title:
The semi-inclusive jet function in SCET and small radius resummation for
  inclusive jet production

abstract:
  We introduce a new kind of jet function: the semi-inclusive jet function
$J_i(z, \omega_J, \mu)$, which describes how a parton $i$ is transformed into a
jet with a jet radius $R$ and energy fraction $z = \omega_J/\omega$, with
$\omega_J$ and $\omega$ being the large light-cone momentum component of the
jet and the corresponding parton $i$ that initiates the jet, respectively.
Within the framework of Soft Collinear Effective Theory (SCET) we calculate
both $J_q(z, \omega_J, \mu)$ and $J_g(z, \omega_J, \mu)$ to the next-to-leading
order (NLO) for cone and anti-k$_{\rm T}$ algorithms. We demonstrate that the
renormalization group (RG) equations for $J_i(z, \omega_J, \mu)$ follow exactly
the usual DGLAP evolution, which can be used to perform the $\ln R$ resummation
for {\it inclusive} jet cross sections with a small jet radius $R$. We clarify
the difference between our RG equations for $J_i(z, \omega_J, \mu)$ and those
for the so-called unmeasured jet functions $J_i(\omega_J, \mu)$, widely used in
SCET for {\it exclusive} jet production. Finally, we present applications of
the new semi-inclusive jet functions to inclusive jet production in $e^+e^-$
and $pp$ collisions. We demonstrate that single inclusive jet production in
these collisions shares the same short-distance hard functions as single
inclusive hadron production, with only the fragmentation functions $D_i^h(z,
\mu)$ replaced by $J_i(z, \omega_J, \mu)$. This can facilitate more efficient
higher-order analytical computations of jet cross sections. We further match
our $\ln R$ resummation at both LL$_{R}$ and NLL$_{R}$ to fixed NLO results and
present the phenomenological implications for single inclusive jet production
at the LHC.


title: A Second Peak in Diphoton (or Diboson) Resonances

abstract:
  Many new physics models contain a neutral scalar resonance that can be
predominantly produced via gluon fusion through loops. In such a case, there
could be important effects of additional particles, that in turn may hadronize
before decaying and form bound states. This interesting possibility may lead to
novel signatures with double peaks that can be searched for at the LHC. We
study the phenomenology of double peak searches in diboson final states from
loop induced production and decay of a new neutral spin-0 resonance at the LHC.
The loop-induced couplings should be mediated by particles carrying color and
electroweak charge that after forming bound states will induce a second peak in
the diboson invariant mass spectrum near twice their mass. A second peak could
be present via loop-induced couplings into $gg$ (dijet), $\gamma\gamma$ and
$Z\gamma$ final states as well as in the $WW$ and $ZZ$ channels for the case of
a pseudo-scalar resonance or for scalars with suppressed tree-level coupling to
gauge bosons.


title: The Impact of Star Formation Feedback on the Circumgalactic Medium

abstract:
  We use idealized 3D hydrodynamic simulations to study the dynamics and
thermal structure of the circumgalactic medium (CGM). Our simulations quantify
the role of cooling, stellar feedback driven galactic winds and cosmological
gas accretion in setting the properties of the CGM in dark matter haloes
ranging from $10^{11}$ to $10^{12}$ M$_\odot$. Our simulations support a
conceptual picture in which the properties of the CGM, and the key physics
governing it, change markedly near a critical halo mass of M$_{\rm crit}
\approx 10^{11.5}$ M$_\odot$. As in calculations without stellar feedback,
above M$_{\rm crit}$ halo gas is supported by thermal pressure created in the
virial shock. The thermal properties at small radii are regulated by feedback
triggered when $t_{\rm cool}/t_{\rm ff}\lesssim10$ in the hot gas. Below
M$_{\rm crit}$, however, there is no thermally supported halo and
self-regulation at $t_{\rm cool}/t_{\rm ff}\sim10$ does not apply. Instead, the
gas is out of hydrostatic equilibrium and largely supported against gravity by
bulk flows (turbulence and coherent inflow/outflow) arising from the
interaction between cosmological gas inflow and outflowing galactic winds. In
these lower mass haloes, the phase structure depends sensitively on the
outflows' energy per unit mass and mass-loading, which may allow measurements
of the CGM thermal state to constrain the nature of galactic winds. Our
simulations account for some of the properties of the multiphase halo gas
inferred from quasar absorption line observations, including the presence of
significant mass at a wide range of temperatures, and the characteristic OVI
and CIV column densities and kinematics. However, we underpredict the neutral
hydrogen content of the $z\sim0$ CGM.


title: The Renaissance of Kaon Flavour Physics

abstract:
  There is no doubt that in the coming years we will witness the renaissance of
kaon flavour physics with crucial measurements of the branching ratios for the
rare decays $K^+\rightarrow\pi^+\nu\bar\nu$ and
$K_{L}\rightarrow\pi^0\nu\bar\nu$ that are very sensitive to new physics (NP)
and are theoretically very clean. Simultaneously the role of
$\varepsilon'/\varepsilon$, $\varepsilon_K$, $\Delta M_K$, $K_L\to\mu^+\mu^-$
and $K_L\to\pi^0\ell^+\ell^-$ in searching for NP will significantly increase
through their improved estimates within the SM. In fact the hints for NP
contributing to $\varepsilon'/\varepsilon$ have been signalled last year
through improved estimates of hadronic matrix elements of QCD and electroweak
penguin operators $Q_6$ and $Q_8$ by lattice QCD and large $N$ dual QCD
approach. Also recent increased tensions between $\varepsilon_K$ and $\Delta
M_{s,d}$ mass differences in $B_{s,d}^0-\bar B_{s,d}^0$ mixing within the SM
and models with constrained MFV tell us that we should have tremendous fun in
chasing NP through all these observables. The present talk discusses the hinted
anomalies in $\varepsilon'/\varepsilon$,and $\Delta F=2$ transitions and
summarizes possible implications of simultaneous anomalies in
$\varepsilon'/\varepsilon$ and $\varepsilon_K$ for
$K^+\rightarrow\pi^+\nu\bar\nu$ and $K_{L}\rightarrow\pi^0\nu\bar\nu$ and
$\Delta M_K$ in models with tree-level $Z$ and $Z^\prime$ exchanges. The
anomalies in $\varepsilon'/\varepsilon$ and $\varepsilon_K$, if confirmed,
would signal new sources of CP violation. This is in contrast to the recent
anomalies in $B$ physics that signal lepton flavour non-universalities and NP
in CP-conserving observables. Highlights from recent flavour analyses of 331
models are briefly described.


title:
Relativistic reverberation in the accretion flow of a tidal disruption
  event

abstract:
  Our current understanding of the curved space-time around supermassive black
holes is based on actively accreting black holes, which make up only ten per
cent or less of the overall population. X-ray observations of that small
fraction reveal strong gravitational redshifts that indicate that many of these
black holes are rapidly rotating; however, selection biases suggest that these
results are not necessarily reflective of the majority of black holes in the
Universe. Tidal disruption events, where a star orbiting an otherwise dormant
black hole gets tidally shredded and accreted onto the black hole, can provide
a short, unbiased glimpse at the space-time around the other ninety per cent of
black holes. Observations of tidal disruptions have hitherto revealed the
formation of an accretion disk and the onset of an accretion-powered jet, but
have failed to reveal emission from the inner accretion flow, which enables the
measurement of black hole spin. Here we report observations of reverberation
arising from gravitationally redshifted iron K photons reflected off the inner
accretion flow in the tidal disruption event Swift J1644+57. From the
reverberation timescale, we estimate the mass of the black hole to be a few
million solar masses, suggesting an accretion rate of 100 times the Eddington
limit or more. The detection of reverberation from the relativistic depths of
this rare super-Eddington event demonstrates that the X-rays do not arise from
the relativistically moving regions of a jet, as previously thought.


title: Criticality in Formal Languages and Statistical Physics

abstract:
  We show that the mutual information between two symbols, as a function of the
number of symbols between the two, decays exponentially in any probabilistic
regular grammar, but can decay like a power law for a context-free grammar.
This result about formal languages is closely related to a well-known result in
classical statistical mechanics that there are no phase transitions in
dimensions fewer than two. It is also related to the emergence of power-law
correlations in turbulence and cosmological inflation through recursive
generative processes. We elucidate these physics connections and comment on
potential applications of our results to machine learning tasks like training
artificial recurrent neural networks. Along the way, we introduce a useful
quantity which we dub the rational mutual information and discuss
generalizations of our claims involving more complicated Bayesian networks.


title: Prospects for natural SUSY

abstract:
  As we anticipate the first results of the 2016 run, we assess the discovery
potential of the LHC to `natural supersymmetry'. To begin with, we explore the
region of the model parameter space that can be excluded with various
centre-of-mass energies (13 TeV and 14 TeV) and different luminosities (20
fb$^{-1}$, 100 fb$^{-1}$, 300 fb$^{-1}$ and 3000 fb$^{-1}$). We find that the
bounds at 95% CL on stops vary from $m_{\tilde{t}_1}\gtrsim 900$ GeV expected
this summer to $m_{\tilde{t}_1}\gtrsim 1500$ GeV at the end of the high
luminosity run, while gluino bounds are expected to range from
$m_{\tilde{g}}\gtrsim 1700$ GeV to $m_{\tilde{g}}\gtrsim 2500$ GeV over the
same time period. However, more pessimistically we find that if no signal
begins to appear this summer, only a very small region of parameter space can
be discovered with 5-$\sigma$ significance. For this conclusion to change, we
find that both theoretical and systematic uncertainties will need to be
significantly reduced.


title:
Clumpy high-z galaxies as a testbed for feedback-regulated galaxy
  formation

abstract:
  We study the dependence of fragmentation in massive gas-rich galaxy disks at
$z > 1$ on feedback model and hydrodynamical method, employing the GASOLINE2
SPH code and the lagrangian mesh-less code GIZMO in finite mass mode. We
compare non-cosmological galaxy disk runs with standard blastwave supernovae
(SN)feedback, which introduces delayed cooling in order to drive winds, and
runs with the new superbubble SN feedback, which produces winds naturally by
modelling the detailed physics of SN-driven bubbles and leads to efficient
self-regulation of star formation. We find that, with blastwave feedback,
massive star forming clumps form in comparable number and with very similar
masses in GASOLINE2 and GIZMO. The typical masses are in the range $10^7-10^8
M_{\odot}$, lower than in most previous works, while giant clumps with masses
above $10^9 M_{\odot}$ are exceedingly rare. With superbubble feedback,
instead, massive bound star forming clumps do not form because galaxies never
undergo a phase of violent disk instability. Only sporadic, unbound star
forming overdensities lasting only a few tens of Myr can arise that are
triggered by perturbations of massive satellite companions. We conclude that
there is a severe tension between explaining massive star forming clumps
observed at $z > 1$ primarily as the result of disk fragmentation driven by
gravitational instability and the prevailing view of feedback-regulated galaxy
formation. The link between disk stability and star formation efficiency should
thus be regarded as a key testing ground for galaxy formation theory.


title: Atmosphere-interior exchange on hot rocky exoplanets

abstract:
  We provide estimates of atmospheric pressure and surface composition on
short-period rocky exoplanets with dayside magma pools and silicate vapor
atmospheres. Atmospheric pressure tends toward vapor-pressure equilibrium with
surface magma, and magma-surface composition is set by the competing effects of
fractional vaporization and surface-interior exchange. We use basic models to
show how surface-interior exchange is controlled by the planet's temperature,
mass, and initial composition. We assume that mantle rock undergoes bulk
melting to form the magma pool, and that winds flow radially away from the
substellar point. With these assumptions, we find that: (1) atmosphere-interior
exchange is fast when the planet's bulk-silicate FeO concentration is low, and
slow when FeO concentration is high; (2) magma pools are compositionally
well-mixed for substellar temperatures $\lesssim$ 2400 K, but compositionally
variegated and rapidly variable for substellar temperatures $\gtrsim$ 2400 K;
(3) currents within the magma pool tend to cool the top of the solid mantle
("tectonic refrigeration"); (4) contrary to earlier work, many magma planets
have time-variable surface compositions.


title: LOFAR VLBI Studies at 55 MHz of 4C 43.15, a z=2.4 Radio Galaxy

abstract:
  The correlation between radio spectral index and redshift has been exploited
to discover high redshift radio galaxies, but its underlying cause is unclear.
It is crucial to characterise the particle acceleration and loss mechanisms in
high redshift radio galaxies to understand why their radio spectral indices are
steeper than their local counterparts. Low frequency information on scales of
$\sim$1 arcsec are necessary to determine the internal spectral index
variation. In this paper we present the first spatially resolved studies at
frequencies below 100 MHz of the $z = 2.4$ radio galaxy 4C 43.15 which was
selected based on its ultra-steep spectral index ($\alpha < -1$; $S_{\nu} \sim
\nu^{\alpha}$ ) between 365 MHz and 1.4 GHz. Using the International Low
Frequency Array (LOFAR) Low Band Antenna we achieve sub-arcsecond imaging
resolution at 55 MHz with VLBI techniques. Our study reveals low-frequency
radio emission extended along the jet axis, which connects the two lobes. The
integrated spectral index for frequencies $<$ 500 MHz is -0.83. The lobes have
integrated spectral indices of -1.31$\pm$0.03 and -1.75$\pm$0.01 for
frequencies $\geq$1.4 GHz, implying a break frequency between 500 MHz and 1.4
GHz. These spectral properties are similar to those of local radio galaxies. We
conclude that the initially measured ultra-steep spectral index is due to a
combination of the steepening spectrum at high frequencies with a break at
intermediate frequencies.


title:
A High Fraction of Double-peaked Narrow Emission Lines in Powerful
  Active Galactic Nuclei

abstract:
  One percent of redshift z~0.1 Active Galactic Nuclei (AGNs) show velocity
splitting of a few hundred km/s in the narrow emission lines in spatially
integrated spectra. Such line profiles have been found to arise from the bulk
motion of ionized gas clouds associated with galactic-scale outflows, merging
pairs of galaxies each harboring a supermassive black hole (SMBH), and/or
galactic-scale disk rotation. It remains unclear, however, how the frequency of
narrow-line velocity splitting may depend on AGN luminosity. Here we study the
correlation between the fraction of Type 2 AGNs with double-peaked narrow
emission lines and AGN luminosity as indicated by [O III]5007 emission-line
luminosity L_[O III]. We combine the sample of Liu et al. (2010) at z~0.1 with
a new sample of 178 Type 2 AGNs with double-peaked [O III] emission lines at
z~0.5. We select the new sample from a parent sample of 2089 Type 2 AGNs from
the SDSS-III/Baryon Oscillation Spectroscopic Survey. We find a statistically
significant (~4.2\sigma) correlation between L_[O III] and the fraction of
objects that exhibit double-peaked narrow emission lines among all Type 2 AGNs,
corrected for selection bias and incompleteness due to [O III] line width,
equivalent width, splitting velocity, and/or equivalent width ratio between the
two velocity components. Our result suggests that galactic-scale outflows
and/or merging pairs of SMBHs are more prevalent in more powerful AGNs,
although spatially resolved follow up observations are needed to resolve the
origin(s) for the narrow-line velocity splitting for individual AGNs.


title:
Kinematical evolution of tidally limited star clusters: the role of
  retrograde stellar orbits

abstract:
  The presence of an external tidal field often induces significant dynamical
evolutionary effects on the internal kinematics of star clusters. Previous
studies investigating the restricted three-body problem with applications to
star cluster dynamics have shown that unbound stars on retrograde orbits (with
respect to the direction of the cluster's orbit) are more stable against escape
than prograde orbits, and predicted that a star cluster might acquire
retrograde rotation through preferential escape of stars on prograde orbits. In
this study we present evidence of this prediction, but we also illustrate that
there are additional effects that cannot be accounted for by the preferential
escape of prograde orbits alone. Specifically, in the early evolution,
initially underfilling models increase their fraction of retrograde stars
without losing significant mass, and acquire a retrograde angular velocity. We
attribute this effect to the development of preferentially eccentric/radial
orbits in the outer regions of star clusters as they are expanding into their
tidal limitation.
  We explore the implications of the evolution of the fraction of prograde and
retrograde stars for the evolution of the cluster internal rotation, and its
dependence on the initial structural properties. Although all the systems
studied here evolve towards an approximately solid-body internal rotation with
angular velocity equal to about half of the angular velocity of the cluster
orbital motion around the host galaxy, the evolutionary history of the radial
profile of the cluster internal angular velocity depends on the cluster initial
structure.


title:
Searching for Scatterers: High-Contrast Imaging of Young Stars Hosting
  Wide-Separation Planetary-Mass Companions

abstract:
  We have conducted an angular differential imaging survey with NIRC2 at Keck
in search of close-in substellar companions to a sample of seven systems with
confirmed planetary-mass companions (PMCs) on wide orbits (>50 AU). These
wide-separation PMCs pose significant challenges to all three possible
formation mechanisms: core accretion plus scattering, disk instability, and
turbulent fragmentation. We explore the possibility that these companions
formed closer in and were scattered out to their present-day locations by
searching for other massive bodies at smaller separations. The typical
sensitivity for this survey is \Delta K ~ 12.5 at 1". We identify eight
candidate companions, whose masses would reach as low as one Jupiter mass if
gravitationally bound. From our multi-epoch astrometry we determine that seven
of these are conclusively background objects, while the eighth near DH Tau is
ambiguous and requires additional monitoring. We rule out the presence of >7
M$_{\rm Jup}$ bodies in these systems down to 15 - 50 AU that could be
responsible for scattering. This result combined with the totality of evidence
suggests that dynamical scattering is unlikely to have produced this population
of PMCs. We detect orbital motion from the companions ROXs 42B b and ROXs 12 b,
and from this determine 95% upper limits on the companions' eccentricities of
0.58 and 0.83 respectively. Finally, we find that the 95% upper limit on the
occurrence rate of additional planets with masses between 5 - 15 M$_{\rm Jup}$
outside of 40 AU in systems with PMCs is 54%.


title:
Embeddings between weighted complementary local Morrey-type spaces and
  weighted local Morrey-type spaces

abstract:
  In this paper embeddings between weighted complementary local Morrey-type
spaces ${\,^{^{\bf c}}\!}LM_{p\theta,\omega}({\mathbb R}^n,v)$ and weighted
local Morrey-type spaces $LM_{p\theta,\omega}({\mathbb R}^n,v)$ are
characterized. In particular, two-sided estimates of the optimal constant $c$
in the inequality
  \begin{equation*}
  \bigg( \int_0^{\infty} \bigg( \int_{B(0,t)} f(x)^{p_2}v_2(x)\,dx
\bigg)^{\frac{q_2}{p_2}} u_2(t)\,dt\bigg)^{\frac{1}{q_2}} \le c \bigg(
\int_0^{\infty} \bigg( \int_{{\,^{^{\bf c}}\!}B(0,t)} f(x)^{p_1}
v_1(x)\,dx\bigg)^{\frac{q_1}{p_1}} u_1(t)\,dt\bigg)^{\frac{1}{q_1}}
  \end{equation*} are obtained, where $p_1,\,p_2,\,q_1,\,q_2 \in (0,\infty)$,
$p_2 \le q_2$ and $u_1,\,u_2$ and $v_1,\,v_2$ are weights on $(0,\infty)$ and
${\mathbb R}^n$, respectively. The proof is based on the combination of duality
techniques with estimates of optimal constants of the embeddings between
weighted local Morrey-type and complementary local Morrey-type spaces and
weighted Lebesgue spaces, which reduce the problem to the solutions of the
iterated Hardy-type inequalities.


title:
Approximate Recovery in Changepoint Problems, from $\ell_2$ Estimation
  Error Rates

abstract:
  In the 1-dimensional multiple changepoint detection problem, we prove that
any procedure with a fast enough $\ell_2$ error rate, in terms of its
estimation of the underlying piecewise constant mean vector, automatically has
an (approximate) changepoint screening property---specifically, each true jump
in the underlying mean vector has an estimated jump nearby. We also show, again
assuming only knowledge of the $\ell_2$ error rate, that a simple
post-processing step can be used to eliminate spurious estimated changepoints,
and thus delivers an (approximate) changepoint recovery
property---specifically, in addition to the screening property described above,
we are assured that each estimated jump has a true jump nearby. As a special
case, we focus on the application of these results to the 1-dimensional fused
lasso, i.e., 1-dimensional total variation denoising, and compare the
implications with existing results from the literature. We also study
extensions to related problems, such as changepoint detection over graphs.


title:
Momentum and charge transport in non-relativistic holographic fluids
  from Ho\v{r}ava gravity

abstract:
  We study the linearized transport of transverse momentum and charge in a
conjectured field theory dual to a black brane solution of Horava gravity with
Lifshitz exponent $z=1$. As expected from general hydrodynamic reasoning, we
find that both of these quantities are diffusive over distance and time scales
larger than the inverse temperature. We compute the diffusion constants and
conductivities of transverse momentum and charge, as well the ratio of shear
viscosity to entropy density, and find that they differ from their relativistic
counterparts. To derive these results, we propose how the holographic
dictionary should be modified to deal with the multiple horizons and differing
propagation speeds of bulk excitations in Horava gravity. When possible, as a
check on our methods and results, we use the covariant Einstein-Aether
formulation of Horava gravity, along with field redefinitions, to re-derive our
results from a relativistic bulk theory.


title: Valence force model and nanomechanics of single-layer phosphorene

abstract:
  In order to understand the relation of strain and material properties, both a
microscopic model connecting a given strain to the displacement of atoms, and a
macroscopic model relating applied stress to induced strain, are required.
Starting from a valence-force model for black phosphorous (phosphorene) [Kaneta
et al., Solid State Communications, 1982, 44, 613] we use recent experimental
and computational results to obtain an improved set of valence-force
parameters. From the model we calculate the phonon dispersion and the elastic
properties of single-layer phosphorene. Finally, we use these results to derive
a complete continuum model, including the bending rigidities, valid for
long-wavelength deformations of phosphorene. This continuum model is then used
to study the properties of pressurized suspended phosphorene sheets.


title:
Sobolev $W_{p}^{1}(\mathbb{R}^{n})$ spaces on $d$-thick closed subsets
  of $\mathbb{R}^{n}$

abstract:
  Let $S \subset \mathbb{R}^{n}$ be a~closed set such that for some $d \in
[0,n]$ and $\varepsilon > 0$ the~$d$-Hausdorff content
$\mathcal{H}^{d}_{\infty}(S \cap Q(x,r)) \geq \varepsilon r^{d}$ for all
cubes~$Q(x,r)$ centered in~$x \in S$ with side length $2r \in (0,2]$. For every
$p \in (1,\infty)$, denote by $W_{p}^{1}(\mathbb{R}^{n})$ the classical Sobolev
space on $\mathbb{R}^{n}$. We give an~intrinsic characterization of the
restriction $W_{p}^{1}(\mathbb{R}^{n})|_{S}$ of the space
$W_{p}^{1}(\mathbb{R}^{n})$ to~the set $S$ provided that $p > \max\{1,n-d\}$.
Furthermore, we prove the existence of a bounded linear operator
$\operatorname{Ext}:W_{p}^{1}(\mathbb{R}^{n})|_{S} \to
W_{p}^{1}(\mathbb{R}^{n})$ such that $\operatorname{Ext}$ is right inverse for
the usual trace operator. In particular, for $p > n-1$ we characterize the
trace space of the Sobolev space $W_{p}^{1}(\mathbb{R}^{n})$ to the closure
$\overline{\Omega}$ of an arbitrary open path-connected set~$\Omega$. Our
results extend those available for $p \in (1,n]$ with much more stringent
restrictions on~$S$.


title: Statistical mechanics of thin spherical shells

abstract:
  We explore how thermal fluctuations affect the mechanics of thin amorphous
spherical shells. In flat membranes with a shear modulus, thermal fluctuations
increase the bending rigidity and reduce the in-plane elastic moduli in a
scale-dependent fashion. This is still true for spherical shells. However, the
additional coupling between the shell curvature, the local in-plane stretching
modes and the local out-of-plane undulations, leads to novel phenomena. In
spherical shells thermal fluctuations produce a radius-dependent negative
effective surface tension, equivalent to applying an inward external pressure.
By adapting renormalization group calculations to allow for a spherical
background curvature, we show that while small spherical shells are stable,
sufficiently large shells are crushed by this thermally generated "pressure".
Such shells can be stabilized by an outward osmotic pressure, but the effective
shell size grows non-linearly with increasing outward pressure, with the same
universal power law exponent that characterizes the response of fluctuating
flat membranes to a uniform tension.


title:
Is there evidence for anomalous dipole anisotropy in the large-scale
  structure?

abstract:
  We probe the anisotropy of the large-scale structure (LSS) with the
WISE-2MASS catalogue. This analysis is performed by a directional comparison of
the galaxy number counts through the entire celestial sphere once systematic
effects, such as star-galaxy separation and foregrounds contamination, are
properly taken into account. We find a maximal hemispherical asymmetry whose
dipolar component is $A = 0.0507 \pm 0.0014$ toward the $(l,b) =
(323^{\circ},-5^{\circ})$ direction, whose result is consistent with previous
estimations of our proper motion in low and intermediate redshifts, as those
carried out with Type Ia Supernovae and similar LSS catalogues. Furthermore,
this dipole amplitude is statistically consistent ($p$-value = $0.061$) with
mock catalogues simulated according to the expected $\Lambda$CDM matter density
fluctuations, in addition to observational biases such as the incomplete
celestial coverage and anisotropic sky exposure. Our results suggest,
therefore, that there is no strong evidence for anomalous anisotropy in the
LSS, given the limitations and systematics of current data, in the concordance
model scenario.


title: IPA-deformations of functions on affine space

abstract:
  We investigate deformations of functions on affine space, deformations in
which the changes specialize to a distinguished point in the zero-locus of the
original function. Such deformations enable us to obtain nice results on the
cohomology of the Milnor fiber of the original function.


title:
Spin- and valley-polarized transport across line defects in monolayer
  MoS2

abstract:
  We address the ballistic transmission of charge carriers across ordered line
defects in monolayer transition metal dichalcogenides. Our study reveals the
presence of a transport gap driven by spin-orbit interactions, spin and valley
filtering, both stemming from a simple picture of spin and momentum
conservation, as well as the electron-hole asymmetry of charge-carrier
transmission. Electronic transport properties of experimentally observed
ordered line defects in monolayer MoS$_2$, in particular, the vacancy lines and
inversion domain boundaries, are further investigated using first-principles
Green's function methodology. Our calculations demonstrate the possibility of
achieving nearly complete spin polarization of charge carriers in
nanoelectronic devices based on engineered periodic line defects in monolayer
transition metal dichalcogenides, thus suggesting a practical scheme for
all-electric control of spin transport.


title:
$\overline{\rm MS}$-on-shell quark mass relation up to four loops in QCD
  and a general SU$(N)$ gauge group

abstract:
  In this paper we compute the relation between heavy quark masses defined in
the modified minimal subtraction and on-shell scheme. Detailed results are
presented for all coefficients of the SU$(N_c)$ colour factors. The reduction
of the four-loop on-shell integrals is performed for a general QCD gauge
parameter. Some of the about 380 master integrals are computed analytically,
others with high numerical precision based on Mellin-Barnes representations,
and the rest numerically with the help of {\tt FIESTA}. We discuss in detail
the precise numerical evaluation of the four-loop master integrals. Updated
relations between various short-distance masses and the $\overline{\rm MS}$
quark mass to next-to-next-to-next-to-leading order accuracy are provided for
the charm, bottom and top quark. We discuss the dependence on the
renormalization and factorization scale.


title: Uniqueness and non-existence of minimal submanifolds

abstract:
  We provide uniqueness results for compact minimal submanifolds in a large
class of Riemannian manifolds of arbitrary dimension. In the case compact and
Cartan-Hadamard manifolds we obtain general results for these submanifolds.
Several applications to Geometric Analysis are also showed.


title: Quantum charge fluctuations of a proximitized nanowire

abstract:
  Motivated by recent experiment, we consider charging of a nanowire which is
proximitized by a superconductor and connected to a normal-state lead by a
single-channel junction. The charge $Q$ of the nanowire is controlled by gate
voltage $e{\cal N}_g/C$. A finite conductance of the contact allows for quantum
charge fluctuations, making the function $Q(\mathcal{N}_g)$ continuous. It
depends on the relation between the superconducting gap $\Delta$ and the
effective charging energy $E^*_C$. The latter is determined by the junction
conductance, in addition to the geometrical capacitance of the proximitized
nanowire. We investigate $Q(\mathcal{N}_g)$ at zero magnetic field $B$, and at
fields exceeding the critical value $B_c$ corresponding to the topological
phase transition. Unlike the case of $\Delta = 0$, the function
$Q(\mathcal{N}_g)$ is analytic even in the limit of negligible level spacing in
the nanowire. At $B=0$ and $\Delta>E^*_C$, the maxima of $dQ/d\mathcal{N}_g$
are smeared by $2e$-fluctuations described by a single-channel "charge Kondo"
physics, while the $B=0$, $\Delta<E^*_C$ case is described by a crossover
between the Kondo and mixed-valence regimes of the Anderson impurity model. In
the topological phase, $Q(\mathcal{N}_g)$ is analytic function of the gate
voltage with $e$-periodic steps. In the weak tunneling limit,
$dQ/d\mathcal{N}_g$ has peaks corresponding to Breit-Wigner resonances, whereas
in the strong tunneling limit (i.e., small reflection amplitude $r$ ) these
resonances are broadened, and $dQ/d\mathcal{N}_g-e \propto r\cos(2\pi
\mathcal{N}_g)$.


title: Vortex and disclination structures in a nematic-superconductor state

abstract:
  The nematic-superconductor state is an example of a quantum liquid crystal
that breaks gauge as well as rotation invariance. It was conjectured to exist
in the pseudogap regime of the cuprates high $T_c$ superconductors. The
nematic-superconductor state is characterized by two complex order parameters:
one of them is related with superconductivity and the other one describes a
nematic order. It supports two main classes of topological defects:
half-vortices and disclinations. In this paper we present a Ginzburg-Landau
approach to study the structure of these topological defects. Due to a
geometrical coupling between the superconductor and the nematic order
parameters, we show that vortices are strongly coupled with disclinations. We
have found a restoring force between vortices and disclinations that produces
harmonic excitations whose natural frequency depends on the geometrical
coupling constant and the superconductor condensation energy. Moreover, in a
regime with high density of defects, we have found a structural phase
transition between vortex-disclination lattices with different symmetries.


title: Comparing cosmic web classifiers using information theory

abstract:
  We introduce a decision scheme for optimally choosing a classifier, which
segments the cosmic web into different structure types (voids, sheets,
filaments, and clusters). Our framework, based on information theory, accounts
for the design aims of different classes of possible applications: (i)
parameter inference, (ii) model selection, and (iii) prediction of new
observations. As an illustration, we use cosmographic maps of web-types in the
Sloan Digital Sky Survey to assess the relative performance of the classifiers
T-web, DIVA and ORIGAMI for: (i) analyzing the morphology of the cosmic web,
(ii) discriminating dark energy models, and (iii) predicting galaxy colors. Our
study substantiates a data-supported connection between cosmic web analysis and
information theory, and paves the path towards principled design of analysis
procedures for the next generation of galaxy surveys. We have made the cosmic
web maps, galaxy catalog, and analysis scripts used in this work publicly
available.


title:
A special structure of the scattering operator and infrared divergences
  in quantum electrodynamics

abstract:
  We assume that the unperturbed operators $A_0$ are known. Then, the fact that
the scattering operators $S$ and the unperturbed operators $A_0$ are pairwise
permutable provides some important information about the structure of the
scattering operators. Using this information and the ideas from the theory of
generalized wave operators, we present a new approach to the divergence
problems in quantum electrodynamics. We show that the so called infrared
divergences appeared because the deviations of the initial and final waves from
the free waves were not taken into account.


title:
Discrete Capacity and Higher-order Differences of Two-state Markov
  Chains

abstract:
  The paper studies the time-homogeneous two-state Markov chains; the states
are assumed to be binary symbols 0 and 1. The higher-order absolute differences
taken from progressive states of a given chain are considered. A discrete
capacity of subsets of natural series is defined and a limiting theorem for
these differences, formulated in terms of Wiener criterion type relation, is
presented.


title:
Interplay between spin-orbit coupling and crystal-field effect in
  topological insulators

abstract:
  Band inversion, one of the key signatures of time-reversal invariant
topological insulators (TIs), arises mostly due to the spin-orbit (SO)
coupling. Here, based on ab initio density-functional calculations, we report a
theoretical investigation of the SO-driven band inversion in isostructural
bismuth and antimony chalcogenide TIs from the viewpoint of its interplay with
the crystal-field effect. We calculate the SO-induced energy shift of states in
the top valence and bottom conduction manifolds and reproduce this behavior
using a simple one-atom model adjusted to incorporate the crystal-field effect.
The crystal-field splitting is shown to compete with the SO coupling, that is,
stronger crystal-field splitting leads to weaker SO band shift. We further show
how both these effects can be controlled by changing the chemical composition,
whereas the crystal-field splitting can be tuned by means of uniaxial strain.
These results provide a practical guidance to the rational design of novel TIs
as well as to controlling the properties of existing materials.


title:
Set-up of a High-Resolution 300 mK Atomic Force Microscope in an
  Ultra-High Vacuum Compatible 3He/10T Cryostat

abstract:
  The design of an atomic force microscope with an all-fiber interferometric
detection scheme capable of atomic resolution at about 500 mK is presented. The
microscope body is connected to a small pumped 3He reservoir with a base
temperature of about 300 mK. The bakeable insert with the cooling stage can be
moved from its measurement position inside the bore of a superconducting 10 T
magnet into an ultra-high vacuum chamber, where tip and sample can be exchanged
in-situ. Moreover, single atoms or molecules can be evaporated onto a cold
substrate located inside the microscope. Two side chambers are equipped with
standard surface preparation and surface analysis tools. The performance of the
microscope at low temperatures is demonstrated by resolving single Co atoms on
Mn/W(110) and by showing atomic resolution on NaCl(001).


title: Modification of the MDR-EFE method for stratified samples

abstract:
  The MDR-EFE method of performing identification of relevant factors within a
given collection X_1,...,X_n is developed for stratified samples in the case of
binary response variable Y. We establish a criterion of strong consistency of
estimates (involving K-cross-validation procedure and penalty) for a specified
prediction error function. The cost approach is proposed to compare experiments
with random and nonrandom number of observations. Analytic results and
simulations demonstrate advantages of the method introduced for stratified
samples over that employed for i.i.d. learning sample.


title: Mixing endomorphisms on toroidal groups and their countable products

abstract:
  We show that all non-trivial continuous endomorphisms of the circle group are
topologically mixing. We also show that there exists a large infinite class of
continuous endomorphisms of any n-dimensional torus group which are
topologically mixing.
  Lastly, we prove that any continuous endomorphism on an abelian polish
semigroup (with an identity) can be extended in a natural way to a
topologically mixing endomorphism on the countable infinite product of said
semigroup. This shows that every countable infinite product of an abelian
polish semigroup has a topologically mixing endomorphism and, in particular,
the countable infinite toroidal group has infinitely many topologically mixing
endomorphisms.


title: On Linial's Conjecture for Spine Digraphs

abstract:
  In this paper we introduce a superclass of split digraphs, which we call
spine digraphs. Those are the digraphs D whose vertex set can be partitioned
into two sets X and Y such that the subdigraph induced by X is traceable and Y
is a stable set. We also show that Linial's Conjecture holds for spine
digraphs.


title:
Absorption of charged particles in a Reissner-Nordstr\"om Black-Hole:
  entropy evolution from Relativistic Quantum Geometry

abstract:
  Using Relativistic Quantum Geometry we show that the entropy can decrease in
very small BHs, under certain circumstances, but always increases in very
massive Black-Holes.


title:
Production of $J/\psi + \chi_c$ and $J/\psi + J/\psi$ with real gluon
  emission at LHC

abstract:
  In the present work we study production of $J/\psi + \chi_c$ and $J/\psi +
J/\psi$ in LHC. The first process is forbidden at the leading order in gluon
fusion due to the $C$-parity conservation, and the first non-vanishing
contribution is given by the process with additional emission of real gluon.
Considering the direct production of $J/\psi + J/\psi$, where the leading order
is allowed, we have found that the contribution from the higher order process
with real gluon emission is comparable and even more significant than the
leading order. Moreover, account of this higher order effect dramatically
changes kinematical distributions. Through the present paper we study in
details different channels of paired $J/\psi + J/\psi$ production: direct
$J/\psi + J/\psi$ production, feed-down from $J/\psi + \chi_c$ channel, double
parton scattering. We also try to find kinematical distributions that are most
suitable to separate these different channels.


title:
Massive black holes interactions during the assembly of heavy
  sub-structures in the centre of galaxy clusters

abstract:
  We performed a series of direct N-body simulations with the aim to follow the
dynamical evolution of a galaxy cluster (GC) ($M_{clus}\simeq 10^{14}
M_{\odot}$) in different environment. The results show the formation of heavy
sub-structures in the cluster centre in consequence of multiple merging among
the innermost galaxies. Moreover we investigate the dynamics of super-massive
black holes (SMBHs) residing in the centre of galaxies that form the most
massive sub-structure.


title: Network Analysis of Urban Traffic with Big Bus Data

abstract:
  Urban traffic analysis is crucial for traffic forecasting systems, urban
planning and, more recently, various mobile and network applications. In this
paper, we analyse urban traffic with network and statistical methods. Our
analysis is based on one big bus dataset containing 45 million bus arrival
samples in Helsinki. We mainly address following questions: 1. How can we
identify the areas that cause most of the traffic in the city? 2. Why there is
a urban traffic? Is bus traffic a key cause of the urban traffic? 3. How can we
improve the urban traffic systems? To answer these questions, first, the
betweenness is used to identify the most import areas that cause most traffics.
Second, we find that bus traffic is not an important cause of urban traffic
using statistical methods. We differentiate the urban traffic and the bus
traffic in a city. We use bus delay as an identification of the urban traffic,
and the number of bus as an identification of the bus traffic. Third, we give
our solutions on how to improve urban traffic by the traffic simulation on road
networks. We show that adding more buses during the peak time and providing
better bus schedule plan in the hot areas like railway station, metro station,
shopping malls etc. will reduce the urban traffic.


title: Beta-delayed gamma decay of 26P: Possible evidence of a proton halo

abstract:
  Background: Measurements of $\beta$ decay provide important nuclear structure
information that can be used to probe isospin asymmetries and inform nuclear
astrophysics studies. Purpose: To measure the $\beta$-delayed $\gamma$ decay of
$^{26}$P and compare the results with previous experimental results and
shell-model calculations. Method: A $^{26}$P fast beam produced using nuclear
fragmentation was implanted into a planar germanium detector. Its
$\beta$-delayed $\gamma$-ray emission was measured with an array of 16
high-purity germanium detectors. Positrons emitted in the decay were detected
in coincidence to reduce the background. Results: The absolute intensities of
$^{26}$P $\beta$-delayed $\gamma$-rays were determined. A total of six new
$\beta$-decay branches and 15 new $\gamma$-ray lines have been observed for the
first time in $^{26}$P $\beta$-decay. A complete $\beta$-decay scheme was built
for the allowed transitions to bound excited states of $^{26}$Si. $ft$ values
and Gamow-Teller strengths were also determined for these transitions and
compared with shell model calculations and the mirror $\beta$-decay of
$^{26}$Na, revealing significant mirror asymmetries. Conclusions: A very good
agreement with theoretical predictions based on the USDB shell model is
observed. The significant mirror asymmetry observed for the transition to the
first excited state ($\delta=51(10)\%$) may be evidence for a proton halo in
$^{26}$P.


title:
A Stackelberg Game Perspective on the Conflict Between Machine Learning
  and Data Obfuscation

abstract:
  Data is the new oil; this refrain is repeated extensively in the age of
internet tracking, machine learning, and data analytics. Social network
analysis, cookie-based advertising, and government surveillance are all
evidence of the use of data for commercial and national interests. Public
pressure, however, is mounting for the protection of privacy. Frameworks such
as differential privacy offer machine learning algorithms methods to guarantee
limits to information disclosure, but they are seldom implemented. Recently,
however, developers have made significant efforts to undermine tracking through
obfuscation tools that hide user characteristics in a sea of noise. These
services highlight an emerging clash between tracking and data obfuscation. In
this paper, we conceptualize this conflict through a dynamic game between users
and a machine learning algorithm that uses empirical risk minimization. First,
a machine learner declares a privacy protection level, and then users respond
by choosing their own perturbation amounts. We study the interaction between
the users and the learner using a Stackelberg game. The utility functions
quantify accuracy using expected loss and privacy in terms of the bounds of
differential privacy. In equilibrium, we find selfish users tend to cause
significant utility loss to trackers by perturbing heavily, in a phenomenon
reminiscent of public good games. Trackers, however, can improve the balance by
proactively perturbing the data themselves. While other work in this area has
studied privacy markets and mechanism design for truthful reporting of user
information, we take a different viewpoint by considering both user and learner
perturbation.


title:
A test of correlation in the random coefficients of an autoregressive
  process

abstract:
  A random coefficient autoregressive process is deeply investigated in which
the coefficients are correlated. First we look at the existence of a strictly
stationary causal solution, we give the second-order stationarity conditions
and the autocorrelation function of the process. Then we study some asymptotic
properties of the empirical mean and the usual estimators of the process, such
as convergence, asymptotic normality and rates of convergence, supplied with
the appropriate assumptions on the driving perturbations. Our objective is to
get an overview of the influence of correlated coefficients in the estimation
step, through a simple model. In particular, the lack of consistency is shown
for the estimation of the autoregressive parameter when the independence
hypothesis is violated in the random coefficients. Finally, a consistent
estimation is given together with a testing procedure for the existence of
correlation in the coefficients. While convergence properties rely on the
ergodicity, we use a martingale approach to reach most of the results.


title:
Stationary and traveling solitons via local dissipations in
  Bose-Einstein condensates in ring optical lattices

abstract:
  A model of a Bose-Einstein condensate in a ring optical lattice with atomic
dissipations applied at a stationary or at a moving location on the ring is
presented. The localized dissipation is shown to generate and stabilize both
stationary and traveling lattice solitons. Among many localized solutions, we
have generated spatially stationary quasiperiodic lattice soltions and a family
of traveling lattice solitons with two intensity peaks per potential well with
no counterpart in the discrete case. Collisions between traveling and
stationary lattice solitons as well as between two traveling lattice solitons
display a critical dependence from the lattice depth. Stable counterpropagating
solitons in ring lattices can find applications in gyroscope interferometers
with ultra-cold gases.


title:
Elementary quantum mechanics of the neutron with an electric dipole
  moment

abstract:
  The neutron, in addition to possibly having a permanent electric dipole
moment as a consequence of violation of time-reversal invariance, develops an
induced electric dipole moment in the presence of an external electric field.
We present here a unified non-relativistic description of these two phenomena,
in which the dipole moment operator, $\vec{\cal D}$, is not constrained to lie
along the spin operator. Although the expectation value of $\vec{\cal D}$ in
the neutron is less than $10^{-13}$ of the neutron radius, $r_n$, the
expectation value of $\vec {\cal D}\,^2$ is of order $r_n^2$. We determine the
spin motion in external electric and magnetic fields, as employed in past and
future searches for a permanent dipole moment, and show that the neutron
electric polarizability, although entering the neutron energy in an external
electric field, does not affect the spin motion. In a simple non-relativistic
model we show that the expectation value of the permanent dipole is, to lowest
order, proportional to the product of the time reversal-violating coupling
strength and the electric polarizability of the neutron.


title:
The Evolution of Active Galactic Nuclei in Clusters of Galaxies from the
  Dark Energy Survey

abstract:
  The correlation between active galactic nuclei (AGN) and environment provides
important clues to AGN fueling and the relationship of black hole growth to
galaxy evolution. In this paper, we analyze the fraction of galaxies in
clusters hosting AGN as a function of redshift and cluster richness for X-ray
detected AGN associated with clusters of galaxies in Dark Energy Survey (DES)
Science Verification data. The present sample includes 33 AGN with L_X > 10^43
ergs s^-1 in non-central, host galaxies with luminosity greater than 0.5 L*
from a total sample of 432 clusters in the redshift range of 0.1<z<0.95.
Analysis of the present sample reveals that the AGN fraction in red-sequence
cluster members has a strong positive correlation with redshift such that the
AGN fraction increases by a factor of ~8 from low to high redshift, and the
fraction of cluster galaxies hosting AGN at high redshifts is greater than the
low-redshift fraction at 3.6 sigma. In particular, the AGN fraction increases
steeply at the highest redshifts in our sample at z>0.7. This result is in good
agreement with previous work and parallels the increase in star formation in
cluster galaxies over the same redshift range. However, the AGN fraction in
clusters is observed to have no significant correlation with cluster mass.
Future analyses with DES Year 1 through Year 3 data will be able to clarify
whether AGN activity is correlated to cluster mass and will tightly constrain
the relationship between cluster AGN populations and redshift.


title:
Strong higher-order resonant contributions to x-ray line polarization in
  hot plasmas

abstract:
  We studied angular distributions of x rays emitted in resonant recombination
of highly charged iron and krypton ions, resolving dielectronic, trielectronic,
and quadruelectronic channels. A tunable electron beam drove these processes,
inducing x rays registered by two detectors mounted along and perpendicular to
the beam axis. The measured emission asymmetries comprehensively benchmarked
full-order atomic calculations. We conclude that accurate polarization
diagnostics of hot plasmas can only be obtained under the premise of inclusion
of higher-order processes that were neglected in earlier work.

categories: physics.atom-ph astro-ph.HE astro-ph.IM physics.plasm-ph


title: Amalgamable diagram shapes

abstract:
  A category has the amalgamation property (AP) if every pushout diagram has a
cocone, and the joint embedding property (JEP) if every finite coproduct
diagram has a cocone. We show that for a finitely generated category $\mathbf
I$, the following are equivalent: (i) every $\mathbf I$-shaped diagram in a
category with the AP and the JEP has a cocone; (ii) every $\mathbf I$-shaped
diagram in the category of sets and injections has a cocone; (iii) a certain
canonically defined category $\mathcal{L}(\mathbf{I})$ of "paths" in $\mathbf
I$ has only idempotent endomorphisms. When $\mathbf I$ is a finite poset, these
are further equivalent to: (iv) every upward-closed subset of $\mathbf I$ is
simply-connected; (v) $\mathbf I$ can be built inductively via some simple
rules. Our proof also shows that these conditions are decidable for finite
$\mathbf I$.


title: Vortex Identification from Local Properties of the Vorticity Field

abstract:
  It has been broadly acknowledged that vortex detection algorithms, usually
based on linear-algebraic properties of the velocity gradient tensor, can be
plagued with severe shortcomings and may become, in practical terms, dependent
on the choice of subjective threshold parameters in their implementations. In
two-dimensions, a large class of standard vortex identification prescriptions
turn out to be equivalent to the "swirling strength criterion"
($\lambda_{ci}$-criterion), which is critically revisited in this work. We
classify the instances where the accuracy of the $\lambda_{ci}$-criterion is
affected by nonlinear superposition effects and propose an alternative vortex
detection scheme based on the local curvature properties of the vorticity graph
$(x,y,\omega)$ -- the "vorticity curvature criterion"
($\lambda_\omega$-criterion) -- which improves over the results obtained with
the $\lambda_{ci}$-criterion in controlled Monte-Carlo tests. We show that the
$\lambda_\omega$-criterion is able to cope with strong shear effects, if a
subtraction of the mean velocity field background is performed, in the spirit
of the Reynolds decomposition procedure. A realistic comparative study for
vortex identification is then carried out for a direct numerical simulation
(DNS) of a turbulent channel flow, including a three-dimensional extension of
the $\lambda_\omega$-criterion. In contrast to the $\lambda_{ci}$-criterion,
the $\lambda_\omega$-criterion indicates in a consistent way the existence of
small scale isotropic turbulent fluctuations in the logarithmic layer, in
consonance with long-standing assumptions commonly taken in turbulent boundary
layer phenomenology.


title:
Electronic properties of GeTe and Ag- or Sb-substituted GeTe studied by
  low temperature 125Te NMR

abstract:
  We have carried out $^{125}$Te nuclear magnetic resonance (NMR) in a wide
temperature range of 1.5 -- 300 K to investigate electronic properties of
Ge$_{50}$Te$_{50}$, Ag$_{2}$Ge$_{48}$Te$_{50}$ and Sb$_{2}$Ge$_{48}$Te$_{50}$
from a microscopic point of view. From the temperature dependence of NMR shift
($K$) and nuclear spin lattice relaxation rate (1/$T_1$), we found that two
bands contribute to the physical properties of the materials. One band overlaps
the Fermi level providing the metallic state where no strong electron
correlations are revealed by Korringa analysis. The other band is separated
from the Fermi level by an energy gap of $E_{\rm g}/k_{\rm B}$ $\sim$ 67 K,
which gives rise to the semiconductor-like properties. First principle
calculation revealed that the metallic band originates from the Ge vacancy
while the semiconductor-like band may be related to the fine structure of the
density of states near the Fermi level. Low temperature $^{125}$Te NMR data for
the materials studied here clearly show that the Ag substitution increases hole
concentration while Sb substitution decreases it.


title: Cell-veto Monte Carlo algorithm for long-range systems

abstract:
  We present a rigorous efficient event-chain Monte Carlo algorithm for
long-range interacting particle systems. Using a cell-veto scheme within the
factorized Metropolis algorithm, we compute each single-particle move with a
fixed number of operations. For slowly decaying potentials such as Coulomb
interactions, screening line charges allow us to take into account periodic
boundary conditions. We discuss the performance of the cell-veto Monte Carlo
algorithm for general inverse-power-law potentials, and illustrate how it
provides a new outlook on one of the prominent bottlenecks in large-scale
atomistic Monte Carlo simulations.


title: Sieve weights and their smoothings

abstract:
  We obtain asymptotic formulas for the $2k$th moments of partially smoothed
divisor sums of the M\"obius function. When $2k$ is small compared with $A$,
the level of smoothing, then the main contribution to the moments come from
integers with only large prime factors, as one would hope for in sieve weights.
However if $2k$ is any larger, compared with $A$, then the main contribution to
the moments come from integers with quite a few prime factors, which is not the
intention when designing sieve weights. The threshold for "small" occurs when
$A=\frac 1{2k} \binom{2k}{k}-1$.
  One can ask analogous questions for polynomials over finite fields and for
permutations, and in these cases the moments behave rather differently, with
even less cancellation in the divisor sums. We give, we hope, a plausible
explanation for this phenomenon, by studying the analogous sums for Dirichlet
characters, and obtaining each type of behaviour depending on whether or not
the character is "exceptional".


title: A construction of distance cospectral graphs

abstract:
  The distance matrix of a connected graph is the symmetric matrix with columns
and rows indexed by the vertices and entries that are the pairwise distances
between the corresponding vertices. We give a construction for graphs which
differ in their edge counts yet are cospectral with respect to the distance
matrix. Further, we identify a subgraph switching behavior which constructs
additional distance cospectral graphs. The proofs for both constructions rely
on a perturbation of (most of) the distance eigenvectors of one graph to yield
the distance eigenvectors of the other.


title:
On the uniqueness of an ergodic measure of full dimension for
  non-conformal repellers

abstract:
  We give a subclass L of Non-linear Lalley-Gatzouras carpets and an open set U
in L such that any carpet in U has a unique ergodic measure of full dimension.
In particular, any Lalley-Gatzouras carpet which is close to a non-trivial
general Sierpinski carpet has a unique ergodic measure of full dimension.


title: Statistical analysis of a comprehensive list of visual binaries

abstract:
  Visual binary stars are the most abundant class of observed binaries. The
most comprehensive list of data on visual binaries compiled recently by
cross-matching the largest catalogues of visual binaries allowed a statistical
investigation of observational parameters of these systems. The dataset was
cleaned by correcting uncertainties and misclassifications, and supplemented
with available parallax data. The refined dataset is free from technical biases
and contains 3676 presumably physical visual pairs of luminosity class V with
known angular separations, magnitudes of the components, spectral types, and
parallaxes. We also compiled a restricted sample of 998 pairs free from
observational biases due to the probability of binary discovery. Certain
distributions of observational and physical parameters of stars of our dataset
are discussed.


title: The effects of bar-spiral coupling on stellar kinematics in the Galaxy

abstract:
  We investigate models of the Milky Way disc taking into account
simultaneously the bar and a two-armed quasi-static spiral pattern. Away from
major resonance overlaps, the mean stellar radial motions in the plane are
essentially a linear superposition of the isolated effects of the bar and
spirals. Thus, provided the bar is strong enough, even in the presence of
spiral arms, these mean radial motions are predominantly affected by the
Galactic bar for large scale velocity fluctuations. This is evident when
comparing the peculiar line-of-sight velocity power spectrum of our coupled
models with bar-only models. However, we show how forthcoming spectroscopic
surveys could disentangle bar-only non-axisymmetric models of the Galaxy from
models in which spiral arms have a significant amplitude. We also point out
that overlaps of low-order resonances are sufficient to enhance stellar
churning within the disc, even when the spirals amplitude is kept constant.
Nevertheless, for churning to be truly non-local, stronger or (more likely)
transient amplitudes would be needed: otherwise the disc is actually mostly
unaffected by churning in the present models. Finally, regarding vertical
breathing modes, the combined effect of the bar and spirals on vertical motions
is a clear non-linear superposition of the isolated effects of both components,
significantly superseding the linear superposition of modes produced by each
perturber separately, thereby providing an additional effect to consider when
analysing the observed breathing mode of the Galactic disc in the extended
Solar neighbourhood.


title: Euclidean Approach for Entropy of Black Shells

abstract:
  We introduce the concept of black shell, consisting on a massive thin
spherical shell contracting toward its gravitational radius from the point of
view of an external observer far from the shell, in order to effectively model
the gravitational collapse. Considering complementary description of
entanglement entropy of a black shell and according to Gibbons-Hawking
Euclidean approach, we calculate the Bekenstein-Hawking entropy retrieving
horizon integral and discarding boundary at infinity.


title:
A gradient flow approach to the porous medium equation with fractional
  pressure

abstract:
  We consider a family of fractional porous media equations, recently studied
by Caffarelli and V\'azquez. We show the construction of a weak solution as
Wasserstein gradient flow of a square fractional Sobolev norm. Energy
dissipation inequality, regularizing effect and decay estimates for the $L^p$
norms are established. Moreover, we show that a classical porous medium
equation can be obtained as a limit case.


title:
Observation of Fermi-Pasta-Ulam Recurrence Induced by Breather Solitons
  in an Optical Microresonator

abstract:
  We present, experimentally and numerically, the observation of
Fermi-Pasta-Ulam recurrence induced by breather solitons in a high-Q SiN
microresonator. Breather solitons can be excited by increasing the pump power
at a relatively small pump phase detuning in microresonators. Out of phase
power evolution is observed for groups of comb lines around the center of the
spectrum compared to groups of lines in the spectral wings. The evolution of
the power spectrum is not symmetric with respect to the spectrum center.
Numerical simulations based on the generalized Lugiato-Lefever equation are in
good agreement with the experimental results and unveil the role of stimulated
Raman scattering in the symmetry breaking of the power spectrum evolution. Our
results shows that optical microresonators can be exploited as a powerful
platform for the exploration of soliton dynamics.


title: Systematic parameter inference in stochastic mesoscopic modeling

abstract:
  We propose a method to efficiently determine the optimal coarse-grained force
field in mesoscopic stochastic simulations of Newtonian fluid and polymer melt
systems modeled by dissipative particle dynamics (DPD) and energy conserving
dissipative particle dynamics (eDPD). The response surfaces of various target
properties (viscosity, diffusivity, pressure, etc.) with respect to model
parameters are constructed based on the generalized polynomial chaos (gPC)
expansion using simulation results on sampling points (e.g., individual
parameter sets). To alleviate the computational cost to evaluate the target
properties, we employ the compressive sensing method to compute the
coefficients of the dominant gPC terms given the prior knowledge that the
coefficients are sparse. The proposed method shows comparable accuracy with the
standard probabilistic collocation method (PCM) while it imposes a much weaker
restriction on the number of the simulation samples especially for systems with
high dimensional parametric space. Fully access to the response surfaces within
the confidence range enables us to infer the optimal force parameters given the
desirable values of target properties at the macroscopic scale. Moreover, it
enables us to investigate the intrinsic relationship between the model
parameters, identify possible degeneracies in the parameter space, and optimize
the model by eliminating model redundancies. The proposed method provides an
efficient alternative approach for constructing mesoscopic models by inferring
model parameters to recover target properties of the physics systems (e.g.,
from experimental measurements), where those force field parameters and
formulation cannot be derived from the microscopic level in a straight forward
way.


title:
Infinite-size density matrix renormalization group with parallel Hida's
  algorithm

abstract:
  In this study, we report a parallel algorithm for the infinite-size density
matrix renormalization group (iDMRG) that is applicable to one-dimensional (1D)
quantum systems with $\ell$-site periods, where $\ell$ is an even number. It
combines Hida's iDMRG applied to random 1D spin systems with a variant of
McCulloch's wavefunction prediction. This allows us to apply $\ell/2$ times of
computational power to accelerate the investigation of multi-leg frustrated
quantum systems in the thermodynamic limit, which is a challenging simulation.
We performed benchmark calculations for a spin-1/2 Heisenberg model on a Kagome
cylinder YC8 using the parallel iDMRG, and found that the proposed iDMRG was
efficiently parallelized for shared memory and distributed memory systems, and
provided such bulk physical quantities as total energy, bond strength on
nearest neighbor spins, and spin--spin correlation functions and their
correlation lengths without finite-size effects. Moreover, the variant of the
wavefunction prediction sped up Lanczos methods in the parallel iDMRG by
approximately three times.


title:
Highly Luminous Supernovae associated with Gamma-Ray Bursts I.: GRB
  111209A/SN 2011kl in the Context of Stripped-Envelope and Superluminous
  Supernovae

abstract:
  GRB 111209A, one of the longest Gamma-Ray Bursts (GRBs) ever observed, is
linked to SN 2011kl, the most luminous GRB-Supernova (SN) detected so far,
which shows evidence for being powered by a magnetar central engine. We place
SN 2011kl into the context of large samples of SNe, addressing in more detail
the question of whether it could be radioactively powered, and whether it
represents an extreme version of a GRB-SN or an underluminous Superluminous SN
(SLSN). We model SN 2011kl using SN 1998bw as a template and derive a
bolometric light curve including near-infrared data. We compare the properties
of SN 2011kl to literature results on stripped-envelope and superluminous
supernovae. Comparison in the k,s context, i.e., comparing it to SN 1998bw
templates in terms of luminosity and light-curve stretch, clearly shows SN
2011kl is the most luminous GRB-SN to date, and it is spectrally very
dissimilar to other events, being significantly bluer/hotter. Although SN
2011kl does not reach the classical luminosity threshold of SLSNe and evolves
faster than any of them, it resembles SLSNe more than the classical
GRB-associated broad-lined Type Ic SNe in several aspects. GRB 111209A was a
very energetic event, both at early (prompt emission) and at very late (SN)
times. We have shown in a further publication that with the exception of the
extreme duration, the GRB and afterglow parameters are in agreement with the
known distributions for these parameters. SN 2011kl, on the other hand, is
exceptional both in luminosity and spectral characteristics, indicating that
GRB 111209A was likely not powered by a standard-model collapsar central
engine, further supporting our earlier conclusions. Instead, it reveals the
possibility of a direct link between GRBs and SLSNe.


title: Arbitrary Multi-Qubit Generation

abstract:
  We propose and analyse a scheme for single-rail-encoded arbitrary multi-qubit
quantum-state generation to provide a versatile tool for quantum optics and
quantum information applications. Our scheme can be realized, for small numbers
of qubits, with current technologies using single photon inputs, passive linear
optics, and heralding measurements. The particular examples of two- and
three-qubit cluster states are studied in detail. We show that such states can
be prepared with a high probability of success. Our analysis quantifies the
effects of experimentally relevant imperfections and inefficiencies. The
general case of arbitrary N-qubit preparation is discussed and some interesting
connections to the boson sampling problem are given.


title: Scalable Semi-supervised Learning with Graph-based Kernel Machine

abstract:
  Acquiring labels are often costly, whereas unlabeled data are usually easy to
obtain in modern machine learning applications. Semi-supervised learning
provides a principled machine learning framework to address such situations,
and has been applied successfully in many real-word applications and
industries. Nonetheless, most of existing semi-supervised learning methods
encounter two serious limitations when applied to modern and large-scale
datasets: computational burden and memory usage demand. To this end, we present
in this paper the Graph-based semi-supervised Kernel Machine (GKM), a method
that leverages the generalization ability of kernel-based method with the
geometrical and distributive information formulated through a spectral graph
induced from data for semi-supervised learning purpose. Our proposed GKM can be
solved directly in the primal form using the Stochastic Gradient Descent method
with the ideal convergence rate $O(\frac{1}{T})$. Besides, our formulation is
suitable for a wide spectrum of important loss functions in the literature of
machine learning (e.g., Hinge, smooth Hinge, Logistic, L1, and
{\epsilon}-insensitive) and smoothness functions (i.e., $l_p(t) = |t|^p$ with
$p\ge1$). We further show that the well-known Laplacian Support Vector Machine
is a special case of our formulation. We validate our proposed method on
several benchmark datasets to demonstrate that GKM is appropriate for the
large-scale datasets since it is optimal in memory usage and yields superior
classification accuracy whilst simultaneously achieving a significant
computation speed-up in comparison with the state-of-the-art baselines.


title: A Delay-Optimal Packet Scheduler for M2M Uplink

abstract:
  In this paper, we present a delay-optimal packet scheduler for processing the
M2M uplink traffic at the M2M application server (AS). Due to the
delay-heterogeneity in uplink traffic, we classify it broadly into
delay-tolerant and delay-sensitive traffic. We then map the diverse delay
requirements of each class to sigmoidal functions of packet delay and formulate
a utility-maximization problem that results in a proportionally fair
delay-optimal scheduler. We note that solving this optimization problem is
equivalent to solving for the optimal fraction of time each class is served
with (preemptive) priority such that it maximizes the system utility. Using
Monte-Carlo simulations for the queuing process at AS, we verify the
correctness of the analytical result for optimal scheduler and show that it
outperforms other state-of-the-art packet schedulers such as weighted round
robin, max-weight scheduler, fair scheduler and priority scheduling. We also
note that at higher traffic arrival rate, the proposed scheduler results in a
near-minimal delay variance for the delay-sensitive traffic which is highly
desirable. This comes at the expense of somewhat higher delay variance for
delay-tolerant traffic which is usually acceptable due to its delay-tolerant
nature.


title: The Fluence and Distance Distributions of Fast Radio Bursts

abstract:
  Fast radio bursts (FRB) are millisecond-duration radio pulses with apparent
extragalactic origins. All but two of the FRBs have been discovered using the
Parkes dish which employs multiple beams formed by an array of feed horns on
its focal plane. In this paper, we show that (i) the preponderance of
multiple-beam detections, and (ii) the detection rates for varying dish
diameters, can be used to infer the index $\alpha$ of the cumulative fluence
distribution function (the log$N$-log$F$ function: $\alpha=1.5$ for a
non-evolving population in a Euclidean universe). If all detected FRBs arise
from a single progenitor population, multiple-beam FRB detection rates from the
Parkes telescope yield the constraint $0.52<\alpha<1.0$ with $90$% confidence.
Searches at other facilities with different dish sizes refine the constraint to
$0.66<\alpha<0.96$. Our results favor FRB searches with smaller dishes, because
for $\alpha<1$, the gain in field-of-view for a smaller dish is more important
than the reduction in sensitivity. Further, our results suggest that (i) FRBs
are not standard candles, and (ii) the distribution of distances to the
detected FRBs is weighted towards larger distances. If FRBs are extragalactic,
these results are consistent with a cosmological population, which would make
FRBs excellent probes of the baryonic content and geometry of the Universe.


title:
Fast generations of tree-type three-dimensional entanglement via
  Lewis-Riesenfeld invariants and transitionless quantum driving

abstract:
  Recently, a novel three-dimensional entangled state called tree-type
entanglement, which is likely to have applications for improving quantum
communication security, was prepared via adiabatic passage by Song et al.
[Phys. Rev. A 93, 062321 (2016)]. Here we propose two schemes for fast
generations of tree-type three-dimensional entanglement among three spatially
separated atoms via shortcuts to adiabatic passage. With the help of quantum
Zeno dynamics, two kinds of different but equivalent methods, Lewis-Riesenfeld
invariants and transitionless quantum driving, are applied to construct
shortcuts to adiabatic passage. The comparisons between the two methods are
discussed. The strict numerical simulations show that the tree-type
three-dimensional entangled states can be fast prepared with quite high
fidelities and the two schemes are both robust against the variations in the
parameters, atomic spontaneous emissions and the cavity-fiber photon leakages.


title:
\'Etude de Probl\`emes d'Optimisation Combinatoire \`a Multiples
  Composantes Interd\'ependantes

abstract:
  This extended abstract presents an overview on NP-hard optimization problems
with multiple interdependent components. These problems occur in many
real-world applications: industrial applications, engineering, and logistics.
The fact that these problems are composed of many sub-problems that are NP-hard
makes them even more challenging to solve using exact algorithms. This is
mainly due to the high complexity of this class of algorithms and the hardness
of the problems themselves. The main source of difficulty of these problems is
the presence of internal dependencies between sub-problems. This aspect of
interdependence of components is presented, and some outlines on solving
approaches are briefly introduced from a (meta)heuristics and evolutionary
computation perspective.


title:
POD/DEIM Reduced-Order Modeling of Time-Fractional Partial Differential
  Equations with Applications in Parameter Identification

abstract:
  In this paper, a reduced-order model (ROM) based on the proper orthogonal
decomposition and the discrete empirical interpolation method is proposed for
efficiently simulating time-fractional partial differential equations (TFPDEs).
Both linear and nonlinear equations are considered. We demonstrate the
effectiveness of the ROM by several numerical examples, in which the ROM
achieves the same accuracy of the full-order model (FOM) over a long-term
simulation while greatly reducing the computational cost. The proposed ROM is
then regarded as a surrogate of FOM and is applied to an inverse problem for
identifying the order of the time-fractional derivative of the TFPDE model.
Based on the Levenberg--Marquardt regularization iterative method with the
Armijo rule, we develop a ROM-based algorithm for solving the inverse problem.
For cases in which the observation data is either uncontaminated or
contaminated by random noise, the proposed approach is able to achieve accurate
parameter estimation efficiently.


title: Sequent Calculus Representations for Quantum Circuits

abstract:
  When considering a sequent-style proof system for quantum programs, there are
certain elements of quantum mechanics that we may wish to capture, such as
phase, dynamics of unitary transformations, and measurement probabilities.
Traditional quantum logics which focus primarily on the abstract orthomodular
lattice theory and structures of Hilbert spaces have not satisfactorily
captured some of these elements. We can start from 'scratch' in an attempt to
conceptually characterize the types of proof rules which should be in a system
that represents elements necessary for quantum algorithms. This present work
attempts to do this from the perspective of the quantum circuit model of
quantum computation. A sequent calculus based on single quantum circuits is
suggested, and its ability to incorporate important conceptual and dynamic
aspects of quantum computing is discussed. In particular, preserving the
representation of phase helps illustrate the role of interference as a resource
in quantum computation. Interference also provides an intuitive basis for a
non-monotonic calculus.


title:
An Overview of Approaches to Modernize Quantum Annealing Using Local
  Searches

abstract:
  I describe how real quantum annealers may be used to perform local (in state
space) searches around specified states, rather than the global searches
traditionally implemented in the quantum annealing algorithm. The quantum
annealing algorithm is an analogue of simulated annealing, a classical
numerical technique which is now obsolete. Hence, I explore strategies to use
an annealer in a way which takes advantage of modern classical optimization
algorithms, and additionally should be less sensitive to problem
mis-specification then the traditional quantum annealing algorithm.


title: The Information Content of Systems in General Physical Theories

abstract:
  What kind of object is a quantum state? Is it an object that encodes an
exponentially growing amount of information (in the size of the system) or more
akin to a probability distribution? It turns out that these questions are
sensitive to what we do with the information. For example, Holevo's bound tells
us that n qubits only encode n bits of classical information but for certain
communication complexity tasks there is an exponential separation between
quantum and classical resources. Instead of just contrasting quantum and
classical physics, we can place both within a broad landscape of physical
theories and ask how non-quantum (and non-classical) theories are different
from, or more powerful than quantum theory. For example, in communication
complexity, certain (non-quantum) theories can trivialise all communication
complexity tasks. In recent work [C. M. Lee and M. J. Hoban, Proc. Royal Soc. A
472 (2190), 2016], we showed that the immense power of the information content
of states in general (non-quantum) physical theories is not limited to
communication complexity. We showed that, in general physical theories, states
can be taken as "advice" for computers in these theories and this advice allows
the computers to easily solve any decision problem. Aaronson has highlighted
the close connection between quantum communication complexity and quantum
computations that take quantum advice, and our work gives further indications
that this is a very general connection. In this work, we review the results in
our previous work and discuss the intricate relationship between communication
complexity and computers taking advice for general theories.


title: Quantum Probability as an Application of Data Compression Principles

abstract:
  Realist, no-collapse interpretations of quantum mechanics, such as Everett's,
face the probability problem: how to justify the norm-squared (Born) rule from
the wavefunction alone. While any basis-independent measure can only be
norm-squared (due to the Gleason-Busch Theorem) this fact conflicts with
various popular, non-wavefunction-based phenomenological measures - such as
observer, outcome or world counting - that are frequently demanded of
Everettians. These alternatives conflict, however, with the wavefunction
realism upon which Everett's approach rests, which seems to call for an
objective, basis-independent measure based only on wavefunction amplitudes. The
ability of quantum probabilities to destructively interfere with each other,
however, makes it difficult to see how probabilities can be derived solely from
amplitudes in an intuitively appealing way. I argue that the use of algorithmic
probability can solve this problem, since the objective, single-case
probability measure that wavefunction realism demands is exactly what
algorithmic information theory was designed to provide. The result is an
intuitive account of complex-valued amplitudes, as coefficients in an optimal
lossy data compression, such that changes in algorithmic information content
(entropy deltas) are associated with phenomenal transitions.


title: Physical Computation, P/poly and P/log*

abstract:
  In this paper we give a framework for describing how abstract systems can be
used to compute if no randomness or error is involved. Using this we describe a
class of classical "physical" computation systems whose computational
capabilities in polynomial time are equivalent to P/poly. We then extend our
framework to describe how measurement and transformation times may vary
depending on their input. Finally we describe two classes of classical
"physical" computation systems in this new framework whose computational
capabilities in polynomial time are equivalent to P/poly and P/log*.


title: A crystal embedding into Lusztig data of type $A$

abstract:
  Let $i$ be a reduced expression of the longest element in the Weyl group of
type $A$, which is adapted to a Dynkin quiver with a single sink. We present a
simple description of the crystal embedding of Young tableaux of arbitrary
shape into $i$-Lusztig data, which also gives an algorithm for the transition
matrix between Lusztig data associated to reduced expressions adapted to
quivers with a single sink.


title:
Experimental demonstration of coherent control in quantum chaotic
  systems

abstract:
  We experimentally demonstrate coherent control of a quantum system, whose
dynamics is chaotic in the classical limit. Interaction of diatomic molecules
with a periodic sequence of ultrashort laser pulses leads to the dynamical
localization of the molecular angular momentum, a characteristic feature of the
chaotic quantum kicked rotor. By changing the phases of the rotational states
in the initially prepared coherent wave packet, we control the rotational
distribution of the final localized state and its total energy. We demonstrate
the anticipated sensitivity of control to the exact parameters of the kicking
field, as well as its disappearance in the classical regime of excitation.


title: Ultrafast Manipulation of Valley Pseudospin

abstract:
  The coherent manipulation of spin and pseudospin underlies existing and
emerging quantum technologies, including NMR, quantum communication, and
quantum computation. Valley polarization, associated with the occupancy of
degenerate, but quantum mechanically distinct valleys in momentum space,
closely resembles spin polarization and has been proposed as a pseudospin
carrier for the future quantum electronics. Valley exciton polarization has
been created in the transition metal dichalcogenide (TMDC) monolayers using
excitation by circularly polarized light and has been detected both optically
and electrically. In addition, the existence of coherence in the valley
pseudospin has been identified experimentally. The manipulation of such valley
coherence has, however, remained out of reach. Here we demonstrate an
all-optical control of the valley coherence by means of the pseudomagnetic
field associated with the optical Stark effect. Using below-bandgap circularly
polarized light, we experimentally rotate the valley exciton pseudospin in
monolayer WSe2 on the femtosecond time scale. Both the direction and speed of
the rotation can be optically manipulated by tuning the dynamic phase of
excitons in opposite valleys. This study completes the
generation-manipulation-detection paradigm for valley pseudospin, enabling the
platform of excitons in 2D materials for the control of this novel degree of
freedom in solids.


title:
Amenable signatures, algebraic solutions, and filtrations of the knot
  concordance group

abstract:
  It is known that each of the successive quotient groups of the grope and
solvable filtrations of the knot concordance group has an infinite rank
subgroup. The generating knots of these subgroups are constructed using
iterated doubling operators. In this paper, for each of the successive
quotients of the filtrations we give a new infinite rank subgroup which
trivially intersects the previously known infinite rank subgroups. Instead of
iterated doubling operators, the generating knots of these new subgroups are
constructed using the notion of algebraic $n$-solutions, which was introduced
by Cochran and Teichner. Moreover, for each slice knot $K$ whose Alexander
polynomial has degree greater than 2, we construct the generating knots such
that they have the same derived quotients and higher-order Alexander invariants
up to a certain order.
  In the proof, we use an $L^2$-theoretic obstruction for a knot to being
$n.5$-solvable given by Cha, which is based on $L^2$-theoretic techniques
developed by Cha and Orr. We also generalize the notion of algebraic
$n$-solutions to the notion of $R$-algebraic $n$-solutions where $R$ is either
rationals or the field of $p$ elements for a prime $p$.


title: SMCQL: Secure Querying for Federated Databases

abstract:
  People and machines are collecting data at an unprecedented rate. Despite
this newfound abundance of data, progress has been slow in sharing it for open
science, business, and other data-intensive endeavors. Many such efforts are
stymied by privacy concerns and regulatory compliance issues. For example, many
hospitals are interested in pooling their medical records for research, but
none may disclose arbitrary patient records to researchers or other healthcare
providers. In this context we propose the Private Data Network (PDN), a
federated database for querying over the collective data of mutually
distrustful parties. In a PDN, each member database does not reveal its tuples
to its peers nor to the query writer. Instead, the user submits a query to an
honest broker that plans and coordinates its execution over multiple private
databases using secure multiparty computation (SMC). Here, each database's
query execution is oblivious, and its program counters and memory traces are
agnostic to the inputs of others. We introduce a framework for executing PDN
queries named SMCQL. This system translates SQL statements into SMC primitives
to compute query results over the union of its source databases without
revealing sensitive information about individual tuples to peer data providers
or the honest broker. Only the honest broker and the querier receive the
results of a PDN query. For fast, secure query evaluation, we explore a
heuristics-driven optimizer that minimizes the PDN's use of secure computation
and partitions its query evaluation into scalable slices.


title: A subspecies of region crossing change, region freeze crossing change

abstract:
  We introduce a local move on a link diagram named a region freeze crossing
change which is close to a region crossing change, but not the same. We study
similarity and difference between region crossing change and region freeze
crossing change.


title:
On the number of cliques in graphs with a forbidden subdivision or
  immersion

abstract:
  How many cliques can a graph on $n$ vertices have with a forbidden
substructure? Extremal problems of this sort have been studied for a long time.
This paper studies the maximum possible number of cliques in a graph on $n$
vertices with a forbidden clique subdivision or immersion. We prove for $t$
sufficiently large that every graph on $n \geq t$ vertices with no
$K_t$-immersion has at most $2^{t+\log^2 t}n$ cliques, which is sharp apart
from the $2^{O(\log^2 t)}$ factor. We also prove that the maximum number of
cliques in an $n$-vertex graph with no $K_t$-subdivision is at most
$2^{1.817t}n$. This improves on the best known exponential constant by Lee and
Oum. We conjecture that the optimal bound is $3^{2t/3 +o(t)}n$, as we proved
for minors in place of subdivision in earlier work.


title:
Where to Focus: Query Adaptive Matching for Instance Retrieval Using
  Convolutional Feature Maps

abstract:
  Instance retrieval requires one to search for images that contain a
particular object within a large corpus. Recent studies show that using image
features generated by pooling convolutional layer feature maps (CFMs) of a
pretrained convolutional neural network (CNN) leads to promising performance
for this task. However, due to the global pooling strategy adopted in those
works, the generated image feature is less robust to image clutter and tends to
be contaminated by the irrelevant image patterns. In this article, we alleviate
this drawback by proposing a novel reranking algorithm using CFMs to refine the
retrieval result obtained by existing methods. Our key idea, called query
adaptive matching (QAM), is to first represent the CFMs of each image by a set
of base regions which can be freely combined into larger regions-of-interest.
Then the similarity between the query and a candidate image is measured by the
best similarity score that can be attained by comparing the query feature and
the feature pooled from a combined region. We show that the above procedure can
be cast as an optimization problem and it can be solved efficiently with an
off-the-shelf solver. Besides this general framework, we also propose two
practical ways to create the base regions. One is based on the property of the
CFM and the other one is based on a multi-scale spatial pyramid scheme. Through
extensive experiments, we show that our reranking approaches bring substantial
performance improvement and by applying them we can outperform the state of the
art on several instance retrieval benchmarks.


title: Link Prediction via Matrix Completion

abstract:
  Inspired by practical importance of social networks, economic networks,
biological networks and so on, studies on large and complex networks have
attracted a surge of attentions in the recent years. Link prediction is a
fundamental issue to understand the mechanisms by which new links are added to
the networks. We introduce the method of robust principal component analysis
(robust PCA) into link prediction, and estimate the missing entries of the
adjacency matrix. On one hand, our algorithm is based on the sparsity and low
rank property of the matrix, on the other hand, it also performs very well when
the network is dense. This is because a relatively dense real network is also
sparse in comparison to the complete graph. According to extensive experiments
on real networks from disparate fields, when the target network is connected
and sufficiently dense, whatever it is weighted or unweighted, our method is
demonstrated to be very effective and with prediction accuracy being
considerably improved comparing with many state-of-the-art algorithms.


title: The Chandra COSMOS Legacy survey: the z>3 sample

abstract:
  We present the largest high-redshift (3<z<6.85) sample of X-ray-selected
active galactic nuclei (AGN) on a contiguous field, using sources detected in
the Chandra COSMOS Legacy survey. The sample contains 174 sources, 87 with
spectroscopic redshift, the other 87 with photometric redshift (z_phot). In
this work we treat z_phot as a probability weighted sum of contributions,
adding to our sample the contribution of sources with z_phot<3 but z_phot
probability distribution >0 at z>3. We compute the number counts in the
observed 0.5-2 keV band, finding a decline in the number of sources at z>3 and
constraining phenomenological models of X-ray background. We compute the AGN
space density at z>3 in two different luminosity bins. At higher luminosities
(logL(2-10 keV) > 44.1 erg/s) the space density declines exponentially,
dropping by a factor ~20 from z~3 to z~6. The observed decline is ~80% steeper
at lower luminosities (43.55 erg/s < logL(2-10 keV) < 44.1 erg/s), from z~3 to
z~4.5. We study the space density evolution dividing our sample in optically
classified Type 1 and Type 2 AGN. At logL(2-10 keV) > 44.1 erg/s, unobscured
and obscured objects may have different evolution with redshift, the obscured
component being three times higher at z~5. Finally, we compare our space
density with predictions of quasar activation merger models, whose calibration
is based on optically luminous AGN. These models significantly overpredict the
number of expected AGN at logL(2-10 keV) > 44.1 erg/s with respect to our data.


title:
Ground state phase diagram of the triangular lattice Hubbard model by
  density matrix renormalization group method

abstract:
  Two-dimensional density-matrix renormalization group method is employed to
examine the ground state phase diagram of the Hubbard model on the triangular
lattice at half filling. The calculation reveals two discontinuities in the
double occupancy with increasing the repulsive Hubbard interaction U at Uc1 =
7.55 t and Uc2 = 9.65 t (t being the hopping integral), indicating that there
are three phases separated by first order transitions. The absence of any
singularity in physical quantities for 0 < U < Uc1 implies that this phase
corresponds to a metallic phase. The local spin density induced by an applied
pinning magnetic field for U > Uc2 exhibits a three sublattice feature, which
is compatible with the Neel ordered state realized in the strong coupling
limit. For Uc1 < U < Uc2, a response to the applied pinning magnetic field is
comparable to that in the metallic phase but a relatively large spin
correlation length is found with neither valence bond nor chiral magnetic
order, suggesting a paramagnetic nature which resembles gapless spin liquid.
The calculation also finds that the pair- ing correlation function
monotonically decreases with increasing U and thus the superconductivity is
unlikely in the intermediate phase.


title:
Dynamics of Elliptical Galaxies with Planetary Nebulae in Modified
  Newtonian Dynamics

abstract:
  The dynamics of an elliptical galaxy within a couple of effective radii can
be probed effectively by stars. However, at larger distances planetary nebulae
(PNe) replace stars as the tracer of the dynamics. Making use of the motion of
PNe, Romanowsky et al. (2003) measured the dynamics of three luminous
elliptical galaxies (NGC821, NGC3379, and NGC4494) at large distances from the
galactic center. They found that little dark matter is needed up to 6 effective
radii. Milgrom & Sanders (2003) showed that this result can be understood in
the framework of MOdified Newtonian Dynamics (MOND). As more data are available
in the past decade, we revisit this problem. We combine PNe data (up to 6{8
effective radii) and stellar data from SAURON of 7 elliptical galaxies,
including those 3 galaxies in Romanowsky et al. (2003) with updated data and 4
other galaxies which have not been analyzed before. We conclude that the
dynamics of these galaxies can be well explained by MOND.


title: Learning Optimal Card Ranking from Query Reformulation

abstract:
  Mobile search has recently been shown to be the major contributor to the
growing search market. The key difference between mobile search and desktop
search is that information presentation is limited to the screen space of the
mobile device. Thus, major search engines have adopted a new type of search
result presentation, known as \textit{information cards}, in which each card
presents summarized results from one domain/vertical, for a given query, to
augment the standard blue-links search results. While it has been widely
acknowledged that information cards are particularly suited to mobile user
experience, it is also challenging to optimize such result sets. Typically,
user engagement metrics like query reformulation are based on whole ranked list
of cards for each query and most traditional learning to rank algorithms
require per-item relevance labels. In this paper, we investigate the
possibility of interpreting query reformulation into effective relevance labels
for query-card pairs. We inherit the concept of conventional learning-to-rank,
and propose pointwise, pairwise and listwise interpretations for query
reformulation. In addition, we propose a learning-to-label strategy that learns
the contribution of each card, with respect to a query, where such
contributions can be used as labels for training card ranking models. We
utilize a state-of-the-art ranking model and demonstrate the effectiveness of
proposed mechanisms on a large-scale mobile data from a major search engine,
showing that models trained from labels derived from user engagement can
significantly outperform ones trained from human judgment labels.


title:
A Poisson likelihood approach to fake lepton estimation with the matrix
  method

abstract:
  Many high-energy physics analyses require the presence of leptons from $W$,
$Z$, or $H$ boson decay. For these analyses, signatures that mimic such leptons
present a `fake lepton' background that must be estimated. Since the magnitude
of this background depends strongly upon details of the detector response, it
can be difficult to estimate with simulation. One data-driven approach is the
`matrix method', in which two categories of leptons are defined (`loose' and
`tight'), with the tight category being a subset of the loose category. Using
the populations of leptons in each category in the analysis sample, and the
efficiencies for both real and fake leptons in the loose category to satisfy
the criteria for the tight category, the fake background yield can be
estimated. This paper describes a Poisson likelihood implementation of the
matrix method, which provides a more precise, reliable, and robust estimate of
the fake background yield compared to an analytic solution. This implementation
also provides a reliable estimate of the background for cases in which the
analysis selection permits more loose leptons than tight leptons, potentially
allowing for greater selection efficiency.