Results for "Vincent J. Hellendoorn"

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Are My Invariants Valid? A Learning ApproachMar 14 2019Ensuring that a program operates correctly is a difficult task in large, complex systems. Enshrining invariants -- desired properties of correct execution -- in code or comments can support maintainability and help sustain correctness. Tools that can ... More
Are My Invariants Valid? A Learning ApproachMar 14 2019Mar 15 2019Ensuring that a program operates correctly is a difficult task in large, complex systems. Enshrining invariants -- desired properties of correct execution -- in code or comments can support maintainability and help sustain correctness. Tools that can ... More
On the "Naturalness" of Buggy CodeJun 03 2015Sep 10 2015Real software, the kind working programmers produce by the kLOC to solve real-world problems, tends to be "natural", like speech or natural language; it tends to be highly repetitive and predictable. Researchers have captured this naturalness of software ... More
The pattern and process of gene family evolutionFeb 11 2011Large scale databases are available that contain homologous gene families constructed from hundreds of complete genome sequences from across the three domains of Life. Here we discuss approches of increasing complexity aimed at extracting information ... More
Dynamical Projective Curvature in GravitationDec 14 2017Dec 26 2018By using a projective connection over the space of two-dimensional affine connections, we are able to show that the metric interaction of Polyakov 2D gravity with a coadjoint element arises naturally through the projective Ricci tensor. Through the curvature ... More
Multi-valuedness of the Luttinger-Ward functional in the Fermionic and Bosonic System with ReplicasDec 31 2018We study the properties of the Luttinger-Ward functional (LWF) in a simplified Hubbard-type model without time or spatial dimensions, but with $N$ identical replicas located on a single site. The simplicity of this $(0+0)d$ model permits an exact solution ... More
Geometry and Surface Plasmon energyMar 10 2011Mar 15 2011We derive a simple rule to determine surface plasmon energies, based on the geometrical properties of the surface of the metal. We apply this concept to obtain the surface plasmon energies in wedges, corners and conical tips. The results presented here ... More
Random subtrees of complete graphsAug 21 2013We study the asymptotic behavior of four statistics associated with subtrees of complete graphs: the uniform probability $p_n$ that a random subtree is a spanning tree of $K_n$, the weighted probability $q_n$ (where the probability a subtree is chosen ... More
On the global evolution problem in 2+1 gravityOct 10 1996Existence of global CMC foliations of constant curvature 3-dimensional maximal globally hyperbolic Lorentzian manifolds, containing a constant mean curvature hypersurface with $\genus(\Sigma) > 1$ is proved. Constant curvature 3-dimensional Lorentzian ... More
Vibron-polaron in alpha-helices. I. Single-vibron statesFeb 07 2005Sep 16 2005The vibron dynamics associated to amide-I vibrations in a 3D alpha-helix is described according to a generalized Davydov model. The helix is modeled by three spines of hydrogen-bonded peptide units linked via covalent bonds. To remove the intramolecular ... More
The decisive future of inflationMar 26 2018May 25 2018How much more will we learn about single-field inflationary models in the future? We address this question in the context of Bayesian design and information theory. We develop a novel method to compute the expected utility of deciding between models and ... More
Discrete transverse superconducting modes in nano-cylindersMay 20 2004Spatial variation in the superconducting order parameter becomes significant when the system is confined at dimensions well below the typical superconducting coherence length. Motivated by recent experimental success in growing single-crystal metallic ... More
Proper Motions of OH Masers and Magnetic Fields in Massive Star-Forming RegionsAug 08 2007We present data of proper motions of OH masers in the massive star-forming regions ON 1, K3-50, and W51 Main/South. OH maser motions in ON 1 are consistent with expansion at approximately 5 km/s, likely tracing the expanding ultracompact H II region. ... More
Full-Polarization Observations of OH Masers in Massive Star-Forming Regions: II. Maser Properties and the Interpretation of PolarizationJan 24 2006We analyze full-polarization VLBA data of ground-state, main-line OH masers in 18 massive star-forming regions previously presented in a companion paper. The OH masers often arise in the shocked neutral gas surrounding ultracompact Hii regions. Magnetic ... More
Large Magnetic Fields and Motions of OH Masers in W75 NNov 02 2006We report on a second epoch of VLBA observations of the 1665 and 1667 MHz OH masers in the massive star-forming region W75 N. We find evidence to confirm the existence of very strong (~40 mG) magnetic fields near source VLA 2. The masers near VLA 2 are ... More
Rheological properties of the soft-disk model of two-dimensional foamsMar 28 2018The soft-disk model previously developed and applied by Durian [D. J. Durian, Phys. Rev. Lett. 75, 4780 (1995)] is brought to bear on problems of foam rheology of longstanding and current interest, using two-dimensional systems. The questions at issue ... More
Relaxation channels of two-vibron bound states in α-helix proteinsOct 15 2003Relaxation channels for two-vibron bound states in an anharmonic alpha-helix protein are studied. It is pointed out that the relaxation originates in the interaction between the dressed anharmonic vibrons and the remaining phonons. This interaction is ... More
Vibron-polaron critical localization in a finite size molecular nanowireMay 04 2004Sep 01 2004The small polaron theory is applied to describe the vibron dynamics in an adsorbed nanowire with a special emphasis onto finite size effects. It is shown that the finite size of the nanowire discriminates between side molecules and core molecules which ... More
The Lind-Lehmer Constant for $\mathbb Z_2^r \times \mathbb Z_{4}^s$May 14 2018We show that the minimal positive logarithmic Lind-Mahler measure for a group of the form $G=\mathbb Z_2^r\times\mathbb Z_4^s$ with $|G|\geq 4$ is $\frac{1}{|G|} \log (|G|-1).$ We also show that for $G=\mathbb Z_2 \times \mathbb Z_{2^n}$ with $n\geq 3$ ... More
Escape Probability, Mean Residence Time and Geophysical Fluid Particle DynamicsJan 22 1999Stochastic dynamical systems arise as models for fluid particle motion in geophysical flows with random velocity fields. Escape probability (from a fluid domain) and mean residence time (in a fluid domain) quantify fluid transport between flow regimes ... More
Comparison of simulated longitudinal profiles of hadronic air showers with MASS2 balloon dataMay 16 2002The KASKADE and CORSIKA air shower generators are compared to the data collected by MASS2 balloon experiment in 1991. The test of longitudinal profile for proton, helium and muon flux production provide good constraints on these air shower generators. ... More
Spin glasses : experimental signatures and salient outcomesSep 29 2017Apr 01 2019Within the wide class of disordered materials, spin glasses occupy a special place because of their conceptually simple definition of randomly interacting spins. Their modelling has triggered spectacular developments of out-of-equilibrium statistical ... More
Joint source and channel coding for MIMO systems: Is it better to be robust or quick?Jan 24 2008We develop a framework to optimize the tradeoff between diversity, multiplexing, and delay in MIMO systems to minimize end-to-end distortion. We first focus on the diversity-multiplexing tradeoff in MIMO systems, and develop analytical results to minimize ... More
Ruling out the light WIMP explanation of the galactic 511 keV lineFeb 02 2016May 05 2016Over the past few decades, an anomalous 511 keV gamma-ray line has been observed from the centre of the Milky Way. Dark matter (DM) in the form of light (< 10 MeV) WIMPs annihilating into electron-positron pairs has been one of the leading hypotheses ... More
Lossy Source Transmission over the Relay ChannelMay 20 2008Lossy transmission over a relay channel in which the relay has access to correlated side information is considered. First, a joint source-channel decode-and-forward scheme is proposed for general discrete memoryless sources and channels. Then the Gaussian ... More
DPG method with optimal test functions for a fractional advection diffusion equationJul 23 2015We develop an ultra-weak variational formulation of a fractional advection diffusion problem in one space dimension and prove its well-posedness. Based on this formulation, we define a DPG approximation with optimal test functions and show its quasi-optimal ... More
A lattice-based approach to the expressivity of deep ReLU neural networksFeb 28 2019We present new families of continuous piecewise linear (CPWL) functions in Rn having a number of affine pieces growing exponentially in $n$. We show that these functions can be seen as the high-dimensional generalization of the triangle wave function ... More
Lateral Gene Transfer, Rearrangement and ReconciliationJun 27 2013Background. Models of ancestral gene order reconstruction have progressively integrated different evolutionary patterns and processes such as unequal gene content, gene duplications, and implicitly sequence evolution via reconciled gene trees. In unicellular ... More
Realisability Semantics for Intersection Types and Expansion VariablesMay 13 2009Expansion was invented at the end of the 1970s for calculating principal typings for $\lambda$-terms in type systems with intersection types. Expansion variables (E-variables) were invented at the end of the 1990s to simplify and help mechanise expansion. ... More
A streamlined approach to particle ALD coating of spherical beadsNov 23 2016Nov 24 2016Conformal Atomic Layer Deposition (ALD) of nanoparticles is an now an established nanofabrication concept employed by many researchers for applications such as creating diffusion barriers, tuning catalysis, or masking a toxic particle core with a biocompatible ... More
The relative influences of disorder and of frustration on the glassy dynamics in magnetic systemsMar 15 2004The magnetisation relaxations of three different types of geometrically frustrated magnetic systems have been studied with the same experimental procedures as previously used in spin glasses. The materials investigated are Y$_2$Mo$_2$O$_7$ (pyrochlore ... More
A Low-Power Content-Addressable-Memory Based on Clustered-Sparse-NetworksFeb 18 2013A low-power Content-Addressable-Memory (CAM) is introduced employing a new mechanism for associativity between the input tags and the corresponding address of the output data. The proposed architecture is based on a recently developed clustered-sparse-network ... More
Aging, rejuvenation and memory effects in re-entrant ferromagnetsMar 06 2002Jul 09 2002We have studied the slow dynamics of the ferromagnetic phases of the re-entrant CdCr_{2x}In_{2-2x}S_4 system for 0.85<x<=1 by means of low frequency ac susceptibility and magnetization measurements. Experimental procedures widely used in the investigation ... More
The XUV irradiation and likely atmospheric escape of the super-Earth $π$ Men cJan 07 2019$\pi$ Men c was recently announced as the first confirmed exoplanet from the TESS mission. The planet has a radius of just 2 R$_{\rm\oplus}$ and it transits a nearby Sun-like star of naked-eye brightness, making it the ideal target for atmospheric characterisation ... More
A complete realisability semantics for intersection types and arbitrary expansion variablesMay 11 2009Expansion was introduced at the end of the 1970s for calculating principal typings for $\lambda$-terms in intersection type systems. Expansion variables (E-variables) were introduced at the end of the 1990s to simplify and help mechanise expansion. Recently, ... More
Asymptotic Dynamical Difference between the Nonlocal and Local Swift-Hohenberg ModelsJun 18 1998In this paper the difference in the asymptotic dynamics between the nonlocal and local two-dimensional Swift-Hohenberg models is investigated. It is shown that the bounds for the dimensions of the global attractors for the nonlocal and local Swift-Hohenberg ... More
On the CVP for the root lattices via folding with deep ReLU neural networksFeb 06 2019Point lattices and their decoding via neural networks are considered in this paper. Lattice decoding in Rn, known as the closest vector problem (CVP), becomes a classification problem in the fundamental parallelotope with a piecewise linear function defining ... More
Neural Lattice DecodersJul 02 2018Feb 04 2019Lattice decoders constructed with neural networks are presented. Firstly, we show how the fundamental parallelotope is used as a compact set for the approximation by a neural lattice decoder. Secondly, we introduce the notion of Voronoi-reduced lattice ... More
A line confusion limited millimeter survey of Orion KL. II: Silicon-bearing speciesDec 09 2010We present a study of the Silicon-bearing species detected in a line confusion limited survey towards Orion KL performed with the IRAM 30-m telescope, which ranges from 80 to 280 GHz. Our aim is to derive physical and chemical conditions for each family ... More
F-theory and Neutrinos: Kaluza-Klein Dilution of Flavor HierarchyApr 09 2009Feb 24 2010We study minimal implementations of Majorana and Dirac neutrino scenarios in F-theory GUT models. In both cases the mass scale of the neutrinos m_nu ~ (M_weak)^2/M_UV arises from integrating out Kaluza-Klein modes, where M_UV is close to the GUT scale. ... More
A nonlinear Stokes-Biot model for the interaction of a non-Newtonian fluid with poroelastic mediaMar 02 2018Feb 04 2019We develop and analyze a model for the interaction of a quasi-Newtonian free fluid with a poroelastic medium. The flow in the fluid region is described by the nonlinear Stokes equations and in the poroelastic medium by the nonlinear quasi-static Biot ... More
Numerical action reconstruction of the dynamical history of dark matter haloes in N-body simulationsDec 15 2005We test the ability of the numerical action method (NAM) to recover the individual orbit histories of mass tracers in an expanding universe in a region of radius 26Mpc/h, given the masses and redshift-space coordinates at the present epoch. The mass tracers ... More
First-principles methodology for quantum transport in multiterminal junctionsSep 10 2008Sep 24 2009We present a generalized approach for computing electron conductance and I-V characteristics in multiterminal junctions from first-principles. Within the framework of Keldysh theory, electron transmission is evaluated employing an O(N) method for electronic-structure ... More
Electron transport in multi-terminal molecular deviceAug 29 2009The electron transport properties of a four-terminal molecular device are computed within the framework of density functional theory and non-equilibrium Keldysh theory. The additional two terminals lead to new properties, including a pronounced negative ... More
Chaotic Scattering on a BilliardJun 26 1997We investigate chaotic scattering on an attractive step potential with a quadrupolar deformation. The phase space features of the bound billiard are studied by using the notion of symmetry lines to find periodic orbits. We show that the scattering dynamics ... More
Ruling out the light WIMP explanation of the galactic 511 keV lineFeb 02 2016Nov 30 2016Over the past few decades, an anomalous 511 keV gamma-ray line has been observed from the centre of the Milky Way. Dark matter (DM) in the form of light weakly interacting massive particles (WIMPs) annihilating into electron-positron pairs has been one ... More
X-ray-binary spectra in the lamp post modelMar 01 2016Mar 24 2016[Abridged] Context. The high-energy radiation from black-hole binaries may be due to the reprocessing of a lamp located on the black hole axis, emitting X-rays. The observed spectrum is made of 3 components: the direct spectrum; the thermal bump; and ... More
Good Things Come to Those Who Swap Objects on PathsMay 10 2019We study a simple exchange market, introduced by Gourv\'{e}s, Lesca and Wilczynski (IJCAI-17), where every agent initially holds a single object. The agents have preferences over the objects, and two agents may swap their objects if they both prefer the ... More
A Wavelet Based Algorithm for the Identification of Oscillatory Event-Related Potential ComponentsJun 20 2014Event Related Potentials (ERPs) are very feeble alterations in the ongoing Electroencephalogram (EEG) and their detection is a challenging problem. Based on the unique time-based parameters derived from wavelet coefficients and the asymmetry property ... More
Electron transport through antidot superlattices in $Si/SiGe$ heterostructures: new magnetoresistance resonances in lattices with large diameter antidotsSep 21 2006In the present work we have investigated the transport properties in a number of Si/SiGe samples with square antidot lattices of different periods. In samples with lattice periods equal to 700 nm and 850 nm we have observed the conventional low-field ... More
The Role of Race, Ethnicity, and Gender in the Congressional Cosponsorship NetworkDec 18 2015Previous research indicates that race, ethnicity, and gender influence legislative behavior in important ways. The bulk of this research, however, focuses on the way these characteristics shape an individual legislator's behavior, making it less clear ... More
The challenges for Systems Engineers of non-classical quantum technologiesOct 16 2017Dec 11 2017Non-classical quantum technologies that rely on manipulation of quantum states and exploitation of quantum superposition and entanglement are approaching a level of maturity sufficient to contemplate commercialization as the basis of practical devices ... More
Reconstructing compositionsOct 16 2006We consider the problem of reconstructing compositions of an integer from their subcompositions, which was raised by Raykova (albeit disguised as a question about layered permutations). We show that every composition w of n\ge 3k+1 can be reconstructed ... More
Constraints on $Λ(t)$-cosmology with power law interacting dark sectorsMay 30 2012May 31 2012Motivated by the cosmological constant and the coincidence problems, we consider a cosmological model where the cosmological constant $\Lambda_0$ is replaced by a cosmological term $\Lambda(t)$ which is allowed to vary in time. More specifically, we are ... More
The large-scale clustering of massive dark matter haloesMay 06 2010The statistics of peaks of the initial, Gaussian density field can be used to interpret the abundance and clustering of massive dark matter haloes. I discuss some recent theoretical results related to their clustering and its redshift evolution. Predictions ... More
Rao-Blackwellization to give Improved Estimates in Multi-List StudiesSep 26 2017Sufficient statistics are derived for the population size and parameters of commonly used closed population mark-recapture models. Rao-Blackwellization details for improving estimators that are not functions of the statistics are presented. As Rao-Blackwellization ... More
Inexact cuts in Deterministic and Stochastic Dual Dynamic Programming applied to linear optimization problemsJan 12 2018Jan 15 2018We introduce an extension of Dual Dynamic Programming (DDP) to solve linear dynamic programming equations. We call this extension IDDP-LP which applies to situations where some or all primal and dual subproblems to be solved along the iterations of the ... More
A Puzzle about Further FactsFeb 04 2018In metaphysics, there are a number of distinct but related questions about the existence of "further facts" -- facts that are contingent relative to the physical structure of the universe. These include further facts about qualia, personal identity, and ... More
Recent Advances on Estimating Population Size with Link-Tracing SamplingSep 22 2017A new approach to estimate population size based on a stratified link-tracing sampling design is presented. The method extends on the Frank and Snijders (1994) approach by allowing for heterogeneity in the initial sample selection procedure. Rao-Blackwell ... More
Definability of types over finite partial order indiscerniblesAug 11 2011In this paper, we show that a partitioned formula \phi is dependent if and only if \phi has uniform definability of types over finite partial order indiscernibles. This generalizes our result from a previous paper [1]. We show this by giving a decomposition ... More
On the non-extendability of quasianalytic germsJun 21 2010Sep 07 2010Let $\mathcal{E}_1(M)^+$ be the local ring of germs at 0 of functions belonging to a given Denjoy-Carleman quasianalytic class in a neighborhood of 0 in $[0,+\infty[$. We show that the ring $\mathcal{E}_1(M)^+$ contains elements that cannot be extended ... More
The Joint Physics Analysis Center WebsiteJan 08 2016The Joint Physics Analysis Center is a collaboration between theorists and experimentalists working in hadronic physics. In order to facilitate the exchange of information between the different actors in hadron spectroscopy, we created an interactive ... More
A very short proof of Forester's rigidity resultJan 24 2003May 22 2003The deformation space of a simplicial G-tree T is the set of G-trees which can be obtained from T by some collapse and expansion moves, or equivalently, which have the same elliptic subgroups as T. We give a short proof of a rigidity result by Forester ... More
Theia: A multi-purpose water-based liquid scintillator detectorSep 17 2018Recent developments in the field of liquid scintillator chemistry and fast-timing photosensors paved the way for a new generation of large-scale detectors capable of tackling a broad range of physics issues. Water-based Liquid Scintillator is a novel ... More
Dessins d'enfants for analystsApr 01 2015We present an algorithmic way of exactly computing Belyi functions for hypermaps and triangulations in genus 0 or 1, and the associated dessins, based on a numerical iterative approach initialized from a circle packing combined with subsequent lattice ... More
Estimates for Weierstrass division in ultradifferentiable classesNov 26 2015Mar 23 2016We study the Weierstrass division theorem for function germs in strongly non-quasianalytic Denjoy-Carleman classes $\mathcal{C}_M$. For suitable divisors $P(x,t)=x^d+a_1(t)x^{d-1}+\cdots+a_d(t)$ with real-analytic coefficients $a_j$, we show that the ... More
Fonctorial Construction of Frobenius CategoriesMar 16 2009Let $\Ascr,\Bscr$ be exact categories with $\Ascr$ karoubian and $M$ be an exact functor. Under suitable adjonction hypotheses for $M$, we are able to show that the direct factors of the objects of $\Ascr$ of the form $MY$ with $Y \in \Bscr$ make up a ... More
Gradient trajectories for plane singular metrics I: oscillating trajectoriesMay 30 2012We construct an example of a real plane analytic singular metric, degenerating only at the origin, such that any gradient trajectory (respectively to this singular metric) of some well chosen function spirals around the origin. The inversion mapping carries ... More
The one-dimensional asymmetric persistent random walkDec 18 2017Feb 12 2018Persistent random walks are intermediate transport processes between a uniform rectilinear motion and a Brownian motion. They are formed by successive steps of random finite lengths and directions travelled at a fixed speed. The isotropic and symmetric ... More
Conic intersections, Maximal Cohen-Macaulay modules and the Four Subspace problemFeb 21 2017Mar 10 2017Let $X$ be a set of $4$ generic points in $\mathbb{P}^2$ with homogeneous coordinate ring $R$. We classify indecomposable graded MCM modules over $R$ by reducing the classification to the Four Subspace problem solved by Nazarova and Gel$'$fand-Ponomarev, ... More
Shtukas for reductive groups and Langlands correspondence for function fieldsMar 10 2018We discuss recent developments in the Langlands program for function fields, and in the geometric Langlands program. In particular we explain a canonical decomposition of the space of cuspidal automorphic forms for any reductive group G over a function ... More
The metric completion of the Riemannian space of Kähler metricsJan 30 2014Apr 09 2014Let $X$ be a compact K\"ahler manifold and $\a \in H^{1,1}(X,\R)$ a K\"ahler class. We study the metric completion of the space $\HH_\a$ of K\"ahler metrics in $\a$, when endowed with the Mabuchi $L^2$-metric $d$. Using recent ideas of Darvas, we show ... More
Numerical Simulations of the Ising Model on the Union Jack LatticeJan 26 2011The Ising model is famous model for magnetic substances in Statistical Physics, and has been greatly studied in many forms. It was solved in one-dimension by Ernst Ising in 1925 and in two-dimensions without an external magnetic field by Lars Onsager ... More
Abelianization of Subgroups of Reflection Group and their Braid Group; an Application to CohomologyMar 03 2010Aug 31 2010The final result of this article gives the order of the extension $$\xymatrix{1\ar[r] & P/[P,P] \ar^{j}[r] & B/[P,P] \ar^-{p}[r] & W \ar[r] & 1}$$ as an element of the cohomology group $H^2(W,P/[P,P])$ (where $B$ and $P$ stands for the braid group and ... More
Cardinality of Rauzy classesJun 04 2011Rauzy classes define a partition of the set of irreducible (or indecomposable) permutations. They were defined by G. Rauzy as part of an induction algorithm for interval exchange transformations. In this article we prove an explicit formula for the cardinality ... More
Lecture notes on Liouville theory and the DOZZ formulaDec 03 2017The purpose of these notes, based on a series of 4 lectures given by the author at IHES, is to explain the recent proof of the DOZZ formula for the three point correlation functions of Liouville conformal field theory (LCFT). We first review the probabilistic ... More
Brick polytopes, lattice quotients, and Hopf algebrasMay 28 2015Nov 30 2017This paper is motivated by the interplay between the Tamari lattice, J.-L. Loday's realization of the associahedron, and J.-L. Loday and M. Ronco's Hopf algebra on binary trees. We show that these constructions extend in the world of acyclic $k$-triangulations, ... More
Many-body renormalisation of forces in f-electron materialsApr 18 2018Aug 30 2018We present the implementation of Dynamical Mean-Field Theory (DMFT) in the CASTEP \emph{ab-initio} code. We explain in detail the theoretical framework for DFT+DMFT and we demonstrate our implementation for three strongly-correlated systems with $f$-shell ... More
A novel way to determine the scale of inflationNov 20 2017Feb 02 2018We show that in the Feebly Interacting Massive Particle (FIMP) model of Dark Matter (DM), one may express the inflationary energy scale $H_*$ as a function of three otherwise unrelated quantities, the DM isocurvature perturbation amplitude, its mass and ... More
Type IIB Supergravity Solutions with AdS${}_5$ From Abelian and Non-Abelian T DualitiesOct 09 2014Oct 31 2014We present a large class of new backgrounds that are solutions of type IIB supergravity with a warped AdS${}_5$ factor, non-trivial axion-dilaton, $B$-field and three-form Ramond-Ramond flux but yet have no five-form flux. We obtain these solutions and ... More
Annealing a Magnetic Cactus into PhyllotaxisFeb 03 2010The appearance of mathematical regularities in the disposition of leaves on a stem, scales on a pine-cone and spines on a cactus has puzzled scholars for millennia; similar so-called phyllotactic patterns are seen in self-organized growth, polypeptides, ... More
A Detailed Investigation of First and Second Order Supersymmetries for Off-Shell N = 2 and N = 4 SupermultipletsJun 27 2011Dec 14 2011This paper investigates the d = 4, N = 4 Abelian, global Super-Yang Mills system (SUSY-YM). It is shown how the N = 2 Fayet Hypermultiplet (FH) and N = 2 vector multiplet (VM) are embedded within. The central charges provide a plethora of information ... More
Exploring dark matter microphysics with galaxy surveysMay 25 2015Nov 30 2017We use present cosmological observations and forecasts of future experiments to illustrate the power of large-scale structure (LSS) surveys in probing dark matter (DM) microphysics and unveiling potential deviations from the standard $\Lambda$CDM scenario. ... More
Fractional Deviations in Precursor Stoichiometry Dictate the Properties, Performance and Stability of Perovskite Photovoltaic DevicesApr 26 2019The last five years have witnessed a remarkable progress in the field of lead halide perovskite materials and devices. Examining the existing body of literature reveals staggering inconsistencies in the reported results among different research groups ... More
Spin Anisotropy and Slow Dynamics in Spin GlassesMay 05 2003Apr 19 2004We report on an extensive study of the influence of spin anisotropy on spin glass aging dynamics. New temperature cycle experiments allow us to compare quantitatively the memory effect in four Heisenberg spin glasses with various degrees of random anisotropy ... More
Comment on "Unraveling the 'Pressure Effect' in Nucleation"Mar 31 2016In a 2008 Letter, Wedekind et al. discussed the influence of an inert carrier gas on the vapor-liquid nucleation rate. They found an additional "pressure-volume work" that is performed against the carrier gas, and also quantified the nonisothermal effects ... More
A generalization of the Goresky-Klapper conjecture, Part IMay 05 2018For a fixed integer $n\geq 2,$ we show that a permutation of the least residues mod $p$ of the form $f(x)=Ax^k$ mod $p$ cannot map a residue class mod $n$ to just one residue class mod $n$ once $p$ is sufficiently large, other than the maps $f(x)=\pm ... More
A new experimental procedure for characterizing quantum effects in small magnetic particle systemsOct 17 1996Mar 27 1997A new experimental procedure is discussed, which aims at separating thermal from quantum behavior independently of the energy barrier distribution in small particle systems. Magnetization relaxation data measured between 60 mK and 5 K on a sample of nanoparticles ... More
Hydrophobic Ice Confined between Graphene and MoS2Jun 02 2017The structure and nature of water confined between hydrophobic molybdenum disulfide (MoS2) and graphene (Gr) are investigated at room temperature by means of atomic force microscopy. We find the formation of two-dimensional (2D) crystalline ice layers. ... More
Bayesian nonparametric generative models for causal inference with missing at random covariatesFeb 27 2017We propose a general Bayesian nonparametric (BNP) approach to causal inference in the point treatment setting. The joint distribution of the observed data (outcome, treatment, and confounders) is modeled using an enriched Dirichlet process. The combination ... More
Aging, rejuvenation and memory phenomena in spin glassesJun 29 2004Oct 22 2004In this paper, we review several important features of the out-of-equilibrium dynamics of spin glasses. Starting with the simplest experiments, we discuss the scaling laws used to describe the isothermal aging observed in spin glasses after a quench down ... More
Exploring quantum chaos with a single nuclear spinMar 15 2017Oct 09 2018Most classical dynamical systems are chaotic. The trajectories of two identical systems prepared in infinitesimally different initial conditions diverge exponentially with time. Quantum systems, instead, exhibit quasi-periodicity due to their discrete ... More
Small permutation classesDec 24 2007Apr 05 2016We establish a phase transition for permutation classes (downsets of permutations under the permutation containment order): there is an algebraic number $\kappa$, approximately 2.20557, for which there are only countably many permutation classes of growth ... More
Maximal independent sets and separating coversNov 21 2009Aug 26 2010In 1973, Katona raised the problem of determining the maximum number of subsets in a separating cover on n elements. The answer to Katona's question turns out to be the inverse to the answer to a much simpler question: what is the largest integer which ... More
Eliciting Single-Peaked Preferences Using Comparison QueriesJan 15 2014Voting is a general method for aggregating the preferences of multiple agents. Each agent ranks all the possible alternatives, and based on this, an aggregate ranking of the alternatives (or at least a winning alternative) is produced. However, when there ... More
Prediction Markets, Mechanism Design, and Cooperative Game TheoryMay 09 2012Prediction markets are designed to elicit information from multiple agents in order to predict (obtain probabilities for) future events. A good prediction market incentivizes agents to reveal their information truthfully; such incentive compatibility ... More
X- and Gamma-Ray Line Emission ProcessesAug 21 2002This chapter is intended to provide a general presentation of the atomic and nuclear processes responsible for X-ray line and gamma-ray line emission in various astrophysical environments. I consider line production from hot plasmas, from accelerated ... More
Can the coincidence problem be solved by a cosmological model of coupled dark energy and dark matter?Jul 23 2013Oct 12 2014Motivated by the cosmological constant and the coincidence problems, we consider a cosmological model where the dark sectors are interacting together through a phenomenological decay law $\dot{\rho}_{\Lambda}=Q\rho_{\Lambda}^n$ in a FRW spacetime with ... More
Baryon acoustic signature in the clustering of density maximaJun 02 2008Oct 22 2008We reexamine the two-point correlation of density maxima in Gaussian initial conditions. Spatial derivatives of the linear density correlation, which were ignored in the calculation of Bardeen, Bond, Kaiser & Szalay (1986), are included in our analysis. ... More
Environmental dependence in the ellipsoidal collapse modelJul 31 2007May 15 2008N-body simulations have demonstrated a correlation between the properties of haloes and their environment. In this paper, we assess whether the ellipsoidal collapse model can produce a similar dependence. First, we explore the statistical correlation ... More