June 2013 arXiv papers — page 35

Oliver Matula, Armen G Hayrapetyan, Valeriy G Serbo, Andrey Surzhykov

We investigate the angular distribution of electrons that are emitted in the ionization of hydrogen-like ions by twisted photons. Analysis is performed based on the first-order perturbation theory and the non-relativistic Schrödinger equation. Special attention is paid to the dependence of the electron emission pattern on the impact parameter b of the ion wi

Anudhyan Boral, Marek Cygan, Tomasz Kociumaka, Marcin Pilipczuk

In the family of clustering problems, we are given a set of objects (vertices of the graph), together with some observed pairwise similarities (edges). The goal is to identify clusters of similar objects by slightly modifying the graph to obtain a cluster graph (disjoint union of cliques). Hueffner et al. [Theory Comput. Syst. 2010] initiated the parameteriz

Matthias Hinreiner, Dmitry A. Ryndyk, Denis Usvyat, Thomas Merz

We investigate the torsional vibrations in biphenyl-like molecular junctions and transport properties in the presence of an external THz field. Ab-initio calculations including external electric fields show that the torsional angle ϕ of a thiolated biphenyl junction exhibits virtually no response. However, if functional groups are added to the molecule, crea

Chen-Cheng Wu, Jiao Sun, Fei-Jie Huang, Yun-De Li

We propose a new approach to create Majorana fermions at the edge of a periodically driven semiconductor-superconductor Heterostructure. We calculate the quasi-energy spectrum of the periodically driven Heterostructure by using the Floquet's theory. When the interaction between different Brillouin zones of quasi-energy is neglected, one Majorana fermion

Timo Hirscher

A real symmetric n times n matrix is called copositive if the corresponding quadratic form is non-negative on the closed first orthant. If the matrix fails to be copositive there exists some non-negative certificate for which the quadratic form is negative. Due to the scaling property, we can find such certificates in every neighborhood of the origin but the

Peter Sarlin, Samuel Rönnqvist

This paper takes an information visualization perspective to visual representations in the general SOM paradigm. This involves viewing SOM-based visualizations through the eyes of Bertin's and Tufte's theories on data graphics. The regular grid shape of the Self-Organizing Map (SOM), while being a virtue for linking visualizations to it, restricts re

Vladimir Turaev

We introduce cyclic bilinear forms on coalgebras and use them to generalize Van den Bergh's Poisson brackets in representation algebras.

Fedor V. Fomin, Archontia C. Giannopoulou, Michał Pilipczuk

A connected graph has tree-depth at most $k$ if it is a subgraph of the closure of a rooted tree whose height is at most $k$. We give an algorithm which for a given $n$-vertex graph $G$, in time $\mathcal{O}(1.9602^n)$ computes the tree-depth of $G$. Our algorithm is based on combinatorial results revealing the structure of minimal rooted trees whose closure

Samuel Rönnqvist, Peter Sarlin

In the wake of the ongoing global financial crisis, interdependencies among banks have come into focus in trying to assess systemic risk. To date, such analysis has largely been based on numerical data. By contrast, this study attempts to gain further insight into bank interconnections by tapping into financial discussion. Co-mentions of bank names are turne

R. D. Johnson, K. Cao, L. C. Chapon, F. Fabrizi

Structural and magnetic chiralities are found to coexist in a small group of materials in which they produce intriguing phenomenologies such as the recently discovered skyrmion phases. Here, we describe a previously unknown manifestation of this interplay in MnSb2O6, a trigonal oxide with a chiral crystal structure. Unlike all other known cases, the MnSb2O6

Sara Angela Filippini, Jacopo Stoppa

We revisit the wall-crossing behaviour of solutions to the Thermodynamic Bethe Ansatz type equations arising in a class of three-dimensional field theories, expressed as sums of "instanton corrections". We explain how to attach to an instanton correction at a critical value a set of (combinatorial types of) tropical curves in R^2 of fixed degree, whi

Changbong Hyeon, D. Thirumalai

As a consequence of the rugged landscape of RNA molecules their folding is described by the kinetic partitioning mechanism according to which only a small fraction ($ϕ_F$) reaches the folded state while the remaining fraction of molecules is kinetically trapped in misfolded intermediates. The transition from the misfolded states to the native state can far e

Michal Rams, Károly Simon

A well studied family of random fractals called fractal percolation is discussed. We focus on the projections of fractal percolation on the plane. Our goal is to present stronger versions of the classical Marstrand theorem, valid for almost every realization of fractal percolation. The extensions go in three directions: {itemize} the statements work for all

K. P. Raju, B. J. I Bromage

The relative Doppler velocities and linewidths in a polar coronal hole and the nearby quiet-Sun region have been obtained from the {\it Solar and Heliospheric Observatory} (SOHO)/{\it Coronal Diagnostic Spectrometer} (CDS) observations using emission lines originating at different heights in the solar atmosphere from the lower transition region (TR) to the l

Michal Rams, Károly Simon

In this paper we study the radial and orthogonal projections and the distance sets of the random Cantor sets $E\subset \mathbb{R}^2 $ which are called Mandelbrot percolation or percolation fractals. We prove that the following assertion holds almost surely: if the Hausdorff dimension of $E$ is greater than 1 then the orthogonal projection to \textbf{every} l

Shi-Song Xiao, Le Zhang, Pan-Pan Guo, Defu Hou

Starting from the Kubo formula and the the QCD low energy theorem, we study the the bulk viscosity of hot dense quark matter in the PNJL model from the equation of state . We show that the bulk viscosity has a sharp peak near the chiral phase transition, and the ratio of bulk viscosity over entropy rises dramatically in the vicinity of the phase transition.

Michal Rams, Károly Simon

\emph{Fractal percolation} or \emph{Mandelbrot percolation} is one of the most well studied families of random fractals. In this paper we study some of the geometric measure theoretical properties (dimension of projections and structure of slices) of these random sets. Although random, the geometry of those sets is quite regular. Our results imply that, deno

Viviane M. Beuter, Daniel Gonçalves

For a free partial action of a group in a set we realize the associated partial skew group ring as an algebra of functions with finite support over an equivalence relation and we use this result to characterize the ideals in the partial skew group ring. This generalizes, to the purely algebraic setting, the known characterization of partial C*-crossed produc

Daniel Archambault, Derek Greene, Pádraig Cunningham

Analysts and social scientists in the humanities and industry require techniques to help visualize large quantities of microblogging data. Methods for the automated analysis of large scale social media data (on the order of tens of millions of tweets) are widely available, but few visualization techniques exist to support interactive exploration of the resul

Daniel Gonçalves

Let $\A$ be a ring with local units, $\E$ a set of local units for $\A$, $\G$ an abelian group and $α$ a partial action of $\G$ by ideals of $\A$ that contain local units and such that the partial skew group ring $\A\star_α \G$ is associative. We show that $\A\star_α \G$ is simple if and only if $\A$ is $\G$-simple and the center of the corner $eδ_0 (\A\star

Akram Ben Aissa

In this paper we give a new formulation of an abstract control problem in terms of a Grushin problem, so that we will reformulate all notions of controllability, observability and stability in a new form that gives readers an easy interpretation of these notions.

Romain Peretti, Cedric Gonnet, Anne-Marie Jurdyc

Ytterbium (Yb) doped fiber lasers are known to be affected by the creation of color centers during lasing (socalled photodarkening (PD)). In a previous work, this defect creation was investigated from a spectroscopic point of view, showing the presence of traces (ppb) of thulium (Tm) in the Yb doped fiber. It was shown that Tm has a strong impact on the defe

Romain Peretti, Guillaume Gomard, Christian Seassal, Xavier Letartre

In this paper, we propose a method for tailoring the absorption in a photonic crystal membrane. For that purpose, we first applied Time Domain Coupled Mode Theory to such a subwavelength membrane and demonstrated that 100% resonant absorption can be reached even for a symmetric membrane, if degenerate modes are involved. Design rules were then derived from t

David Godinho, Cristobal Quininao

This paper deals with a sub-critical Keller-Segel equation. Starting from the stochastic particle system associated with it, we show well-posedness results and the propagation of chaos property. More precisely, we show that the empirical measure of the system tends towards the unique solution of the limit equation as the number of particles goes to infinity.

Haichao Zhang, David Wipf

Typical blur from camera shake often deviates from the standard uniform convolutional script, in part because of problematic rotations which create greater blurring away from some unknown center point. Consequently, successful blind deconvolution requires the estimation of a spatially-varying or non-uniform blur operator. Using ideas from Bayesian inference

V. I. Chilin, I. G. Ganiev

We present versions of ergodic theorems for $L_1$--$L_\infty$ contractions in Banach--Kantorovich $L_p$-lattices associated with the Maharam measure taking values in the algebra of measurable functions.

Zdzislaw Burda, Jennifer Kornelsen, Maciej A. Nowak, Bartosz Porebski

We study collective behavior of Brodmann regions of human cerebral cortex using functional Magnetic Resonance Imaging (fMRI) and Random Matrix Theory (RMT). The raw fMRI data is mapped onto the cortex regions corresponding to the Brodmann areas with the aid of the Talairach coordinates. Principal Component Analysis (PCA) of the Pearson correlation matrix for

A. E. Sand, S. L. Dudarev, K. Nordlund

Recent experiments on in-situ high-energy self-ion irradiation of tungsten (W) show the occurrence of unusual cascade damage effects resulting from single ion impacts, shedding light on the nature of radiation damage expected in the tungsten components of a fusion reactor. In this paper, we investigate the dynamics of defect production in 150 keV collision c

Adam Ingram, Michiel van der Klis

Many statistical properties of the aperiodic variability observed in X-ray radiation from accreting compact objects can be naturally explained by the propagating fluctuations model. This considers variations in mass accretion rate to be stirred up throughout the accretion flow. Variations from the outer regions of the accretion flow will propagate towards th

Yanguang Chen, Feng Xu

The attraction measure, scaling exponent, and impedance function of the gravity model are redefined using the concepts from fractals and spatial complexity. Firstly, the attraction measure of spatial interaction in human systems is defined by the product of traffic inflow and outflow. Based on the new definition, the gravity model originating from the Newton

Pavel Etingof

Let A be a comodule algebra for a finite dimensional Hopf algebra K over an algebraically closed field k, and let A^K be the subalgebra of invariants. Let Z be a central subalgebra in A, which is a domain with quotient field Q. Assume that Q\otimes_Z A is a central simple algebra over Q, and either A is a finitely generated torsion-free Z-module and Z is int

Yanguang Chen, Fahui Wang

Fourier analysis and cross-correlation function are successfully applied to improving the conventional gravity model of interaction between cities by introducing a time variable to the attraction measures (e.g., city sizes). The traditional model assumes spatial interaction as instantaneous, while the new model considers the interaction as a temporal process

Yanguang Chen

The area-perimeter scaling can be employed to evaluate the fractal dimension of urban boundaries. However, the formula in common use seems to be not correct. By means of mathematical method, a new formula of calculating the boundary dimension of cities is derived from the idea of box-counting measurement and the principle of dimensional consistency in this p

Jelena Beban-Brkić, Marija Šimić Horvath

This paper gives a complete classification of conics in $PE_2(\mathbb{R})$. The classification has been made earlier (Reveruk [5]), but it showed to be incomplete and not possible to cite and use in further studies of properties of conics, pencil of conics, and of quadratic forms in pseudo-Euclidean spaces. This paper provides that. A pseudo-orthogonal matri

Oliver Mason, Fabian Wirth

For finite-dimensional linear semigroups which leave a proper cone invariant it is shown that irreducibility with respect to the cone implies the existence of an extremal norm. In case the cone is simplicial a similar statement applies to absolute norms. The semigroups under consideration may be generated by discrete-time systems, continuous-time systems or

Berta Cillero-Pastor, Gert Eijkel, Andras Kiss, Francisco J. Blanco

Osteoarthritis (OA) is a pathology that ultimately causes joint destruction. The cartilage is one of the principal affected tissues. Alterations in the lipid mediators and an imbalance in the metabolism of cells that form the cartilage (chondrocytes) have been described as contributors to the OA development. In this study, we have studied the distribution of

François Boulogne, Marc-Antoine Fardin, Sandra Lerouge, Ludovic Pauchard

We report on the Rayleigh-Plateau instability in films of giant micelles solutions coating a vertical fibre. We observe that the dynamics of thin films coating the fibre could be very different from the Newtonian or standard Non-Newtonian cases. By varying the concentration of the components of the solutions and depending on the film thickness, we show for t

P. Bakule, G. A. Beer, D. Contreras, M. Esashi

Emission of muonium ($μ^{+}e^{-}$) atoms from silica aerogel into vacuum was observed. Characteristics of muonium emission were established from silica aerogel samples with densities in the range from 29 mg cm$^{-3}$ to 178 mg cm$^{-3}$. Spectra of muonium decay times correlated with distances from the aerogel surfaces, which are sensitive to the speed distr

Mihailo Stojnic

It has been known for a long time that the classical spherical perceptrons can be used as storage memories. Seminal work of Gardner, \cite{Gar88}, started an analytical study of perceptrons storage abilities. Many of the Gardner's predictions obtained through statistical mechanics tools have been rigorously justified. Among the most important ones are of

Zayd Hajjej

In this paper we study time semi-discrete approximations of a class of polynomially stable infinite dimensional systems modeling the damped vibrations. We prove that adding a suitable numerical viscosity term in the numerical scheme, one obtains approximations that are uniformly polynomially stable with respect to the discretization parameter.

Tadeusz Kosztołowicz

Subdiffusion in a system in which mobile particles $A$ can chemically react with static particles $B$ according to the rule $A+B\rightarrow B$ is considered within a persistent random walk model. This model, which assumes a correlation between successive steps of particles, provides hyperbolic Cattaneo normal diffusion or fractional subdiffusion equations fo

Arkady Pikovsky

We study dynamics of a serial array of spin-torque-oscillators with a parallel inductor-capacitor-resistor (LCR) load. In a large range of parameters the fully synchronous regime, where all the oscillators have the same state and the output field is maximal, is shown to be stable. However, not always such a robust complete synchronization develops from the r

Francesca Mantese, Alberto Tonolo

In this paper we characterize the modules and the complexes involved in the dualities induced by a 1-cotilting bimodule in terms of a linear compactness condition. Our result generalizes the classical characterization of reflexive modules with respect to Morita dualities. The linear compactness notion considered, permits us to obtain finiteness properties of

Zayd Hajjej, Mohamed Balegh

In this paper we study time semi-discrete approximations of a class of exponentially stable infinite dimensional systems with unbounded feedbacks. It has recently been proved that for time semi-discrete systems, due to high frequency spurious components, the exponential decay property may be lost as the time step tends to zero. We prove that adding a suitabl

Luca Ferrari

We generalize the matroid-theoretic approach to greedy algorithms to the setting of poset matroids, in the sense of Barnabei, Nicoletti and Pezzoli (1998) [BNP]. We illustrate our result by providing a generalization of Kruskal algorithm (which finds a minimum spanning subtree of a weighted graph) to abstract simplicial complexes.

Marco Robalo

We continue the work initiated in arXiv:1206.3645, where we introduced a new stable symmetric monoidal $(\infty,1)$-category $SH_{nc}$ encoding a motivic stable homotopy theory for the noncommutative spaces of Kontsevich and obtained a canonical monoidal colimit-preserving functor $SH\to SH_{nc}$ relating this new theory to the $(\infty,1)$-category encoding

Donald F. Smith, Andriy Kharchenko, Marco Konijnenburg, Ivo Klinkert

Mass spectrometry imaging by Fourier transform ion cyclotron resonance yields hundreds of unique peaks, many of which cannot be resolved by lower performance mass spectrometers. The high mass accuracy and high mass resolving power allow confident identification of small molecules and lipids directly from biological tissue sections. Here, calibration strategi

J. L. Doménech, M. Cueto, V. J. Herrero, I. Tanarro

The high resolution spectrum of the v4 band of NH3D+ has been measured by difference frequency IR laser spectroscopy in a multipass hollow cathode discharge cell. From the set of molecular constants obtained from the analysis of the spectrum, a value of 262817(6) MHz (3sigma) has been derived for the frequency of the 1(0)-0(0) rotational transition. This val

Michael Bonitz, Andrea Scharnhorst

Biographical essay at the occasion of the first death anniversary of Manfred Bonitz

C. Pallanca, B. Lanzoni, E. Dalessandro, F. R. Ferraro

We present the identification of the companion star to the intermediate mass binary pulsar J1439-5501 obtained by means of ground-based deep images in the B, V and I bands, acquired with FORS2 mounted at the ESO-VLT. The companion is a massive white dwarf (WD) with B=23.57+-0.02, V=23.21+-0.01 and I=22.96+-0.01, located at only ~0.05" from the pulsar rad

Xiaoping Xu

In this article, we introduce a moving-frame approach to the geophysical equation of two-dimensional uniformly stratified rotational fluid in oceans and find a family of exact solutions containing ten arbitrary parameter functions.

Balaram Dey, Debasish Mondal, Deepak Pandit, S. Mukhopadhyay

We report on the neutron response of the LAMBDA spectrometer developed earlier for high-energy gamma-ray measurement. The energy dependent neutron detection efficiency of the spectrometer has been measured using the time-of-flight (TOF) technique and compared with that of an organic liquid scintillator based neutron detector (BC501A). The extracted efficienc

Richard Smiraglia, Andrea Scharnhorst, Almila Akdag Salah, Cheng Gao

The UDC (Universal Decimal Classification) is not only a classification language with a long history; it also presents a complex cognitive system worthy of the attention of complexity theory. The elements of the UDC: classes, auxiliaries, and operations are combined into symbolic strings, which in essence represent a complex networks of concepts. This networ

H. -Y. Lo, J. Alonso, D. Kienzler, B. C. Keitch

We describe laser systems for photoionization, Doppler cooling and quantum state manipulation of beryllium ions. For photoionization of neutral beryllium, we have developed a continuous-wave 235 nm source obtained by two stages of frequency doubling from a diode laser at 940 nm. The system delivers up to 400 mW at 470 nm and 28 mW at 235 nm. For control of t

David Bücher, Andreas Gärtner, Burkhard Kümmerer, Walter Reußwig

We study a class of quantum Markov processes that, on the one hand, is inspired by the micromaser experiment in quantum optics and, on the other hand, by classical birth and death processes. We prove some general geometric properties and irreducibility for non-degenerated parameters. Furthermore, we analyze ergodic properties of the corresponding transition

Mihailo Stojnic

Recent studies of under-determined linear systems of equations with sparse solutions showed a great practical and theoretical efficiency of a particular technique called $\ell_1$-optimization. Seminal works \cite{CRT,DOnoho06CS} rigorously confirmed it for the first time. Namely, \cite{CRT,DOnoho06CS} showed, in a statistical context, that $\ell_1$ technique

Sarel Cohen, Amos Fiat, Moshik Hershcovitch, Haim Kaplan

We give a new successor data structure which improves upon the index size of the Pǎtraşcu-Thorup data structures, reducing the index size from $O(n w^{4/5})$ bits to $O(n \log w)$ bits, with optimal probe complexity. Alternatively, our new data structure can be viewed as matching the space complexity of the (probe-suboptimal) $z$-fast trie of Belazzougui et

Mihailo Stojnic

In this paper we revisit under-determined linear systems of equations with sparse solutions. As is well known, these systems are among core mathematical problems of a very popular compressed sensing field. The popularity of the field as well as a substantial academic interest in linear systems with sparse solutions are in a significant part due to seminal re

Gérald Gurtner, Stefania Vitali, Marco Cipolla, Fabrizio Lillo

We show that the European airspace can be represented as a multi-scale traffic network whose nodes are airports, sectors, or navigation points and links are defined and weighted according to the traffic of flights between the nodes. By using a unique database of the air traffic in the European airspace, we investigate the architecture of these networks with

Šárka Hudecová, Michal Pešta

A common approach to the claims reserving problem is based on generalized linear models (GLM). Within this framework, the claims in different origin and development years are assumed to be independent variables. If this assumption is violated, the classical techniques may provide incorrect predictions of the claims reserves or even misleading estimates of th

Netanel Raviv

Complexity theory offers a variety of concise computational models for computing boolean functions - branching programs, circuits, decision trees and ordered binary decision diagrams to name a few. A natural question that arises in this context with respect to any such model is this: Given a function f:{0,1}^n \to {0,1}, can we compute the optimal complexity

E. A. Levchenko, A. V. Shapovalov, A. Yu Trifonov

We have investigated the pattern formation in systems described by the nonlocal Fisher--Kolmogorov--Petrovskii--Piskunov equation for the cases where the dimension of the pattern concentration area is less than that of independent variables space. We have obtained a system of integro-differential equations which describe the dynamics of the concentration are

Mihailo Stojnic

In this paper we look at a class of random optimization problems that arise in the forms typically known as Hopfield models. We view two scenarios which we term as the positive Hopfield form and the negative Hopfield form. For both of these scenarios we define the binary optimization problems that essentially emulate what would typically be known as the grou

Alexander Kushpel, Jeremy Levesley

We develop a general method for derivative pricing. This approach has its roots in Shannon's Information Theory. The notion of $λ$-analyticity of Lévy models is introduced on the basis of which new representations of the pricing integral are obtained. It is shown that popular in applications Lévy models are $λ$-analytic. We apply these results to derive

Virginie Bonnaillie-Noël, Christophe Lacave, Nader Masmoudi

We investigate the influence of a perforated domain on the 2D Euler equations. Small inclusions of size $\varepsilon$ are uniformly distributed on the unit segment or a rectangle, and the fluid fills the exterior. These inclusions are at least separated by a distance $\varepsilon^α$ and we prove that for $α$ small enough (namely, less than 2 in the case of t

Trung Duc Nguyen, Rodney Van Meter

Reversible logic has applications in low-power computing and quantum computing. However, there are few existing designs for reversible floating-point adders and none suitable for quantum computation. In this paper we propose a space-efficient reversible floating-point adder, suitable for binary quantum computation, improving the design of Nachtigal et al. Ou

G. Bauer, D. -A. Deckert, Detlef Dürr, Günter Hinrichs

The direct interaction theory of electromagnetism, also known as Wheeler-Feynman electrodynamics, is often misinterpreted and found unappealing because of its reference to the absorber and, more importantly, to the so-called absorber condition. Here we remark that the absorber condition is indeed questionable and presumably not relevant for the explanation o

Benjamin A. Laken, Hannu Parviainen, Enric Pallé, Tariq Shahbaz

We estimate the frequency of Saharan mineral dust outbreak events observed over the North Atlantic island of La Palma based on in situ nightly atmospheric extinction measurements recorded almost continuously since 1984 by the Carlsberg Meridian Telescope at the Roque de los Muchachos observatory. The outbreak frequency shows a well-defined seasonal peak in t

Viacheslav Burenkov, He Xu, Bing Qi, Robert H. Hadfield

We report on the observation of a non-uniform dark count rate in Superconducting Nanowire Single Photon Detectors (SNSPDs), specifically focusing on an afterpulsing effect present when the SNSPD is operated at a high bias current regime. The afterpulsing exists for real detection events (triggered by input photons) as well as for dark counts (no laser input)

W. A. Li, L. F. Wei

Traditional polarizer provides a way to convert an unknown polarization into a specified polarization. According to Malus, the intensity of the transmission is directly proportional to the square of the cosine of angle between the transmission axes of the polarizer and the incident polarization. There, the intensity refers to the collective behavior of many

H. Park, A. Udalski, C. Han, A. Gould

Gravitational microlensing events produced by lenses composed of binary masses are important because they provide a major channel to determine physical parameters of lenses. In this work, we analyze the light curves of two binary-lens events OGLE-2006-BLG-277 and OGLE-2012-BLG-0031 for which the light curves exhibit strong deviations from standard models. Fr

David Jewitt, Jing Li, Jessica Agarwal

We report the discovery of a comet-like tail on asteroid (3200) Phaethon when imaged at optical wavelengths near perihelion. In both 2009 and 2012, the tail appears >=350" (2.5x10^8 m) in length and extends approximately in the projected anti-solar direction. We interpret the tail as being caused by dust particles accelerated by solar radiation pressure.

Menghui Li, Hailin Zou, Shuguang Guan, Xiaofeng Gong

The dynamical origin of complex networks, i.e., the underlying principles governing network evolution, is a crucial issue in network study. In this paper, by carrying out analysis to the temporal data of Flickr and Epinions--two typical social media networks, we found that the dynamical pattern in neighborhood, especially the formation of triadic links, play

Zeng Zhang, Zhaoyang Yin

In this paper we investigate well-posedness of the Cauchy problem of the three dimensional generalized Navier-Stokes system. We first establish local well-posedness of the GNS system for any initial data in the Fourier-Herz space $χ^{-1}$. Then we show that if the $χ^{-1}$ norm of the initial data is smaller than C$ν$ in the GNS system where $ν$ is the visco

J. Hu, J. J. He, S. W. Xu, H. Yamaguchi

Proton resonant states in $^{18}$Ne have been investigated by the resonant elastic scattering of $^{17}$F+$p$. The $^{17}$F beam was separated by the CNS radioactive ion beam separator (CRIB), and bombarded a thick H$_2$ gas target at 3.6 MeV/nucleon. The recoiled light particles were measured by using three sets of $Δ$E-E Si telescope at scattering angles o

Lulu Fan, Guanwen Fang, Yang Chen, Zhizheng Pan

In this letter, we use a two-color (J-L) vs. (V-J) selection criteria to search massive, quiescent galaxy candidates at 2.5<z<4.0 in the CANDELS-COSMOS field. We construct a H-selected catalogue and complement it with public auxiliary data. We finally obtain 19 passive VJL-selected (hereafter pVJL) galaxies as the possible massive quiescent galaxy candidates

Arun Tejasvi Chaganty, Percy Liang

Discriminative latent-variable models are typically learned using EM or gradient-based optimization, which suffer from local optima. In this paper, we develop a new computationally efficient and provably consistent estimator for a mixture of linear regressions, a simple instance of a discriminative latent-variable model. Our approach relies on a low-rank lin

J. -T. Hsiang, Rong Zhou, B. L. Hu

In this paper we study a system of $N$ coupled quantum oscillators interacting with each other directly with varying coupling strengths and indirectly through linear couplings to a scalar massless quantum field as its environment. The influence of the quantum field on the system is calculated with the use of the influence functional formalism. We take the di

Lin Chen, Deshi Ye, Guochuan Zhang

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

Cong Yu, Lei Huang

We propose a catastrophic magnetospheric model for magnetar precursors and their successive giant flares. Axisymmetric models of the magnetosphere, which contain both a helically twisted flux rope and a current sheet, are established based on force-free field configurations. In this model, the helically twisted flux rope would lose its equilibrium and erupt

Georgios Vernardos, Christopher J. Fluke

Cosmological gravitational microlensing is a useful technique for understanding the structure of the inner parts of a quasar, especially the accretion disk and the central supermassive black hole. So far, most of the cosmological microlensing studies have focused on single objects from ~90 currently known lensed quasars. However, present and planned all-sky

Regine Frank

A gas of ultracold interacting quantum degenerate Fermions is considered in a three dimensional optical lattice which is externally modulated in the fre- quency and the amplitude. This theoretical study utilizes the Keldysh formalism to account for the system being out of thermodynamical equilibrium. A dynamical mean field theory, extended to non-equilibrium

Y. F. Ren, L. Wang, Z. Liu, M. W. Wu

We investigate the energy spectra of three electrons in SiGe/Si/SiGe equilateral triangular and symmetric linear triple quantum dots in the presence of magnetic (in either Faraday or Voigt configuration) and electric fields with single valley approximation by using the real-space configuration interaction method. The strong electron-electron Coulomb interact

C. Neill, A. Megrant, R. Barends, Yu Chen

Superconducting resonators, used in astronomy and quantum computation, couple strongly to microscopic two-level defects. We monitor the microwave response of superconducting resonators and observe fluctuations in dissipation and resonance frequency. We present a unified model where the observed dissipative and dispersive effects can be explained as originati

Xiaoming Chen, Rui Yin

Channel state information (CSI) at the transmitter is of importance to the performance of physical layer security based on multi-antenna networks. Specifically, CSI is not only beneficial to improve the capacity of the legitimate channel, but also can be used to degrade the performance of the eavesdropper channel. Thus, the secrecy rate increases accordingly

Haizhong Li, Yong Wei

Let $(N,g)$ be an $n$-dimensional complete Riemannian manifold with nonempty boundary $\pt N$. Assume that the Ricci curvature of $N$ has a negative lower bound $Ric\geq -(n-1)c^2$ for some $c>0$, and the mean curvature of the boundary $\pt N$ satisfies $H\geq (n-1)c_0>(n-1)c$ for some $c_0>c>0$. Then a known result (see \cite{LN}) says that $\sup_{x\in N}d(

Akihito Kikuchi

This article is an introduction to a new approach to first principles electronic structure calculation. The starting point is the Hartree-Fock-Roothaan equation, in which molecular integrals are approximated by polynomials by way of Taylor expansion with respect to atomic coordinates and other variables. It leads to a set of polynomial equations whose soluti

Harald Höller, Antti Koskela, Ernst Dorfi, Werner Benger

Context. High-resolution numerical methods have been developed for nonlinear, discontinuous problems as they appear in simulations of astrophysical objects. One of the strategies applied is the concept of artificial viscosity. Aims. Grid-based numerical simulations ideally utilize problem-oriented grids in order to minimize the necessary number of cells at a

Stefano Beltraminelli, Danilo Merlini, Sergey Sekatskii

We propose an architecture of a conjecture concerning the Riemann Hypothesis in the form of an &#34;alternative&#34; to the Pólya strategy: we construct a Hamiltonian H_Polya whose spectrum coincides exactly with that of the Harmonic Oscillator Hamiltonian H_osc if and only if the Riemann Hypothesis holds true. In other words, it can be said that we formulat

Antoine Canaguier-Durand, James A. Hutchison, Cyriaque Genet, Thomas W. Ebbesen

We calculate optical forces and torques exerted on a chiral dipole by chiral light fields and reveal genuinely chiral forces in combining the chiral contents of both light field and dipolar matter. Here, the optical chirality is characterized in a general way through the definition of optical chirality density and chirality flow. We show in particular that b

William Fithian, Trevor Hastie

For classification problems with significant class imbalance, subsampling can reduce computational costs at the price of inflated variance in estimating model parameters. We propose a method for subsampling efficiently for logistic regression by adjusting the class balance locally in feature space via an accept-reject scheme. Our method generalizes standard

Michal R. Przybylek

This paper shows how internal models for polymorphic lambda calculi arise in any 2-category with a notion of discreteness. We generalise to a 2-categorical setting the famous theorem of Peter Freyd saying that there are no sufficiently (co)complete non-degenerate categories. As a simple corollary, we obtain a variant of Freyd theorem for categories internal

Jim Conant

We study the cokernel of the Johnson homomorphism for the mapping class group of a surface with one boundary component. A graphical trace map simultaneously generalizing trace maps of Enomoto-Satoh and Conant-Kassabov-Vogtmann is given, and using technology from the author&#39;s work with Kassabov and Vogtmann, this is is shown to detect a large family of re

Ronen Eldan, Joseph Lehec

Chaining techniques show that if X is an isotropic log-concave random vector in R^n and Gamma is a standard Gaussian vector then E |X| < C n^{1/4} E |Gamma| for any norm |*|, where C is a universal constant. Using a completely different argument we establish a similar inequality relying on the thin-shell constant sigma_n = sup ((var|X|^){1/2} ; X isotropic a

Peng Ye, Juven Wang

A large class of symmetry-protected topological phases (SPT) in boson / spin systems have been recently predicted by the group cohomology theory. In this work, we consider SPT states at least with charge symmetry (U(1) or Z$_N$) or spin $S^z$ rotation symmetry (U(1) or Z$_N$) in 2D, 3D, and the surface of 3D. If both are U(1), we apply external electromagnet

J. Matthews, F. Battista, D. Sanchez, P. Samuelsson

Symmetry relations are manifestations of fundamental principles and constitute cornerstones of modern physics. An example are the Onsager relations between coefficients connecting thermodynamic fluxes and forces, central to transport theory and experiments. Initially formulated for classical systems, these reciprocity relations are also fulfilled in quantum

Shachar Shayovitz, Dan Rapaheli

In this work, a new low complexity iterative algorithm for decoding data transmitted over strong phase noise channels is presented. The algorithm is based on the Sum & Product Algorithm (SPA) with phase noise messages modeled as Tikhonov mixtures. Since mixture based Bayesian inference such as SPA, creates an exponential increase in mixture order for consecu

Felipe Sánchez-Martínez, Isabel Martínez-Sempere, Xavier Ivars-Ribes, Rafael C. Carrasco

The IMPACT-es diachronic corpus of historical Spanish compiles over one hundred books --containing approximately 8 million words-- in addition to a complementary lexicon which links more than 10 thousand lemmas with attestations of the different variants found in the documents. This textual corpus and the accompanying lexicon have been released under an open

Robert Krauthgamer, Boaz Nadler, Dan Vilenchik

Estimating the leading principal components of data, assuming they are sparse, is a central task in modern high-dimensional statistics. Many algorithms were developed for this sparse PCA problem, from simple diagonal thresholding to sophisticated semidefinite programming (SDP) methods. A key theoretical question is under what conditions can such algorithms r

Fatma Şengüler-Çiftçi

The present paper attempts to show an alternative approach with regards to rational Pythagorean-hodograph (PH) curves and especially more natural approach for rational PH helices (i.e. rational helices). It exploits geometric features of rational helices to obtain a simpler construction of these curves and apply this to related subjects. One of these applica