Results for "Ralf Ramsauer"

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Observing Custom Software Modifications: A Quantitative Approach of Tracking the Evolution of Patch StacksJul 04 2016Modifications to open-source software (OSS) are often provided in the form of "patch stacks" - sets of changes (patches) that modify a given body of source code. Maintaining patch stacks over extended periods of time is problematic when the underlying ... More
The List is the Process: Reliable Pre-Integration Tracking of Commits on Mailing ListsFeb 08 2019A considerable corpus of research on software evolution focuses on mining changes in software repositories, but omits their pre-integration history. We present a novel method for tracking this otherwise invisible evolution of software changes on mailing ... More
Look Mum, no VM Exits! (Almost)May 19 2017Multi-core CPUs are a standard component in many modern embedded systems. Their virtualisation extensions enable the isolation of services, and gain popularity to implement mixed-criticality or otherwise split systems. We present Jailhouse, a Linux-based, ... More
Coulomb GANs: Provably Optimal Nash Equilibria via Potential FieldsAug 29 2017Jan 30 2018Generative adversarial networks (GANs) evolved into one of the most successful unsupervised techniques for generating realistic images. Even though it has recently been shown that GAN training converges, GAN models often end up in local Nash equilibria ... More
Yang-Mills thermodynamicsOct 04 2007Nov 05 2009We present a quantitative analysis of Yang-Mills thermodynamics in 4D flat spacetime. The focus is on the gauge group SU(2). Results for SU(3) are mentioned in passing. Although all essential arguments and results were reported elsewhere we summarize ... More
Spontaneously broken, local Z$_2$ symmetry and the anatomy of a leptonDec 03 2003Feb 11 2004In the framework of the gauge symmetry ${SU(2)}_{\tiny{CMB}}\times {SU(2)}_{\tiny{e}}\times {SU(2)}_{\tiny{\mu}}\times {SU(2)}_{\tiny{\tau}}$ we provide a microscopic argument why a spontaneously broken, local Z$_2$ symmetry surviving the 1$^{\tiny{st}}$ ... More
Reshuffling the OPE: Delocalized Operator ExpansionJul 29 2002A generalization of the operator product expansion for Euclidean correlators of gauge invariant QCD currents is presented. Each contribution to the modified expansion, which is based on a delocalized multipole expansion of a perturbatively determined ... More
Modifying operator product expansions by non-perturbative non-localitySep 02 2001Nov 12 2001Local quark-hadron duality violations in conventional applications of the operator product expansion are proposed to have their origin in the fact that the QCD vacuum or a hadronic state is not only characterized by nonvanishing expectation values of ... More
Confinement, Chiral Symmetry Breaking, and Axial Anomaly from Domain Formation at Intermediate ResolutionMar 26 2001Jul 02 2001Based on general renormalization group arguments, Polyakov's loop-space formalism, and recent analytical lattice arguments, suggesting, after Abelian gauge fixing, a description of pure gluodynamics by means of a Georgi-Glashow like model, the corresponding ... More
Analytical approach to nonperturbative Yang-Mills thermodynamicsDec 03 2003Dec 05 2003An analytical and inductive approach to hot SU(N) Yang-Mills dynamics is developed. For N=2,3 pressure and energy density are pointwise compared with lattice data.
Towards OPE based local quark-hadron duality: Light-quark channelsSep 02 2001Various light-quark channel current-current correlators are subjected to the concept of a non-perturbative component of coarse graining in operator product expansions introduced in a parallel work. This procedure allows for low-energy structure of the ... More
Neutrino Masses and Mixing Angles in SUSY-GUT Theories with explicit R-Parity BreakingNov 10 1995Sep 10 1996In minimal SUSY GUT models the $R$-parity breaking terms are severely constrained by SU(5) gauge invariance. We consider the particular case where the explicit $R$-parity breaking occurs only via dimension 2 terms of the superpotential. This model possesses ... More
Towards Generic RefactoringMar 01 2002We study program refactoring while considering the language or even the programming paradigm as a parameter. We use typed functional programs, namely Haskell programs, as the specification medium for a corresponding refactoring framework. In order to ... More
Neutral pions and eta mesons as probes of the expanding hadronic fireball in nucleus-nucleus collisions at SISMar 02 1998The production of neutral pions and eta mesons in collisions of light, intermediate-mass, and heavy nuclei at beam energies between 0.8 A GeV and 2.0 A GeV is discussed in the framework of a model assuming equilibrium at hadrochemical and thermal freeze-out, ... More
A mapping between Lorentz-violating and conventional electrodynamicsNov 29 2007Feb 17 2011The Chern-Simons-type term in the photon sector of the Lorentz- and CPT-breaking minimal Standard-Model Extension (mSME) is considered. It is argued that under certain circumstances this term can be removed from the mSME. In particular, it is demonstrated ... More
Aspects of spacetime-symmetry violationsFeb 19 2006The violation of spacetime symmetries provides a promising candidate signal for underlying physics, possibly arising at the Planck scale. This talk gives an overview over various aspects in the field, including some mechanisms for Lorentz breakdown, the ... More
Cosmology and spacetime symmetriesAug 31 2005Cosmological models often contain scalar fields, which can acquire global nonzero expectation values that change with the comoving time. Among the possible consequences of these scalar-field backgrounds, an accelerated cosmological expansion, varying ... More
Quantum-gravity phenomenology, Lorentz symmetry, and the SMEMar 16 2007Violations of spacetime symmetries have recently been identified as promising signatures for physics underlying the Standard Model. The present talk gives an overview over various topics in this field: The motivations for spacetime-symmetry research, ... More
Quantum gravity and spacetime symmetriesDec 30 2006Small violations of spacetime symmetries have recently been identified as promising Planck-scale signals. This talk reviews how such violations can arise in various approaches to quantum gravity, how the emergent low-energy effects can be described within ... More
Lorentz violation as a quantum-gravity signatureAug 29 2005Many theoretical approaches to quantum gravity predict the breakdown of Lorentz symmetry at Planck energies. Kinematical cosmic-ray studies are a sensitive tool in the search for such effects. This talk discusses the construction of test dispersion relations ... More
On the geometry of global function fields, the Riemann-Roch theorem, and finiteness properties of S-arithmetic groupsAug 21 2010Jan 30 2011Harder's reduction theory provides filtrations of euclidean buildings that allow one to deduce cohomological and homological properties of S-arithmetic groups over global function fields. In this survey I will sketch the main points of Harder's reduction ... More
Emergent Horizons in the LaboratoryApr 15 2010The concept of a horizon known from general relativity describes the loss of causal connection and can be applied to non-gravitational scenarios such as out-of-equilibrium condensed-matter systems in the laboratory. This analogy facilitates the identification ... More
Recreating Fundamental Effects in the Laboratory?Apr 14 2010This article provides a brief (non-exhaustive) overview of some possibilities for recreating fundamental effects which are relevant for black holes (and other gravitational scenarios) in the laboratory. Via suitable condensed matter analogues and other ... More
The galactic population of white dwarfsMar 12 2009The contribution of white dwarfs of the different Galactic populations to the stellar content of our Galaxy is only poorly known. Some authors claim a vast population of halo white dwarfs, which would be in accordance with some investigations of the early ... More
Modeling Star Formation from Turbulent FragmentationOct 03 2001Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud material. Using ... More
Star Formation from Turbulent FragmentationNov 10 2000Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud material. Efficiency, ... More
Lineare Rekurrenzen, Potenzreihen und ihre erzeugenden FunktionenApr 19 2007Apr 20 2007Diese kurze Einfuehrung in Theorie und Berechnung linearer Rekurrenzen versucht, eine Luecke in der Literatur zu fuellen. Zu diesem Zweck sind viele ausfuehrliche Beispiele angegeben. This short introduction to theory and usage of linear recurrences tries ... More
Excision in Hochschild and cyclic homology without continuous linear sectionsDec 18 2009We prove that continuous Hochschild and cyclic homology satisfy excision for extensions of nuclear H-unital Frechet algebras and use this to compute them for the algebra of Whitney functions on an arbitrary closed subset of a smooth manifold. Using a ... More
Homological algebra for Schwartz algebras of reductive p-adic groupsJan 31 2005Jun 02 2005Let G be a reductive group over a non-Archimedean local field. Then the canonical functor from the derived category of smooth tempered representations of G to the derived category of all smooth representations of G is fully faithful. Here we consider ... More
L(R) absoluteness under proper forcingsSep 08 1999We isolate a new large cardinal concept, "remarkability." Consistencywise, remarkable cardinals are between ineffable and omega-Erdos cardinals. They are characterized by the existence of "0^sharp-like" embeddings; however, they relativize down to L. ... More
Combable groups have group cohomology of polynomial growthOct 28 2004Aug 06 2018Group cohomology of polynomial growth is defined for any finitely generated discrete group, using cochains that have polynomial growth with respect to the word length function. We give a geometric condition that guarantees that it agrees with the usual ... More
On Hopf algebra structures over free operadsApr 26 2005Nov 30 2005The operad Lie can be constructed as the operad of primitives Prim As from the operad As of associative algebras. This is reflected by the theorems of Friedrichs, Poincare'-Birkhoff-Witt and Cartier-Milnor-Moore. We replace As by families of free operads ... More
A geometric model for cluster categories of type $D_n$Aug 10 2006Aug 30 2006We give a geometric realization of cluster categories of type $D_n$ using a polygon with $n$ vertices and one puncture in its center as a model. In this realization, the indecomposable objects of the cluster category correspond to certain homotopy classes ... More
Equivariant Kasparov theory and generalized homomorphismsJan 17 2000Apr 30 2000Let G be a locally compact group. We describe elements of KK^G (A,B) by equivariant homomorphisms, following Cuntz's treatment in the non-equivariant case. This yields another proof for the universal property of KK^G: It is the universal split exact stable ... More
The cyclic homology and K-theory of certain adelic crossed productsDec 16 2003The multiplicative group of a global field acts on its adele ring by multiplication. We consider the crossed product algebra of the resulting action on the space of Schwartz functions on the adele ring and compute its Hochschild, cyclic and periodic cyclic ... More
The deconfining phase of SU(2) Yang-Mills thermodynamicsJul 17 2006Nov 27 2006We present an overview on nonperturbative thermodynamics in the deconfining phase of an SU(2) Yang-Mills theory. In a unique effective theory the maximal resolution of trivial-topology fluctuations is constrained by coarse-grained, interacting calorons ... More
Nonperturbative and analytical approach to Yang-Mills thermodynamicsApr 29 2004Nov 25 2004An analytical, macroscopic approach to SU(N) Yang-Mills thermodynamics is developed, tested,and applied.
Deconfining by Winding: The Magnetic Monopole Vacua at High TemperaturesJun 15 2000Oct 05 2000Characterizing the vacuum of a thermalized SU(3) Yang-Mills theory in the dual Ginzburg-Landau description, the possibility of topologically nontrivial, classical monopole fields in the deconfining phase is explored. These fields are assumed to be Bogomoln'yi-Prasad-Sommerfield ... More
Gauge boson pair production at LEP and NLCMay 24 1996We compute the dominant one-loop radiative corrections to the cross-section for $e^+ e^- \rightarrow V_1 V_2$ $(V_{1/2} = \gamma, Z, W^\pm$) in the MSSM. We find that the genuine vertex corrections are very small. The oblique corrections are potentially ... More
Lorentz and CPT tests involving antiprotonsFeb 11 2006Lorentz and CPT tests involving matter-antimatter comparisons at low temperatures are discussed. SME predictions for transition frequencies in such systems include both matter-antimatter differences and sidereal variations. In hydrogen-antihydrogen spectroscopy, ... More
Vibrational Bandstructures of Bottom-Up Built Nanoscale Phononic CrystalsNov 02 2015The vibrational properties of a phononic crystal assembled from Si nanoparticles and nanowires is studied with large-scale molecular-dynamics simulations. The phonon dispersion relations derived from the simulations show the existence of acoustic band ... More
Spin dependent fragmentatation functions at BelleMay 17 2006Spin dependent fragmentation functions are an important tool to understand the spin structure of the nucleon. The Collins fragmentation function for example describes the fragmentation of a transversely polarized quark into a hadron via the creation of ... More
Heavy-flavor production at RHICMay 14 2005May 19 2005Experimental results on heavy-quark production in proton-proton, deuteron-gold, and gold-gold collisions at sqrt(s_(NN)) = 200 GeV at the Relativistic Heavy Ion Collider (RHIC) are reviewed.
Refractive index perturbations -- Unruh effect, Hawking radiation or dynamical Casimir effect?Oct 27 2011Motivated by recent experimental progress to manipulate the refractive index of dielectric materials by strong laser beams, we study some aspects of the quantum radiation created by such refractive index perturbations.
A nice acyclic matching on the nerve of the partition latticeApr 12 2012Aug 28 2015The author has already proven that the space \Delta(\Pi_n)/G is homotopy equivalent to a wedge of spheres of dimension n-3 for all natural numbers n>=3 and all subgroups G<S_1 X S_{n-1}. We wish to construct an acyclic matching on \Delta(\Pi_n)/G that ... More
Relativity tests and their motivationFeb 14 2011Some motivations for Lorentz-symmetry tests in the context of quantum-gravity phenomenology are reiterated. The description of the emergent low-energy effects with the Standard-Model Extension (SME) is reviewed. The possibility of constraining such effects ... More
In-Medium Vector Mesons, Dileptons and Chiral RestorationOct 08 2010Medium modifications of the electromagnetic spectral function in hadronic and quark-gluon matter are reviewed. A strong broadening of the $\rho$ meson, which dominates the spectral function in the low-mass regime, is quantitatively consistent with dilepton ... More
Monodromy Groups of Vector Bundles on p-adic CurvesMay 28 2010In [DW05] and [DW07], C. Deninger and A. Werner developed a partial p-adic analogue of the classical Narasimhan-Seshadri correspondence between vector bundles and representations of the fundamental group. We will investigate the various monodromy groups ... More
Tests of Lorentz symmetryAug 10 2010A number of approaches to fundamental physics can lead to the violation of Lorentz and CPT symmetry. This talk discusses the low-energy phenomenology associated with such effects and reviews various sample experiments within this context.
Low-frequency line temperatures of the CMBFeb 16 2009Jul 11 2009Based on SU(2) Yang-Mills thermodynamics we interprete Aracde2's and the results of earlier radio-surveys on low-frequency CMB line temperatures as a phase-boundary effect. We explain the excess at low frequencies by evanescent, nonthermal photon fields ... More
Exoplanet search with astrometryApr 07 2009Searching for extrasolar planets by direct detection is extremely challenging for current instrumentation. Indirect methods, that measure the effect of a planet on its host star, are much more promising and have indeed led to the discovery of nearly all ... More
Comparisons between periodic, analytic and local cyclic cohomologyMay 27 2002Dec 18 2003We compute periodic, analytic and local cyclic cohomology for convolution algebras of compact Lie groups in order to exhibit differences between these theories. A surprising result is that the periodic and analytic cyclic cohomology of the smooth convolution ... More
Monodromy of subvarieties of PEL-Shimura varietiesSep 26 2012The aim of this paper is to generalize results of C.-L. Chai about the monodromy of Hecke invariant subvarieties to Shimura varieties of PEL-type.
Dynamical zero-temperature phase transitions and cosmic inflation/deflationMay 26 2005For a rather general class of scenarios, sweeping through a zero-temperature phase transition by means of a time-dependent external parameter entails universal behavior: In the vicinity of the critical point, excitations behave as quantum fields in an ... More
Analytic cyclic cohomologyJun 29 1999We prove excision in entire and periodic cyclic cohomology and construct a Chern-Connes character for Fredholm modules over a C*-algebra without summability restrictions, taking values in a variant of Connes's entire cyclic cohomology. Before these results ... More
On the classification of group actions on C*-algebras up to equivariant KK-equivalenceJun 26 2019We study the classification of group actions on C*-algebras up to equivariant KK-equivalence. We show that any group action is equivariantly KK-equivalent to an action on a simple, purely infinite C*-algebra. We show that a conjecture of Izumi is equivalent ... More
Bornological versus topological analysis in metrizable spacesOct 15 2003Feb 09 2004Given a metrizable topological vector space, we can also use its von Neumann bornology or its bornology of precompact subsets to do analysis. We show that the bornological and topological approaches are equivalent for many problems. For instance, they ... More
Cardinal arithmetic and Woodin cardinalsMar 08 2002Suppose that there is a measurable cardinal. If \aleph_\omega is a strong limit cardinal, but the power of \aleph_\omega is bigger than \aleph_{\omega_1}, then there is an inner model with a Woodin cardinal. Modulo the need of the measurable cardinal ... More
Discrete Compactness for p-Version of Tetrahedral Edge ElementsJan 07 2009We consider the first family of $\Hcurl$-conforming Ned\'el\'ec finite elements on tetrahedral meshes. Spectral approximation ($p$-version) is achieved by keeping the mesh fixed and raising the polynomial degree $p$ uniformly in all mesh cells. We prove ... More
On the Critical Exponent of Infinitely Generated Veech GroupsApr 08 2014We prove the existence of Veech groups having a critical exponent strictly greater than any elementary Fuchsian group (i.e. $>\frac{1}{2}$) but strictly smaller than any lattice (i.e. $<1$). More precisely, every affine covering of a primitive L-shaped ... More
The isolated, uniformly moving electron: Selfintersecting SU(2) Yang-Mills center vortex loop and Louis de Broglie's hidden thermodynamicsJun 27 2017We propose that the one-fold selfintersecting center-vortex loop, being the stable excitation in the confining phase of SU(2) Yang-Mills thermodynamics of scale $\Lambda\sim 0.5\,$MeV, after an electric-magnetically dual interpretation of this theory ... More
Magnetic Resonance Imaging of Granular MaterialsMar 03 2017Magnetic Resonance Imaging (MRI) has become one of the most important tools to screen humans in medicine, virtually every modern hospital is equipped with an NMR tomograph. The potential of NMR in 3D imaging tasks is by far greater, but there is only ... More
SU(2) Yang-Mills Theory: Waves, Particles, and Quantum ThermodynamicsApr 14 2016We elucidate how Quantum Thermodynamics at temperature $T$ emerges from pure and classical SU(2) Yang-Mills theory on a four-dimensional Euclidean spacetime slice $S_1\times {\bf R}^3$. The concept of a (deconfining) thermal ground state, composed of ... More
On the work of Rodriguez Hertz on rigidity in dynamicsJun 02 2016This paper is a survey about recent progress in measure rigidity and global rigidity of Anosov actions, and celebrates the profound contributions by Federico Rodriguez Hertz to rigidity in dynamical systems.
Review of recent forward physics results from the CMS experimentApr 29 2019There is a rich program of forward physics measurements within the CMS Collaboration covering a wide range of topics. In many cases there is a connection to quantities and effects relevant for very high energy cosmic ray interaction. Some of the recent ... More
Finite- and infinite-volume thermodynamics around the zero of the pressure in deconfining SU(2) Quantum Yang-Mills theorySep 21 2018Jan 02 2019We re-address the self-intersection region in a figure-eight shaped center-vortex loop containing a frequently perturbed {\sl BPS monopole} subject to a core-oscillation frequency $\omega_0$, rectifying a numerical error in estimating the system's radius ... More
SU(2) Quantum Yang-Mills Thermodynamics: Some Theory and Some ApplicationsSep 11 2018Nov 13 2018In the first part of this talk we review some prerequisites for and essential arguments involved in the construction of the thermal-ground-state estimate for the deconfining phase in the thermodynamics of SU(2) Quantum Yang-Mills theory and how this structure ... More
\nabla_κ, remarkable cardinals, and 0^#May 25 2001For an uncountable regular cardinal \kappa we let \nabla_\kappa(A) be the statement that A \subset \kappa and for all regular \theta > \kappa, the set of all X \in [\theta]^<\kappa such that X \cap \kappa \in \kappa and otp(X \cap OR) is a cardinal in ... More
A universal weasel without large cardinals in VNov 13 2000We prove in the theory "ZFC + there is no inner model with a Woodin cardinal" that there is a universal weasel. This shows in particular that one doesn't have to assume the existence of large cardinals in V to prove the existence of some such weasel.
Divide-and-conquer generating functions. Part I. Elementary sequencesJul 02 2003Divide-and-conquer functions satisfy equations in F(z),F(z^2),F(z^4)... Their generated sequences are mainly used in computer science, and they were analyzed pragmatically, that is, now and then a sequence was picked out for scrutiny. By giving several ... More
Theory of Soft Electromagnetic Emission in Heavy-Ion CollisionsOct 19 2011A status report of utilizing soft electromagnetic radiation (aka thermal photons and dileptons) in the diagnosis of strongly interacting matter in ultrarelativistic heavy-ion collisions is given. After briefly elaborating on relations of the electromagnetic ... More
Synchronization Transition in the Kuramoto Model with Colored NoiseMar 08 2010We present a linear stability analysis of the incoherent state in a system of globally coupled, identical phase oscillators subject to colored noise. In that we succeed to bridge the extreme time scales between the formerly studied and analytically solvable ... More
Dileptons, Charm and Charmonium at Finite Temperature and Chemical PotentialAug 23 2009We discuss how dileptons, open charm and charmonia may be utilized in heavy-ion collisions to extract information specific to hot and dense matter at finite quark chemical potential, $\mu_q$. For each observable we briefly discuss underlying theoretical ... More
Fluid dynamics of planetary icesMar 23 2009The role of water ice in the solar system is reviewed from a fluid-dynamical point of view. On Earth and Mars, water ice forms ice sheets, ice caps and glaciers at the surface, which show glacial flow under their own weight. By contrast, water ice is ... More
Quantum graphs and their spectraOct 17 2011We show that families of leafless quantum graphs that are isospectral for the standard Laplacian are finite. We show that the minimum edge length is a spectral invariant. We give an upper bound for the size of isospectral families in terms of the total ... More
Violations of Einstein's Relativity: Motivations, Theory, and PhenomenologyFeb 17 2011One of the most difficult questions in present-day physics concerns a fundamental theory of space, time, and matter that incorporates a consistent quantum description of gravity. There are various theoretical approaches to such a quantum-gravity theory. ... More
Theory of Heavy Flavor in the Quark-Gluon PlasmaJan 27 2011Heavy-quark interactions in the Quark-Gluon Plasma are analyzed in terms of a selfconsistent Brueckner scheme using a thermodynamic $T$-matrix based on a potential model. The interrelations between quarkonium correlators, spectral functions and zero-modes, ... More
Dirac theory within the Standard-Model ExtensionJan 12 2004The modified Dirac equation in the Lorentz-violating Standard-Model Extension (SME) is considered. Within this framework, the construction of a hermitian Hamiltonian to all orders in the Lorentz-breaking parameters is investigated, discrete symmetries ... More
Threshold analyses and Lorentz violationApr 02 2003In the context of threshold investigations of Lorentz violation, we discuss the fundamental principle of coordinate invariance, the role of an effective dynamical framework, and the conditions of positivity and causality. Our analysis excludes a variety ... More
Theoretical topics in spacetime-symmetry violationsOct 02 2007The Lorentz- and CPT-violating Chern-Simons extension of electrodynamics is considered. In the context of N=4 supergravity in four spacetime dimensions, it is argued that cosmological solutions can generate this extension. Within Chern-Simons electrodynamics, ... More
CPT- and Lorentz-symmetry breaking: a reviewNov 13 2006Dec 28 2006The breakdown of spacetime symmetries has recently been identified as a promising candidate signal for underlying physics, possibly arising through quantum-gravitational effects. This talk gives an overview over various aspects of CPT- and Lorentz-violation ... More
Mass Spectra from Turbulent FragmentationJun 19 2001Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass from the surrounding cloud material. Molecular cloud regions without turbulent driving sources, or where turbulence is driven on large scales, ... More
A Model for Dwarf Spheroidal Satellite Galaxies without Dark MatterJan 09 1998Self-consistent simulations of the dynamical evolution of low-mass satellite galaxies without dark matter on different orbits interacting with an extended Galactic dark halo are described. The calculations proceed for many orbital periods until well after ... More
The Formation of Stellar Clusters: Mass Spectra from Turbulent Molecular Cloud FragmentationApr 07 2001Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass from the surrounding cloud material. This process is investigated, using numerical models of self-gravitating molecular cloud dynamics. Molecular ... More
On near Chandrasekhar mass central stars of planetary nebulaeMar 23 2006A recent spectroscopic analysis of central stars of planetary nebulae (CSPNe) claims that the sample includes five CSPNe with masses very close to the Chandrasekhar limit of white dwarfs. This claim should be verified or discarded from the available kinematical ... More
Spectroscopic investigation of old planetaries IV. Model atmosphere analysisAug 17 1999The results of a NLTE model atmosphere analysis of 27 hydrogen-rich central stars of old planetary nebulae (PN) are reported. These stars were selected from a previous paper in this series, where we gave classifications for a total of 38 central stars. ... More
Yang-Mills thermodynamics: The preconfining phaseJul 13 2005Nov 27 2006We summarize recent nonperturbative results obtained for the thermodynamics of an SU(2) and an SU(3) Yang-Mills theory being in its preconfining (magnetic) phase. We focus on an explanation of the involved concepts and derivations, and we avoid technical ... More
Analytical approach to SU(2) Yang-Mills thermodynamicsAug 10 2004We propose an analytical approach to SU(2) Yang-Mills thermodynamics. The existence of a macroscopic and rigid adjoint Higgs field, generated by dilute trivial-holonomy calorons at large temperature $T$ (electric phase), implies a twofold degeneracy of ... More
Galaxies in the infraredJul 21 2000The mid infrared spectra of the starbursts show the 9.7$\mu m$ silicate absorption feature and strong mid infrared emission bands centered at 6.2, 7.7, and 11.3 $\mu$m. Illustrative models of the {\it active} galaxies are presented: As the starbursts ... More
SUSY without R-parity: symmetry breaking and LSP phenomenologyFeb 25 1997We have studied the predictions for the LSP decay within the framework of a radiatively broken unified supergravity model without R-parity. Assuming that Higgs/slepton mixing is the only source of R-parity breaking and responsible for the observed neutrino ... More
Coupling Constant Unification in Extended SUSY ModelsFeb 01 1995The unification of gauge coupling constants in the minimal supersymmetric model (MSSM) is unaffected at the one-loop level by the inclusion of additional mass-degenerate SU(5) multiplets. Perturbativity puts an upper limit on the number of additional ... More
Can the Supersymmetric $μ$ parameter be generated dynamically without a light Singlet?Apr 12 1994It is generally assumed that the dynamical generation of the Higgs mass parameter of the superpotential, $\mu$, implies the existence of a light singlet at or below the supersymmetry breaking scale, $\msusy$. We present a counter-example in which the ... More
Prove or Disprove. 100 Conjectures from the OEISSep 27 2004Nov 27 2004Presented here are over one hundred conjectures ranging from easy to difficult, from many mathematical fields. I also summarize briefly methods and tools that have led to this collection.
Update on Chiral Symmetry Restoration in the Context of Dilepton DataOct 13 2012We evaluate currently available information on low-mass dilepton and direct-photon emission spectra measured in ultrarelativistic heavy-ion collisions. In the first part an attempt is made to develop a consistent picture of the in-medium effects on the ... More
On the Particle Definition in the presence of Black HolesMar 07 2000Oct 23 2000A canonical particle definition via the diagonalisation of the Hamiltonian for a quantum field theory in specific curved space-times is presented. Within the provided approach radial ingoing or outgoing Minkowski particles do not exist. An application ... More
P not= NP for infinite time Turing machinesJun 11 2001We state a version of the P=?NP problem for infinite time Turing machines. It is observed that P not= NP for this version.
Smooth and rough modules over self-induced algebrasNov 19 2009A non-unital algebra in a closed monoidal category is called self-induced if the multiplication induces an isomorphism between A\otimes_A A and A. For such an algebra, we define smoothening and roughening functors that retract the category of modules ... More
Recovering quantum graphs from their Bloch spectrumJan 31 2011Feb 10 2011We define the Bloch spectrum of a quantum graph to be the collection of the spectra of a family of Schrodinger operators parametrized by the cohomology of the quantum graph. We show that the Bloch spectrum determines the Albanese torus, the block structure ... More
Hermite Interpolation and data processing errors on Riemannian matrix manifoldsAug 16 2019The main contribution of this paper is twofold: On the one hand, a general framework for performing Hermite interpolation on Riemannian manifolds is presented. The method is applicable, if algorithms for the associated Riemannian exponential and logarithm ... More
On Hopf algebra structures over operadsJul 06 2004Nov 30 2005We study P-Hopf algebras with one coassociative cooperation over different operads P. For example, we consider the Loday-Ronco dendriform Hopf algebra and its isomorphisms with the noncommutative planar Connes-Kreimer Hopf algebra and with a Hopf algebra ... More