Results for "Carlota Andres"

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Extracting $\hat{q}$ from single inclusive data at RHIC and at the LHC for different centralities: a new puzzle?Dec 20 2016We present here an extraction of the jet transport coefficient, $\hat{q}$, using RHIC and LHC single-inclusive high-$p_T$ data for different centralities. We fit a $K$-factor that determines the deviation of this coefficient from an ideal estimate, $K ... More
Extracting $\hat{q}$ in event-by-event hydrodynamics and the centrality/energy puzzleMay 03 2017In our analysis, we combine event-by-event hydrodynamics, within the EKRT formulation, with jet quenching -ASW Quenching Weights- to obtain high-$p_T$ $R_{\rm AA}$ for charged particles at RHIC and LHC energies for different centralities. By defining ... More
Constraining energy loss from high-$p_{\rm T}$ azimuthal asymmetriesFeb 20 2019The nuclear modification factor $R_{\rm AA}$ has been satisfactorily described by various jet quenching models. Nonetheless, all these formalisms, until very recently, underpredicted the high-$p_{\rm T}$ (> 10 GeV) elliptic flow $v_2$. We find that the ... More
Jet quenching as a probe of the initial stages in heavy-ion collisionsFeb 08 2019Jet quenching provides a very flexible variety of observables which are sensitive to different energy- and time-scales of the strongly interacting matter created in heavy-ion collisions. Exploiting this versatility would make jet quenching an excellent ... More
Self-similar lifting and persistent touch-down points in the thin-film equationAug 01 2017We study self-similar solutions of the thin-film equation, with mobility exponent m in (0,4], that describe the lifting of an isolated touch-down point given by an initial profile of the form |x|. This provides a mechanism for non-uniqueness of the thin-film ... More
Logic Blog 2015fFeb 14 2016The 2015 Logic Blog contains a large variety of results connected to logic, some of them unlikely to be submitted to a journal. For the first time there is a group theory part. There are results in higher randomness, and in computable ergodic theory.
Norms of geodesic restrictions for eigenfunctions on hyperbolic surfaces and representation theoryMar 25 2004Mar 24 2010We consider restrictions along closed geodesics and geodesic circles for eigenfunctions of the Laplace-Beltrami operator on a compact hyperbolic Riemann surface. We obtain a non-trivial bound on the L^2-norm of such restrictions as the eigenvalue tends ... More
Review of SU(2)-CalibrationsOct 27 2005The purpose of this article is to provide a review of SU(2)-calibrations. The focus is on developing all techniques in full detail by studying selected examples. The supergravity point of view and the string theoretic one are explained.
A New Track Reconstruction Algorithm suitable for Parallel Processing based on Hit Triplets and Broken LinesNov 05 2016Track reconstruction in high track multiplicity environments at current and future high rate particle physics experiments is a big challenge and very time consuming. The search for track seeds and the fitting of track candidates are usually the most time ... More
Heavy-flavour production in pp and Pb-Pb collisions at ALICEJun 06 2011In this contribution, recent ALICE measurements of the production cross section of single electrons, single muons and open charmed mesons in proton-proton collisions at sqrt(s) = 7 TeV are reported. The data are compared to next-to-leading-order perturbative ... More
Towards a Comprehensive Fueling-Controlled Theory on the Growth of Massive Black Holes and Host SpheroidsMay 30 2007We study the relation between nuclear massive black holes and their host spheroid gravitational potential. Using AMR numerical simulations, we analyze how gas is transported in the nuclear (central kpc) regions of galaxies. We study the gas fueling onto ... More
On the Fueling of Massive Black Holes and the Properties of their Host SpheroidsApr 24 2006Aug 31 2006We study the relation between nuclear massive black holes and their host spheroid gravitational potential. Using simple models, we analyze how gas is expected to be transported in the nuclear regions of galaxies. When we couple it with the expected gas ... More
On the "equivalence" of the Maxwell and Dirac equationsJan 25 2002Apr 04 2002It is shown that Maxwell's equation cannot be put into a spinor form that is equivalent to Dirac's equation. First of all, the spinor \psi in the representation \vec{F} = \psi \vec{u} \bar{\psi} of the electromagnetic field bivector depends on only three ... More
Explicit closed-form parametrization of SU(3) and SU(4) in terms of complex quaternions and elementary functionsNov 22 2002Nov 22 2002Remarkably simple closed-form expressions for the elements of the groups SU(n), SL(n,R), and SL(n,C) with n=2, 3, and 4 are obtained using linear functions of biquaternions instead of n x n matrices. These representations do not directly generalize to ... More
Highlights of Current Higgs Boson SearchesNov 02 2010Over the last years the Tevatron Run-II has extended several limits on Higgs boson masses and coupling which were pioneered during the LEP accelerator operation between 1989 and 2000. Higgs boson searches will also be at the forefront of research at the ... More
Search for New Particles at LEPNov 23 1999The latest preliminary results of the searches for Higgs bosons and Supersymmetric particles at LEP are reviewed. The results include the data-taking in 1999 up to center-of-mass energies of 196 GeV. The combination of the results from the four LEP experiments ... More
The orbital counting problem for hyperconvex representationsMar 01 2012Jul 12 2014We give a precise counting result on the symmetric space of a noncompact real algebraic semisimple group $G,$ for a class of discrete subgroups of $G$ that contains, for example, representations of a surface group on $\textrm{PSL}(2,\mathbb R)\times\textrm{PSL}(2,\mathbb ... More
Exact Black Holes and Universality in the Backreaction of non-linear Sigma Models with a potential in (A)dS4Apr 12 2012May 22 2012The aim of this paper is to construct accelerated, stationary and axisymmetric exact solutions of the Einstein theory with self interacting scalar fields in (A)dS4. To warm up, the backreaction of the (non)-minimally coupled scalar field is solved, the ... More
Simulations of the Temperature Dependence of the Charge Transfer Inefficiency in a High-Speed CCDDec 27 2007Results of detailed simulations of the charge transfer inefficiency of a prototype serial readout CCD chip are reported. The effect of radiation damage on the chip operating in a particle detector at high frequency at a future accelerator is studied, ... More
Stability of rotating spherical stellar systemsAug 30 2002The stability of rotating isotropic spherical stellar systems is investigated by using N-body simulations. Four spherical models with realistic density profiles are studied: one of them fits the luminosity profile of globular clusters, while the remaining ... More
Quantum Theory of Self-Induced TransparencyMay 15 1995It is known that classical electromagnetic radiation at a frequency in resonance with energy splittings of atoms in a dielectric medium can be described using the classical sine-Gordon equation. In this paper we quantize the electromagnetic field and ... More
On sequents of $Σ$ formulasApr 26 2017Jul 24 2017We investigate the position that foundational theories should be modelled on ordinary computability. In this context, we investigate the metamathematics of $\Sigma$ formulas. We consider theories whose axioms are implications between $\Sigma$ formulas, ... More
Quantum FunctionsJan 10 2011Jan 11 2015Weaver has recently defined the notion of a quantum relation on a von Neumann algebra. We demonstrate that the corresponding notion of a quantum function between two von Neumann algebras coincides with that of a normal unital $*$-homomorphism in the opposite ... More
Singularities of Lagrangian mean curvature flow: monotone caseAug 15 2006We study the formation of singularities for the mean curvature flow of monotone Lagrangians in $\C^n$. More precisely, we show that if singularities happen before a critical time then the tangent flow can be decomposed into a finite union of area-minimizing ... More
The Principle of Similitude in Biology: From Allometry to the Formulation of Dimensionally Homogenous `Laws'Jul 07 2017Jan 07 2019Meaningful laws of nature must be independent of the units employed to measure the variables. The principle of similitude (Rayleigh 1915) or dimensional homogeneity, states that only commensurable quantities (ones having the same dimension) may be compared, ... More
Scale invariant cosmology II: model equations and propertiesMay 19 2016We want to establish the basic properties of a scale invariant cosmology, that also accounts for the hypothesis of scale invariance of the empty space at large scales. We write the basic analytical properties of the scale invariant cosmological models. ... More
Genetic Algorithms for the Imitation of Genomic Styles in Protein BacktranslationApr 05 2003Several technological applications require the translation of a protein into a nucleic acid that codes for it (``backtranslation''). The degeneracy of the genetic code makes this translation ambiguous; moreover, not every translation is equally viable. ... More
Sampling as optimization in the space of measures: The Langevin dynamics as a composite optimization problemFeb 22 2018Jun 06 2018We study sampling as optimization in the space of measures. We focus on gradient flow-based optimization with the Langevin dynamics as a case study. We investigate the source of the bias of the unadjusted Langevin algorithm (ULA) in discrete time, and ... More
Dynamical effects of the scale invariance of the empty space: The fall of dark matter ?Oct 31 2017The hypothesis of the scale invariance of the macroscopic empty space, which intervenes through the cosmological constant, has led to new cosmological models. They show an accelerated cosmic expansion and satisfy several major cosmological tests. No unknown ... More
Microlocal lifts of eigenfunctions on hyperbolic surfaces and trilinear invariant functionalsApr 16 2004S. Zelditch introduced an equivariant version of a pseudo-differential calculus on a hyperbolic Riemann surface. We recast his construction in terms of trilinear invariant functionals on irreducible unitary representations of PGL(2,R). This allows us ... More
On the stability of four legged tablesOct 17 2005Aug 15 2006We prove that a perfect four-feet square table, posed in a continuous irregular ground with a local slope of at most 15 degrees can be put in equilibrium on the ground by a "rotation" of less than 90 degrees. We also discuss the case of non-square tables ... More
La conjecture du facteur directSep 01 2016Building on his reduction to the case of an unramified complete regular local ring R of mixed characteristic, we propose a proof in the framework of P. Scholze's perfectoid theory. The main ingredients are the perfectoid "Abhyankar lemma" and an analysis ... More
Kinetic Theory of Soft Matter. The Penetrable-Sphere ModelJan 05 2005The penetrable-sphere model has been introduced in the literature to describe the peculiar thermodynamic behavior of some colloidal systems. In this model the interaction potential is $\phi(r)=\epsilon>0$ if the two spheres are overlapped ($r<\sigma$) ... More
Invariance Principle for the Random Conductance Model with dynamic bounded ConductancesFeb 03 2012Oct 11 2012We study a continuous time random walk X in an environment of dynamic random conductances. We assume that the conductances are stationary ergodic, uniformly bounded and bounded away from zero and polynomially mixing in space and time. We prove a quenched ... More
A Periodicity Theorem for the Octahedron RecurrenceApr 12 2006Oct 26 2006We investigate a variant of the octahedron recurrence which lives in a 3-dimensional lattice contained in [0,n] x [0,m] x R. Generalizing results of David Speyer math.CO/0402452, we give an explicit non-recursive formula for the values of this recurrence ... More
Conformal nets are factorization algebrasNov 17 2016We prove that conformal nets of finite index are an instance of the notion of a factorization algebra. This result is an ingredient in our proof that, for $G=SU(n)$, the Drinfel'd center of the category of positive energy representations of the based ... More
The transfinite meanAug 22 2017Dec 31 2018We define a generalization of the arithmetic mean to bounded transfinite sequences of real numbers. We show that every probability space admits a transfinite sequences of points such that the measure of each measurable subset is equal to the frequency ... More
Left Invariant Contact Structures on Lie GroupsMar 31 2004Sep 24 2004A result from Gromov ensures the existence of a contact structure on any connected non-compact odd dimensional Lie group. But in general such structures are not invariant under left translations of the Lie group. The problem of finding which Lie groups ... More
Look-Back and Look-Ahead in the Conversion of Hidden Markov Models into Finite State TransducersFeb 02 1998This paper describes the conversion of a Hidden Markov Model into a finite state transducer that closely approximates the behavior of the stochastic model. In some cases the transducer is equivalent to the HMM. This conversion is especially advantageous ... More
Finite State Transducers Approximating Hidden Markov ModelsJul 17 1997This paper describes the conversion of a Hidden Markov Model into a sequential transducer that closely approximates the behavior of the stochastic model. This transformation is especially advantageous for part-of-speech tagging because the resulting transducer ... More
The Structure of Differential Invariants and Differential Cut EliminationApr 11 2011Nov 23 2012The biggest challenge in hybrid systems verification is the handling of differential equations. Because computable closed-form solutions only exist for very simple differential equations, proof certificates have been proposed for more scalable verification. ... More
The factor paradox: Common factors can be correlated with the variance not accounted for by the common factors!Aug 19 2013The case that the factor model does not account for all the covariances of the observed variables is considered. This is a quite realistic condition because some model error as well as some sampling error should usually occur with empirical data. It is ... More
Coding Methods in Computability Theory and Complexity TheoryAug 29 2013A major part of computability theory focuses on the analysis of a few structures of central importance. As a tool, the method of coding with first-order formulas has been applied with great success. For instance, in the c.e. Turing degrees, it has been ... More
A power law for the lowest eigenvalue in localized massive gravityNov 17 2000Nov 27 2000This short note contains a detailed analysis to find the right power law the lowest eigenvalue of a localized massive graviton bound state in a four dimensional AdS background has to satisfy. In contrast to a linear dependence of the cosmological constant ... More
Status of Higgs Boson Searches at the TevatronMar 25 2009Over the last years the Tevatron Run-II has extended several limits on Higgs boson masses and coupling which were pioneered during the LEP accelerator operation between 1989 and 2000. Higgs boson searches will also be at the forefront of research at the ... More
Higgs Physics: from LEP to a Future Linear ColliderFeb 01 2005New preliminary combined results from the LEP experiments on searches for the Higgs boson beyond the Standard Model are presented. The new determination of the top quark mass at the Tevatron in 2004 influences the interpretations of the LEP results in ... More
Highlights of Higgs Physics at LEPFeb 22 2004Final results from the combined data of the four LEP experiments ALEPH, DELPHI, L3 and OPAL on Standard Model (SM) Higgs boson searches are presented. New preliminary results of searches in extended models are reviewed.
Cross-sections and branching ratios for charged Higgs searchesJul 09 2009For the preparation of the experimental search for charged Higgs bosons at the LHC detailed studies have been made to determine the expected charged Higgs boson production cross-sections and decay branching ratios at sqrts = 14 TeV. In the mass regime ... More
Alignment of the Central D-Zero DetectorApr 25 2006The alignment procedure of the Silicon Microstrip Tracker, SMT, and the Central Fiber Tracker, CFT, is described. Alignment uncertainties and resulting systematic errors in physics analyses are addressed.
Higgs physics at a high luminosity e+e- linear colliderSep 30 2002Since the TESLA Technical Design Report (TDR) was published in 2001, the physics programme of an electron-positron linear collider (LC) has been further developed and a wide consensus has been reached on the physics case and the need for a high luminosity ... More
Complete LEP Data: Status of Higgs Boson SearchesDec 05 2001The LEP experiments completed data-taking in November 2000. New preliminary combined results of the four LEP experiments ALEPH, DELPHI, L3 and OPAL are presented for various Higgs boson searches.
Higgs Boson Searches at LEP Up To sqrt(s) = 202 GeVApr 03 2000The latest preliminary combined results of the Higgs boson searches from the LEP experiments ALEPH, DELPHI, L3 and OPAL are presented. A general scan of the MSSM parameters is performed and leads to stringent lower mass limits and for the first time excludes ... More
Heavy-flavour production in hot quark matterNov 23 2010Recent results from RHIC and first measurements from the ALICE experiment at the CERN-Large Hadron Collider (LHC) on open heavy-flavour are presented. We focus on RHIC measurements of single electrons and jet-like heavy-flavour particle correlations. ... More
Recent high pT measurements in STARApr 12 2005Apr 14 2005After five years of data taking, the STAR experiment at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory provides precise measurements of particle production at high transverse momentum in p-p, d-Au, and Au-Au collisions at ... More
Depleted-Uranium Weapons: the Whys and WhereforesJan 23 2003May 08 2003The only military application in which depleted-uranium (DU) alloys out-perform present-day tungsten alloys is long-rod penetration into a main battle-tank's armor. However, this advantage is only on the order of 10%, and it disappears when the comparison ... More
Observational properties of the open cluster system of the Milky Way and what they tell us about our GalaxyNov 09 2009Almost 80 years have passed since Trumpler's analysis of the Galactic open cluster system laid one of the main foundations for understanding the nature and structure of the Milky Way. Since then, the open cluster system has been recognised as a key source ... More
On the global triggering mechanism of star formation in galaxiesSep 23 2009We study the large-scale triggering of star formation in galaxies. We find that the largest mass-scale not stabilized by rotation, a well defined quantity in a rotating system and with clear dynamical meaning, strongly correlates with the star formation ... More
What Chern-Simons theory assigns to a pointMar 21 2015In this note, we answer the questions "What does Chern-Simons theory assign to a point?" and "What kind of mathematical object does Chern-Simons theory assign to a point?". Our answer to the first question is representations of the based loop group. More ... More
On the Functional Form of the Universal Star Formation LawNov 25 2014Feb 19 2015We study the functional form of the star formation law, using the Vaschy-Buckingham Pi theorem. We find that that it should have a form $\rm \dot{\Sigma}_{\star} \propto \sqrt{\frac{G}{L}}\Sigma_{gas}^{3/2}$, where L is a characteristic length that is ... More
A Possible Explanation for the Size Difference of Red and Blue Globular ClustersAug 17 2004Most observations of the projected half-light radii of metal-rich globular clusters in a variety of galaxies have shown them to be ~20% smaller than those of their metal-poor counterparts. We show using multi-mass isotropic Michie-King models that the ... More
Strong Coupling Fixed Points of Current Interactions and Disordered Fermions in 2DNov 23 2000Apr 05 2001The all-orders beta function is used to study disordered Dirac fermions in 2D. The generic strong coupling fixed `points' of anisotropic current-current interactions at large distances are actually isotropic manifolds corresponding to subalgebras of the ... More
Gauge Invariance and the Critical Properties of Quantum Hall Plateaux TransitionsApr 28 1999May 14 1999A model consisting of a single massless scalar field with a topological coupling to a pure gauge field is defined and studied. It possesses an SL(2,Z) symmetry as a consequence of the gauge invariance. We propose that by adding impurities the model can ... More
QED for a Fibrillar Medium of Two-Level AtomsApr 17 1996May 31 1996We consider a fibrillar medium with a continuous distribution of two-level atoms coupled to quantized electromagnetic fields. Perturbation theory is developed based on the current algebra satisfied by the atomic operators. The one-loop corrections to ... More
Spectrum Generating Affine Lie Algebras in Massive Field TheoryMay 21 1993Nov 01 1993We present a new application of affine Lie algebras to massive quantum field theory in 2 dimensions, by investigating the $q\to 1$ limit of the q-deformed affine $\hat{sl(2)}$ symmetry of the sine-Gordon theory, this limit occuring at the free fermion ... More
Quantum Solitons in Non-Linear Optics: Resonant Dielectric MediaOct 06 1994It is known that classical electromagnetic radiation at a frequency in resonance with energy splittings of atoms in a dielectric medium can be described using the classical sine-Gordon equation. In this paper we quantize the electromagnetic field and ... More
Limiting cycles and periods of Maass formsApr 03 2017We consider (generalized) periods of Maass forms along non-closed geodesics having a closed geodesic as the limit set.
The Classification of Homogeneous Simple 3-graphsMay 05 2015We classify the ultrahomogeneous complete 3-edge-coloured graphs (3-graphs) with simple theory. This extends Lachlan's result (a corollary of the Effective Classification Theorem for stable structures) classifying the stable homogeneous 3-graphs. The ... More
Singularities of Lagrangian mean curvature flow: zero-Maslov class caseAug 15 2006We study singularities of Lagrangian mean curvature flow in $\C^n$ when the initial condition is a zero-Maslov class Lagrangian. We start by showing that, in this setting, singularities are unavoidable. More precisely, we construct Lagrangians with arbitrarily ... More
Universality and Decidability of Number-Conserving Cellular AutomataJun 17 2003Number-conserving cellular automata (NCCA) are particularly interesting, both because of their natural appearance as models of real systems, and because of the strong restrictions that number-conservation implies. Here we extend the definition of the ... More
Logic Blog 2018Feb 23 2019Mar 14 2019Some notions from algorithmic randomness are extended to measures and to quantum states. There is a lot on group theory and its relation to logic. This includes some new results on oligomorphic groups. There's also metric spaces and Scott rank, and interpretability. ... More
Notes on Clans and TribesOct 27 2017The purpose of these notes is to give a categorical presentation/analysis of homotopy type theory. The notes are incomplete as they stand (October 2017). The chapter on univalent tribes is missing. The references are not always connected to the text. ... More
Scale invariant cosmology III: dynamical models and comparisons with observationsMay 19 2016We examine the properties of the scale invariant cosmological models, also making the specific hypothesis of the scale invariance of the empty space at large scales. Numerical integrations of the cosmological equations for different values of the curvature ... More
Scale invariant cosmology I: the vacuum and the cosmological constantMay 19 2016The source of the acceleration of the expansion of the Universe is still unknown. We examine some consequences of the possible scale invariance of the empty space at large scales. The central hypothesis of this work is that, at macroscopic and large scales ... More
Seidel's Representation on the Hamiltonian Group of a Cartesian ProductMay 09 2008Let $(M,\omega)$ be a closed symplectic manifold and $\textup{Ham}(M,\omega)$ the group of Hamiltonian diffeomorphisms of $(M,\omega)$. Then the Seidel homomorphism is a map from the fundamental group of $\textup{Ham}(M,\omega)$ to the quantum homology ... More
Does the Chapman-Enskog expansion for viscous granular flows converge?Apr 16 2008This paper deals with the convergence/divergence issue of the Chapman-Enskog series expansion of the shear and normal stresses for a granular gas of inelastic hard spheres. From the exact solution of a simple kinetic model in the uniform shear and longitudinal ... More
Longitudinal Viscous Flow in Granular GasesSep 10 2008The flow characterized by a linear longitudinal velocity field $u_x(x,t)=a(t)x$, where $a(t)={a_0}/({1+a_0t})$, a uniform density $n(t)\propto a(t)$, and a uniform temperature $T(t)$ is analyzed for dilute granular gases by means of a BGK-like model kinetic ... More
A simple model kinetic equation for inelastic Maxwell particlesAug 29 2006The model of inelastic Maxwell particles (IMP) allows one to derive some exact results which show the strong influence of inelasticity on the nonequilibrium properties of a granular gas. The aim of this work is to propose a simple model kinetic equation ... More
Granular fluid thermostatted by a bath of elastic hard spheresJan 20 2003Feb 28 2003The homogeneous steady state of a fluid of inelastic hard spheres immersed in a bath of elastic hard spheres kept at equilibrium is analyzed by means of the first Sonine approximation to the (spatially homogeneous) Enskog--Boltzmann equation. The temperature ... More
Transport coefficients of d-dimensional inelastic Maxwell modelsApr 03 2002Oct 17 2002Due to the mathematical complexity of the Boltzmann equation for inelastic hard spheres, a kinetic model has recently been proposed whereby the collision rate (which is proportional to the relative velocity for hard spheres) is replaced by an average ... More
Studies on the Pea Pattern SequenceAug 22 2017Aug 23 2018The paper will formally define the family of sequences know as "Pea Pattern". It will then anaylize its behaviour and conditions for fixed and periodic points. The paper ends with a list of fixed points and cycles.
Geodesic restrictions for the Casimir operatorDec 13 2010Jul 27 2011We consider the hyperbolic Casimir operator C defined on the tangent sphere bundle SY of a compact hyperbolic Riemann surface Y. We prove a nontrivial bound on the L^2-norm of the restriction of eigenfunctions of C to certain natural hypersurfaces in ... More
Can one improve the Froissart bound?Dec 03 2008Feb 20 2009We explain why we hope that the Froissart bound can be improved, either qualitatively or, more likely, quantitatively, by making a better use of unitarity, in particular elastic unitarity. In other instances (Gribov's theorem) elastic unitarity played ... More
The status of the heavy quark systemsMay 15 2007We review various inequalities on the order and the spacing of energy levels, wave function at the origin, etc... which were obtained since 1977 in the framework of the Schrodinger equation and applied to quarkonium and also to muonic atoms and alcaline ... More
Singular integration towards a spectrally accurate finite difference operatorJun 28 2019It is an established fact that a finite difference operator approximates a derivative with a fixed algebraic rate of convergence. Nevertheless, we exhibit a new finite difference operator and prove it has spectral accuracy. Its rate of convergence is ... More
An action of the cactus groupMay 21 2007We construct an action of the big cactus group (the fundamental group of the Deligne-Mumford compactification of the moduli space of real curves of genus zero with n undistinguished marked points) on Fock-Goncharov's SL_m analog of the decorated Teichmuller ... More
Bicommutant categories from conformal netsJan 09 2017Jun 27 2017We prove that the category of solitons of a finite index conformal net is a bicommutant category, and that its Drinfel'd center is the category of representations of the conformal net. In the special case of a chiral WZW conformal net with finite index, ... More
Three-tier CFTs from Frobenius algebrasApr 27 2013Dec 23 2013These are lecture notes of a course given at the Summer School on Topology and Field Theories held at the Centre for Mathematics of the University of Notre Dame, Indiana, from May 29 to June 2, 2012. The idea of extending quantum field theories to manifolds ... More
Ambiguity theory, old and newMay 16 2008This is a introductory survey of some recent developments of "Galois ideas" in Arithmetic, Complex Analysis, Transcendental Number Theory and Quantum Field Theory, and of some of their interrelations.
Standard Model FitsJun 24 2002Recent results of tests of the Standard Model of electroweak interactions are presented. Data are used from the four LEP experiments, ALEPH, DELPHI, L3, OPAL, the SLD experiment at SLC, the TEVATRON p-pbar experiments CDF and D0 and the NuTeV neutrino ... More
Process chain approach to high-order perturbation calculus for quantum lattice modelsNov 14 2008Jun 29 2009A method based on Rayleigh-Schroedinger perturbation theory is developed that allows to obtain high-order series expansions for ground-state properties of quantum lattice models. The approach is capable of treating both lattice geometries of large spatial ... More
Exact Hairy Black HolesNov 12 2012Nov 13 2012This proceeding reviews the recent finding of a certain class of, regular on and outside the horizon, exact hairy black hole solutions in four dimensional general relativity. Their construction follow from the integrability of a cohomogeneity two Weyl ... More
On the equivalence of the SO(2,1) gauged WZW form and Liouville theoryApr 14 2009Jul 25 2011It is proved that Liouville theory and the two dimensional SO(2,1) gauged Wess-Zumino-Witten term are on-shell equivalent. This shed light on a possible higher dimensional generalization of the former theory.
Chains of End Elementary Extensions of Models of Set TheoryNov 13 1996Large cardinals arising from the existence of arbitrarily long end elementary extension chains over models of set theory are studied here. In particular, we show that the large cardinals obtained that way (`Unfoldable cardinals') behave as a `boundary' ... More
Heights of Models of $ZFC$ and the Existence of End Elementary ExtensionsNov 13 1996The existence of End Elementary Extensions of models M of ZFC is related to the ordinal height of M, according to classical results due to Keisler, Morley and Silver. In this paper, we further investigate the connection between the height of M and the ... More
Moving Five-Branes and CosmologyOct 03 2002We discuss low-energy heterotic M-theory with five-branes in four and five dimensions and its application to moving brane cosmology.
Logic Blog 2012Feb 15 2013The 2012 logic blog has focussed on the following: Randomness and computable analysis/ergodic theory; Systematizing algorithmic randomness notions; Traceability; Higher randomness; Calibrating the complexity of equivalence relations from computability ... More
Calibrating the complexity of Delta 2 sets via their changesFeb 03 2013The computational complexity of a Delta 2 set will be calibrated by the amount of changes needed for any of its computable approximations. Firstly, we study Martin-Loef random sets, where we quantify the changes of initial segments. Secondly, we look ... More
BYOD and the Mobile Enterprise - Organisational challenges and solutions to adopt BYODDec 12 2015Bring Your Own Device, also known under the term BOYD refers to the trend in employees bringing their personal mobile devices into organisations to use as a primary device for their daily work activities. With the rapid development in computing technology ... More
Probabilistic Tagging with Feature StructuresOct 25 1994The described tagger is based on a hidden Markov model and uses tags composed of features such as part-of-speech, gender, etc. The contextual probability of a tag (state transition probability) is deduced from the contextual probabilities of its feature-value-pairs. ... More
An Ab Initio Study of the Structures and Relative Stabilities of Doubly Charged [(NaCl)m(Na)2]2+ Cluster IonsJan 26 2001We present ab initio perturbed ion calculations on the structures and relative stabilities of doubly charged [(NaCl)_m(Na)_2]2+ cluster ions. The obtained stabilities show excellent agreement with experimental abundances obtained from mass spectra. Those ... More