Results for "Jens Kling"
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Dynamical Properties of a Rotating Bose-Einstein CondensateNov 01 2007Within a variational approach to solve the Gross-Pitaevskii equation we investigate dynamical properties of a rotating Bose-Einstein condensate which is confined in an anharmonic trap. In particular, we calculate the eigenfrequencies of low-energy excitations ... More String Field Theory Vertices for Fermions of Integral WeightJun 25 2003Feb 26 2004We construct Witten-type string field theory vertices for a fermionic first order system with conformal weights (0,1) in the operator formulation using delta-function overlap conditions as well as the Neumann function method. The identity, the reflector ... More M-brane singularity formationDec 09 2008We derive self-similar string solutions in a graph representation, near the point of singularity formation, which can be shown to extend to point-like singularities on M-branes, as well as to the radially symmetric case. Basic Network Creation Games with Communication InterestsJul 23 2012Network creation games model the creation and usage costs of networks formed by a set of selfish peers. Each peer has the ability to change the network in a limited way, e.g., by creating or deleting incident links. In doing so, a peer can reduce its ... More FASER: ForwArd Search ExpeRiment at the LHCAug 30 2017Jun 14 2018New physics has traditionally been expected in the high-$p_T$ region at high-energy collider experiments. If new particles are light and weakly-coupled, however, this focus may be completely misguided: light particles are typically highly concentrated ... More Chromatic weight systems and the corresponding knot invariantsJan 13 1997This paper contains a proof that chromatic weight systems, introduced by Chmutov, Duzhin and Lando, can be expressed in terms of weight systems associated with direct sums of the Lie algebras gl_n and so_n. As a consequence the Vassiliev invariants of ... More Anomaly Cancellation in Six DimensionsApr 22 1993I show that anomaly cancellation conditions are sufficient to determine the two most important topological numbers relevant for Calabi-Yau compactification to six dimensions. This reflects the fact that K3 is the only non-trivial CY manifold in two complex ... More Breakdown of Duality in (0,2) Superstring ModelsJun 16 1993After pointing out the role of the compactification lattice for spectrum calculations in orbifold models, I discuss modular discrete symmetry groups for $Z_N$ or\-bi\-folds. I consider the $Z_7$ orbifold as a nontrivial example of a (2,2) model and give ... More U(1) invariant Membranes and SingularitiesMay 30 2008A formulation of U(1) - symmetric classical membrane motions (preserving one rotational symmetry) is given, and reductions to systems of ODE's, as well as some ideas concerning singularities and integrability. M-brane dynamical symmetry and quantizationJan 22 2011The recently discovered dynamical symmetry for relativistic extended objects is derived from first principles, and analogues commutators are obtained for the corresponding formal quantum expressions Tests of the Electroweak Standard ModelSep 14 2012Sep 24 2012Electroweak precision tests of the Standard Model of the fundamental interactions are reviewed ranging from the lowest to the highest energy experiments. Results from global fits are presented with particular emphasis on the extraction of fundamental ... More Which spectral distortions does $Λ$CDM actually predict?Mar 08 2016May 20 2016Ever refined cosmological measurements have established the $\Lambda$CDM concordance model, with the key cosmological parameters being determined to percent-level precision today. This allows us to make explicit predictions for the spectral distortions ... More Tropical multiplier sequencesMay 23 2015We prove that the diagonal operator defined by a positive sequence preserves tropical and central indices if and only if the sequence is log-concave. In particular we obtain an elementary proof of that such an operator preserves the set of sign-independently ... More Quantum LeaksMar 28 2005We show that eigenfunctions of the Laplacian on certain non-compact domains with finite area may localize at infinity--provided there is no extreme level clustering--and thus rule out quantum unique ergodicity for such systems. The construction is elementary ... More Selberg's trace formula: an introductionJul 16 2004Feb 13 2008These lecture notes provide a basic introduction to Selberg's trace formula. We discuss the simplest possible case: the spectrum of the Laplacian on a compact Riemannian surface of constant negative curvature. (To appear in Springer LNP.) On modular semifinite index theoryNov 28 2011We propose a definition of a modular spectral triple which covers existing examples arising from KMS-states, Podles sphere and quantum SU(2). The definition also incorporates the notion of twisted commutators appearing in recent work of Connes and Moscovici. ... More On harmonic and asymptotically harmonic homogeneous spacesSep 20 2004Oct 04 2005We classify noncompact homogeneous spaces which are Einstein and asymptotically harmonic. This completes the classification of Riemannian harmonic spaces in the homogeneous case: Any simply connected homogeneous harmonic space is flat, or rank-one symmetric, ... More Hydrodynamic theory of de-wettingDec 24 2003A prototypical problem in the study of wetting phenomena is that of a solid plunging into or being withdrawn from a liquid bath. In the latter, de-wetting case, a critical speed exists above which a stationary contact line is no longer sustainable and ... More Dynamics of nanojetsJan 02 2002We study the breakup of a liquid jet a few nanometers in diameter, based on a stochastic differential equation derived recently by Moseler and Landman [Science {\bf 289}, 1165 (2000)]. In agreement with their simulations, we confirm that noise qualitatively ... More Designs and codes in affine geometryMay 12 2016May 23 2016Classical designs and their (projective) q-analogs can both be viewed as designs in matroids, using the matroid of all subsets of a set and the matroid of linearly independent subsets of a vector space, respectively. Another natural matroid is given by ... More Block-diagonalisation of matrices and operatorsOct 14 2008In this short note we deal with a constructive scheme to decompose a continuous family of matrices $A(\rho)$ asymptotically as $\rho\to0$ into blocks corresponding to groups of eigenvalues of the limit matrix A(0). We also discuss the extension of the ... More Entry and return times for semi-flowsMay 09 2016Dec 05 2016Haydn, Lacroix and Vaienti [Ann. Probab. 33 (2005)] proved that, for a given ergodic map, the entry time distribution converges in the small target limit, if and only if the corresponding return time distribution converges. The present note explains how ... More Pair correlation densities of inhomogeneous quadratic formsOct 14 2002Apr 20 2004Under explicit diophantine conditions on $(\alpha,\beta)\in\RR^2$, we prove that the local two-point correlations of the sequence given by the values $(m-\alpha)^2+\break (n-\beta)^2$, with $(m,n)\in\ZZ^2$, are those of a Poisson process. This partly ... More Fit to Electroweak Precision DataJun 12 2006A brief review of electroweak precision data from LEP, SLC, the Tevatron, and low energies is presented. The global fit to all data including the most recent results on the masses of the top quark and the W boson reinforces the preference for a relatively ... More The Probability Density of the Higgs Boson MassOct 15 2000Jan 11 2001The LEP Collaborations have reported a small excess of events in their combined Higgs boson analysis at center of mass energies up to about 208 GeV. In this communication, I present the result of a calculation of the probability distribution function ... More Alpha_s with GAPPFeb 27 2011Details are provided how GAPP evaluates the strong coupling constant from Z and tau decays and the corresponding uncertainties. Radiative Corrections and Z'Sep 29 2009Radiative corrections to parity violating deep inelastic electron scattering are reviewed including a discussion of the renormalization group evolution of the weak mixing angle. Recently obtained results on hypothetical Z' bosons - for which parity violating ... More Electroweak Precision Data and New Gauge BosonsJul 05 2009I review constraints on the Standard Model (SM) Higgs boson from high energy electroweak (EW) precision data. The same data set also strongly limits various mixing effects of hypothetical extra neutral gauge bosons (Z') with the ordinary Z. I also discuss ... More Electroweak Radiative Corrections to Semileptonic Tau DecaysNov 22 2002Nov 25 2002I present an update on the electroweak radiative correction factor to semileptonic tau decays, including a next-to-leading order resummation of large logarithms. My result differs both qualitatively and quantitatively from the one recently obtained by ... More Chiral Models of Weak Scale SupersymmetryJun 05 2000I discuss supersymmetric extensions of the Standard Model containing an extra U(1)' gauge symmetry which provide a solution to the mu-problem and at the same time protect the proton from decaying via dimension 4 operators. Moreover, all fields are protected ... More Asymmetric Orbifolds and Higher Level ModelsFeb 07 1996Nov 29 1996I introduce a class of string constructions based on asymmetric orbifolds leading to level two models. In particular, I derive in detail various models with gauge groups $E_6$ and SO(10), including a four generation $E_6$ model with two adjoint representations. ... More The SLD Asymmetry in View of the LEP ResultsJun 30 1994LEP determines $\sin^2 \theta_{\rm eff}$, by combining the various asymmetry measurements to be $0.2321 \pm 0.0005$. On the other hand, the left-right asymmetry as measured at SLC corresponds to \seff = $0.2292 \pm 0.0010$. I will discuss the possibilities ... More Surface Motions and Fluid DynamicsMay 02 1994Jul 20 1994A certain class of surface motions, including those of a relativistic membrane minimizing the 3-dimensional volume swept out in Minkowski-space, is shown to be equivalent to 3-dimensional steady-state irrotational inviscid isentropic gas-dynamics. The ... More Autotools for writing portable softwareOct 20 2002Nov 01 2002Most of the scientific software is developed in the same manner: It starts at a lab and the scientist says "This part of software is only for my private use". But the software grows and grows, and it comes the time, that other scientists want to use it, ... More Reassembling trees for the traveling salesmanFeb 12 2015Jan 05 2016Many recent approximation algorithms for different variants of the traveling salesman problem (asymmetric TSP, graph TSP, s-t-path TSP) exploit the well-known fact that a solution of the natural linear programming relaxation can be written as convex combination ... More Kinetic limits of dynamical systemsAug 06 2014Since the pioneering work of Maxwell and Boltzmann in the 1860s and 1870s, a major challenge in mathematical physics has been the derivation of macroscopic evolution equations from the fundamental microscopic laws of classical or quantum mechanics. Macroscopic ... More The supernova/gamma-ray burst/jet connectionApr 29 2013The observed association between supernovae and gamma-ray bursts represents a cornerstone in our understanding of the nature of gamma-ray bursts. The collapsar model provides a theoretical framework for this connection. A key element is the launch of ... More Weighing in on the HiggsJan 03 2012Sep 13 2012Assuming the validity of the Standard Model, or more generally that possible physics beyond it would have only small effects on production cross sections, branching ratios and electroweak radiative corrections, I determine the mass of the Higgs boson ... More Limitations of Skeptical Default ReasoningFeb 06 2013Poole has shown that nonmonotonic logics do not handle the lottery paradox correctly. In this paper we will show that Pollock's theory of defeasible reasoning fails for the same reason: defeasible reasoning is incompatible with the skeptical notion of ... More Invariant Differential PairingsMar 29 2007Apr 12 2008In this paper the notion of an M-th order invariant bilinear differential pairing is introduced and a formal definition is given. If the manifold has an AHS structure, then various first order pairings are constructed. This yields a classification of ... More Morita invariance of unbounded bivariant K-theoryDec 26 2016We introduce a notion of Morita equivalence for non-selfadjoint operator algebras equipped with a completely isometric involution (operator *-algebras). We then show that the unbounded Kasparov product by a Morita equivalence bimodule induces an isomorphism ... More Instability of a moving contact lineJan 18 2005We study a solid plate plunging into or being withdrawn from a liquid bath, to highlight the fundamental difference between the local behavior of an advancing or a receding contact line, respectively. It is assumed that the liquid partially wets the solid, ... More On the multivariate Fujiwara bound for exponential sumsDec 12 2016We prove the multivariate Fujiwara bound for exponential sums: for a $d$-variate exponential sum $f$ with scaling parameter $\mu$, if $x$ is contained in the amoeba $\mathscr{A}(f)$, then the distance from $x$ to the Archimedean tropical variety associated ... More Horospheres and Farey fractionsMar 24 2010Mar 30 2010We embed multidimensional Farey fractions in large horospheres and explain under which conditions they become uniformly distributed in the ambient homogeneous space. This question has recently been investigated in the case of SL(d,Z) to prove the asymptotic ... More Modified scattering for a wave equation with weak dissipationSep 10 2005We consider the Cauchy problem for the weakly dissipative wave equation $$ \square u+\frac\mu{1+t} u_t=0 $$ with parameter $\mu\ge2$. Based on the explicit representations of solutions provided in [Math. Meth. Appl. Sci. 2004; {\bf 27}:101-124] sharp ... More On 7D TFT and 6D chiral CFTJun 13 2002Jul 04 2002We perform a canonical and BRST analysis of a seven-dimensional Chern-Simons theory on a manifold with boundary. The main result is that the 7D theory induces for consistency a chiral two-form on the 6D boundary. We also comment on similar behaviour in ... More On the Deformation of Time Harmonic FlowsDec 02 1996It is shown that time-harmonic motions of spherical and toroidal surfaces can be deformed non-locally without loosing the existence of infinitely many constants of the motion. Fundamental Parameters from Precision TestsFeb 12 2001I review how electroweak precision observables can be used to constrain the Higgs boson mass and the strong coupling constant. Implications for physics beyond the Standard Model are also addressed. Electroweak Physics at LHCJul 28 2006Jul 30 2006The prospects for electroweak physics at the LHC are reviewed focusing mainly on precision studies. This includes projections for measurements of the effective Z pole weak mixing angle, of top quark, W boson, and Higgs scalar properties, and new physics ... More Truthful Feedback for Sanctioning Reputation MechanismsMar 15 2012For product rating environments, similar to that of Amazon Reviews, it has been shown that the truthful elicitation of feedback is possible through mechanisms which pay buyer reports contingent on the reports of other buyers. We study whether similar ... More The Gutzwiller Trace Formula for Quantum Systems with SpinApr 10 2001The Gutzwiller trace formula provides a semiclassical approximation for the density of states of a quantum system in terms of classical periodic orbits. In its original form Gutzwiller derived the trace formula for quantum systems without spin. We will ... More Coamoebas of polynomials supported on circuitsJan 20 2016We study coamoebas of polynomials supported on circuits. Our results include an explicit description of the space of coamoebas, a relation between connected components of the coamoeba complement and critical points of the polynomial, an upper bound on ... More The Union-Closed Sets Conjecture for Small FamiliesAug 24 2015Aug 25 2015We prove that the union-closed sets conjecture is true for separating union-closed families $\mathcal{A}$ with $|\mathcal{A}| \leq 2\left(m+\frac{m}{\log_2(m)-\log_2\log_2(m)}\right)$ where $m$ denotes the number of elements in $\mathcal{A}$. On t-dependent hyperbolic systems. Part 2Aug 11 2015Oct 18 2016We consider hyperbolic equations with time-dependent coefficients and develop an abstract framework to derive the asymptotic behaviour of the representation of solutions for large times. We are dealing with generic situations where the large-time asymptotics ... More On the Combination Procedure of Correlated ErrorsJul 29 2015When averages of different experimental determinations of the same quantity are computed, each with statistical and systematic error components, then frequently the statistical and systematic components of the combined error are quoted explicitly. These ... More