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Rounds in a combinatorial search problemNov 30 2016We consider the following combinatorial search problem: we are given some excellent elements of $[n]$ and we should find at least one, asking questions of the following type: "Is there an excellent element in $A \subset [n]$?". G.O.H. Katona proved sharp ... More

Coloring points with respect to squaresDec 07 2015We consider the problem of $2$-coloring geometric hypergraphs. Specifically, we show that there is a constant $m$ such that any finite set $\mathcal{S}$ of points in the plane can be $2$-colored such that every axis-parallel square that contains at least ... More

A discrete isodiametric result: the Erdős-Ko-Rado theorem for multisetsDec 05 2012Mar 09 2014There are many generalizations of the Erd\H{o}s-Ko-Rado theorem. We give new results (and problems) concerning families of $t$-intersecting $k$-element multisets of an $n$-set and point out connections to coding theory and classical geometry. We establish ... More

Regular graphs are antimagicApr 30 2015In this note we prove - with a slight modification of an argument of Cranston et al. \cite{cranston} - that $k$-regular graphs are antimagic for $k\ge 2$.

An improvement on the maximum number of $k$-Dominating Independent SetsSep 14 2017Erd\H{o}s and Moser raised the question of determining the maximum number of maximal cliques or equivalently, the maximum number of maximal independent sets in a graph on $n$ vertices. Since then there has been a lot of research along these lines. A $k$-dominating ... More

Line Percolation in Finite Projective PlanesAug 01 2016We study combinatorial parameters of a recently introduced bootstrap percolation problem in finite projective planes. We present sharp results on the size of the minimum percolating sets and the maximal non-percolating sets. Additional results on the ... More

Correlation bound for distant parts of factor of IID processesMar 28 2016Apr 08 2016We study factor of i.i.d. processes on the $d$-regular tree for $d \geq 3$. We show that if such a process is restricted to two distant connected subgraphs of the tree, then the two parts are basically uncorrelated. More precisely, any functions of the ... More

On the Turán number of some ordered even cyclesOct 20 2017Jul 17 2018A classical result of Bondy and Simonovits in extremal graph theory states that if a graph on $n$ vertices contains no cycle of length $2k$ then it has at most $O(n^{1+1/k})$ edges. However, matching lower bounds are only known for $k=2,3,5$. In this ... More

Finding a non-minority ball with majority answersSep 28 2015Sep 28 2016Suppose we are given a set of $n$ balls $\{b_1,\ldots,b_n\}$ each colored either red or blue in some way unknown to us. To find out some information about the colors, we can query any triple of balls $\{b_{i_1},b_{i_2},b_{i_3}\}$. As an answer to such ... More

Majority problems of large query sizeOct 28 2016The aim of this paper is twofold: we present improvements of results of De Marco and Kranakis [6] on majority models, and we also survey recent results concerning the generalizations of the pairing model with query size k, and also provide bounds on their ... More

Grundy dominating sequences and zero forcing setsFeb 02 2017In a graph $G$ a sequence $v_1,v_2,\dots,v_m$ of vertices is Grundy dominating if for all $2\le i \le m$ we have $N[v_i]\not\subseteq \cup_{j=1}^{i-1}N[v_j]$ and is Grundy total dominating if for all $2\le i \le m$ we have $N(v_i)\not\subseteq \cup_{j=1}^{i-1}N(v_j)$. ... More

Dominating sequences in grid-like and toroidal graphsJul 01 2016A longest sequence $S$ of distinct vertices of a graph $G$ such that each vertex of $S$ dominates some vertex that is not dominated by its preceding vertices, is called a Grundy dominating sequence; the length of $S$ is the Grundy domination number of ... More

The variety of domination gamesJul 07 2018Domination game [SIAM J.\ Discrete Math.\ 24 (2010) 979--991] and total domination game [Graphs Combin.\ 31 (2015) 1453--1462] are by now well established games played on graphs by two players, named Dominator and Staller. In this paper, Z-domination ... More

Regular graphs are antimagicApr 30 2015Jan 09 2019An undirected simple graph $G=(V,E)$ is called antimagic if there exists an injective function $f:E\rightarrow\{1,\dots,|E|\}$ such that $\sum_{e\in E(u)} f(e)\neq\sum_{e\in E(v)} f(e)$ for any pair of different nodes $u,v\in V$. In a previous version ... More

A note on $\mathtt{V}$-free $2$-matchingsMay 14 2015Motivated by a conjecture of Liang [Y.-C. Liang. {\em Anti-magic labeling of graphs}. PhD thesis, National Sun Yat-sen University, 2013.], we introduce a restricted path packing problem in bipartite graphs that we call a $\mathtt{V}$-free $2$-matching. ... More

The minimum number of vertices in uniform hypergraphs with given domination numberMar 11 2016Jul 16 2016The \textit{domination number} $\gamma(\mathcal{H})$ of a hypergraph $\mathcal{H}=(V(\mathcal{H}),E(\mathcal{H})$ is the minimum size of a subset $D\subset V(\mathcal{H}$ of the vertices such that for every $v\in V(\mathcal{H})\setminus D$ there exist ... More

t-wise Berge and t-heavy hypergraphsFeb 08 2019In many proofs concerning extremal parameters of Berge hypergraphs one starts with analyzing that part of that shadow graph which is contained in many hyperedges. Capturing this phenomenon we introduce two new types of hypergraphs. A hypergraph $\mathcal{H}$ ... More

On the ratio of maximum and minimum degree in maximal intersecting familiesSep 06 2011To study how balanced or unbalanced a maximal intersecting family $\mathcal{F}\subseteq \binom{[n]}{r}$ is we consider the ratio $\mathcal{R}(\mathcal{F})=\frac{\Delta(\mathcal{F})}{\delta(\mathcal{F})}$ of its maximum and minimum degree. We determine ... More

Domination game on uniform hypergraphsOct 01 2017In this paper we introduce and study the domination game on hypergraphs. This is played on a hypergraph $\mathcal{H}$ by two players, namely Dominator and Staller, who alternately select vertices such that each selected vertex enlarges the set of vertices ... More

A Potts Model for Night Light and Human PopulationJan 17 2015The Potts model was one of the most popular physics models of the twentieth century in an interdisciplinary context. It has been applied to a large variety of problems. Many generalizations exists and a whole range of models were inspired by this statistical ... More

Boundary regularity of stochastic PDEsMay 15 2017May 21 2018The boundary behaviour of solutions of stochastic PDEs with Dirichlet boundary conditions can be surprisingly - and in a sense, arbitrarily - bad: as shown by Krylov, for any $\alpha>0$ one can find a simple $1$-dimensional constant coefficient linear ... More

Game saturation of intersecting familiesNov 30 2012Jan 06 2014We consider the following combinatorial game: two players, Fast and Slow, claim $k$-element subsets of $[n]=\{1,2,...,n\}$ alternately, one at each turn, such that both players are allowed to pick sets that intersect all previously claimed subsets. The ... More

Forbidding rank-preserving copies of a posetOct 25 2017The maximum size, $La(n,P)$, of a family of subsets of $[n]=\{1,2,...,n\}$ without containing a copy of $P$ as a subposet, has been intensively studied. Let $P$ be a graded poset. We say that a family $\mathcal{F}$ of subsets of $[n]=\{1,2,...,n\}$ contains ... More

A universal linear algebraic model for conformal geometriesMar 22 2016Sep 08 2016This article describes an entirely algebraic model for conformal geometries, which include the Euclidean, spherical and hyperbolic geometries. On one hand, their relationship is usually shown analytically, through systematic comparison of the measurement ... More

Homological codes and abelian anyonsMay 05 2015We study a generalization of Kitaev's abelian toric code model defined on CW complexes. In this model qudits are attached to n dimensional cells and the interaction is given by generalized star and plaquette operators. These are defined in terms of coboundary ... More

Towards a classification of $6\times 6$ complex Hadamard matricesFeb 02 2007Complex Hadamard matrices have received considerable attention in the past few years due to their appearance in quantum information theory. While a complete characterization is currently available only up to order 5 (in \cite{haagerup}), several new constructions ... More

Localization errors in solving stochastic partial differential equations in the whole spaceAug 22 2015Apr 23 2017Cauchy problems with SPDEs on the whole space are localized to Cauchy problems on a ball of radius $R$. This localization reduces various kinds of spatial approximation schemes to finite dimensional problems. The error is shown to be exponentially small. ... More

On the boundedness of solutions of SPDEsDec 13 2013Jan 03 2015In this paper estimates for the uniform norm of solutions of parabolic SPDEs are derived. The result is obtained through iteration techniques, motivated by the work of Moser in deterministic settings. As an application of the main result, solvability ... More

On the regularisation of the noise for the Euler-Maruyama scheme with irregular driftDec 11 2018The strong rate of convergence of the Euler-Maruyama scheme for nondegenerate SDEs with irregular drift coefficients is considered. In the case of $\alpha$-H\"older drift in recent literature the rate $\alpha/2$ was proved in many related situations. ... More

Characterizing variability in nonlinear recurrent neuronal networksOct 10 2016In this note, we develop semi-analytical techniques to obtain the full correlational structure of a stochastic network of nonlinear neurons described by rate variables. Under the assumption that pairs of membrane potentials are jointly Gaussian -- which ... More

A Feynman-Kac formula for stochastic Dirichlet problemsNov 13 2016A representation formula for solutions of stochastic partial differential equations with Dirichlet boundary conditions is proved. The scope of our setting is wide enough to cover the general situation when the backward characteristics that appear in the ... More

Localization errors in solving stochastic partial differential equations in the whole spaceAug 22 2015Cauchy problems with SPDEs on the whole space are localized to Cauchy problems on a ball of radius $R$. This localization reduces various kinds of spatial approximation schemes to finite dimensional problems. The error is shown to be exponentially small. ... More

On the density of planar sets without unit distancesSep 14 2018We improve the upper bound of the density of a planar, measurable set containing no two points at distance 1 to 0:25688 by involving higher order convolutions of the autocorrelation function of the set.

On Grundy total domination number in product graphsDec 23 2017A longest sequence $(v_1,\ldots,v_k)$ of vertices of a graph $G$ is a Grundy total dominating sequence of $G$ if for all $i$, $N(v_i) \setminus \bigcup_{j=1}^{i-1}N(v_j)\not=\emptyset$. The length $k$ of the sequence is called the Grundy total domination ... More

Qudit homological product codesMay 28 2015In this note we show that the random homological product code construction of Bravyi and Hastings can be extended to qudits of dimension D with D an odd prime. While the result is not surprising, the proof does require new ideas.

Local $L_\infty$-estimates, weak Harnack inequality, and stochastic continuity of solutions of SPDEsMar 15 2015Oct 17 2016We consider stochastic partial differential equations under minimal assumptions: the coefficients are merely bounded and measurable and satisfy the stochastic parabolicity condition. In particular, the diffusion term is allowed to be scaling-critical. ... More

The Hamiltonian BrainJul 03 2014Jul 04 2014A venerable history of models have shown that simple and complex cell responses in the primary visual cortex (V1) are adapted to the statistics of natural images. These models are based, either explicitly or implicitly, on the assumption that neural responses ... More

Finite difference schemes for stochastic partial differential equations in Sobolev spacesAug 21 2013Jan 28 2015We discuss $L_p$-estimates for finite difference schemes approximating parabolic, possibly degenerate, SPDEs, with initial conditions from $W^m_p$ and free terms taking values in $W^m_p.$ Consequences of these estimates include an asymptotic expansion ... More

Search for methane isotope fractionation due to Rayleigh distillation on TitanApr 08 2016We search for meridional variation in the abundance of CH$_3$D relative to CH$_4$ on Titan using near-IR spectra obtained with NIRSPAO at Keck, which have a photon-limited signal-to-noise ratio of $\sim$50. Our observations can rule out a larger than ... More

On the real linear polarization constant problemDec 01 2006The present paper deals with lower bounds for the norm of products of linear forms. It has been proved by J. Arias-de-Reyna \cite{ARIAS}, that %for ${\mathbb C}^n$, the so-called $n^{\rm th}$ linear polarization constant $c_n({\mathbb C}^n)$ is $n^{n/2}$, ... More

Geometry of Permutation LimitsSep 13 2016Sep 27 2016We investigate the limit theory of permutation valued stochastic processes with the goal of understanding geometric behaviour of large random sorting networks. The theory builds on the limit theory of permutations, called permutons. We use the limit theory ... More

Slowly decaying averages and fat towersSep 18 2016Let $(X,\Sigma,m,\tau)$ be an ergodic system, that is, $(X, \Sigma, m)$ is a probability space and $\tau: X \to X$ is an invertible ergodic $m$-preserving transformation. For a function $f:X\to\mathbb R$, let $A_Nf$ denote the $N$th ergodic average, $A_Nf(x)=\frac{1}{N}\cdot ... More

On the solvability of degenerate stochastic partial differential equations in Sobolev spacesApr 16 2014Systems of parabolic, possibly degenerate parabolic SPDEs are considered. Existence and uniqueness are established in Sobolev spaces. Similar results are obtained for a class of equations generalizing the deterministic first order symmetric hyperbolic ... More

Constructions of complex Hadamard matrices via tiling Abelian groupsJul 11 2006Oct 05 2006Applications in quantum information theory and quantum tomography have raised current interest in complex Hadamard matrices. In this note we investigate the connection between tiling Abelian groups and constructions of complex Hadamard matrices. First, ... More

Random differences in Szemerédi's theorem and related resultsJul 07 2013May 06 2014We introduce a new, elementary method for studying random differences in arithmetic progressions and convergence phenomena along random sequences of integers. We apply our method to obtain significant improvements on previously known results.

On Fuglede's conjecture and the existence of universal spectraDec 01 2006Recent methods developed by Tao \cite{tao}, Kolountzakis and Matolcsi \cite{nspec} have led to counterexamples to Fugelde's Spectral Set Conjecture in both directions. Namely, in $\RR^5$ Tao produced a spectral set which is not a tile, while Kolountzakis ... More

Under recurrence in the Khintchine recurrence theoremMar 24 2016May 23 2016The Khintchine recurrence theorem asserts that on a measure preserving system, for every set $A$ and $\varepsilon>0$, we have $\mu(A\cap T^{-n}A)\geq \mu(A)^2-\varepsilon$ for infinitely many $n\in \mathbb{N}$. We show that there are systems having under-recurrent ... More

The changing rotational excitation of C_3 in comet 9P/Tempel 1 during Deep ImpactJul 05 2012The 4050\AA\ band of C$_3$ was observed with Keck/HIRES echelle spectrometer during the {\em Deep Impact} encounter. We perform a 2-dimensional analysis of the exposures in order to study the spatial, spectral, and temporal changes in the emission spectrum ... More

X-ray Ionization of Heavy Elements Applied to Protoplanetary DisksMay 17 2011The consequences of the Auger effect on the population of heavy element ions are analyzed for the case of relatively cool gas irradiated by keV X-rays, with intended applications to the accretion disks of young stellar ob jects. Highly charged ions are ... More

An application of positive definite functions to the problem of MUBsDec 28 2016We present a new approach to the problem of mutually unbiased bases (MUBs), based on positive definite functions on the unitary group. The method provides a new proof of the fact that there are at most $d+1$ MUBs in ${\mathbb C}^d$. It may also lead to ... More

Fast sampling for Bayesian inference in neural circuitsApr 14 2014Apr 23 2014Time is at a premium for recurrent network dynamics, and particularly so when they are stochastic and correlated: the quality of inference from such dynamics fundamentally depends on how fast the neural circuit generates new samples from its stationary ... More

On Convergence of Modulated Ergodic Hilbert TransformsOct 17 2016Let $p(t)$ be a Hardy field function which grows "super-linearly" and stays "sufficiently far" from polynomials. We show that for each measure-preserving system, $(X,\Sigma,\mu,\tau)$, with $\tau$ a measure-preserving $\mathbb{Z}$-action, the modulated ... More

On the role of time in perceptual decision makingFeb 10 2015According to the dominant view, time in perceptual decision making is used for integrating new sensory evidence. Based on a probabilistic framework, we investigated the alternative hypothesis that time is used for gradually refining an internal estimate ... More

Transfer matrix approach for the Kerr and Faraday rotation in layered nanostructuresMar 07 2016To study the optical rotation of the polarization of light incident on multilayer systems consisting of atomically thin conductors and dielectric multilayers we present a general method based on transfer matrices. The transfer matrix of the atomically ... More

Robustness of flight leadership relations in pigeonsOct 25 2016Collective animal movements produce spectacular natural phenomena that arise from simple local interactions among group members. Flocks of homing pigeons, Columba livia, provide a useful model for the study of collective motion and decision making. During ... More

Higher order anisotropies in the Buda-Lund model: Disentangling flow and density field anisotropiesApr 25 2016Oct 12 2016The Buda-Lund hydro model describes an expanding ellipsoidal fireball, and fits the observed elliptic flow and oscillating HBT radii successfully. Due to fluctuations in energy depositions, the fireball shape however fluctuates on an event-by-event basis. ... More

FUV Irradiated Disk Atmospheres: Ly$α$ and the Origin of Hot H$_2$ EmissionDec 14 2015Protoplanetary disks are strongly irradiated by a stellar FUV spectrum that is dominated by Ly$\alpha$ photons. We investigate the impact of stellar Ly$\alpha$ irradiation on the terrestrial planet region of disks ($\lesssim 1$AU) using an updated thermal-chemical ... More

Optical phonons for Peierls chains with long-range Coulomb interactionsNov 14 2016We consider a chain of atoms that are bound together by a harmonic force. Spin-1/2 electrons that move between neighboring chain sites (H\"uckel model) induce a lattice dimerization at half band filling (Peierls effect). We supplement the H\"uckel model ... More

Kerr-de Sitter Quasinormal Modes via Accessory Parameter ExpansionNov 29 2018Feb 06 2019Quasinormal modes are characteristic oscillatory modes that control the relaxation of a perturbed physical system back to its equilibrium state. In this work, we calculate QNM frequencies and angular eigenvalues of Kerr--de Sitter black holes using a ... More

Shielding by Water and OH in FUV and X-ray Irradiated Protoplanetary DisksMar 31 2014We present an integrated thermal-chemical model for the atmosphere of the inner region of a protoplanetary disk that includes irradiation by both far ultraviolet (FUV) and X-ray radiation. We focus on how the photodissociation of water and OH affects ... More

Observations of a Stationary Mid-Latitude Cloud System on TitanMar 12 2010We report the observation of a cloud system on Titan that remained localized near 40S latitude and 60W longitude for at least 34 hours. Ground-based observations obtained with the SINFONI imaging spectrograph at the Very Large Telescope over 4 consecutive ... More

Bayesian Active Learning for Classification and Preference LearningDec 24 2011Information theoretic active learning has been widely studied for probabilistic models. For simple regression an optimal myopic policy is easily tractable. However, for other tasks and with more complex models, such as classification with nonparametric ... More

Self-organized UAV Traffic in Realistic EnvironmentOct 29 2016We investigated different dense multirotor UAV traffic simulation scenarios in open 2D and 3D space, under realistic environments with the presence of sensor noise, communication delay, limited communication range, limited sensor update rate and finite ... More

Thermal soaring flight of birds and unmanned aerial vehiclesDec 02 2010Thermal soaring saves much energy, but flying large distances in this form represents a great challenge for birds, people and Unmanned Aerial Vehicles (UAVs). The solution is to make use of so-called thermals, which are localized, warmer regions in the ... More

Static and dynamic shear viscosity of a single layer complex plasmaMar 01 2011Jun 24 2011We measured the static and dynamic (complex) shear viscosity of a single layer complex plasma by applying, respectively, a stationary and a periodically modulated shear stress induced by the light pressure of manipulating laser beams. Under static conditions ... More

How (not) to assess the importance of correlations for the matching of spontaneous and evoked activityJan 28 2013Mar 27 2013A comment on `Population rate dynamics and multineuron firing patterns in sensory cortex' by Okun et al. Journal of Neuroscience 32(48):17108-17119, 2012 and our response to the corresponding reply by Okun et al's (arXiv, 2013).

Hückel--Hubbard-Ohno modeling of $\boldsymbolπ$-bonds in ethene and ethyne with application to trans-polyacetyleneDec 10 2015Quantum chemistry calculations provide the potential energy between two carbon atoms in ethane (H$_3$C$-$CH$_3$), ethene (H$_2$C$=$CH$_2$), and ethyne (HC$\equiv$CH) as a function of the atomic distance. Based on the energy function for the $\sigma$-bond ... More

Simulation of 1+1 dimensional surface growth and lattices gases using GPUsDec 02 2010Mar 30 2011Restricted solid on solid surface growth models can be mapped onto binary lattice gases. We show that efficient simulation algorithms can be realized on GPUs either by CUDA or by OpenCL programming. We consider a deposition/evaporation model following ... More

Self-organized UAV Traffic in Realistic EnvironmentsOct 29 2016Nov 24 2016We investigated different dense multirotor UAV traffic simulation scenarios in open 2D and 3D space, under realistic environments with the presence of sensor noise, communication delay, limited communication range, limited sensor update rate and finite ... More

HBT radii from the multipole Buda-Lund modelMar 21 2016Mar 23 2016The Buda-Lund model describes an expanding hydrodynamical system with ellipsoidal symmetry and fits the observed elliptic flow and oscillating HBT radii successfully. The ellipsoidal symmetry can be characterized by the second order harmonics of the transverse ... More

The biased odd cycle gameOct 16 2012Apr 11 2013In this paper we consider biased Maker-Breaker games played on the edge set of a given graph $G$. We prove that for every $\delta>0$ and large enough $n$, there exists a constant $k$ for which if $\delta(G)\geq \delta n$ and $\chi(G)\geq k$, then Maker ... More

Cognitive Deep Machine Can Train ItselfDec 02 2016Machine learning is making substantial progress in diverse applications. The success is mostly due to advances in deep learning. However, deep learning can make mistakes and its generalization abilities to new tasks are questionable. We ask when and how ... More

The ^{144}Sm-αoptical potential at astrophysically relevant energies derived from ^{144}Sm(α,α)^{144}Sm elastic scatteringDec 10 1996For the determination of the $^{144}Sm-\alpha$ optical potential we measured the angular distribution of $^{144}Sm(\alpha,\alpha)^{144}Sm$ scattering at the energy $E_{lab} = 20 MeV$ with high accuracy. Using the known systematics of $\alpha$-nucleus ... More

Comparison of Different Parallel Implementations of the 2+1-Dimensional KPZ Model and the 3-Dimensional KMC ModelApr 23 2012Jul 25 2012We show that efficient simulations of the Kardar-Parisi-Zhang interface growth in 2 + 1 dimensions and of the 3-dimensional Kinetic Monte Carlo of thermally activated diffusion can be realized both on GPUs and modern CPUs. In this article we present results ... More

Patterns, transitions and the role of leaders in the collective dynamics of a simple robotic flockFeb 03 2012We have developed an experimental setup of very simple self-propelled robots to observe collective motion emerging as a result of inelastic collisions only. A circular pool and commercial RC boats were the basis of our first setup, where we demonstrated ... More

Better bounds for planar sets avoiding unit distancesDec 31 2014Oct 26 2015A $1$-avoiding set is a subset of $\mathbb{R}^n$ that does not contain pairs of points at distance $1$. Let $m_1(\mathbb{R}^n)$ denote the maximum fraction of $\mathbb{R}^n$ that can be covered by a measurable $1$-avoiding set. We prove two results. First, ... More

On the size of planarly connected crossing graphsSep 08 2015Aug 30 2016We prove that if an $n$-vertex graph $G$ can be drawn in the plane such that each pair of crossing edges is independent and there is a crossing-free edge that connects their endpoints, then $G$ has $O(n)$ edges. Graphs that admit such drawings are related ... More

A Study of Ro-vibrational OH Emission from Herbig Ae/Be StarsAug 02 2016We present a study of ro-vibrational OH and CO emission from 21 disks around Herbig Ae/Be stars. We find that the OH and CO luminosities are proportional over a wide range of stellar ultraviolet luminosities. The OH and CO line profiles are also similar, ... More

Testing and improving shear viscous phase space correction modelsJul 04 2017Comparison of hydrodynamic calculations with experimental data inevitably requires a model for converting the fluid to particles. In this work, nonlinear $2\to 2$ kinetic theory is used to assess the overall accuracy of various shear viscous fluid-to-particle ... More

Strong random correlations in networks of heterogeneous agentsOct 11 2012Feb 24 2014Correlations and other collective phenomena in a schematic model of heterogeneous binary agents (individual spin-glass samples) are considered on the complete graph and also on 2d and 3d regular lattices. The system's stochastic dynamics is studied by ... More

Large spin relaxation anisotropy and valley-Zeeman spin-orbit coupling in WSe2/Gr/hBN heterostructuresDec 15 2017Dec 18 2017Large spin-orbital proximity effects have been predicted in graphene interfaced with a transition metal dichalcogenide layer. Whereas clear evidence for an enhanced spin-orbit coupling has been found at large carrier densities, the type of spin-orbit ... More

Certifying an irreducible 1024-dimensional photonic state using refined dimension witnessesOct 12 2017Jun 12 2018We report on a new class of dimension witnesses, based on quantum random access codes, which are a function of the recorded statistics and that have different bounds for all possible decompositions of a high-dimensional physical system. Thus, it certifies ... More

The 106Cd(alpha,alpha)106Cd elastic scattering in a wide energy range for gamma-process studiesApr 29 2015Alpha elastic scattering angular distributions of the 106Cd(alpha,alpha)106Cd reaction were measured at three energies around the Coulomb barrier to provide a sensitive test for the alpha + nucleus optical potential parameter sets. Furthermore, the new ... More

$^{92}$Mo($α,α$)$^{92}$Mo scattering,the $^{92}$Mo--$α$ optical potential, and the $^{96}$Ru($γ,α$)$^{92}$Mo reaction rate at astrophysically relevant energiesOct 18 2001The elastic scattering cross section of$^{92}$Mo($\alpha$,$\alpha$)$^{92}$Mo has been measured at energies of $E_{\rm{c.m.}} \approx$ 13, 16, and 19 MeV in a wide angular range. The real and imaginary parts of the optical potential for the system $^{92}$Mo ... More

Meridional variation in tropospheric methane on Titan observed with AO spectroscopy at Keck and VLTSep 29 2015The spatial distribution of the tropospheric methane on Titan was measured using near-infrared spectroscopy. Ground-based observations at 1.5$\mu{\rm m}$ (H-band) were performed during the same night using instruments with adaptive optics at both the ... More

Identifying codes and searching with balls in graphsMay 29 2014Jun 02 2014Given a graph $G$ and a positive integer $R$ we address the following combinatorial search theoretic problem: What is the minimum number of queries of the form "does an unknown vertex $v \in V(G)$ belong to the ball of radius $r$ around $u$?" with $u ... More

Geometric explanation of the rich-club phenomenon in complex networksFeb 08 2017Dec 04 2017The rich club organization (the presence of highly connected hub core in a network) influences many structural and functional characteristics of networks including topology, the efficiency of paths and distribution of load. Despite its major role, the ... More

Diverging dc conductivity due to a flat band in disordered pseudospin-1 Dirac-Weyl fermionsMay 27 2013Several lattices, such as the dice or the Lieb lattice, possess Dirac cones and a flat band crossing the Dirac point, whose effective model is the pseudospin-1 Dirac-Weyl equation. We investigate the fate of the flat band in the presence of disorder by ... More