Results for "Mathias Fischer"

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Symplectic Lie algebras with degenerate centerSep 12 2016Every symplectic Lie algebra with degenerate (including non-abelian nilpotent symplectic Lie algebras) has the structure of a quadratic extension. We give a standard model and describe the equivalence classes on the level of corresponding quadratic cohomology ... More
Metric Symplectic Lie AlgebrasSep 12 2016Every metric symplectic Lie algebra has the structure of a quadratic extension. We give a standard model and describe the equivalence classes on the level of corresponding quadratic cohomology sets. Finally, we give a scheme to classify the isomorphism ... More
Lattices of oscillator groupsMar 08 2013Aug 01 2013This paper is concerned with discrete, uniform subgroups (lattices) of oscillator groups, which are certain semidirect products of the Heisenberg group and the additive group of real numbers. The present paper rectifies the uncertainties in [1] of Medina ... More
Vincia for Hadron CollidersMay 19 2016Jun 14 2016We present the first public implementation of antenna-based QCD initial- and final-state showers. The shower kernels are $2\to 3$ antenna functions, which capture not only the collinear dynamics but also the leading soft (coherent) singularities of QCD ... More
Enhanced Performance and Privacy for TLS over TCP Fast OpenMay 09 2019Small TCP flows make up the majority of web flows. For them, the TCP three-way handshake represents a significant delay overhead. The TCP Fast Open (TFO) protocol provides zero round-trip time (0-RTT) handshakes for subsequent TCP connections to the same ... More
Efficient Attack Correlation and Identification of Attack Scenarios based on Network-MotifsMay 16 2019An Intrusion Detection System (IDS) to secure computer networks reports indicators for an attack as alerts. However, every attack can result in a multitude of IDS alerts that need to be correlated to see the full picture of the attack. In this paper, ... More
Performance comparison between iSCSI and other hardware and software solutionsMay 30 2003We report on our investigations on some technologies that can be used to build disk servers and networks of disk servers using commodity hardware and software solutions. It focuses on the performance that can be achieved by these systems and gives measured ... More
Quantum Corrections in Quintessence ModelsJun 12 2006Sep 12 2006We investigate the impact of quantum fluctuations on a light rolling quintessence field from three different sources, namely, from a coupling to the standard model and dark matter, from its self-couplings and from its coupling to gravity. We derive bounds ... More
Sur la rigidité de polyèdres hyperboliques en dimension 3 : cas de volume fini, cas hyperidéal, cas fuchsienNov 18 2002A hyperbolic semi-ideal polyedron is a polyedron whose vertices lie inside the hyperbolic space $\mathbf{H}^{3}$ or at infinity. A hyperideal polyedron is, in the projective model, the intersection of $\mathbf{H}^{3}$ with a projective polyhedron whose ... More
Replica-deformation of the SU(2)-invariant Thirring model via solutions of the qKZ equationJul 17 1999The response of an integrable QFT under variation of the Unruh temperature has recently been shown to be computable from an S-matrix preserving (`replica') deformation of the form factor approach. We show that replica-deformed form factors of the SU(2)-invariant ... More
Polynomial Recursion Equations in Form Factors of ADE Toda Field TheoriesMay 20 1997It is shown that the problem of calculating form factors in ADE affine Toda field theories can be reduced to the nonperturbative recursive calculation of polynomials symmetric in each sort of variables. We determine these recursion equations explicitly ... More
Selfdual 2-form formulation of gravity and classification of energy-momentum tensorsApr 17 1995Dec 17 1996It is shown how the different irreducibility classes of the energy-momentum tensor allow for a Lagrangian formulation of the gravity-matter system using a selfdual 2-form as a basic variable. It is pointed out what kind of difficulties arise when attempting ... More
Statistical modeling of ground motion relations for seismic hazard analysisMay 14 2012Jul 13 2013We introduce a new approach for ground motion relations (GMR) in the probabilistic seismic hazard analysis (PSHA), being influenced by the extreme value theory of mathematical statistics. Therein, we understand a GMR as a random function. We derive mathematically ... More
Logical Inference Algorithms and Matrix Representations for Probabilistic Conditional IndependenceMay 09 2012Logical inference algorithms for conditional independence (CI) statements have important applications from testing consistency during knowledge elicitation to constraintbased structure learning of graphical models. We prove that the implication problem ... More
Likelihood ratio tests and singularitiesMar 12 2007Apr 02 2009Many statistical hypotheses can be formulated in terms of polynomial equalities and inequalities in the unknown parameters and thus correspond to semi-algebraic subsets of the parameter space. We consider large sample asymptotics for the likelihood ratio ... More
The Pólya sum kernel and Bayes estimationFeb 21 2012May 10 2012We consider a particular Cox process from a Bayesian viewpoint and show that the Bayes estimator of the intensity measure is the so-called P\'olya sum kernel, which occurred recently in the context of the construction of the so-called Papangelou processes. ... More
Bayesian inverse problems with unknown operatorsJan 30 2018Apr 06 2018We consider the Bayesian approach to linear inverse problems when the underlying operator depends on an unknown parameter. Allowing for finite dimensional as well as infinite dimensional parameters, the theory covers several models with different levels ... More
A determinant-like formula for the Kostka numbersJan 10 2005Sep 01 2005Young tableaux are ubiquitous in various branches of mathematics. There are two counting formulas for standard Young tableaux. The first involves a determinant and goes back to Frobenius and Young, and the second is the hook formula by Frame, Robinson ... More
Correlations of Quantum Fields on Robertson-Walker SpacetimesNov 09 1995It is a well known fact that quantum fields on Minkowski spacetime are correlated for each pair of spacetime regions. In Robertson-Walker spacetimes there are spacelike separated regions with disjoint past horizons but the absence of correlations in that ... More
On the deformability of Heisenberg algebrasAug 24 1995Based on the vanishing of the second Hochschild cohomology group of the enveloping algebra of the Heisenberg algebra it is shown that differential algebras coming from quantum groups do not provide a non-trivial deformation of quantum mechanics. For the ... More
B-L-symmetric Baryogenesis with Leptonic QuintessenceDec 12 2006We discuss a toy model where baryogenesis and cosmic acceleration are driven by a leptonic quintessence field coupled to the standard model sector via a massive mediating scalar field. It does not require the introduction of B-L-violating interactions ... More
Recent developments in quarkonium and open flavour production calculationsSep 08 2011This report reviews recent theory progress in the field of heavy quarkonium and open heavy flavour production calculations.
Markov Chains on Orbits of Permutation GroupsJun 23 2012Jun 28 2012We present a novel approach to detecting and utilizing symmetries in probabilistic graphical models with two main contributions. First, we present a scalable approach to computing generating sets of permutation groups representing the symmetries of graphical ... More
Symmetry-Aware Marginal Density EstimationApr 09 2013The Rao-Blackwell theorem is utilized to analyze and improve the scalability of inference in large probabilistic models that exhibit symmetries. A novel marginal density estimator is introduced and shown both analytically and empirically to outperform ... More
Consideration of prior information in the inference for the upper bound earthquake magnitudeApr 15 2018Jul 27 2018The upper bound earthquake magnitude (maximum possible magnitude) of a truncated Gutenberg-Richter relation is the right truncation point (right end-point) of a truncated exponential distribution and is important in the probabilistic seismic hazard analysis. ... More
Blossoming bijection for higher-genus mapsNov 15 2017Jun 07 2018In 1997, Schaeffer described a bijection between Eulerian planar maps and some trees. In this work we generalize his work to a bijection between bicolorable maps on a surface of any fixed genus and some unicellular maps with the same genus. An important ... More
Discriminative Gaifman ModelsOct 28 2016We present discriminative Gaifman models, a novel family of relational machine learning models. Gaifman models learn feature representations bottom up from representations of locally connected and bounded-size regions of knowledge bases (KBs). Considering ... More
Dark matter in GUT inspired $Z^\prime$ portal scenariosSep 08 2016We consider simple dark matter extensions of the standard model in $Z^\prime$ portal scenarios inspired by grand unification theory constructions and we study the phenomenology of such models by considering Spin Dependent and Spin Independent direct detection ... More
The Lyddane-Sachs-Teller relationship for polar vibrations in materials with monoclinic and triclinic crystal systemsFeb 28 2016A generalization of the Lyddane-Sachs-Teller relation is presented for polar vibrations in materials with monoclinic and triclinic crystal systems. The generalization is derived from an eigen displacement vector summation approach, which is equivalent ... More
Comment on Pisarenko et al. "Characterization of the Tail of the Distribution of Earthquake Magnitudes by Combining the GEV and GPD Descriptions of Extreme Value Theory"Jan 05 2015Jan 29 2015In this short note, I comment on the research of Pisarenko et al. (2014) regarding the extreme value theory and statistics in case of earthquake magnitudes. The link between the generalized extreme value distribution (GEVD) as an asymptotic model for ... More
Dark Matter phenomenology : from simplified WIMP models to refined alternative solutionsJan 17 2019One of the most puzzling problems of modern physics is the identification of the nature a non-relativistic matter component present in the universe, contributing to more than 25$\%$ of the total energy budget, known as Dark Matter. Weakly Interacting ... More
Charge Fluctuations as Thermometer for Heavy-Ion CollisionsNov 15 2013We present a determination of freeze-out conditions in heavy-ion collisions based on ratios of cu- mulants of net electric charge fluctuations obtained from lattice QCD. These ratios can reliably be calculated for a wide range of chemical potential values ... More
Gröbner strata in the Hilbert scheme of pointsJul 02 2009Jan 22 2011The present paper shall provide a framework for working with Gr\"obner bases over arbitrary rings $k$ with a prescribed finite standard set $\Delta$. We show that the functor associating to a $k$-algebra $B$ the set of all reduced Gr\"obner bases with ... More
A KMS-like state of Hadamard type on Robertson-Walker spacetimes and its time evolutionSep 09 1997In this work we define a new state on the Weyl algebra of the free massive scalar Klein-Gordon field on a Robertson-Walker spacetime and prove that it is a Hadamard state. The state is supposed to approximate a thermal equilibrium state on a Robertson-Walker ... More
Form Factors in $D_n^{(1)}$ Affine Toda Field TheoriesDec 12 1996May 02 1997We derive closed recursion equations for the symmetric polynomials occuring in the form factors of $D_n^{(1)}$ affine Toda field theories. These equations follow from kinematical- and bound state residue equations for the full form factor. We also discuss ... More
q-Deformed Relativistic Wave EquationsOct 15 1993Based on the representation theory of the $q$-deformed Lorentz and Poincar\'e symmeties $q$-deformed relativistic wave equation are constructed. The most important cases of the Dirac-, Proca-, Rarita-Schwinger- and Maxwell- equations are treated explicitly. ... More
Using ZDDs in the mapping of quantum circuitsJan 08 2019In quantum compilation, one step translates a technology-independent quantum circuit into a technology-dependent quantum circuit for a targeted device. Besides mapping quantum gates into the supported gate set, it is necessary to map pseudo qubits in ... More
Rayleigh-Taylor instability for the two-phase Navier-Stokes equations with surface tension in cylindrical domainsMar 15 2017This article is concerned with the dynamic behaviour of two immiscible and incompressible fluids in a cylindrical domain, which are separated by a sharp interface. In case that the heavy fluid is situated on top of the light fluid, one expects that the ... More
Quantile estimation for Lévy measuresMay 27 2014Jan 01 2015Generalizing the concept of quantiles to the jump measure of a L\'evy process, the generalized quantiles $q_{\tau}^{\pm}>0$, for $\tau>0$, are given by the smallest values such that a jump larger than $q_{\tau}^{+}$ or a negative jump smaller than $-q_{\tau}^{-}$, ... More
Maximal multihomogeneity of algebraic hypersurface singularitiesNov 08 2006From the degree zero part of logarithmic vector fields along an algebraic hypersurface singularity we indentify the maximal multihomogeneity of a defining equation in form of a maximal algebraic torus in the embedded automorphism group. We show that all ... More
Information bounds for inverse problems with application to deconvolution and Lévy modelsJul 24 2013May 06 2014If a functional in an inverse problem can be estimated with parametric rate, then the minimax rate gives no information about the ill-posedness of the problem. To have a more precise lower bound, we study semiparametric efficiency in the sense of H\'ajek-Le ... More
Discrete chain graph modelsSep 04 2009The statistical literature discusses different types of Markov properties for chain graphs that lead to four possible classes of chain graph Markov models. The different models are rather well understood when the observations are continuous and multivariate ... More
Multiple solutions to the likelihood equations in the Behrens-Fisher problemMay 31 2007The Behrens-Fisher problem concerns testing the equality of the means of two normal populations with possibly different variances. The null hypothesis in this problem induces a statistical model for which the likelihood function may have more than one ... More
The Pólya sum process: Limit theorems for conditioned random fieldsJan 20 2012In \cite{hZ09}, Zessin constructed the so-called P\'olya sum process via partial integration technique. This process shares some important properties with the Poisson process such as complete randomness and infinite divisibility. This work discusses H-sufficient ... More
The differential structure of the Brieskorn latticeJun 05 2003Dec 01 2004We describe an algorithm to compute M. Saito's matrices A0 and A1 for an isolated hypersurface singularity. They determine the differential structure of the Brieskorn lattice, the spectral pairs and Hodge numbers, and the complex monodromy of the singularity. ... More
Extremal results for random discrete structuresMar 02 2016May 17 2016We study thresholds for extremal properties of random discrete structures. We determine the threshold for Szemer\'edi's theorem on arithmetic progressions in random subsets of the integers and its multidimensional extensions and we determine the threshold ... More
Combinatorial duality of Hilbert schemes of points in the affine planeDec 31 2013Jul 02 2014The Hilbert scheme of $n$ points in the affine plane contains the open subscheme parametrizing $n$ distinct points in the affine plane, and the closed subscheme parametrizing ideals of codimension $n$ supported at the origin of the affine plane. Both ... More
Enhanced Performance for the encrypted Web through TLS Resumption across HostnamesFeb 07 2019TLS can resume previous connections via abbreviated resumption handshakes that significantly decrease the delay and save expensive cryptographic operations. For that, cryptographic TLS state from previous connections is reused. TLS version 1.3 recommends ... More
Vincia for Hadron CollidersMay 19 2016Nov 07 2016We present the first public implementation of antenna-based QCD initial- and final-state showers. The shower kernels are $2\to 3$ antenna functions, which capture not only the collinear dynamics but also the leading soft (coherent) singularities of QCD ... More
Tracking Users across the Web via TLS Session ResumptionOct 16 2018User tracking on the Internet can come in various forms, e.g., via cookies or by fingerprinting web browsers. A technique that got less attention so far is user tracking based on TLS and specifically based on the TLS session resumption mechanism. To the ... More
QUICker connection establishment with out-of-band validation tokensApr 12 2019May 03 2019QUIC is a secure transport protocol that improves the performance of HTTPS. An initial QUIC handshake that enforces a strict validation of the client's source address requires two round-trips. In this work, we extend QUIC's address validation mechanism ... More
QUICker connection establishment with out-of-band validation tokensApr 12 2019QUIC is a secure transport protocol and aims to improve the performance of HTTPS traffic. It is a design goal of QUIC to reduce the delay overhead of its connection establishment. However, an initial handshake enforcing strict validation of the client's ... More
The VINCIA Antenna Shower for Hadron CollidersSep 23 2016We summarise the main features of VINCIA's antenna-based treatment of QCD initial- and final-state showers, which includes iterated tree-level matrix-element corrections and automated evaluations of perturbative shower uncertainties. The latter are computed ... More
Vincia for Hadron CollidersMay 19 2016Nov 11 2016We present the first public implementation of antenna-based QCD initial- and final-state showers. The shower kernels are $2\to 3$ antenna functions, which capture not only the collinear dynamics but also the leading soft (coherent) singularities of QCD ... More
Energy Loss by Gravitational ViscosityMay 12 2008Due to Lorentz invariance of General Relativity gravitational interaction is limited to the speed of light. Thus for particles, moving within a matter field, retardation leads to loss of energy by emission of gravitational radiation. This 'gravitomagnetic' ... More
The properties of dark matterMar 30 2011Observations of density profiles of galaxies and clusters constrain the properties of dark matter. Formation of stable halos by collisional fluids with very low mass particles appears as the most probable interpretation, while halos formed by high mass ... More
Enumeration of rhombus tilings of a hexagon which contain a fixed rhombus in the centreJun 15 1999We compute the number of rhombus tilings of a hexagon with side lengths a,b,c,a,b,c which contain the central rhombus and the number of rhombus tilings of a hexagon with side lengths a,b,c,a,b,c which contain the `almost central` rhombus above the centre. ... More
High-order behaviour and summation methods in perturbative QCDDec 11 1995After reviewing basic facts about large-order behaviour of perturbation expansions in various fields of physics, I consider several alternatives to the Borel summation method and discuss their relevance to different physical situations. Then I convey ... More
Fast and Parallel Runge-Kutta Approximation of Fractional Evolution EquationsMar 14 2018We consider a linear inhomogeneous fractional evolution equation which is obtained from a Cauchy problem by replacing its first-order time derivative with Caputo's fractional derivative. The operator in the fractional evolution equation is assumed to ... More
Intrinsic pseudodifferential calculi on any compact Lie groupSep 27 2014Mar 16 2015In this paper, we define in an intrinsic way operators on a compact Lie group by means of symbols using the representations of the group. The main purpose is to show that these operators form a symbolic pseudo-differential calculus which coincides or ... More
Unicity Concepts for SudokuOct 02 2014This paper deals with a generalized Sudoku problem and investigates the unicity of a given solution. We introduce constraint sets, which is a generalization of the rows, columns and blocks of a classical Sudoku puzzle. The unicity property is characterized ... More
A Necessary Solution Condition for SudokuOct 23 2012We develop a new discrete mathematical model which includes the classical Sudoku puzzle, Latin Squares and gerechte designs. This problem is described by integer equations and a special type of inequality constraint. We consider solutions of this generalized ... More
Model-Based Development of Distributed Embedded Systems by the Example of the Scicos/SynDEx FrameworkOct 19 2010The embedded systems engineering industry faces increasing demands for more functionality, rapidly evolving components, and shrinking schedules. Abilities to quickly adapt to changes, develop products with safe design, minimize project costs, and deliver ... More
Search for neutrinoless double-beta decay with SNO+Sep 17 2018The SNO+ experiment, located in SNOLAB, 2 kilometers underground in the Creighton mine, near Sudbury, Canada, is a large scale neutrino detector whose main purpose is to search for neutrinoless double-beta decay and thus probe the Majorana nature of the ... More
On the role of power expansions in quantum field theoryApr 18 1997Methods of summation of power series relevant to applications in quantum theory are reviewed, with particular attention to expansions in powers of the coupling constant and in inverse powers of an energy variable. Alternatives to the Borel summation method ... More
Photonics Explorer - An European program to foster science education with hands-on experimentsMay 04 2012The Photonics Explorer program aims to equip science teachers at Europe's secondary schools free-of-charge with up-to-date educational material to really engage, excite and educate students about the fascination of working with light.
Constant term formulas for refined enumerations of Gog and Magog trapezoidsApr 19 2018Gog and Magog trapezoids are certain arrays of positive integers that generalize alternating sign matrices (ASMs) and totally symmetric self-complementary plane partitions (TSSCPPs) respectively. Zeilberger used constant term formulas to prove that there ... More
The bounded spherical functions for the free two step nilpotent Lie groupDec 08 2010In this paper, we give the expressions for the bounded spherical functions, or equivalently the spherical functions of positive type, for the free two-step nilpotent Lie groups endowed with the actions of orthogonal groups or their special subgroups. ... More
Linear relations of refined enumerations of alternating sign matricesAug 03 2010In recent papers we have studied refined enumerations of alternating sign matrices with respect to a fixed set of top and bottom rows. The present paper is a first step towards extending these considerations to alternating sign matrices where in addition ... More
A new proof of the refined alternating sign matrix theoremJul 13 2005In the early 1980s, Mills, Robbins and Rumsey conjectured, and in 1996 Zeilberger proved a simple product formula for the number of $n \times n$ alternating sign matrices with a 1 at the top of the $i$-th column. We give an alternative proof of this formula ... More
Another refinement of the Bender-Knuth (ex-)ConjectureJan 19 2004We compute the generating function of column-strict plane partitions with parts in {1,2,...,n}, at most c columns, p rows of odd length and k parts equal to n. This refines both, Krattenthaler's ["The major counting of nonintersecting lattice paths and ... More
A method for proving polynomial enumeration formulasJan 10 2003Sep 17 2003We present an elementary method for proving enumeration formulas which are polynomials in certain parameters if others are fixed and factorize into distinct linear factors over Z. Roughly speaking the idea is to prove such formulas by ``explaining'' their ... More
A symmetry theorem on a modified jeu de taquinDec 23 2001For their bijective proof of the hook-length formula for the number of standard tableaux of a fixed shape Novelli, Pak and Stoyanovskii define a modified jeu de taquin which transforms an arbitrary filling of the Ferrers diagram with $1,2,...,n$ (tabloid) ... More
Moments of inertia associated with the lozenge tilings of a hexagonDec 15 2000Consider the probability that an arbitrary chosen lozenge tiling of the hexagon with side lengths a, b, c, a, b, c contains the horizontal lozenge with lowest vertex (x,y) as if it described the distribution of mass in the plane. We compute the horizontal ... More
Equilibria in Quitting Games - BasicsJan 12 2011Quitting games are one of the simplest stochastic games in which at any stage each player has only two possible actions, continue and quit. The game ends as soon as at least one player chooses to quit. The players then receive a payoff, which depends ... More
On the connection between symmetric $N$-player games and mean field gamesMay 06 2014Sep 08 2015Mean field games are limit models for symmetric $N$-player games with interaction of mean field type as $N\to\infty$. The limit relation is often understood in the sense that a solution of a mean field game allows to construct approximate Nash equilibria ... More
Clues on the Majorana scale from scalar resonances at the LHCJul 01 2016In order to address the observation of the neutrino oscillations and the metastability of the Standard Model, we extend the fermion sector with two right-handed (i.e. sterile) neutrinos, and the scalar sector of the SM with a real scalar, the Hill field. ... More
Thermal structure of gas in relaxed clusters of galaxiesJan 06 2004Gas clouds under the influence of gravitation in thermodynamic equilibrium cannot be isothermal due to the Dufour effect, the energy flux induced by density gradients. In galaxy clusters this effect may be responsible for most of the "cooling flows" instead ... More
Absence of two energy scales in the two-impurity Kondo modelJul 09 1998It is believed that the successive antiferromagnetic scattering of the conduction electrons on two magnetic impurities in a metal, induces a magnetic interaction between the impurities which sets an energy scale for the system, in addition to the Kondo ... More
The number of monotone triangles with prescribed bottom rowJan 07 2005We show that the number of monotone triangles with prescribed bottom row (k_1,...,k_n) is given by a simple product formula which remarkably involves (shift) operators. Monotone triangles with bottom row (1,2,...,n) are in bijection with $n \times n$ ... More
Consumption processes and positively homogeneous projection propertiesNov 27 2007We constructively prove the existence of time-discrete consumption processes for stochastic money accounts that fulfill a pre-specified positively homogeneous projection property (PHPP) and let the account always be positive and exactly zero at the end. ... More
Existence, uniqueness, and minimality of the Jordan measure decompositionJun 23 2012Jun 27 2012This is a note of purely didactical purpose as the proof of the Jordan measure decomposition is often omitted in the related literature. Elementary proofs are provided for the existence, the uniqueness, and the minimality property of the Jordan decomposition ... 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
The choice of representative volumes in the approximation of effective properties of random materialsJul 02 2018The effective large-scale properties of materials with random heterogeneities on a small scale are typically determined by the method of representative volumes: A sample of the random material is chosen - the representative volume - and its effective ... More
Combined Data Structure for Previous- and Next-Smaller-ValuesFeb 02 2011Let $A$ be a static array storing $n$ elements from a totally ordered set. We present a data structure of optimal size at most $n\log_2(3+2\sqrt{2})+o(n)$ bits that allows us to answer the following queries on $A$ in constant time, without accessing $A$: ... More
Optimal Succinctness for Range Minimum QueriesDec 15 2008Dec 02 2009For a static array A of n ordered objects, a range minimum query asks for the position of the minimum between two specified array indices. We show how to preprocess A into a scheme of size 2n+o(n) bits that allows to answer range minimum queries on A ... More
A shorter proof of Lemma A.6 (arXiv:1005.0768)Jun 21 2012For the convenience of readers of the article {\em No-arbitrage pricing under systemic risk: accounting for cross-ownership} (Fischer, 2012, arXiv:1005.0768), a full proof of Lemma A.5 and a shorter proof of Lemma A.6 of that paper are provided.
A New Weak Lensing Analysis of MS1224.7+2007Jan 29 1999Galaxy cluster mass distributions are useful probes of Omega_0 and the nature of the dark matter. Large clusters will distort the observed shapes of background galaxies through gravitational lensing allowing the measurement of the cluster mass distributions. ... More
Sequences of labeled trees related to Gelfand-Tsetlin patternsApr 04 2011By rewriting the famous hook-content formula it easily follows that there are $\prod\limits_{1 \le i < j \le n} \frac{k_j - k_i + j -i}{j-i}$ semistandard tableaux of shape $(k_n,k_{n-1},...,k_1)$ with entries in $\{1,2,...,n\}$ or, equivalently, Gelfand-Tsetlin ... More
Refined enumerations of alternating sign matrices: monotone (d,m)-trapezoids with prescribed top and bottom rowJul 02 2009Monotone triangles are plane integer arrays of triangular shape with certain monotonicity conditions along rows and diagonals. Their significance is mainly due to the fact that they correspond to $n \times n$ alternating sign matrices when prescribing ... More
The operator formula for monotone triangles - simplified proof and three generalizationsMar 26 2009We provide a simplified proof of our operator formula for the number of monotone triangles with prescribed bottom row, which enables us to deduce three generalizations of the formula. One of the generalizations concerns a certain weighted enumeration ... More
The beta function of the multichannel Kondo modelNov 17 1998The beta function of the multichannel Kondo model is calculated exactly in the limit of large spin N and channel number M=gamma*N, with constant gamma. There are no corrections in any finite order of 1/N. One zero is found at a finite coupling strength, ... More
A primer on reflexivity and price dynamics under systemic riskJan 27 2013A simple quantitative example of a reflexive feedback process and the resulting price dynamics after an exogenous price shock to a financial network is presented. Furthermore, an outline of a theory that connects financial reflexivity, which stems from ... More
Minimal elements of stopping time $σ$-algebrasDec 12 2011Jun 19 2012We show how minimal elements of a stopping time $\sigma$-algebra can be expressed in terms of the minimal elements of the $\sigma$-algebra of the underlying filtration. This facilitates an intuitive interpretation of stopping time $\sigma$-algebras. An ... More
Stopping times are hitting times: a natural representationDec 07 2011Jun 19 2012There exists a simple, didactically useful one-to-one relationship between stopping times and adapted c\`agl\`ad (LCRL) processes that are non-increasing and take the values 0 and 1 only. As a consequence, stopping times are always hitting times.
Alternating sign trapezoids and a constant term approachApr 23 2018We show that there is the same number of (n,l)-alternating sign trapezoids as there is of column strict shifted plane partitions of class l-1 with at most n parts in the top row, thereby proving a result that was conjectured independently by Behrend and ... More
Enumeration of alternating sign triangles using a constant term approachApr 10 2018Alternating sign triangles (ASTs) have recently been introduced by Ayyer, Behrend and the author, and it was proven that there is the same number of ASTs with n rows as there is of nxn alternating sign matrices (ASMs). We prove a conjecture by Behrend ... More
Adjusting estimators for marginal distributions in contingency tablesSep 20 2016To take sample biases and skewness in the observations in account, practitioners frequently weight their observations. Considering discrete distributions, the present paper explores the effect of weighted data from an asymptotic point of view. If one ... More
Unsupervised Discovery of MorphemesMay 21 2002We present two methods for unsupervised segmentation of words into morpheme-like units. The model utilized is especially suited for languages with a rich morphology, such as Finnish. The first method is based on the Minimum Description Length (MDL) principle ... More
Transfinite Approximation of Hindman's TheoremJan 07 2010Jul 01 2011Hindman's Theorem states that in any finite coloring of the integers, there is an infinite set all of whose finite sums belong to the same color. This is much stronger than the corresponding finite form, stating that in any finite coloring of the integers ... More