that is \begin{equation*} \Delta^2 u = |x|^a u^p \ \ \
\ \text {in }\ \ \mathbb{R}^n \end{equation*} for some $a\ge0$ and $p>1$.
Motivated by the Moser's proof of the Harnack's inequality as well as Moser
iteration type arguments in the regularity theory, we develop an iteration
argument to prove the above pointwise inequality. As far as we know this is the
first time that such an argument is applied towards constructing pointwise
inequalities for partial differential equations. An interesting point is that
the coefficient $\frac{2}{n-4}$ also appears in the fourth order $Q$-curvature
and the Paneitz operator. This in particular implies that the scalar curvature
of the conformal metric with conformal factor $u^\frac{4}{n-4}$ is positive.


title: Large-degree asymptotics of rational Painleve-II functions. I

abstract:
  Rational solutions of the inhomogeneous Painleve-II equation and of a related
coupled Painleve-II system have recently arisen in studies of fluid vortices
and of the sine-Gordon equation. For the sine-Gordon application in particular
it is of interest to understand the large-degree asymptotic behavior of the
rational Painleve-II functions. We explicitly compute the leading-order
large-degree asymptotics of these two families of rational functions valid in
the whole complex plane with the exception of a neighborhood of a certain
piecewise-smooth closed curve. We obtain rigorous error bounds by using the
Deift-Zhou nonlinear steepest-descent method for Riemann-Hilbert problems.


title:
On sets of integers which contain no three terms in geometric
  progression

abstract:
  The problem of looking for subsets of the natural numbers which contain no
3-term arithmetic progressions has a rich history. Roth's theorem famously
shows that any such subset cannot have positive upper density. In contrast,
Rankin in 1960 suggested looking at subsets without three-term geometric
progressions, and constructed such a subset with density about 0.719. More
recently, several authors have found upper bounds for the upper density of such
sets. We significantly improve upon these bounds, and demonstrate a method of
constructing sets with a greater upper density than Rankin's set. This
construction is optimal in the sense that our method gives a way of effectively
computing the greatest possible upper density of a geometric-progression-free
set. We also show that geometric progressions in Z/nZ behave more like Roth's
theorem in that one cannot take any fixed positive proportion of the integers
modulo a sufficiently large value of n while avoiding geometric progressions.


title: Closed hierarchy of correlations in Markovian open quantum systems

abstract:
  We study the Lindblad master equation in the space of operators and provide
simple criteria for closeness of the hierarchy of equations for correlations.
We separately consider the time evolution of closed and open systems and show
that open systems satisfying the closeness conditions are not necessary of
Gaussian type. In addition, we show that dissipation can induce the closeness
of the hierarchy of correlations in interacting quantum systems. As an example
we study an interacting optomechanical model, the Fermi-Hubbard model, and the
Rabi model, all coupled to a fine-tuned Markovian environment and obtain exact
analytic expressions for the time evolution of two-point correlations.


title: A Mathematical Model, Implementation and Study of a Swarm System

abstract:
  The work reported in this paper is motivated towards the development of a
mathematical model for swarm systems based on macroscopic primitives. A pattern
formation and transformation model is proposed. The pattern transformation
model comprises two general methods for pattern transformation, namely a
macroscopic transformation and mathematical transformation method. The problem
of transformation is formally expressed and four special cases of
transformation are considered. Simulations to confirm the feasibility of the
proposed models and transformation methods are presented. Comparison between
the two transformation methods is also reported.


title:
Nonlinear energy transfers and phase diagrams for geostrophically
  balanced rotating--stratified flows

abstract:
  Equilibrium statistical mechanics tools have been developed to obtain
indications about the natural tendencies of nonlinear energy transfers in
two-dimensional and quasi two-dimensional flows like rotating and stratified
flows in geostrophic balance. In this article, we consider a simple model of
such flows with a non-trivial vertical structure, namely two-layer
quasi-geostrophic flows, which remain amenable to analytical study. We obtain
the statistical equilibria of the system in the case of a linear
vorticity-stream function relation, build the corresponding phase diagram, and
discuss the most probable outcome of nonlinear energy transfers, both on the
horizontal and on the vertical, in the presence of stratification and rotation.


title: Understanding and Controlling Regime Switching in Molecular Diffusion

abstract:
  Diffusion can be strongly affected by ballistic flights (long jumps) as well
as long-lived sticking trajectories (long sticks). Using statistical inference
techniques in the spirit of Granger causality, we investigate the appearance of
long jumps and sticks in molecular-dynamics simulations of diffusion in a
prototype system, a benzene molecule on a graphite substrate. We find that
specific fluctuations in certain, but not all, internal degrees of freedom of
the molecule can be linked to either long jumps or sticks. Furthermore, by
changing the prevalence of these predictors with an outside influence, the
diffusion of the molecule can be controlled. The approach presented in this
proof of concept study is very generic, and can be applied to larger and more
complex molecules. Additionally, the predictor variables can be chosen in a
general way so as to be accessible in experiments, making the method feasible
for control of diffusion in applications. Our results also demonstrate that
data-mining techniques can be used to investigate the phase-space structure of
high-dimensional nonlinear dynamical systems.

categories: cond-mat.stat-mech cond-mat.mes-hall nlin.CD physics.chem-ph physics.data-an


title:
Darboux integrable discrete equations possessing an autonomous
  first-order integral

abstract:
  All Darboux integrable difference equations on the quad-graph are described
in the case of the equations that possess autonomous first-order integrals in
one of the characteristics. A generalization of the discrete Liouville equation
is obtained from a subclass of these equation via a non-point transformation.
The general proposition on the symmetry structure of the quad-graph equations
is proved as an auxiliary result.


title: Spectral approximation on the unit ball

abstract:
  Spectral approximation by polynomials on the unit ball is studied in the
frame of the Sobolev spaces $W^{s}_p(\ball)$, $1<p<\infty$. The main results
give sharp estimates on the order of approximation by polynomials in the
Sobolev spaces and explicit construction of approximating polynomials. One
major effort lies in understanding the structure of orthogonal polynomials with
respect to an inner product of the Sobolev space $W_2^s(\ball)$. As an
application, a direct and efficient spectral-Galerkin method based on our
orthogonal polynomials is proposed for the second and the fourth order elliptic
equations on the unit ball, its optimal error estimates are explicitly derived
for both procedures in the Sobolev spaces and, finally, numerical examples are
presented to illustrate the theoretic results.


title: Light dark matter for Fermi-LAT and CDMS observations

abstract:
  Light fermionic/scalar dark matter (DM) (m_DM ~ 8 GeV) neutral under the
standard model can be responsible for the CDMS and CoGeNT signals, and the
Fermi-LAT gamma-ray excesses. In order to explain them in a relatively simple
framework, we have explored various DM annihilation and scattering processes,
discussing important phenomenological constraints coming from particle physics.
Assuming that the two independent observations have a common DM origin and the
processes arise through a common mediator, DM should annihilate into
tau/anti-tau lepton pairs through an s-channel, and scatter with nuclei through
a t-channel process. To avoid the p-wave suppression, a new Higgs-like scalar
field with a mass of O(1) TeV is necessary as a common mediator of both the
processes. We propose a supersymmetric model realizing the scenario.

categories: hep-ph astro-ph.CO astro-ph.GA astro-ph.HE hep-ex


title:
Phase field model of cell motility: sharp interface limit in
  sub-critical case

abstract:
  We consider a system of two PDEs arising in modeling of motility of
eukariotic cells on substrates. This system consists of the Allen-Cahn equation
for the scalar phase field function coupled with another vectorial parabolic
equation for the orientation of the actin filament network. The two key
properties of this system are (i) presence of gradients in the coupling terms
(gradient coupling) and (ii) mass (volume) preservation constraints. We first
prove that the sharp interface property of initial conditions is preserved in
time. Next we formally derive the equation of the motion of the interface,
which is the mean curvature motion perturbed by a nonlinear term that appears
due to the properties (i)-(ii). This novel term leads to surprising features of
the the motion of the interface. Because of these properties maximum principle
and classical comparison techniques do not apply to this system. Furthermore,
the system can not be written in a form of gradient flow, which is why recently
developed Gamma-convergence techniques also can not be used for the
justification of the formal derivation. Such justification is presented in a
one-dimensional model problem and it leads to a stability result in a class of
'sharp interface' initial data.


title: Core level spectra in XPS of pristine and doped graphene

abstract:
  Spectra of the C1s core hole, created in XPS and screened by electronic
excitations in pristine and doped graphene, are calculated and discussed. We
find that singular effects in the lineshapes are not possible in the pristine
graphene, and their observation should be connected with the doping. However,
the structure of the low energy excitation spectrum in the region where the
singular behaviour is expected leads to asymmetries in the core hole lineshapes
in pristine graphene similar to those in doped graphene. This makes the
analysis more complex than in the case of metals and may lead to incorrect or
incomplete interpretation of experimental results.


title: Embedded Morse theory and relative splitting of cobordisms of manifolds

abstract:
  We prove that an embedded cobordism between manifolds with boundary can be
split into a sequence of right product and left product cobordisms, if the
codimension of the embedding is at least two. This is a topological counterpart
of the algebraic splitting theorem for embedded cobordisms of the first author,
A. Nemethi and A. Ranicki. In the codimension one case, we provide a slightly
weaker statement. We also give proofs of rearrangement and cancellation
theorems for handles of embedded submanifolds with boundary.


title: Heat kernel and Green function estimates on affine buildings

abstract:
  We obtain the optimal global upper and lower bounds for the transition
density $p_n(x,y)$ of a finite range isotropic random walk on affine buildings.
We present also sharp estimates for the corresponding Green function.


title:
Subband coding for large-scale scientific simulation data using JPEG
  2000

abstract:
  The ISO/IEC JPEG 2000 image coding standard is a family of source coding
algorithms targeting high-resolution image communications. JPEG 2000 features
highly scalable embedded coding features that allow one to interactively zoom
out to reduced resolution thumbnails of enormous data sets or to zoom in on
highly localized regions of interest with very economical communications and
rendering requirements. While intended for fixed-precision input data, the
implementation of the irreversible version of the standard is often done
internally in floating point arithmetic. Moreover, the standard is designed to
support high-bit-depth data. Part 2 of the standard also provides support for
three-dimensional data sets such as multicomponent or volumetric imagery. These
features make JPEG 2000 an appealing candidate for highly scalable
communications coding and visualization of two- and three-dimensional data
produced by scientific simulation software. We present results of initial
experiments applying JPEG 2000 to scientific simulation data produced by the
Parallel Ocean Program (POP) global ocean circulation model, highlighting both
the promise and the many challenges this approach holds for scientific
visualization applications.


title: Modelling Complexity for Policy: Opportunities and Challenges

abstract:
  This chapter reviews the purpose and use of models from the field of complex
systems and, in particular, the implications of trying to use models to
understand or make decisions within complex situations, such as policy makers
usually face. A discussion of the different dimensions one can formalise
situations, the different purposes for models and the different kinds of
relationship they can have with the policy making process, is followed by an
examination of the compromises forced by the complexity of the target issues.
Several modelling approaches from complexity science are briefly described,
with notes as to their abilities and limitations. These approaches include
system dynamics, network theory, information theory, cellular automata, and
agent-based modelling. Some examples of policy models are presented and
discussed in the context of the previous analysis. Finally we conclude by
outlining some of the major pitfalls facing those wishing to use such models
for policy evaluation.


title: Interactive Function Computation with Reconstruction Constraints

abstract:
  This paper investigates two-terminal interactive function computation with
reconstruction constraints. Each terminal wants to compute a (possibly
different) function of two correlated sources, but can only access one of the
sources directly. In addition to distortion constraints at the terminals, each
terminal is required to estimate the computed function value at the other
terminal in a lossy fashion, leading to the constrained reconstruction
constraint. A special case of constrained reconstruction is the common
reconstruction constraint, in which both terminals agree on the functions
computed with probability one. The terminals exchange information in multiple
rate constrained communication rounds. A characterization of the multi-round
rate-distortion region for the above problem with constrained reconstruction
constraints is provided. To gain more insights and to highlight the value of
interaction and order of communication, the rate-distortion region for
computing various functions of jointly Gaussian sources according to common
reconstruction constraints is studied.


title: Information driven current in a quantum Maxwell demon

abstract:
  We describe a minimal model of a quantum Maxwell demon obeying Hamiltonian
dynamics. The model is solved exactly, and we analyze its steady-state
behavior. We find that writing information to a quantum memory induces a
probability current through the demon, which is the quantum analog of the
classical Maxwell demon's action. Our model offers a simple and pedagogical
paradigm for investigating the thermodynamics of quantum information
processing.


title:
Cyclostationary Approach for Heart and Respiration Rates Monitoring with
  Body Movement Cancellation Using Radar Doppler System

abstract:
  Heart and respiration rate measurement using Doppler radar is a non-contact
and non-obstructive way for remote thorough-clothing monitoring of vital signs.
The modulated back-scattered radar signal in the presence of high noise and
interference is non-stationary with hidden periodicities, which cannot be
detected by ordinary Fourier analysis. In this paper we propose a
cyclostationary approach for such signals and show that by using non-linear
transformation and then Fourier analysis of the radar signal, the hidden
periodicities can be accurately obtained. Numerical results show that the vital
signs can be extracted as cyclic frequencies, independent of SNR and without
any filtering or phase unwrapping.


title: The gravo-magneto disc instability with a viscous dead zone

abstract:
  We consider the evolution of accretion discs that contain some turbulence
within a disc dead zone, a region about the disc midplane of a disc that is not
sufficiently ionised for the magneto-rotational instability (MRI) to drive
turbulence. In particular, we determine whether additional sources of
turbulence within a dead zone are capable of suppressing gravo-magneto (GM)
disc outbursts that arise from a rapid transition from gravitationally produced
to MRI produced turbulence. With viscous $\alpha$ disc models we consider two
mechanisms that may drive turbulence within the dead zone. First, we examine a
constant $\alpha$ parameter within the dead zone. This may be applicable to
hydrodynamical instability, such as baroclinic instability, where the
turbulence level is independent of the MRI active surface layer properties. In
this case, we find that the disc will not become stable to the outbursts unless
the dead zone turbulent viscosity is comparable to that in the MRI active
surface layers. Under such conditions, the accretion rate through the dead zone
must be larger than that through the MRI active layers. In a second model, we
assume that the accretion flow though the dead zone is a constant fraction
(less than unity) of that through the active layers. This may be applicable to
turbulence driven by hydrodynamic waves that are excited by the MRI active
surface layers. We find that the instability is hardly affected by the viscous
dead zone. In both cases however, we find that the triggering of the MRI during
the outburst may be due to the heating from the viscosity in the dead zone,
rather than self-gravity. Thus, neither mechanism for generating turbulence
within the dead zone can significantly stabilise a disc or the resulting
outburst behaviour.


title: Cluster Magnification & the Mass-Richness Relation in CFHTLenS

abstract:
  Gravitational lensing magnification is measured with a significance of 9.7
sigma on a large sample of galaxy clusters in the Canada-France-Hawaii
Telescope Lensing Survey (CFHTLenS). This survey covers ~154 deg^2 and contains
over 18,000 cluster candidates at redshifts 0.2 <= z <= 0.9, detected using the
3D-Matched Filter cluster-finder of Milkeraitis et al. (2010). We fit
composite-NFW models to the ensemble, accounting for cluster miscentering,
source-lens redshift overlap, as well as nearby structure (the 2-halo term),
and recover mass estimates of the cluster dark matter halos in range of ~10^13
M_sun to 2*10^14 M_sun. Cluster richness is measured for the entire sample, and
we bin the clusters according to both richness and redshift. A mass-richness
relation M_200 = M_0 (N_200 / 20)^beta is fit to the measurements. For two
different cluster miscentering models we find consistent results for the
normalization and slope, M_0 = (2.3 +/- 0.2)*10^13 M_sun, beta = 1.4 +/- 0.1
and M_0 = (2.2 +/- 0.2)*10^13 M_sun, beta = 1.5 +/- 0.1. We find that
accounting for the full redshift distribution of lenses and sources is
important, since any overlap can have an impact on mass estimates inferred from
flux magnification.


title: Interactive Relay Assisted Source Coding

abstract:
  This paper investigates a source coding problem in which two terminals
communicating through a relay wish to estimate one another's source within some
distortion constraint. The relay has access to side information that is
correlated with the sources. Two different schemes based on the order of
communication, \emph{distributed source coding/delivery} and \emph{two cascaded
rounds}, are proposed and inner and outer bounds for the resulting
rate-distortion regions are provided. Examples are provided to show that
neither rate-distortion region includes the other one.


title:
Producing type Iax supernovae from a specific class of helium-ignited WD
  explosions?

abstract:
  It has recently been proposed that one sub-class of type Ia supernovae (SNe
Ia) is sufficiently both distinct and common to be classified separately from
the bulk of SNe Ia, with a suggested class name of "type Iax supernovae" (SNe
Iax), after SN 2002cx. However, their progenitors are still uncertain. We study
whether the population properties of this class might be understood if the
events originate from a subset of sub-Chandrasekhar mass explosions. In this
potential progenitor population, a carbon--oxygen white dwarf (CO WD)
accumulates a helium layer from a non-degenerate helium star; ignition of that
helium layer then leads to ignition of the CO WD. We incorporated detailed
binary evolution calculations for the progenitor systems into a binary
population synthesis model to obtain rates and delay times for such events. The
predicted Galactic event rate of these explosions is ~1.5\times10^{-3}{yr}^{-1}
according to our standard model, in good agreement with the measured rates of
SNe Iax. In addition, predicted delay times are ~70Myr-800Myr, consistent with
the fact that most of SNe Iax have been discovered in late-type galaxies. If
the explosions are assumed to be double-detonations -- following current model
expectations -- then based on the CO WD masses at explosion we also estimate
the distribution of resulting SN brightness (-13 \gtrsim M_{bol} \gtrsim
-19mag), which can reproduce the empirical diversity of SNe Iax. We speculate
on why binaries with non-degenerate donor stars might lead to SNe Iax if
similar systems with degenerate donors do not. We suggest that the high mass of
the helium layer necessary for ignition at the lower accretion rates typically
delivered from non-degenerate donors might be necessary to produce SN
2002cx-like characteristics, perhaps even by changing the nature of the CO
ignition.


title: SAT-based Preprocessing for MaxSAT (extended version)

abstract:
  State-of-the-art algorithms for industrial instances of MaxSAT problem rely
on iterative calls to a SAT solver. Preprocessing is crucial for the
acceleration of SAT solving, and the key preprocessing techniques rely on the
application of resolution and subsumption elimination. Additionally,
satisfiability-preserving clause elimination procedures are often used. Since
MaxSAT computation typically involves a large number of SAT calls, we are
interested in whether an input instance to a MaxSAT problem can be preprocessed
up-front, i.e. prior to running the MaxSAT solver, rather than (or, in addition
to) during each iterative SAT solver call. The key requirement in this setting
is that the preprocessing has to be sound, i.e. so that the solution can be
reconstructed correctly and efficiently after the execution of a MaxSAT
algorithm on the preprocessed instance. While, as we demonstrate in this paper,
certain clause elimination procedures are sound for MaxSAT, it is well-known
that this is not the case for resolution and subsumption elimination. In this
paper we show how to adapt these preprocessing techniques to MaxSAT. To achieve
this we recast the MaxSAT problem in a recently introduced labelled-CNF
framework, and show that within the framework the preprocessing techniques can
be applied soundly. Furthermore, we show that MaxSAT algorithms restated in the
framework have a natural implementation on top of an incremental SAT solver. We
evaluate the prototype implementation of a MaxSAT algorithm WMSU1 in this
setting, demonstrate the effectiveness of preprocessing, and show overall
improvement with respect to non-incremental versions of the algorithm on some
classes of problems.


title: Search for Exotic Top Partners at sqrt(s) = 8 TeV

abstract:
  We present searches for heavy top and bottom quark partners at CMS using data
collected at sqrt(s) = 8 TeV. Such partners, if vector-like, occur in models
such as the Little Higgs and Large Extra Dimensions. Fermionic top partners
could also occur in composite Higgs models. The searches presented here span a
wide range of final states, from lepton plus jets to multi-leptonic, and
exclusion limits are set on mass and production cross sections as a function of
branching ratios of the heavy quarks to their decay products.


title: Speculative Staging for Interpreter Optimization

abstract:
  Interpreters have a bad reputation for having lower performance than
just-in-time compilers. We present a new way of building high performance
interpreters that is particularly effective for executing dynamically typed
programming languages. The key idea is to combine speculative staging of
optimized interpreter instructions with a novel technique of incrementally and
iteratively concerting them at run-time.
  This paper introduces the concepts behind deriving optimized instructions
from existing interpreter instructions---incrementally peeling off layers of
complexity. When compiling the interpreter, these optimized derivatives will be
compiled along with the original interpreter instructions. Therefore, our
technique is portable by construction since it leverages the existing
compiler's backend. At run-time we use instruction substitution from the
interpreter's original and expensive instructions to optimized instruction
derivatives to speed up execution.
  Our technique unites high performance with the simplicity and portability of
interpreters---we report that our optimization makes the CPython interpreter up
to more than four times faster, where our interpreter closes the gap between
and sometimes even outperforms PyPy's just-in-time compiler.


title: WISE detections of known QSOs at redshifts greater than six

abstract:
  We present WISE All-Sky mid-infrared (IR) survey detections of 55% (17/31) of
the known QSOs at z>6 from a range of surveys: the SDSS, the CFHT-LS, FIRST,
Spitzer and UKIDSS. The WISE catalog thus provides a substantial increase in
the quantity of IR data available for these sources: 17 are detected in the
WISE W1 (3.4-micron) band, 16 in W2 (4.6-micron), 3 in W3 (12-micron) and 0 in
W4 (22-micron). This is particularly important with Spitzer in its warm-mission
phase and no faint follow-up capability at wavelengths longwards of 5 microns
until the launch of JWST. WISE thus provides a useful tool for understanding
QSOs found in forthcoming large-area optical/IR sky surveys, using PanSTARRS,
SkyMapper, VISTA, DES and LSST. The rest-UV properties of the WISE-detected and
the WISE-non-detected samples differ: the detections have brighter i/z-band
magnitudes and redder rest-UV colors. This suggests that a more aggressive hunt
for very-high-redshift QSOs, by combining WISE W1 and W2 data with red observed
optical colors could be effective at least for a subset of dusty candidate
QSOs. Stacking the WISE images of the WISE-non-detected QSOs indicates that
they are on average significantly fainter than the WISE-detected examples, and
are thus not narrowly missing detection in the WISE catalog. The WISE-catalog
detection of three of our sample in the W3 band indicates that their mid-IR
flux can be detected individually, although there is no stacked W3 detection of
sources detected in W1 but not W3. Stacking analyses of WISE data for large AGN
samples will be a useful tool, and high-redshift QSOs of all types will be easy
targets for JWST.


title:
Non-CMC Solutions of the Einstein Constraint Equations on Compact
  Manifolds with Apparent Horizon Boundaries

abstract:
  In this article we continue our effort to do a systematic development of the
solution theory for conformal formulations of the Einstein constraint equations
on compact manifolds with boundary. By building in a natural way on our recent
work in Holst and Tsogtgerel (2013), and Holst, Nagy, and Tsogtgerel (2008,
2009), and also on the work of Maxwell (2004, 2005, 2009) and Dain (2004),
under reasonable assumptions on the data we prove existence of both near- and
far-from-constant mean curvature solutions for a class of Robin boundary
conditions commonly used in the literature for modeling black holes, with a
third existence result for constant mean curvature (CMC) appearing as a special
case. Dain and Maxwell addressed initial data engineering for space-times that
evolve to contain black holes, determining solutions to the conformal
formulation on an asymptotically Euclidean manifold in the CMC setting, with
interior boundary conditions representing excised interior black hole regions.
Holst and Tsogtgerel compiled the interior boundary results covered by Dain and
Maxwell, and then developed general interior conditions to model the apparent
horizon boundary conditions of Dain and Maxwell for compact manifolds with
boundary, and subsequently proved existence of solutions to the Lichnerowicz
equation on compact manifolds with such boundary conditions. This paper picks
up where Holst and Tsogtgerel left off, addressing the general non-CMC case for
compact manifolds with boundary. As in our previous articles, our focus here is
again on low regularity data and on the interaction between different types of
boundary conditions. While our work here serves primarily to extend the
solution theory for the compact with boundary case, we also develop several
technical tools that have potential for use with the asymptotically Euclidean
case.


title: The Einstein Constraint Equations on Compact Manifolds with Boundary

abstract:
  We continue the study of the Einstein constraint equations on compact
manifolds with boundary initiated by Holst and Tsogtgerel. In particular, we
consider the full system and prove existence of solutions in both the near-CMC
and far-from-CMC (for Yamabe positive metrics) cases. We also make partial
progress in proving the results of previous "limit equation" papers by Dahl,
Gicquaud, Humbert and Sakovich.


title: Mirror symmetry for Pfaffian Calabi-Yau 3-folds via conifold transitions

abstract:
  In this note we construct conifold transitions between several Calabi-Yau
threefolds given by Pfaffians in weighted projective spaces and Calabi-Yau
threefolds appearing as complete intersections in toric varieties. We use the
obtained results to predict mirrors following ideas of \cite{BCKS,
Batsmalltoricdegen}. In particular we consider the family of Calabi--Yau
threefolds of degree 25 in $\mathbb{P}^9$ obtained as a transverse intersection
of two Grassmannians in their Plucker embeddings.


title: Gain scaling for multirate filter banks

abstract:
  Eliminating two trivial degrees of freedom corresponding to the lowpass DC
response and the highpass Nyquist response in a two-channel multirate filter
bank seems simple enough. Nonetheless, the ISO/IEC JPEG 2000 image coding
standard manages to make this mundane task look totally mysterious. We reveal
the true meaning behind JPEG 2000's arcane specifications for filter bank
normalization and point out how the seemingly trivial matter of gain scaling
leads to highly nontrivial issues concerning uniqueness of lifting
factorizations.


title:
Robust Adaptive Control for Circadian Dynamics: Poincare Approach to
  Backstepping Method

abstract:
  A mathematical model of the circadian dynamics in the form of Van der Pol
equation with an external force as a control is investigated. The combination
of backstepping method and differential-topological techniques based on the
Poincare's ideas is used. The robust model identification adaptive control for
a specific adaptation law is designed.


title: An inquiry-based laboratory on friction

abstract:
  Sliding friction is usually introduced in high school, but rarely through
activities in laboratory. A qualitative introduction to friction is presented
by proposing exploration of different kind of materials in order to suggest
which aspects can be relevant and which interaction is involved. Different
quantitative experiments are proposed for studying Leonardo's laws for
friction. The learning path was tested with two high school classes during an
instruction trip at department. Students were engaged in the inquiry-based
introductory activity and seemed to realize with care the measurements.
However, the analysis of their reports shows some learning difficulties.


title:
Two charges on plane in a magnetic field I. "Quasi-equal" charges and
  neutral quantum system at rest cases

abstract:
  Low-lying bound states for the problem of two Coulomb charges of finite
masses on a plane subject to a constant magnetic field $B$ perpendicular to the
plane are considered. Major emphasis is given to two systems: two charges with
the equal charge-to-mass ratio (quasi-equal charges) and neutral systems with
concrete results for the Hydrogen atom and two electrons (quantum dot). It is
shown that for these two cases, but when a neutral system is at rest (the
center-of-mass momentum is zero), some outstanding properties occur: in double
polar coordinates in CMS $(R, \phi)$ and relative $(\rho, \varphi)$ coordinate
systems (i) the eigenfunctions are factorizable, all factors except for
$\rho$-dependent are found analytically, they have definite relative angular
momentum, (ii) dynamics in $\rho$-direction is the same for both systems being
described by a funnel-type potential; (iii) at some discrete values of
dimensionless magnetic fields $b \leq 1$ the system becomes {\it
quasi-exactly-solvable} and a finite number of eigenfunctions in $\rho$ are
polynomials. The variational method is employed. Trial functions are based on
combining for the phase of a wavefunction (a) the WKB expansion at large
distances, (b) the perturbation theory at small distances (c) with a form of
the known analytically (quasi-exactly-solvable) eigenfunctions. For the lowest
states with relative magnetic quantum numbers $s=0,1,2$ this approximation
gives not less than 7 s.d., 8 s.d., 9 s.d., respectively, for the total energy
$E(B)$ for magnetic fields $0.049\, \text{a.u.} < B < 2000\, \text{a.u.} $
(Hydrogen atom) and $0.025\, \text{a.u.}\eqslantless B \eqslantless 1000\,
\text{a.u.} $ (two electrons).


title:
Orbital orientation evolution of massive binary black holes at the
  centres of non-spherical galaxies

abstract:
  At the centre of a spherical and kinematically isotropic galaxy, the
orientation of a massive binary black hole (BBH) orbit (i.e., the direction of
the BBH orbital angular momentum) undergoes a random walk. If the stars in a
spherical system have a non-zero total angular momentum, the BBH orbital
orientation evolves towards aligning with the total stellar angular momentum
direction. In this paper, we show that a triaxial galaxy has an
alignment-erasing effect, that is, the alignment of the BBH orientations
towards the galaxy rotation axis can be decreased significantly or erased. We
also show that in a non-rotating axisymmetric galaxy, the BBH orbital
orientation evolves towards the axisymmetric axis and precesses about it in a
retrograde direction. Our results provide a step towards understanding the spin
orientations of the final merged BH (and hence probable orientation of any jet
produced) within its host galaxy, and may help to constrain the recoiling
velocity of the merged BH arose from gravitational wave radiation as well.


title:
On the birationality of complete intersections associated to
  nef-partitions

abstract:
  We prove that generic complete intersections associated to multiple mirror
nef-partitions are all birational. This result solves a conjecture by Batyrev
and Nill under some mild assumptions.


title:
Fixed-node errors in quantum Monte Carlo: interplay of electron density
  and node nonlinearities

abstract:
  We elucidate the origin of large differences (two-fold or more) in the
fixed-node errors between the first- vs second-row systems for
single-configuration trial wave functions in quantum Monte Carlo calculations.
This significant difference in the fixed-node biases is studied across a set of
atoms, molecules, and also Si, C solid crystals. The analysis is done over
valence isoelectronic systems that share similar correlation energies, bond
patterns, geometries, ground states, and symmetries. We show that the key
features which affect the fixed-node errors are the differences in electron
density and the degree of node nonlinearity. The findings reveal how the
accuracy of the quantum Monte Carlo varies across a variety of systems, provide
new perspectives on the origins of the fixed-node biases in electronic
structure calculations of molecular and condensed systems, and carry
implications for pseudopotential constructions for heavy elements

categories: physics.comp-ph cond-mat.mtrl-sci physics.atom-ph physics.chem-ph


title: Generalized Fourier frames in terms of balayage

abstract:
  Based on Beurling's theory of balayage, we develop the theory of non-uniform
sampling in the context of the theory of frames for the settings of the Short
Time Fourier Transform and pseudo-differential operators. There is sufficient
complexity to warrant new examples generally, and to resurrect the formulation
of balayage in terms of covering criteria with an eye towards an expanded
theory as well as computational implementation.


title: Optical Asymmetry Induced by PT-symmetric Nonlinear Fano Resonances

abstract:
  We introduce a new type of Fano resonances, realized in a photonic circuit
which consists of two nonlinear PT-symmetric micro-resonators side-coupled to a
waveguide, which have line-shape and resonance position that depends on the
direction of the incident light. We utilize these features in order to induce
asymmetric transport up to 47 dBs in the optical C-window. Our set-up requires
low input power and does not compromise the power and frequency characteristics
of the output signal.


title:
First Searches for Optical Counterparts to Gravitational-wave Candidate
  Events

abstract:
  During the LIGO and Virgo joint science runs in 2009-2010, gravitational wave
(GW) data from three interferometer detectors were analyzed within minutes to
select GW candidate events and infer their apparent sky positions. Target
coordinates were transmitted to several telescopes for follow-up observations
aimed at the detection of an associated optical transient. Images were obtained
for eight such GW candidates. We present the methods used to analyze the image
data as well as the transient search results. No optical transient was
identified with a convincing association with any of these candidates, and none
of the GW triggers showed strong evidence for being astrophysical in nature. We
compare the sensitivities of these observations to several model light curves
from possible sources of interest, and discuss prospects for future joint
GW-optical observations of this type.


title: Regular CW-complexes and poset resolutions of monomial ideals

abstract:
  We use the natural homeomorphism between a regular CW-complex X and its face
poset P_X to establish a canonical isomorphism between the cellular chain
complex of X and the result of applying the poset construction of
arXiv:0806.4532v1 to P_X. For a monomial ideal whose free resolution is
supported on a regular CW-complex, this isomorphism allows the free resolution
of the ideal to be realized as a CW-poset resolution. Conversely, any CW-poset
resolution of a monomial ideal gives rise to a resolution supported on a
regular CW-complex.


title: Dielectric Bow-tie Nanocavity

abstract:
  We propose a novel dielectric bow-tie nanocavity consisting of two tip-to-tip
opposite triangle semiconductor nanowires, whose end faces are coated by silver
nanofilms. Based on the advantages of the dielectric slot and tip structures,
and the high reflectivity from the silver mirror, light can be confined in this
nanocavity with low loss. We demonstrate that the mode excited in this
nanocavity has a deep subwavelength mode volume of 2.8*10^-4 um3 and a high
quality factor of 4.9*10^4 (401.3), consequently an ultrahigh Purcell factor of
1.6*10^7 (1.36*10^5), at 4.5 K (300 K) around the resonance wavelength of 1550
nm. This dielectric bow-tie nanocavity may find applications for integrated
nanophotonic circuits, such as high-efficiency single photon source,
thresholdless nanolaser, and cavity QED strong coupling experiments.


title: Why X(3915) is so narrow as a $\chi_{c0}(2P)$ state

abstract:
  New resonance X(3915) was identified as the charmonium $\chi_{c0}(2P)$ by
BABAR Collaboration, but there seems still open question of this assignment:
why its full width is so narrow? To answer this question, we calculate the
Okubo-Zweig-Iizuka (OZI) allowed strong decays $X(3915)\to D \bar D$, where
X(3915) is assigned as a $\chi_{c0}(2P)$ state, and estimate its full width in
the cooperating framework of $^3/!P_0^{}$ model and the Bethe-Salpeter (BS)
method using the Mandelstam Formalism, during which non-perturbative QCD
effects of the hadronic matrix elements are well considered by overlapping
integral over the relativistic Salpeter wave functions of the initial and
finial states. We find the node structure of $\chi_{c0}(2P)$ wave function
resulting in the narrow width of X(3915) and show the dependence of the decay
width on the variation of the initial mass of X(3915). We point out that the
rate of $\frac{\Gamma(X(3915)\to D^+ D^-)}{\Gamma(X(3915)\to D^0 \bar D^0)}$ is
crucial to confirm whether X(3915) is the $\chi_{c0}(2P)$ state or not.