Results for "Johan Hastad"

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On the List-Decodability of Random Linear CodesJan 09 2010For every fixed finite field $\F_q$, $p \in (0,1-1/q)$ and $\epsilon > 0$, we prove that with high probability a random subspace $C$ of $\F_q^n$ of dimension $(1-H_q(p)-\epsilon)n$ has the property that every Hamming ball of radius $pn$ has at most $O(1/\epsilon)$ ... More
Super-polylogarithmic hypergraph coloring hardness via low-degree long codesNov 28 2013We prove improved inapproximability results for hypergraph coloring using the low-degree polynomial code (aka, the 'short code' of Barak et. al. [FOCS 2012]) and the techniques proposed by Dinur and Guruswami [FOCS 2013] to incorporate this code for inapproximability ... More
Making the long code shorter, with applications to the Unique Games ConjectureNov 02 2011The long code is a central tool in hardness of approximation, especially in questions related to the unique games conjecture. We construct a new code that is exponentially more efficient, but can still be used in many of these applications. Using the ... More
Connected, Disconnected and Strange Quark Contributions to HVPSep 06 2016We calculate all neutral vector two-point functions in Chiral Perturbation Theory (ChPT) to two-loop order and use these to estimate the ratio of disconnected to connected contributions as well as contributions involving the strange quark. We extend the ... More
Pion light-by-light contributions to the muon $g-2$Aug 04 2016This paper contains some new results on the hadronic light-by-light contribution (HLbL) to the muon $g-2$. The first part argues that we can expect large effects from disconnected diagrams in present and future calculations by lattice QCD of HLbL. The ... More
Masses, decay constants and electromagnetic form-factors with twisted boundary conditionsSep 24 2015Jan 07 2016We discuss some of the effects of twisted boundary conditions in finite volume using continuum SU(3) Chiral Perturbation Theory. We point out how broken cubic symmetry affects the definitions of quantities such as form-factors. Using the $\pi^+$ as an ... More
Vector two-point functions in finite volume using partially quenched chiral perturbation theoryOct 12 2017Dec 14 2017We calculate vector-vector correlation functions at two loops using partially quenched chiral perturbation theory including finite volume effects and twisted boundary conditions. We present expressions for the flavor neutral cases and the flavor charged ... More
Chiral Perturbation Theory at Finite Volume and/or with Twisted Boundary ConditionsNov 18 2016In this talk we discuss a number of ChPT calculations relevant for lattice QCD. These include the finite volume corrections at two-loop order for masses and decay constants. The second part is about hadronic vacuum polarization where we present the two-loop ... More
Connected, Disconnected and Strange Quark Contributions to HVPSep 06 2016Nov 03 2016We calculate all neutral vector two-point functions in Chiral Perturbation Theory (ChPT) to two-loop order and use these to estimate the ratio of disconnected to connected contributions as well as contributions involving the strange quark. We extend the ... More
A Lorentzian Gromov-Hausdoff notion of distanceAug 22 2003Nov 18 2003This paper is the first of three in which I study the moduli space of isometry classes of (compact) globally hyperbolic spacetimes (with boundary). I introduce a notion of Gromov-Hausdorff distance which makes this moduli space into a metric space. Further ... More
One-parameter representations on C*-algebrasJul 28 1997Strongly continuous one-parameter representations on C*-algebras and their extension to the multiplier algebra are investigated. We give also a proof of the Stone theorem on Hilbert C*-modules and look into some related problems.
The analytic structure of an algebraic quantum groupJul 28 1997A. Van Daele introduced and investigated so-called algebraic quantum groups. We proved that such algebraic quantum groups give rise to C*-algebraic quantum groups in the sense of Masuda, Nakagami & Woronowicz. We prove in this paper that the analytic ... More
Chiral perturbation theory in the meson sectorSep 25 2009The present status of Chiral Perturbation Theory in the meson sector is discussed concentrating on recent developments. This write-up contains short discussions on a listing a few historical papers, the principles behind ChPT, two-flavour ChPT including ... More
Status of Strong ChPTApr 23 2009The present status of Chiral Perturbation Theory (ChPT) in the strong mesonic sector is discussed. A very short introduction to ChPT is followed by an overview of existing two-loop calculations and the determination of the Low-Energy-Constants (LECs). ... More
Chiral LagrangiansAug 13 2001Sep 04 2001An overview of the field of Chiral Lagrangians is given. This includes Chiral Perturbation Theory and resummations to extend it to higher energies, applications to the muon anomalous magnetic moment, $\epsilon^\prime/\epsilon$ and others.
Effective Lagrangians for Light QuarksNov 29 1994The class of phenomenological Lagrangians used for light constituent quarks is discussed. The Nambu-Jona-Lasinio model is then argued to be a good phenomenological choice and the quality of its prediction in the purely hadronic sector including several ... More
$η$ and $η'$ decays and what can we learn from them?Nov 07 2005Feb 02 2006In this talk a short overview of $\eta$ and $\eta'$ decays is given with an emphasis on what can be learned for the strong interaction from them. The talk consists of a short introduction to ChPT, a discussion of $\eta\to3\pi$ beyond $p^4$ and some of ... More
Quark Asymmetries and Intrinsic Charm in NucleonsAug 11 2005We have developed a physical model for the non-perturbative x-shape of parton density functions in the proton, based on Gaussian fluctuations in momenta, and quantum fluctuations of the proton into meson-baryon pairs. The model describes the proton structure ... More
MATCHIG: A program for matching charged Higgs boson production at hadron collidersMar 14 2005This manual describes how to use the MatCHig code for matching the charged Higgs boson production processes gg->tbH+/- and gb->tH+/-. A negative term, correcting for the double-counting between these processes, is implemented as an external process to ... More
Quantifying SuperpositionDec 17 2006Measures are introduced to quantify the degree of superposition in mixed states with respect to orthogonal decompositions of the Hilbert space of a quantum system. These superposition measures can be regarded as analogues to entanglement measures, but ... More
Bimodules in group graded ringsAug 30 2016In this article we introduce the notion of a controlled group graded ring. Let $G$ be a group, with identity element $e$, and let $R=\oplus_{g\in G} R_g$ be a unital $G$-graded ring. We say that $R$ is $G$-controlled if there is a one-to-one correspondence ... More
Physical Origin of Elementary Particle MassesFeb 04 2014In contemporary particle physics, the masses of fundamental particles are incalculable constants, being supplied by experimental values. Inspired by observation of the empirical particle mass spectrum, and their corresponding physical interaction couplings, ... More
Commuting Conformal and Dual Conformal Symmetries in the Regge limitMar 22 2010Jun 02 2010In this paper we continue our study of the dual SL(2,C) symmetry of the BFKL equation, analogous to the dual conformal symmetry of N=4 Super Yang Mills. We find that the ordinary and dual SL(2,C) symmetries do not generate a Yangian, in contrast to the ... More
Two-colored noncommutative Gerstenhaber formality and infinity Duflo isomorphismApr 12 2011Using new configuration spaces, we give an explicit construction that extends Kontsevich's Lie-infinity quasi-isomorphism from polyvector fields to Hochschild cochains to a quasi-isomorphism of A-infinity algebras equipped with actions by homotopy derivations ... More
Examining the dual of an algebraic quantum groupApr 21 1997In the first part of this paper, we implement the multiplier algebra of the dual of an algebraic quantum group (A,Delta) as a space of linear functionals on A. In the second part, we construct the universal corepresentation of (A,Delta) and use it to ... More
Robust Report Level Cluster-to-Track FusionMay 16 2003In this paper we develop a method for report level tracking based on Dempster-Shafer clustering using Potts spin neural networks where clusters of incoming reports are gradually fused into existing tracks, one cluster for each track. Incoming reports ... More
Fast Dempster-Shafer clustering using a neural network structureMay 16 2003In this article we study a problem within Dempster-Shafer theory where 2**n - 1 pieces of evidence are clustered by a neural structure into n clusters. The clustering is done by minimizing a metaconflict function. Previously we developed a method based ... More
Cluster-based Specification Techniques in Dempster-Shafer Theory for an Evidential Intelligence Analysis of MultipleTarget Tracks (Thesis Abstract)May 16 2003In Intelligence Analysis it is of vital importance to manage uncertainty. Intelligence data is almost always uncertain and incomplete, making it necessary to reason and taking decisions under uncertainty. One way to manage the uncertainty in Intelligence ... More
Simultaneous Dempster-Shafer clustering and gradual determination of number of clusters using a neural network structureMay 16 2003In this paper we extend an earlier result within Dempster-Shafer theory ["Fast Dempster-Shafer Clustering Using a Neural Network Structure," in Proc. Seventh Int. Conf. Information Processing and Management of Uncertainty in Knowledge-Based Systems (IPMU'98)] ... More
Fast Dempster-Shafer clustering using a neural network structureMay 16 2003In this paper we study a problem within Dempster-Shafer theory where 2**n - 1 pieces of evidence are clustered by a neural structure into n clusters. The clustering is done by minimizing a metaconflict function. Previously we developed a method based ... More
Specifying nonspecific evidenceMay 16 2003In an earlier article [J. Schubert, On nonspecific evidence, Int. J. Intell. Syst. 8(6), 711-725 (1993)] we established within Dempster-Shafer theory a criterion function called the metaconflict function. With this criterion we can partition into subsets ... More
Mixing times for the interchange processOct 25 2012Consider the interchange process on a connected graph $G=(V,E)$ on $n$ vertices. I.e.\ shuffle a deck of cards by first placing one card at each vertex of $G$ in a fixed order and then at each tick of the clock, picking an edge uniformly at random and ... More
A Gravitational Double Scattering Mechanism for Generating High Velocity ObjectsSep 15 2014We present a dynamical model describing how halo particles can receive a significant energy kick from the merger between their own host halo and a target halo. This is highly relevant for understanding the growth of cosmological halos, and could especially ... More
Extracting Periodic Transit Signals from Noisy Light Curves using Fourier SeriesMar 11 2015Jul 08 2015We present a simple and powerful method for extracting transit signals associated with a known transiting planet from noisy light curves. Assuming the orbital period of the planet is known and the signal is periodic, we illustrate that systematic noise ... More
Trapping massless Dirac particles in a rotating saddleMar 01 2013Jul 04 2013We study particle motion in rotating saddle-shaped potentials. It is known that such rotating potentials can generate bounded motion for particles with a parabolic dispersion law through the combination of potential, centrifugal and Coriolis forces in ... More
Faithful fermionic representations of the Kondo lattice modelFeb 25 2011Jun 13 2011We study the Kondo lattice model using a class of canonical transformations that allow us to faithfully represent the model entirely in terms of fermions without constraints. The transformations generate interacting theories that we study using mean field ... More
The strange algebra of combinatorial gamesDec 02 2009We present an algebraic framework for the analysis of combinatorial games. This framework embraces the classical theory of partizan games as well as a number of misere games, comply-constrain games, and card games that have been studied more recently. ... More
Modular forms applied to the computational inverse Galois problemSep 30 2011For each of the groups PSL2(F25), PSL2(F32), PSL2(F49), PGL2(F25), and PGL2(F27), we display the first explicitly known polynomials over Q having that group as Galois group. Each polynomial is related to a Galois representation associated to a modular ... More
Lower bounds in some power sum problemsApr 15 2007We study the power sum problem max_{v=1,...,m} | sum_{k=1}^n z_k^v | and by using features of Fejer kernels we give new lower bounds in the case of unimodular complex numbers z_k and m cn^2 for constants c>1.
Breakdown of adiabatic invariance in spherical tokamaksMay 30 2001Thermal ions in spherical tokamaks have two adiabatic invariants: the magnetic moment and the longitudinal invariant. For hot ions, variations in magnetic-field strength over a gyro period can become sufficiently large to cause breakdown of the adiabatic ... More
Voronin Universality in several complex variablesSep 10 2018We prove the Voronin universality theorem for the multiple Hurwitz zeta-function with rational or transcendental parameters in $\mathbb{C}^n$ answering a question of Matsumoto. In particular this implies that the Euler-Zagier multiple zeta-function is ... More
A Geometric Obstruction to Almost Global Synchronization on Riemannian ManifoldsAug 02 2018Mar 18 2019Multi-agent systems on nonlinear spaces sometimes fail to synchronize. This is usually attributed to the initial configuration of the agents being too spread out, the graph topology having certain undesired symmetries, or both. Besides nonlinearity, the ... More
The Mumford--Tate conjecture for products of abelian varietiesApr 18 2018Let $X$ be a smooth projective variety over a finitely generated field $K$ of characteristic~$0$ and fix an embedding $K \subset \mathbb{C}$. The Mumford--Tate conjecture is a precise way of saying that certain extra structure on the $\ell$-adic \'etale ... More
Shifted double Lie-Rinehart algebrasFeb 16 2018We generalize the notions of shifted double Poisson and shifted double Lie-Rinehart structures, defined by Van den Bergh in [VdB08a, VdB08b], to monoids in a symmetric monoidal abelian category. The main result is that an n-shifted double Lie-Rinehart ... More
Fast mixing for Latent Dirichlet allocationJan 11 2017Nov 01 2017Markov chain Monte Carlo (MCMC) algorithms are ubiquitous in probability theory in general and in machine learning in particular. A Markov chain is devised so that its stationary distribution is some probability distribution of interest. Then one samples ... More
The PANDA Experiment at FAIR - Subatomic Physics with AntiprotonsOct 10 2016The non-perturbative nature of the strong interaction leads to spectacular phenomena, such as the formation of hadronic matter, color confinement, and the generation of the mass of visible matter. To get deeper insight into the underlying mechanisms remains ... More
Hadronic light-by-light contribution to $a_μ$: extended Nambu-Jona-Lasinio, chiral quark models and chiral LagrangiansOct 20 2015This talk discusses our old work on the hadronic light-by-light contribution to the muon anomalous magnetic moment and some more recent contributions. I discuss the various contributions starting with pseudo-scalar meson exchange, the quark- and pion-loop, ... More
Fully quantum fluctuation theoremsJan 06 2016Feb 12 2018Systems that are driven out of thermal equilibrium typically dissipate random quantities of energy on microscopic scales. Crooks fluctuation theorem relates the distribution of these random work costs with the corresponding distribution for the reverse ... More
On the computation of Galois representations associated to level one modular formsOct 05 2007In this paper we explicitly compute mod-l Galois representations associated to modular forms. To be precise, we look at cases with l<=23 and the modular forms considered will be cusp forms of level 1 and weight up to 22. We present the result in terms ... More
Finding dissimilar explanations in Bayesian networks: Complexity resultsOct 26 2018Dec 11 2018Finding the most probable explanation for observed variables in a Bayesian network is a notoriously intractable problem, particularly if there are hidden variables in the network. In this paper we examine the complexity of a related problem, that is, ... More
Bimodules in group graded ringsAug 30 2016Jan 09 2017In this article we introduce the notion of a controlled group graded ring. Let $G$ be a group, with identity element $e$, and let $R=\oplus_{g\in G} R_g$ be a unital $G$-graded ring. We say that $R$ is $G$-controlled if there is a one-to-one correspondence ... More
On the Entropy of a Family of Random SubstitutionsMar 24 2011Mar 09 2012The generalised random Fibonacci chain is a stochastic extension of the classical Fibonacci substitution and is defined as the rule mapping $0\mapsto 1$ and $1 \mapsto 1^i01^{m-i}$ with probability $p_i$, where $p_i\geq 0$ with $\sum_{i=0}^m p_i=1$, and ... More
On the Entropy of a Two Step Random Fibonacci SubstitutionMar 11 2013We consider a random generalisation of the classical Fibonacci substitution. The substitution we consider is defined as the rule mapping $\mathtt{a}\mapsto \mathtt{baa}$ and $\mathtt{b} \mapsto \mathtt{ab}$ with probability $p$ and $\mathtt{b} \mapsto ... More
One- versus multi-component regular variation and extremes of Markov treesFeb 06 2019A Markov tree is a random vector indexed by the nodes of a tree whose distribution is determined by the distributions of pairs of neighbouring variables and a list of conditional independence relations. Upon an assumption on the tails of the Markov kernels ... More
Strong-coupling diagrammatics for lattice fermions and spins based on irreducible verticesSep 02 2019We describe a controllable and unbiased strong coupling technique that is applicable to a wide range of fermionic systems and spin models. Unlike previous works that generally rely on the Grassmannian Hubbard-Stratonovich transformation, our construction ... More
A Space Efficient Algorithm for the Calculation of the Digit Distribution in the Kolakoski SequenceOct 19 2011Mar 09 2012With standard algorithms for generating the classical Kolakoski sequence, the numerical calculation of the digit distribution requires a linear amount of space. Here, we present an algorithm for calculating the distribution of the digits in the classical ... More
Non universality on the critical lineJul 20 2012Jun 08 2016We prove that the Riemann zeta-function is not universal on the critical line by using the fact that the Hardy Z-function is real, and some elementary considerations. This is a related to a recent result of Garunkstis and Steuding. We also prove conditional ... More
Generalized Gravity I : Kinematical Setting and reformalizing Quantum Field TheoryJan 28 2008Apr 20 2008The first part of this work deals with the development of a natural differential calculus on non-commutative manifolds. The second part extends the covariance and equivalence principle as well studies its kinematical consequences such as the arising of ... More
Lorentzian Gromov Hausdorff theory as a tool for quantum gravity kinematicsJan 30 2004This thesis start by a review of different approaches to classical and quantum gravity. The main theme is Lorentzian Gromov Hausdorff theory which is an active diffeomorphism invariant theory on the space of Lorentz spaces (think about globally hyperbolic ... More
The $ΔI=1/2$ rule and other matrix elementsOct 07 1999Recent work by J.Prades and myself on $K\to\pi\pi$ is described. The method we use to consistently connect long and short distances is described and numerical results for the $\Delta I=1/2$ rule and on $B_6$, the parameter relevant for the strong part ... More
Progress in $K\toππ$ DecaysJul 12 1999Recent work by J.~Prades and myself on $K\to\pi\pi$ is described. The first part describes our method to connect in a systematic fashion the short-distance evolution with long-distance matrix-element calculations taking the scheme dependence of the short-distance ... More
Goldstone Boson Production and DecayOct 14 1997Various topics in and around Goldstone Boson Production and Decay in CHPT are discussed, in particular I describe some of the progress in $p^6$ Chiral Perturbation Theory Calculations, the progress in calculating hadronic contributions to the muon anomalous ... More
Quark Mass dependence at Two Loops for Meson PropertiesAug 10 2007Aug 28 2007This talks contains a short introduction to Chiral Perturbation Theory and the existing calculations to two-loop order in the mesonic sector. I include a discussion on which quantities the expansion can be organized in. The present best values of the ... More
A simple explanation of the non-appearance of physical gluons and quarksAug 14 2002We show that the non-appearance of gluons and quarks as physical particles is a rigorous and automatic result of the full, i.e. nonperturbative, nonabelian nature of the color interaction in quantum chromodynamics. This makes it in general impossible ... More
A possible experimental test to decide if quantum mechanical randomness is due to deterministic chaos in the underlying dynamicsJun 18 2000A simple experiment using radioactive decay is proposed to test the possibility of a determinsistic, but chaotic, origin of quantum mechanical randomness.
A new topology on the space of Lorentzian metrics on a fixed manifoldApr 10 2011We give a covariant definition of closeness between (time oriented) Lorentzian metrics on a manifold M, using a family of functions which measure the difference in volume form on one hand and the difference in causal structure relative to a volume scale ... More
KMS-weights on C*-algebrasApr 29 1997In this paper, we build a solid framework for KMS-weights on C*-algebras. We use another definition than the one introduced by Combes, but prove that they are equivalent.
Formal weights in Kontsevich's formality construction and multiple zeta valuesOct 30 2014We construct a functor that associates to any dg cooperad of dg commutative algebras (satisfying some conditions) an augmented commutative algebra. When applied to the cohomology operad of Francis Brown's moduli spaces it produces an algebra that formally ... More
Clustering belief functions based on attracting and conflicting metalevel evidenceMay 16 2003In this paper we develop a method for clustering belief functions based on attracting and conflicting metalevel evidence. Such clustering is done when the belief functions concern multiple events, and all belief functions are mixed up. The clustering ... More
Managing Inconsistent IntelligenceMay 16 2003In this paper we demonstrate that it is possible to manage intelligence in constant time as a pre-process to information fusion through a series of processes dealing with issues such as clustering reports, ranking reports with respect to importance, extraction ... More
Finding a Posterior Domain Probability Distribution by Specifying Nonspecific EvidenceMay 16 2003This article is an extension of the results of two earlier articles. In [J. Schubert, On nonspecific evidence, Int. J. Intell. Syst. 8 (1993) 711-725] we established within Dempster-Shafer theory a criterion function called the metaconflict function. ... More
Total Irregularity and $f_t$-Irregularity of Linear Jaco Graphs$Jun 24 2014Jan 12 2016Total irregularity of a simple undirected graph $G$ is defined to be $irr_t(G) = \frac{1}{2}\sum\limits_{u, v \in V(G)}|d(u) - d(v)|$. See Abdo and Dimitrov [2]. We allocate the \emph{Fibonacci weight,} $f_i$ to a vertex $v_j$ of a simple connected graph, ... More
ChPT loops for the lattice: pion mass and decay constant, HVP at finite volume and $n\bar n$-oscillationsOct 13 2017I present higher loop order results for several calculations in Chiral perturbation Theory. 1) Two-loop results at finite volume for hadronic vacuum polarization. 2) A three-loop calculation of the pion mass and decay constant in two-flavour ChPT. For ... More
Blenders near polynomial product maps of $\mathbb C^2$Feb 07 2017Jul 26 2017In this paper we show that if $p$ is a polynomial which bifurcates then the product map $(z,w)\mapsto(p(z),q(w))$ can be approximated by polynomial skew products possessing special dynamical objets called blenders. Moreover, these objets can be chosen ... More
Low energy paths for octahedral tilting in inorganic halide perovskitesFeb 26 2018Dec 04 2018Instabilities relating to cooperative octahedral tilting is common in materials with perovskite structures, and in particular in the sub class of halide perovskites. In this work, the energetics of octahedral tilting in the inorganic metal halide perovskites ... More
Bounded prime gaps in short intervalsJun 03 2013Jun 06 2013We generalise Zhang's and Pintz recent results on bounded prime gaps to give a lower bound for the the number of prime pairs bounded by 6*10^7 in the short interval $[x,x+x (\log x)^{-A}]$. Our result follows only by analysing Zhang's proof of Theorem ... More
On the solutions to a power sum problemSep 21 2006Oct 15 2006In a recent paper we proved that if (*)=\inf_{|z_k|=1}\max_{v=1,...,n^2-n} |\sum_{k=1}^n z_k^v|, then (*)=\sqrt{n-1} if n-1 is a prime power. We proved that a construction of Fabrykowski gives minimal systems (z_1,...,z_n) to this problem. The construction ... More
A Compactness Theorem for Invariant ConnectionsApr 10 1997Aug 01 1997Necessary and sufficient conditions are given for the Palais-Smale Condition C to hold for the Yang-Mills functional for invariant connections on a principal bundle over a compact manifold of any dimension. It is assumed that the connections are invariant ... More
Simplicity of skew group rings of abelian groupsNov 30 2011Mar 30 2012Given a group G, a (unital) ring A and a group homomorphism $\sigma : G \to \Aut(A)$, one can construct the skew group ring $A \rtimes_{\sigma} G$. We show that a skew group ring $A \rtimes_{\sigma} G$, of an abelian group G, is simple if and only if ... More
A polynomial with Galois group SL2(F16)Jan 16 2007In this paper we show an explicit polynomial in Q[x] that has Galois group SL2(F16), filling in a gap in the tables of Juergen Klueners and Gunther Malle. The computation of this polynomial uses modular forms and their Galois representations.
Burchnall-Chaundy theory for Ore extensionsSep 17 2013Nov 11 2013We begin by reviewing a classical result on the algebraic dependence of commuting elements in Weyl algebras. We proceed by describing generalizations of this result to various classes of Ore extensions, both results that have already been published and ... More
When only the last one will doApr 15 2011An unknown positive number of items arrive at independent uniformly distributed times in the interval [0,1] to a selector, whose task is to pick online the last one. We show that under the assumption of an adversary determining the number of items, there ... More
Mergelyan's approximation theorem with nonvanishing polynomials and universality of zeta-functionsOct 05 2010Dec 21 2012We prove a variant of the Mergelyan approximation theorem that allows us to approximate functions that are analytic and nonvanishing in the interior of a compact set K with connected complement, and whose interior is a Jordan domain, with nonvanishing ... More
Lavrentiev's approximation theorem with nonvanishing polynomials and universality of zeta-functionsOct 03 2010We prove a variant of the Lavrentiev's approximation theorem that allows us to approximate a continuous function on a compact set K in C without interior points and with connected complement, with polynomial functions that are nonvanishing on K. We use ... More
CHIRON: a package for ChPT numerical results at two loopsDec 02 2014This document describes the package CHIRON which includes two libraries, chiron itself and jbnumlib. CHIRON is a set of routines useful for two-loop numerical results in Chiral Perturbation Theory (ChPT). It includes programs for the needed one- and two-loop ... More
Equidistribution speed towards the Green current for endomorphisms of P^kNov 02 2010Let f be a non-invertible holomorphic endomorphism of P^k. For a hypersurface H of P^k, generic in the Zariski sense, we give an explicit speed of convergence of f^{-n}(H) towards the dynamical Green (1,1)-current of f.
The spectral problem of the ABJ Fermi gasJul 02 2014The partition function on the three-sphere of ABJ theory can be rewritten into a partition function of a non-interacting Fermi gas, with an accompanying one-particle Hamiltonian. We study the spectral problem defined by this Hamiltonian. We determine ... More
Solving integral equations on piecewise smooth boundaries using the RCIP method: a tutorialJul 29 2012May 29 2016Recursively Compressed Inverse Preconditioning (RCIP) is a numerical method for solving Fredholm second kind boundary integral equations in situations where the boundary shape induces a non-smooth behavior in the solution. The method originated in 2008 ... More
Hard Pion Chiral Perturbation Theory: What is it and is it relevant for $η^\prime$ decays?Oct 27 2011In this talk I give a short introduction to hard pion Chiral Perturbation Theory and an overview of the available applications $K\to\pi\pi$, $B,D\to D,\pi,K,\eta$ semileptonic decays and $\chi_{c0,2}\to\pi\pi,KK$. It is pointed out that the reults for ... More
Legendrian contact homology in the product of a punctured Riemann surface and the real lineAug 07 2011Jun 03 2015We give a combinatorial description of the Legendrian differential graded algebra associated to a Legendrian knot in PxR, where P is a punctured Riemann surface. As an application we show that for any integer k and any homology class h in H_1(PxR) there ... More
Asymptotics of empirical copula processes under non-restrictive smoothness assumptionsDec 09 2010Jul 05 2012Weak convergence of the empirical copula process is shown to hold under the assumption that the first-order partial derivatives of the copula exist and are continuous on certain subsets of the unit hypercube. The assumption is non-restrictive in the sense ... More
Nonlinear gauge interactions: a possible solution to the "measurement problem" in quantum mechanicsJan 18 2010Two fundamental, and unsolved problems in physics are: i) the resolution of the "measurement problem" in quantum mechanics ii) the quantization of strongly nonlinear (nonabelian) gauge theories. The aim of this paper is to suggest that these two problems ... More
Reality or Locality? - Proposed test to decide \textit{how} Nature breaks Bell's inequalityApr 11 2011Bell's theorem, and its experimental tests, has shown that the two premises for Bell's inequality - locality and objective reality - cannot both hold in nature, as Bell's inequality is broken. A simple test is proposed, which for the first time may decide ... More
Towards a fully consistent relativistic quantum mechanics and a change of perspective on quantum gravityAug 26 2005Oct 10 2005This paper can be seen as an exercise in how to adapt quantum mechanics from a strict relativistic perspective while being respectful and critical towards the experimental achievements of the contemporary theory. The result is a fully observer independent ... More
Regular C*-valued weightsMar 13 1997We introduce the notion of a C*-valued weight between two C*-algebras as a generalization of an ordinary weight on a C*-algebra and as a C*-version of operator valued weights on von Neumann algebras. Also, some form of lower semi-continuity will be discussed ... More
Chiral Meson Physics at Two LoopsSep 07 2004An overview of Chiral Perturbation Theory calculations in the mesonic sector at the two Loop level is given. Discussed in some detail are the partially quenched case relevant for lattice QCD, the general fitting procedures and $\pi\pi$,$\pi K$ scattering ... More
Penguins 2002: Penguins in $K\toππ$ DecaysJul 05 2002This talk contains a short overview of the history of the interplay of the weak and the strong interaction and CP-violation. It describes the phenomenology and the basic physics mechanisms involved in the Standard Model calculations of $K\to\pi\pi$ decays ... More
Chiral Lagrangians and Nambu-Jona-Lasinio like modelsFeb 17 1995We discuss the low-energy analysis of models involving quarks and four-fermion couplings. The relation with QCD and with other models of mesons and meson plus quarks at low energies is discussed. A short description of how the heat-kernel expansion can ... More
Chiral Dynamics in the Meson Sector at two LoopsJul 07 2003I give a very short introduction to Chiral Perturbation Theory and an overview of the next-to-next-to-leading order three-flavour calculations done. I discuss those relevant for an improvement in the accuracy of the measurement of $V_{us}$ in more detail. ... More
Weak Interactions of Light FlavoursOct 23 2000An overview is given of weak interaction physics of the light flavours. It starts with the definition of the CKM matrix and the measurement of its components in the light-flavour sector via semi-leptonic decays. The main part of the lectures is devoted ... More